Search

Patterning graphene into nanoribbons (graphene nanoribbons, GNR) allows for tunability in the emerging fields of plasmonic devices in the mid-infrared and terahertz regime. However, the fabrication processes of GNR arrays for plasmonic devices often include a low-throughput electron beam lithography step that cannot be easily scaled to large areas. In this study, we developed a GNR fabrication method using block copolymer (BCP) lithography that takes advantage of the wetting transparency of graphene. One major advantage of this method is that the self-assembled domains of the polystyrene- block -poly(methyl methacrylate) BCP are oriented perpendicularly directly on top of the graphene where they can later serve as an etch mask. Large area (cm 2 scale, 3 μm × 3 μm defect-free area) 13–51 nm wide GNR arrays were successfully fabricated using this scalable protocol. This wetting transparency-assisted GNR fabrication method could be useful for high-throughput production of various plasmonic devices, including biosensors, and photodetectors. [ABSTRACT FROM AUTHOR]

Background: Serotonergic abnormalities are hypothesized to contribute to obsessive-compulsive disorder (OCD). This study used positron emission tomography with the radioligand [11C]MDL 100907 to examine whether the distribution of serotonin 2A (5-HT2A) receptors is altered in OCD. Methods: Nineteen OCD subjects, free of psychiatric medications and depression, and 19 matched healthy subjects underwent positron emission tomography scans following injection of [11C]MDL 100907. Total distribution volumes were derived by kinetic analysis using the arterial input function. Two measures of 5-HT2A availability were computed: the ratio at equilibrium of specifically bound radiotracer either to nondisplaceable radiotracer in tissue (BPND) or to unmetabolized tracer in arterial plasma (BPp). Groups were compared using a region of interest (ROI) analysis and voxelwise analysis of spatially normalized parametric maps. ROIs included cortical (orbitofrontal, dorsolateral prefrontal, medial prefrontal, anterior cingulate, temporal, parietal, occipital, and insular cortex) and limbic (entorhinal cortex, parahippocampal gyrus, and medial temporal lobe) regions. Results: No significant group differences were observed in [11C]MDL 100907 BPND or BPp in the ROIs or in the voxelwise analysis of BPND maps. There was a significant correlation in the orbitofrontal cortex between [11C]MDL 100907 binding and age of onset, with earlier age of onset associated with higher binding. Conclusions: Adults with OCD are not characterized as a group by major changes in 5-HT2A availability in cortical or limbic brain regions. Further research is warranted to examine potential differences in 5-HT2A availability between early- and late-onset OCD and to assess 5-HT2A function in relation to other neurotransmitter systems implicated in OCD. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, the Virtual Training Academy (VTA) was established to rapidly develop a contact-tracing workforce for California. Through June 2021, more than 10 000 trainees enrolled in a contact-tracing or case investigation course at the VTA. To evaluate program effectiveness, we analyzed trainee pre- and postassessment results using the Wilcoxon signed-rank test. There was a statistically significant ( P  < .001) improvement in knowledge and self-perceived skills after course completion, indicating success in training a competent contact-tracing workforce. ( Am J Public Health . 2021;111(11):1934-1938. https://doi.org/10.2105/AJPH.2021.306468).

Polarity-switching photopatternable guidelines can be directly used to both orient and direct the self-assembly of block copolymers. We report the orientation and alignment of poly(styrene- block -4-trimethylsilylstyrene) (PS- b -PTMSS) with a domain periodicity, L 0 , of 44 nm on thin photopatternable grafting surface treatments (pGSTs) and cross-linkable surface treatments (pXSTs), containing acid-labile 4- tert -butoxystyrene monomer units. The surface treatment was exposed using electron beam lithography to create well-defined linear arrays of neutral and preferential regions. Directed self-assembly (DSA) of PS- b -PTMSS with much lower defectivity was observed on pXST than on pGST guidelines. The study of the effect of film thickness on photoacid diffusion by Fourier transform infrared spectroscopy and near-edge X-ray absorption fine structure spectroscopy suggested slower diffusion in thinner films, potentially enabling production of guidelines with sharper interfaces between the unexposed and exposed lines, and thus, the DSA of PS- b -PTMSS on thinner pXST guidelines resulted in better alignment control.

