Enhanced Water Splitting by Fe 2

The effect of TiO2 layer applied to the conventional Fe2O3/FTO photoanode to improve the photoelectrochemical performance was assessed from the viewpoint of the microstructure and energy band structure. Regardless of the location of the TiO2 layer in the photoanodes, that is, Fe2O3/TiO2/FTO or TiO2/Fe2O3/FTO, high performance was obtained when α-Fe2O3 and H-TiNT/anatase-TiO2 phases existed in the constituent Fe2O3 and TiO2 layers after optimized heat treatments. The presence of the Fe2O3 nanoparticles with high uniformity in the each layer of the Fe2O3/TiO2/FTO photoanode achieved by a simple dipping process seemed to positively affect the performance improvement by modifying the energy band structure to a more favorable one for efficient electrons transfer. Our current study suggests that the application of the TiO2 interlayer, together with α-Fe2O3 nanoparticles present in the each constituent layers, could significantly contribute to the performance improvement of the conventional Fe2O3 photoanode

Electrochemical Properties of Chemically Processed SiO

A SiOx coating material for Si anode in lithium-ion battery was processed by using SiCl4 and ethylene glycol. The produced SiOx particles after heat treatment at 725°C for 1 h were porous and irregularly shaped with amorphous structure. Pitch carbon added to SiOx was found to strongly affect solid electrolyte interphase stabilization and cyclic stability. When mixed with an optimal amount of 30 wt% pitch carbon, the SiOx showed a high charge/discharge cyclic stability of about 97% for the 2nd to the 50th cycle. The initial specific capacity of the SiOx was measured to be 1401 mAh/g. On the basis of the evaluation of the SiOx coating material, the process utilized in this study is considered an efficient method to produce SiOx with high performance in an economical way

False Memory and Alzheimer’s Disease Pathology in Patients with Amnestic Mild Cognitive Impairment: A Study with Amyloid PET

Introduction: False memory, observed as intrusion errors or false positives (FPs), is prevalent in patients with Alzheimer’s disease, but has yet to be thoroughly investigated in patients with amnestic mild cognitive impairment (a-MCI) with Alzheimer’s disease pathology (ADP). We analyzed false versus veridical memory in individuals with a-MCI and measured the utility of false memory for ADP discrimination. Methods: Patients with a-MCI who received neuropsychological testing and amyloid PET were included. Patients were categorized into “with” and “without ADP” groups according to PET results. Memory tests assessed veridical and false memory, and the verity of patient responses was analyzed. A logistic regression model was used to evaluate false memory efficiency in discriminating ADP, and the sensitivity and specificity at the optimal level were estimated using the receiver-operating characteristic curve. Results: Thirty-seven ADP and 46 non-ADP patients were enrolled. The ADP group made more FPs in the recognition tests, and their response verity was significantly lower in every delayed memory test. No group difference, however, was observed in the veridical memory. The logistic regression analysis demonstrated that as the FPs increased, the risk of ADP increased 1.31 and 1.36 times in the verbal and visual recognition tests, respectively. The discriminatory accuracy of the FPs was estimated “low” to “moderate” in the visual and verbal recognition, respectively, with an optimal cutoff above 2.5. Conclusion: Increased false memory was the only feature to discriminate ADP from non-ADP in individuals with a-MCI. Further studies regarding false memory and its mechanism are warranted

Approaching isotropic transfer integrals in crystalline organic semiconductors

Dynamic disorders, which possess a finite charge delocalization, play a critical role in the charge transport properties of high-mobility molecular organic semiconductors. The use of two-dimensional (2D) charge transport in crystalline organic semiconductors can effectively facilitate reducing the sensitivity of charge carriers to thermal energetic disorders existing in even single crystals to enhance the carrier mobility. An isotropic transfer integral among adjacent molecules enables a dimensional transition from quasi-one-dimensional to 2D for charge transport among molecules. Herein, a tuned molecular packing, especially molecular rotation, was achieved in highly crystalline organic thin films via a brush-coating method. This tuned molecular packing was favorable for approaching isotropic transfer integrals. Consequently, high-performance organic transistors with a carrier mobility up to 21.5cm2V−1s−1 and low angle dependence were obtained. This work presents a unique modulation of molecular packing at the molecular scale to enable less sensitivity of the charge transport to dynamic disorders, providing an alternative route for enhancing the electrical performance of organic electronic devices

