1,915 research outputs found

    Low-operating-voltage polymer thin-film transistors based on poly(3-hexylthiophene) with hafnium oxide as the gate dielectric

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    The effects of hafnium oxide (hboxHfO2)(hbox{HfO}-{2}) gate dielectric annealing treatment in oxygen (hboxO2)(hbox{O}-{2}) and ammonia (hboxNH3)(hbox{NH}-{3}) ambient on the electrical performance of polymer thin-film transistors (PTFTs) based on poly(3-hexylthiophene) are investigated. The PTFTs with hboxHfO2hbox{HfO}-{2} gate dielectric and also octadecyltrichlorosilane surface modification, prepared by spin-coating process, exhibit good performance, such as a small threshold voltage of -0.5 V and an operating voltage as low as -4 V. Results indicate that the PTFT with hboxNH3hbox{NH}-{3}-annealed hboxHfO2 hbox{HfO}-{2} shows higher carrier mobility, larger on/off current ratio, smaller subthreshold swing, and lower threshold voltage than the PTFT with hboxO2hbox{O}-{2}-annealed hboxHfO2 hbox{HfO}-{2}. Capacitancevoltage analysis for metal-polymer-oxide-silicon structures indicates that the better electrical performance of the PTFT with hboxNH3hbox{NH}-{3} -annealed hboxHfO2hbox{HfO}-{2} is attributed to improved dielectric/polymer interface and reduced series resistance in the transistor. © 2006 IEEE.published_or_final_versio

    Bias-stress-induced instability of polymer thin-film transistor based on poly(3-hexylthiophene)

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    A polymer thin-film transistor (PTFT) based on poly(3-hexylthiophene) (P3HT) is fabricated by a spin-coating process and characterized. Its bias-stress-induced instability during operation is investigated as a function of time and temperature. For negative gate-bias stress, the carrier mobility remains unchanged, the off-state current decreases, and the threshold voltage shifts toward the negative direction. On the other hand, for negative drain-bias stress, the carrier mobility decreases slightly, the off-state current increases, and the threshold voltage shifts toward the positive direction. The threshold shifts under gate- and drain-bias stresses are observed to be logarithmically dependent on time, and the decay rate of the threshold-voltage shift is independent of temperature. The results suggest that the origin of the threshold-voltage shift upon negative gate-bias stress is predominantly associated with holes trapped within the SiO 2 gate dielectric or at the P3HT/SiO 2 interface, while time-dependent charge trapping in the deep trap states and creation of defect states in the channel region are responsible for the drain-bias stress effect on the PTFT. © 2011 IEEE.published_or_final_versio

    Clinical and Social Outcomes five years after closing a mental hospital: a trial of cognitive behavioural interventions

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    BACKGROUND: To investigate the outcome of patients transferred from hospital to community care in Como, Italy after 6 months intensive psychosocial rehabilitation prior to discharge. METHOD: All 149 residents with a primary psychiatric diagnosis were assigned to receive either a 6-month pre-discharge course of goal-oriented rehabilitation, (IT), or routine management, (RT). BPRS and GAF ratings were made by blind, independent assessors before and at 12, 24, 36, 48, and 60 months after discharge and the results examined with repeated measures analysis of variance. RESULTS: Overall change in residence was achieved without any major detriment to the health and welfare of most patients. The cohort of patients who received intensive rehabilitation, (IT), prior to discharge showed significantly lower impairment and disability throughout the five years compared to the cohort receiving routine management, (RT), prior to discharge. Total BPRS scores remained significant when initial differences in the cohorts were covaried, whereas GAF failed to remain significant (p = 0.051). CONCLUSION: The treatment provided prior to transfer from long-stay hospital to community residence may have long-term clinical benefits for chronically disabled patients

    Novel insertions in the mitochondrial maxicircle of Trypanosoma musculi, a mouse trypanosome