We report the dynamic behavior of a sphere-forming poly(styrene)- block -poly(1,4-butadiene) (PS-PB) diblock copolymer comprising 20 vol % PB below the order-disorder transition temperature ( T ODT = 153 °C) using dynamic mechanical spectroscopy (DMS) and X-ray photon correlation spectroscopy (XPCS). A time-temperature transformation diagram was constructed by monitoring the elasticity of the sample as a function of time following rapid quenches of the disordered melt to various temperatures T < T ODT . Isothermal frequency spectra acquired prior to nucleation of the ordered BCC phase were time-temperature superposed, and the shift factors were fit using the Williams-Landel-Ferry (WLF) equation. For comparison, XPCS measurements were used to extract relaxation times from the supercooled liquid as a function of the quench temperature. Alignment of the temperature dependence of the XPCS-based relaxation times with that of the WLF shift factors in the range T = 125-140 °C indicates that both techniques probe the fluctuating mesomorphic micelle dynamics mediated by the relaxation modes of individual chains, including interparticle chain exchange. For deeper quench temperatures, T ODT - T ≥ 28 °C, departure of the XPCS time constant from WLF behavior is consistent with a jamming transition, analogous to that encountered in concentrated colloidal systems. We postulate that the dominant relaxation mode in the supercooled disordered liquid transitions from ergodic dynamics governed by chain exchange to a nonergodic regime dominated by local rearrangement of micellar particles at T ≈ T erg , where T erg denotes the ergodicity temperature.

We report a new analytical framework for interpreting data from X-ray photon correlation spectroscopy measurements on polycrystalline materials characterized by strong scattering intensity variations at fixed wavevector magnitude (i.e., anisotropic scattering). Currently, no analytical method exists for the interpretation of the time-dependent anisotropic scattering from such materials. The framework is applied to interrogate the dynamics of a spherical micelle-forming diblock copolymer melt below the order-disorder transition, wherein finite size grains of a micellar body-centered cubic structure produce anisotropic scattering. A wealth of analytical information is recovered from a simple measurement, including distributions of relaxation times and speeds associated with micelles within grains. The findings of this study demonstrate the efficacy of this new analytical method, which may be readily adapted for application to a variety of materials and systems.

The linear viscoelastic behavior of poly(norbornene)- graft -poly(±-lactide) was investigated as a function of grafting density and overall molar mass. Eight sets of polymers with grafting densities ranging from 0 to 100% were synthesized by living ring-opening metathesis copolymerization. Within each set, the graft chain molar mass and spacing between grafts were fixed, while the total backbone length was varied. Dynamic master curves reveal that these polymers display Rouse and reptation dynamics with a sharp transition in the zero-shear viscosity data, demonstrating that grafting density strongly impacts the entanglement molar mass. The entanglement modulus ( G e ) scales with inverse grafting density ( n g ) as G e ∼ n g 1.2 and G e ∼ n g 0 in accordance with scaling theory in the high and low grafting density limits, respectively. However, a sharp transition between these limiting behaviors occurs, which does not conform to existing theoretical models for graft polymers. A molecular interpretation based on thin flexible chains at low grafting density and thick semiflexible chains at high grafting density anticipates the sharp transition between the limiting dynamical regimes.

The structure, stability, and reorganization of lamella-forming block copolymer thin film surface topography ("islands" and "holes") were studied under boundary conditions driving the formation of 0.5 L 0 thick structures at short thermal annealing times. Self-consistent field theory predicts that the presence of one perfectly neutral surface renders 0.5 L 0 topography thermodynamically stable relative to 1 L 0 thick features, in agreement with previous experimental observations. The calculated through-film structures match cross-sectional scanning electron micrographs, collectively demonstrating the pinning of edge dislocations at the neutral surface. Remarkably, near-neutral surface compositions exhibit 0.5 L 0 topography metastability upon extended thermal treatment, slowly transitioning to 1 L 0 islands or holes as evidenced by optical and atomic force microscopy. Surface restructuring is rationalized by invoking commensurability effects imposed by slightly preferential surfaces. The results described herein clarify the impact of interfacial interactions on block copolymer self-assembly and solidify an understanding of 0.5 L 0 topography, which is frequently used to determine neutral surface compositions of considerable importance to contemporary technological applications.

