The field of organic electronics thrives on the hope of enabling low‐cost, solution‐processed electronic devices with mechanical, optoelectronic, and chemical properties not available from inorganic ...semiconductors. A key to the success of these aspirations is the ability to controllably dope organic semiconductors with high spatial resolution. Here, recent progress in molecular doping of organic semiconductors is summarized, with an emphasis on solution‐processed p‐type doped polymeric semiconductors. Highlighted topics include how solution‐processing techniques can control the distribution, diffusion, and density of dopants within the organic semiconductor, and, in turn, affect the electronic properties of the material. Research in these areas has recently intensified, thanks to advances in chemical synthesis, improved understanding of charged states in organic materials, and a focus on relating fabrication techniques to morphology. Significant disorder in these systems, along with complex interactions between doping and film morphology, is often responsible for charge trapping and low doping efficiency. However, the strong coupling between doping, solubility, and morphology can be harnessed to control crystallinity, create doping gradients, and pattern polymers. These breakthroughs suggest a role for molecular doping not only in device function but also in fabrication—applications beyond those directly analogous to inorganic doping.
Strong interactions between molecular dopants and organic semiconductor morphology are often responsible for charge trapping and low doping efficiency. This study reviews how solution‐processing techniques can control these interactions and render them useful for engineering diffusion rates, doping gradients, and film topography. These breakthroughs suggest new roles for molecular doping in device fabrication as well as function.
The blood-brain barrier (BBB) limits entry of blood-derived products, pathogens, and cells into the brain that is essential for normal neuronal functioning and information processing. Post-mortem ...tissue analysis indicates BBB damage in Alzheimer's disease (AD). The timing of BBB breakdown remains, however, elusive. Using an advanced dynamic contrast-enhanced MRI protocol with high spatial and temporal resolutions to quantify regional BBB permeability in the living human brain, we show an age-dependent BBB breakdown in the hippocampus, a region critical for learning and memory that is affected early in AD. The BBB breakdown in the hippocampus and its CA1 and dentate gyrus subdivisions worsened with mild cognitive impairment that correlated with injury to BBB-associated pericytes, as shown by the cerebrospinal fluid analysis. Our data suggest that BBB breakdown is an early event in the aging human brain that begins in the hippocampus and may contribute to cognitive impairment.
In this Letter we study a system consisting of two nearly degenerate mechanical modes that couple to a single mode of an optical cavity. We show that this coupling leads to nearly complete (99.5%) ...hybridization of the two mechanical modes into a bright mode that experiences strong optomechanical interactions and a dark mode that experiences almost no optomechanical interactions. We use this hybridization to transfer energy between the mechanical modes with 40% efficiency.
This study investigated the efficacy and tolerability of wearing frozen gloves (FGs) during chemotherapy to prevent chemotherapy-induced peripheral neuropathy (CIPN) as reported by patients and ...influence on quality of life (QoL).
Cancer patients starting treatment with oxaliplatin, docetaxel or paclitaxel between February 2013 and May 2016 at the medical oncology department were eligible. Patients were randomized into groups wearing FGs on both hands during treatment and those not wearing FGs during treatment. Self-reported CIPN and QoL were measured with the European Organisation for the Research and Treatment of Cancer Quality of Life (EORTC QLQ) CIPN20 and QLQ-C30 at four time points: baseline (t0), after three cycles (t1), end of chemotherapy (t2) and after 6 months (t3).
The study included 180 patients with 90 patients in both arms. They mostly underwent treatment of colorectal or breast cancer. Thirty-one patients (34%) discontinued FGs, mainly due to discomfort. Intention-to-treat analyses showed no important differences in reported EORTC QLQ CIPN20 subscales between the FG group and control group; however, the analyses showed the patients experienced reduced tingling in fingers/hands β = −10.20, 95% confidence interval (CI) = −3.94 to −3.14, P = 0.005 and less trouble opening a jar or bottle due to loss of strength in hands (β = −6.97, 95% CI = −13.53 to −0.40, P = 0.04) in the FG group compared with the control group. Per-protocol analyses showed similar results: reduced aching or burning pain in fingers/hands (β = −4.37, 95% CI = −7.90 to −0.83, P = 0.02) and cramps in hands (β = −3.76, 95% CI = −7.38 to −0.14, P = 0.04). Differences in tingling in fingers/hands at t1 were clinically relevant. In addition, those treated with FGs reported overall better QoL (β = 4.79, 95% CI = 0.37 to 9.22, P = 0.03) and physical functioning (β = 5.66, 95% CI = 1.59 to 9.73, P = 0.007) than the control. No difference in dose reductions was observed.
No difference in CIPN subscales was reported between intervention arms. Wearing FGs might reduce some neuropathy symptoms in the hands, potentially resulting in a better QoL; however, one-third of the FG group discontinued the study before the end of treatment. Future studies should focus on the method of limb hypothermia to prevent CIPN.
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•CIPN is a common side-effect of taxanes and oxaliplatin.•No improvement in CIPN-subscales was reported in patients wearing frozen gloves.•FGs reduce some neuropathy symptoms in hands potentially resulting in a better QOL.