The Effects of Monetary Policy, Fiscal Policy, and College Share on the U.S. Economy

Chapter 1 suggests an efficient and simple regression-based approach for consistent estimation of dynamic effects of structural shocks in vector autoregressions (VAR) with proxy variables for the shocks. First, we show that the existing Proxy Structural VAR (Proxy-SVAR) approach using the proxy as an instrument variable yields a consistent estimator of the shape of the impulse-response function (IRF) if and only if the proxy does not have any direct forecasting ability in the VAR. Second, we prove that in the linear model, the shape of the IRF can be consistently estimated by adding the current and past values of the proxy variable in the VAR regardless of its direct forecasting ability or measurement error. Third, we show both theoretically and empirically that the formulation in Gertler and Karadi (2015) misestimates the effect of a monetary policy shock. Applying our unrestricted approach to GK's specification results in a substantially different conclusion from the Proxy-SVAR. In Chapter 2, We build a Markov-switching structural VAR to estimate state-dependent government spending multipliers in the U.S. We show that the multipliers are statistically larger during recessions than during expansions. Our model has two features. First, we combine quantitative data and qualitative indicators to infer the regimes of the economy across which the multipliers differ. Second, we propose a recursive method to estimate IRFs that allows the economy to switch regimes after the shock. We argue that these two features are important for reconciling the main findings in previous studies.Chapter 3 extends the Rosen-Roback spatial equilibrium model to show that increasing city-level college share affects welfare distribution by changing both wages and housing costs across individuals with different education levels. Using the PSID from 1980 to 2013, we confirm that high skilled workers gain greater benefits from living in cities with a rising college share, as the increase in their wage premiums outweighs their rent growth. However, earnings increase of the unskilled are completely offset by higher housing rents. In response influxes of college graduates, housing wealth also increases significantly more for college graduates, further widening the welfare gap

Validity of Korean Version of Functional Outcomes of Sleep Questionnaire in Patients with Simple Snoring and Obstructive Sleep Apnea

Background and Objective We developed a Korean version of the Functional Outcomes of Sleep Questionnaire (K-FOSQ) and investigated its reliability and validity in simple snorer or obstructive sleep apnea (OSA) patients. Methods A total 432 participants (70% men, 84% OSA, mean age 50.0 ± 9.8 years) who were simple snorers or had OSA were included. We assessed the internal consistency, test-retest reliability, factor analysis, multitrait scaling analysis, and the concurrent validity of the K-FOSQ. Participants completed a battery of questionnaires including the Epworth Sleepiness Scale (ESS), Short Form-36 Health Survey (SF-36), Medical Outcomes Study-Sleep (MOS-Sleep) Scale, and Beck Depression Inventory (BDI). Results Factor analysis identified five factors, in which only 24 items met the loading criteria. The five factors of K-FOSQ accounted for 73.0% of the variance. Cronbach’s alpha coefficient for all domains exceeded the 0.70 standard for internal consistency. Test-retest reliability was acceptable (r = 0.41–0.93). Item-domain correlations ranged from 0.37 to 0.90. Only one item did not reach the threshold of 0.40. Floor effects were not observed, but ceiling effects were marked on all K-FOSQ subscales except one. All domains of K-FOSQ were significantly correlated with the corresponding scores of all tested instruments. The global K-FOSQ had a strong correlations (r > 0.50) with ESS and Sleep Problem Index-2 of MOS-Sleep, and had medium-sized correlations (r = 0.40–0.50) with BDI and SF-36 total scores. The K-FOSQ global and subscales did discriminate between participants with and without daytime sleepiness, but not between simple snorers and OSA patients. Conclusions The K-FOSQ is a reliable and valid instrument for assessing functional outcome in participants with daytime sleepiness

