556 research outputs found
Quantum confinement effect in ZnO/Mg0.2Zn0.8O multishell nanorod heterostructures
We report on photoluminescence measurements of Mg0.2Zn0.8O/ZnO/Mg0.2Zn0.8O multishell layers on ZnO core nanorods. Dominant excitonic emissions in the photoluminescence spectra show a blueshift depending on the ZnO shell layer thickness attributed to the quantum confinement effect in the nanorod heterostructure radial direction. Furthermore, near-field scanning optical microscopy clearly shows sharp photoluminescence peaks from the individual nanorod quantum structures, corresponding to subband levels.open114747sciescopu
Signal transducer and activator of transcription 3-mediated CD133 up-regulation contributes to promotion of hepatocellular carcinoma
published_or_final_versio
Altered Brain Activation in Ventral Frontal-Striatal Regions Following a 16-week Pharmacotherapy in Unmedicated Obsessive-Compulsive Disorder
Recent studies have reported that cognitive inflexibility associated with impairments in a frontal-striatal circuit and parietal region is a core cognitive deficit of obsessive-compulsive disorder (OCD). However, few studies have examined progressive changes in these regions following clinical improvement in obsessive-compulsive symptoms. To determine if treatment changes the aberrant activation pattern associated with task switching in OCD, we examined the activation patterns in brain areas after treatment. The study was conducted on 10 unmedicated OCD patients and 20 matched controls using event-related functional magnetic resonance imaging. Treatment improved the clinical symptoms measured by the Yale-Brown Obsessive Compulsive Scale and behavioral flexibility indicated by the switching cost. At baseline, OCD showed significantly less activation in the dorsal and ventral frontal-striatal circuit and parietal regions under the task-switch minus task-repeat condition compared with controls. After treatment, the neural responses in the ventral frontal-striatal circuit in OCD were partially normalized, whereas the activation deficit in dorsal frontoparietal regions that mediate shifting attention or behavioral flexibility persisted. It is suggested that altered brain activation in ventral frontal-striatal regions in OCD patients is associated with their cognitive flexibility and changes in these regions may underlie the pathophysiology of OCD
Effect of Crystallization Modes in TIPS-Pentacene/Insulating Polymer Blends on the Gas Sensing Properties of Organic Field-Effect Transistors
Blending organic semiconductors with insulating polymers has been known to be an effective way to overcome the disadvantages of single-component organic semiconductors for high-performance organic field-effect transistors (OFETs). We show that when a solution processable organic semiconductor (6,13-bis(triisopropylsilylethynyl)pentacene, TIPS-pentacene) is blended with an insulating polymer (PS), morphological and structural characteristics of the blend films could be significantly influenced by the processing conditions like the spin coating time. Although vertical phase-separated structures (TIPS-pentacene-top/PS-bottom) were formed on the substrate regardless of the spin coating time, the spin time governed the growth mode of the TIPS-pentacene molecules that phase-separated and crystallized on the insulating polymer. Excess residual solvent in samples spun for a short duration induces a convective flow in the drying droplet, thereby leading to one-dimensional (1D) growth mode of TIPS-pentacene crystals. In contrast, after an appropriate spin-coating time, an optimum amount of the residual solvent in the film led to two-dimensional (2D) growth mode of TIPS-pentacene crystals. The 2D spherulites of TIPS-pentacene are extremely advantageous for improving the field-effect mobility of FETs compared to needle-like 1D structures, because of the high surface coverage of crystals with a unique continuous film structure. In addition, the porous structure observed in the 2D crystalline film allows gas molecules to easily penetrate into the channel region, thereby improving the gas sensing properties
Altered resting-state connectivity in subjects at ultra-high risk for psychosis: an fMRI study
<p>Abstract</p> <p>Background</p> <p>Individuals at ultra-high risk (UHR) for psychosis have self-disturbances and deficits in social cognition and functioning. Midline default network areas, including the medial prefrontal cortex and posterior cingulate cortex, are implicated in self-referential and social cognitive tasks. Thus, the neural substrates within the default mode network (DMN) have the potential to mediate self-referential and social cognitive information processing in UHR subjects.</p> <p>Methods</p> <p>This study utilized functional magnetic resonance imaging (fMRI) to investigate resting-state DMN and task-related network (TRN) functional connectivity in 19 UHR subjects and 20 matched healthy controls. The bilateral posterior cingulate cortex was selected as a seed region, and the intrinsic organization for all subjects was reconstructed on the basis of fMRI time series correlation.</p> <p>Results</p> <p>Default mode areas included the posterior/anterior cingulate cortices, the medial prefrontal cortex, the lateral parietal cortex, and the inferior temporal region. Task-related network areas included the dorsolateral prefrontal cortex, supplementary motor area, the inferior parietal lobule, and middle temporal cortex. Compared to healthy controls, UHR subjects exhibit hyperconnectivity within the default network regions and reduced anti-correlations (or negative correlations nearer to zero) between the posterior cingulate cortex and task-related areas.</p> <p>Conclusions</p> <p>These findings suggest that abnormal resting-state network activity may be related with the clinical features of UHR subjects. Neurodevelopmental and anatomical alterations of cortical midline structure might underlie altered intrinsic networks in UHR subjects.</p
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Growing vegetables in a warming world - a review of crop response to drought stress, and strategies to mitigate adverse effects in vegetable production
Drought stress caused by climate change is increasingly affecting the productivity and quality of vegetable crops worldwide. This review comprehensively analyzes the physiological, biochemical, and molecular mechanisms that vegetable crops employ to cope with drought stress. In particular, it highlights the significance of key hormonal regulation pathways, such as abscisic acid (ABA), jasmonic acid (JA), and ethylene (ET), which play crucial roles in mediating stress responses. Additionally, the role of antioxidant defense systems in mitigating oxidative damage caused by reactive oxygen species (ROS) is discussed. Advances in agricultural technologies, such as the use of smart irrigation systems and biostimulants, have shown promising results in enhancing drought resistance and optimizing crop yields. Integrating these strategies with the development of drought resistant varieties through gene editing and traditional breeding techniques will ensure sustainable agricultural production in drought stressed environments. This review aims to support future research into sustainable agricultural development to enhance drought tolerance in vegetable production and secure global food supply
Development of a compact ICRF antenna for high-power and long-pulse plasma heating in the KSTAR
For the high-power and long-pulse ion cyclotron range of frequencies (ICRF) heating of the KSTAR plasma, we developed the compact ICRF antenna (CIA). The target injection power of CIA is 2 MW for 300 s. In order to continue injecting the power into plasma even if drastic instantaneous changes occur in the plasma condition, such as ELM events, we adopted the internal conjugate-T method for the load resilience. Between antenna heads and the junction point, impedance transformers were inserted to satisfy the condition of conjugate-T in a limited space keeping the electric field on the transformer low enough. To reduce the risk of water leakage into the vacuum chamber, only the backsides of antenna heads are water-cooled in the in-vessel region
- …