Importance: Obsessive-compulsive disorder (OCD) is one of the world's most disabling illnesses according to the World Health Organization. Serotonin reuptake inhibitors (SRIs) are the only medications approved by the Food and Drug Administration to treat OCD, but few patients achieve minimal symptoms from an SRI alone. In such cases, practice guidelines recommend adding antipsychotics or cognitive-behavioral therapy consisting of exposure and ritual prevention (EX/RP)., Objective: To compare the effects of these 2 SRI augmentation strategies vs pill placebo for the first time, to our knowledge, in adults with OCD., Design, Setting, and Participants: A randomized clinical trial (conducted January 2007-August 2012) at 2 academic outpatient research clinics that specialize in OCD and anxiety disorders. Patients (aged 18-70 years) were eligible if they had OCD of at least moderate severity despite a therapeutic SRI dose for at least 12 weeks prior to entry. Of 163 who were eligible, 100 were randomized (risperidone, n = 40; EX/RP, n = 40; and placebo, n = 20), and 86 completed the trial., Interventions: While continuing their SRI at the same dose, patients were randomized to the addition of 8 weeks of risperidone (up to 4 mg/d), EX/RP (17 sessions delivered twice weekly), or pill placebo. Independent assessments were conducted every 4 weeks., Main Outcome and Measure: The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) to measure OCD severity., Results: Patients randomized to EX/RP had significantly greater reduction in week 8 Y-BOCS scores based on mixed-effects models (vs risperidone: mean [SE], -9.72 [1.38]; P < .001 vs placebo: mean [SE], -10.10 [1.68]; P < .001). Patients receiving risperidone did not significantly differ from those receiving placebo (mean [SE], -0.38 [1.72]; P = .83). More patients receiving EX/RP responded (Y-BOCS score decrease ≥25%: 80% for EX/RP, 23% for risperidone, and 15% for placebo; P < .001). More patients receiving EX/RP achieved minimal symptoms (Y-BOCS score ≤12: 43% for EX/RP, 13% for risperidone, and 5% for placebo; P = .001). Adding EX/RP was also superior to risperidone and placebo in improving insight, functioning, and quality of life., Conclusions and Relevance: Adding EX/RP to SRIs was superior to both risperidone and pill placebo. Patients with OCD receiving SRIs who continue to have clinically significant symptoms should be offered EX/RP before antipsychotics given its superior efficacy and less negative adverse effect profile., Trial Registration: clinicaltrials.gov Identifier: NCT00389493.

Block copolymers (BCPs) must necessarily have high interaction parameters (χ), a fundamental measure of block incompatibility, to self-assemble into sub-10-nanometer features. Unfortunately, a high χ often results from blocks that have disparate interfacial energies, which makes the formation of useful thin-film domain orientations challenging. To mitigate interfacial forces, polymers composed of maleic anhydride and two other components have been designed as top coats that can be spin-coated from basic aqueous solution in the ring-opened, acid salt form. When baked, the anhydride reforms and switches polarity to create a neutral layer enabling BCP feature alignment not possible by thermal annealing alone. Top coats were applied to the lamella-forming block copolymers poly(styrene-block-trimethylsilylstyrene-block-styrene) and poly(trimethylsilylstyrene-block-lactide), which were thermally annealed to produce perpendicular features with linewidths of 15 and 9 nanometers, respectively.