Lithium benzoate doped high performance n-type diketopyrrolopyrrole based organic thin-film transistors

We report lithium benzoate (LB) as an effective electron dopant for commonly used diketopyrrolopyrrole (DDP) based electron donor-acceptor conjugated polymers and its application in organic thin-film transistors (OTFTs). Three DPP derivative classes were considered: ambipolar, electron dominant, and hole dominant semiconducting polymers. Applying LB dopant at the contact or semiconducting layer bulk significantly improved overall n-channel performance more than 100-fold, such as electron mobility and on/off current ratio for solution -processed DPP based OTFTs compared with pristine devices. The best DPP based OTFTs with LB achieved high electron mobility (0.6 cm(2) V-1 s(-1)) with excellent operational stability. In particular, complete ambipolar transport modulation to unipolar n-type was achieved for n-channel dominant OTFTs devices.11Nsciescopu

Effects of the Bradyrhizobium japonicum waaL (rfaL) Gene on Hydrophobicity, Motility, Stress Tolerance, and Symbiotic Relationship with Soybeans

We cloned and sequenced the waaL (rfaL) gene from Bradyrhizobium japonicum, which infects soybean and forms nitrogen-fixing nodules on soybean roots. waaL has been extensively studied in the lipopolysaccharide (LPS) biosynthesis of enteric bacteria, but little is known about its function in (brady)rhizobial LPS architecture. To characterize its role as O-antigen ligase in the LPS biosynthesis pathway, we constructed a waaL knock-out mutant and its complemented strain named JS015 and CS015, respectively. LPS analysis showed that an LPS structure of JS015 is deficient in O-antigen as compared to that of the wild type and complemented strain CS015, suggesting that WaaL ligates the O-antigen to lipid A-core oligosaccharide to form a complete LPS. JS015 also revealed increased cell surface hydrophobicity, but it showed decreased motility in soft agar plates. In addition to the alteration in cell surface properties, disruption of the waaL gene caused increased sensitivity of JS015 to hydrogen peroxide, osmotic pressure, and novobiocin. Specifically, plant tests revealed that JS015 failed to nodulate the host plant soybean, indicating that the rhizobial waaL gene is responsible for the establishment of a symbiotic relationship between soybean and B. japonicum

Synthesis and Characterization of Diketopyrrolopyrrole-Based Conjugated Polymers with Bithiophene and Biselenophene for Organic Thin Film Transistors

In this study, two new thieno[3,2-b] thiophene-diketopyrrolopyrrole (DPP)-based polymers, poly{2,5-bis(2-dodecylhexadecyl)-3,6-bis(thieno[3,2-b] thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-2,2'-bithiophene} (PTTDPP-BT) and {2,5-bis(2-dodecylhexadecyl)-3,6-bis(thieno[3,2-b] thiophen-2-yl) pyrrolo[3,4-c] pyrrole-1,4(2H, 5H)-dione-alt-2,2'-selenophene} (PTTDPP-BSe), which contained bithiophene (BT) and biselenophene (BSe) units, respectively, were designed and synthesized. The introduction of BT and BSe units affected the optical, electrochemical, morphological, and charge transport properties of the polymers. Experimental results revealed that the frontier molecular orbital energy levels of PTTDPP-BT were slightly higher because of the relatively strong electron donating ability of the sulfur atom and the polymer also exhibited good solubility. The maximum mobility in the case of PTTDPP-BT at 250 degrees C was 0.068 cm(2) V-1 s(-1) and that of PTTDPP-BSe was 0.029 cm(2) V-1 s(-1) (at 200 degrees C).11Nsci