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    Trypanosoma musculi is a, globally distributed, mouse-specific haemoflagellate, of the family Trypanosomatidae, which shares similar characteristics in morphology with Trypanosoma lewisi. The kinetoplast (mitochondrial) DNA of Trypanosomatidae flagellates is comprised of catenated maxicircles and minicircles. However, genetic information on the T. musculi kinetoplast remains largely unknown. In this study, the T. musculi maxicircle genome was completely assembled, with PacBio and Illumina sequencing, and the size was confirmed at 34 606 bp. It consisted of 2 distinct parts: the coding region and the divergent regions (DRs, DRI and II). In comparison with other trypanosome maxicircles (Trypanosoma brucei, Trypanosoma cruzi and T. lewisi), the T. musculi maxicircle has a syntenic distribution of genes and shares 73.9, 78.0 and 92.7% sequence identity, respectively, over the whole coding region. Moreover, novel insertions in MURF2 (630 bp) and in ND5 (1278 bp) were found, respectively, which are homologous to minicircles. These findings support an evolutionary scenario similar to the one proposed for insertions in Trypanosoma cruzi, the pathogen of American trypanosomiasis. These novel insertions, together with a deletion (281 bp) in ND4, question the role of Complex I in T. musculi. A detailed analysis of DRII indicated that it contains numerous repeat motifs and palindromes, the latter of which are highly conservative and contain A5C elements. The comprehensively annotated kinetoplast maxicircle of T. musculi reveals a high degree of similarity between this parasite and the maxicircle of T. lewisi and suggests that the DRII could be a valuable marker for distinguishing these evolutionarily related species

    Patterns of analgesic use, pain and self-efficacy: a cross-sectional study of patients attending a hospital rheumatology clinic

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    Background: Many people attending rheumatology clinics use analgesics and non-steroidal anti-inflammatories for persistent musculoskeletal pain. Guidelines for pain management recommend regular and pre-emptive use of analgesics to reduce the impact of pain. Clinical experience indicates that analgesics are often not used in this way. Studies exploring use of analgesics in arthritis have historically measured adherence to such medication. Here we examine patterns of analgesic use and their relationships to pain, self-efficacy and demographic factors. Methods: Consecutive patients were approached in a hospital rheumatology out-patient clinic. Pattern of analgesic use was assessed by response to statements such as 'I always take my tablets every day.' Pain and self-efficacy (SE) were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Arthritis Self-Efficacy Scale (ASES). Influence of factors on pain level and regularity of analgesic use were investigated using linear regression. Differences in pain between those agreeing and disagreeing with statements regarding analgesic use were assessed using t-tests. Results: 218 patients (85% of attendees) completed the study. Six (2.8%) patients reported no current pain, 26 (12.3%) slight, 100 (47.4%) moderate, 62 (29.4%) severe and 17 (8.1%) extreme pain. In multiple linear regression self efficacy and regularity of analgesic use were significant (p < 0.01) with lower self efficacy and more regular use of analgesics associated with more pain. Low SE was associated with greater pain: 40 (41.7%) people with low SE reported severe pain versus 22 (18.3%) people with high SE, p < 0.001. Patients in greater pain were significantly more likely to take analgesics regularly; 13 (77%) of those in extreme pain reported always taking their analgesics every day, versus 9 (35%) in slight pain. Many patients, including 46% of those in severe pain, adjusted analgesic use to current pain level. In simple linear regression, pain was the only variable significantly associated with regularity of analgesic use: higher levels of pain corresponded to more regular analgesic use (p = 0.003). Conclusion: Our study confirms that there is a strong inverse relationship between self-efficacy and pain severity. Analgesics are often used irregularly by people with arthritis, including some reporting severe pain

    Multi-level evidence of an allelic hierarchy of USH2A variants in hearing, auditory processing and speech/language outcomes.

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    Language development builds upon a complex network of interacting subservient systems. It therefore follows that variations in, and subclinical disruptions of, these systems may have secondary effects on emergent language. In this paper, we consider the relationship between genetic variants, hearing, auditory processing and language development. We employ whole genome sequencing in a discovery family to target association and gene x environment interaction analyses in two large population cohorts; the Avon Longitudinal Study of Parents and Children (ALSPAC) and UK10K. These investigations indicate that USH2A variants are associated with altered low-frequency sound perception which, in turn, increases the risk of developmental language disorder. We further show that Ush2a heterozygote mice have low-level hearing impairments, persistent higher-order acoustic processing deficits and altered vocalizations. These findings provide new insights into the complexity of genetic mechanisms serving language development and disorders and the relationships between developmental auditory and neural systems

    Quasi-Normal Modes of Stars and Black Holes

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    Perturbations of stars and black holes have been one of the main topics of relativistic astrophysics for the last few decades. They are of particular importance today, because of their relevance to gravitational wave astronomy. In this review we present the theory of quasi-normal modes of compact objects from both the mathematical and astrophysical points of view. The discussion includes perturbations of black holes (Schwarzschild, Reissner-Nordstr\"om, Kerr and Kerr-Newman) and relativistic stars (non-rotating and slowly-rotating). The properties of the various families of quasi-normal modes are described, and numerical techniques for calculating quasi-normal modes reviewed. The successes, as well as the limits, of perturbation theory are presented, and its role in the emerging era of numerical relativity and supercomputers is discussed.Comment: 74 pages, 7 figures, Review article for "Living Reviews in Relativity
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