Objective: To examine the effects of patient adherence on outcome from exposure and response prevention (EX/RP) therapy in adults with obsessive-compulsive disorder (OCD)., Method: Thirty adults with OCD were randomized to EX/RP (n = 15) or EX/RP augmented by motivational interviewing strategies (n = 15). Both treatments included 3 introductory sessions and 15 exposure sessions. Because there were no significant group differences in adherence or outcome, the groups were combined to examine the effects of patient adherence on outcome. Independent evaluators assessed OCD severity using the Yale-Brown Obsessive Compulsive Scale. Therapists assessed patient adherence to between-session EX/RP assignments at each session using the Patient EX/RP Adherence Scale (PEAS). Linear regression models were used to examine the effects of PEAS scores on outcome, adjusting for baseline severity. The relationship between patient adherence and other predictors of outcome was explored using structural equation modeling., Results: Higher average PEAS ratings significantly predicted lower posttreatment OCD severity in intent-to-treat and completer samples. PEAS ratings in early sessions (5-9) also significantly predicted posttreatment OCD severity. The effects of other significant predictors of outcome in this sample (baseline OCD severity, hoarding subtype, and working alliance) were fully mediated by patient adherence., Conclusions: Patient adherence to between-session EX/RP assignments significantly predicted treatment outcome, as did early patient adherence and change in early adherence. Patient adherence mediated the effects of other predictors of outcome. Future research should develop interventions that increase adherence and then test whether increasing adherence improves outcome. If effective, these interventions could then be used to personalize care., ((c) 2011 APA, all rights reserved.)

Exposure and response prevention (EX/RP) is an efficacious treatment for obsessive-compulsive disorder (OCD). However, patients often do not adhere fully to EX/RP procedures. Motivational interviewing (MI) has been shown to improve treatment adherence in other disorders. This pilot study used a randomized controlled design to examine whether MI can be successfully added to EX/RP and whether this intervention (EX/RP+MI) could improve patient adherence to between-session EX/RP procedures relative to EX/RP alone. Thirty adults with OCD were randomized to 18 sessions of EX/RP or EX/RP+MI. Therapists rated patient adherence at each exposure session. Independent evaluators assessed change in OCD and depressive symptoms, and patients completed self-report measures of readiness for change and quality of life. The two treatment conditions differed in degree of congruence with MI but not in conduct of EX/RP procedures. Both groups experienced clinically significant improvement in OCD symptoms, without significant group differences in patient adherence. There are several possible reasons why EX/RP+MI had no effect on patient adherence compared to standard EX/RP, each of which has important implications for the design of future MI studies in OCD. We recommend that MI be further evaluated in OCD by exploring alternative modes of delivery and by focusing on patients less ready for change than the current sample., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Empirical gay, lesbian, bisexual, and transgender (GLBT) research has passed through three stages. Transitions between stages have been caused by an interaction of empirical research and institutional policies. The first period is from the late 1800s up to 1972, when research focused on categorizing homosexuality as a disease, treatments for homosexuality, and then research refuting the disease model. The second period ran from 1972 to approximately 1990, when researchers began to apply the disease model not to GLBT persons, but rather to those having negative attitudes toward homosexuality (homophobia), and researchers began to look at what it was like to be a GLBT person from GLBT persons' perspectives. The third period began in the early 1990s and continues today, when researchers focus on institutions, particularly action research aimed at changing institutions.

The researchers conducted a survey of undergraduates living in residence halls at Loyola University Chicago, a Jesuit Catholic university. The survey included 20 statements on topics currently being debated in the Church. The researchers hypothesized that those who indicated some level of agreement with the statement, Homosexuality is wrong , would show strong correlations with other statements about sexuality, while those indicating disagreement with the statement would show strong correlations with statements about discrimination. Results showed that the question of the morality of homosexuality seemed to be tied to a broader way of thinking that pits Catholic Church authority against a sort of wisdom of the world. This way of thinking is operational regardless of whether the young Catholic is accepting or not of homosexuality. The hypothesis was rejected. Attitudes toward homosexuality are tied with attitudes regarding sexuality and Church authority. Knowing gay and lesbian people seems to be the major factor that causes young Catholics to be more accepting of homosexuality. The majority of young Catholics is accepting of homosexuality and inclined to question Church teaching and Church authority.