Molecular doping—the use of redox‐active small molecules as dopants for organic semiconductors—has seen a surge in research interest driven by emerging applications in sensing, bioelectronics, and ...thermoelectrics. However, molecular doping carries with it several intrinsic problems stemming directly from the redox‐active character of these materials. A recent breakthrough was a doping technique based on ion‐exchange, which separates the redox and charge compensation steps of the doping process. Here, the equilibrium and kinetics of ion exchange doping in a model system, poly(2,5‐bis(3‐alkylthiophen‐2‐yl)thieno(3,2‐b)thiophene) (PBTTT) doped with FeCl3 and an ionic liquid, is studied, reaching conductivities in excess of 1000 S cm−1 and ion exchange efficiencies above 99%. Several factors that enable such high performance, including the choice of acetonitrile as the doping solvent, which largely eliminates electrolyte association effects and dramatically increases the doping strength of FeCl3, are demonstrated. In this high ion exchange efficiency regime, a simple connection between electrochemical doping and ion exchange is illustrated, and it is shown that the performance and stability of highly doped PBTTT is ultimately limited by intrinsically poor stability at high redox potential.
An extremely efficient ion‐exchange doping process for conjugated polymers which enables conductivities exceeding 1000 S cm−1 is demonstrated. Factors which affect ion exchange, such as electrolyte concentration, doping solvent, and film crystallinity are discussed. When exchange is efficient there is a direct correspondence between ion exchange electrochemical doping, which is used to reveal the detrimental impact of off‐target oxidation reactions.
Use of hypnotics is often associated with next‐morning residual effects and a higher risk of motor vehicle accidents. Measuring next‐morning effects on driving performance is therefore advised by ...regulatory agencies. Here, we examined driving performance following administration of daridorexant, a new dual orexin receptor antagonist developed to treat insomnia. Sixty healthy male and female subjects (50–79 years of age) were randomized in a placebo‐ and active‐controlled, four‐way cross‐over study. Each subject received evening administration of daridorexant 50 and 100 mg, zopiclone 7.5 mg, and placebo, in separate treatment phases of 4 days. Simulated driving performance was assessed after initial (day 2) and repeated dosing (day 5), 9 hours postdose. Standard deviation of the lateral position (SDLP) was the main outcome. On both days, with zopiclone, SDLP increased significantly compared with placebo, which confirmed sensitivity of the simulator. With daridorexant, on day 2, the placebo‐corrected mean (97.5% confidence interval) SDLP increased by 2.19 cm (0.46–3.93) and 4.43 cm (2.72–6.15) for 50 and 100 mg, respectively. On day 5, SDLP values for both daridorexant doses were significantly below the prespecified threshold of impairment (2.6 cm) and statistically not different from placebo. Daridorexant showed a lower self‐rated driving quality and higher effort compared to placebo on day 2 but not on day 5. In non‐insomnia subjects, daridorexant impaired simulated driving after initial but not after repeated dosing. Subjects should be cautioned about driving until they know how daridorexant affects them.
While figures on Black women and girls' degree attainment suggest that as a group they are achieving in society, the reality is that their experiences are far from monolithic, that the educational ...system from early on and through college imposes barriers and inequities, pushing many out of school, criminalizing their behavior, and leading to a high rate of incarceration. The purpose of this book is to illuminate scholarship on Black women and girls throughout the educational pipeline. The contributors--all Black women educators, scholars, and advocates--name the challenges Black women and girls face while pursuing their education as well as offer implications and recommendations for practitioners, policymakers, teachers, and administrators to consider in ensuring the success of Black women and girls. This book is divided into four sections, each identifying the barriers Black girls and women encounter at the stages of their education and offering strategies to promote their success and agency within and beyond educational contexts. In Part One, the contributors explore the importance of mattering for Black girls in terms of redefining success and joy; centering Black girl literacy pedagogies that encourage them to thrive; examining how to make STEM more accessible to them; and recounting how Black girls' emotions and emotional literacy can either disempower them or promote their sense of agency to navigate educational contexts. Part Two uncovers the violence directed toward and the criminalization of Black women and girls, and how they are situated in educational and justice systems that collude to fail them. The contributors address incarceration and the process of rehabilitation and reentry; the outcomes of disciplinary action in schools on women who pursue college; and describe how the erasure and disregard of Black women and girls leaves them absent from the educational policies that deeply affect their lives and wellbeing. Part Three focuses on how Black women are left to navigate without resources that could make their collegiate pathways smoother; covers how hair politics impact their acceptance in college leadership roles, particularly at HBCUs; illuminates the importance of social/emotional and mental health for Black undergraduate women and the lack of adequate resources; and explores how women with disabilities navigate higher education. The final part of this book describes transformative approaches to supporting the educational needs of Black women and girls, including the use of a politicized ethic of care, intergenerational love and dialogue, and constructing communities, including digital environments, to ensure they thrive through their education and beyond. Foreword written by Cynthia B. Dillard.
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