This study examined the relationship of the cognitive, mood, and somatic components of depression on perceptions of social support and social demand among older adults (n = 851) over two years. Factor-analyses confirmed the factor structure of our multicomponential model of depression. Results supported our proposal that interpersonal specificity, as measured by depressive cognition about self and others, is important to predicting changes in perceived support and demand over time. Each component of depression was related to social support and social demand cross-sectionally, whereas only the cognitive component of depression predicted changes in support and demand prospectively. Future research should consider the pathways linking depressive cognition to perceived support and demand., ((c) 2006 APA, all rights reserved)

The paper describes a study of gay and lesbian religious groups located in the United States between the Mississippi River and the Pacific Ocean between March of 1989 and June of 1993. The researcher found 684 groups to have existed at some time in the region and conducted interviews to document 468 of these groups. While a history of these groups dates back to the 1930s in the region, large groups still existing today did not begin to form until the late 1960s. The six most common goals of the groups were social and support needs, worship, denominational and social politics, community service, and leadership in the gay and lesbian community. Being focused on gay and lesbian issues has an influence on when and how they came into existence (in the beginnings of the gay and lesbian movement, in response to the AIDS crisis, in response to anti-gay legislative initiatives), has an influence on the kinds of key themes addressed (ordination of gay and lesbian people, same-sex marriage, service for people with AIDS, sexual ethics in scripture), and has an influence on relationships with the larger community (shunning or inclusion in the larger society and in the larger religious community). However, the stronger influence is their identity as religious (and, therefore, social) institutions. They experience the same pressures of mainstream religion and as social institutions by facing issues of diversity, gender, age, politics, race, and disease. They face the same challenges as any religious institution today of being prophetic, responsive, changing, traditional, true, relevant, and even noticed. A distinct feature is their role on the fringes. They are on the fringe of religious life and on the fringe of gay and lesbian life.

Subjective reports of sleep disturbance indicate that 70-91% of patients with post-traumatic stress disorder (PTSD) have difficulty falling or staying asleep. Nightmares are reported by 19-71% of patients, depending on the severity of their PTSD and their exposure to physical aggression. Objective measures of sleep disturbance are inconsistent, with some studies that used these measures indicating poor sleep and others finding no differences compared with non-PTSD controls. Future research in this area may benefit from examining measures of instability in the microstructure of sleep. Additionally, recent findings suggest that sleep disordered breathing (SDB) and sleep movement disorders are more common in patients with PTSD than in the general population and that these disorders may contribute to the brief awakenings, insomnia and daytime fatigue in patients with PTSD. Overall, sleep problems have an impact on the development and symptom severity of PTSD and on the quality of life and functioning of patients. In terms of treatments, SSRIs are commonly used to treat PTSD, and evidence suggests that they have a small but significant positive effect on sleep disruption. Studies of serotonin-potentiating non-SSRIs suggest that nefazodone and trazodone lead to significant reductions in insomnia and nightmares, whereas cyproheptadine may exacerbate sleep problems in patients with PTSD. Prazosin, a centrally acting alpha1-adrenoceptor antagonist, has led to large reductions in nightmares and insomnia in small studies of patients with PTSD. Augmentation of SSRIs with olanzapine, an atypical antipsychotic, may be effective for treatment-resistant nightmares and insomnia, although adverse effects can be significant. Additional medications, including zolpidem, buspirone, gabapentin and mirtazapine, have been found to improve sleep in patients with PTSD. Large randomised, placebo-controlled trials are needed to confirm the above findings. In contrast, evidence suggests that benzodiazepines, TCAs and MAOIs are not useful for the treatment of PTSD-related sleep disorders, and their adverse effect profiles make further studies unlikely. Cognitive behavioural interventions for sleep disruption in patients with PTSD include strategies targeting insomnia and imagery rehearsal therapy (IRT) for nightmares. One large randomised controlled trial of group IRT demonstrated significant reductions in nightmares and insomnia. Similarly, uncontrolled studies combining IRT and insomnia strategies have demonstrated good outcomes. Uncontrolled studies of continuous positive airway pressure for SDB in patients with PTSD show that this treatment led to significant decreases in nightmares, insomnia and PTSD symptoms. Controlled studies are needed to confirm these promising findings.