Electronic Properties of Boron and Nitrogen doped graphene: A first principles study

Effect of doping of graphene either by Boron (B), Nitrogen (N) or co-doped by B and N is studied using density functional theory. Our extensive band structure and density of states calculations indicate that upon doping by N (electron doping), the Dirac point in the graphene band structure shifts below the Fermi level and an energy gap appears at the high symmetric K-point. On the other hand, by B (hole doping), the Dirac point shifts above the Fermi level and a gap appears. Upon co-doping of graphene by B and N, the energy gap between valence and conduction bands appears at Fermi level and the system behaves as narrow gap semiconductor. Obtained results are found to be in well agreement with available experimental findings.Comment: 11 pages, 4 figures, 1 table, submitted to J. Nanopart. Re

Theta and alpha oscillations in attentional interaction during distracted driving

© 2018 Wang, Jung and Lin. Performing multiple tasks simultaneously usually affects the behavioral performance as compared with executing the single task. Moreover, processing multiple tasks simultaneously often involve more cognitive demands. Two visual tasks, lane-keeping task and mental calculation, were utilized to assess the brain dynamics through 32-channel electroencephalogram (EEG) recorded from 14 participants. A 400-ms stimulus onset asynchrony (SOA) factor was used to induce distinct levels of attentional requirements. In the dual-task conditions, the deteriorated behavior reflected the divided attention and the overlapping brain resources used. The frontal, parietal and occipital components were decomposed by independent component analysis (ICA) algorithm. The event- and response-related theta and alpha oscillations in selected brain regions were investigated first. The increased theta oscillation in frontal component and decreased alpha oscillations in parietal and occipital components reflect the cognitive demands and attentional requirements as executing the designed tasks. Furthermore, time-varying interactive over-additive (O-Add), additive (Add) and under-additive (U-Add) activations were explored and summarized through the comparison between the summation of the elicited spectral perturbations in two single-task conditions and the spectral perturbations in the dual task. Add and U-Add activations were observed while executing the dual tasks. U-Add theta and alpha activations dominated the posterior region in dual-task situations. Our results show that both deteriorated behaviors and interactive brain activations should be comprehensively considered for evaluating workload or attentional interaction precisely

The potential of the weed, Commelina diffusa L., as a fodder crop for ruminants

The objective of this study was to evaluate the potential of Commelina diffusa L. as a ruminant feed. Commelina diffusa belongs to the Commelinaceae family, a family of plants that is generally poorly investigated with respect to ruminant nutrition. The species was evaluated in terms of its chemical composition, and through the in sacco technique, its rumen degradation characteristics. Rumen degradability was determined in three mature female goats, each fitted with a permanent rumen cannula. Commelina diffusa contained 177 g crude protein (CP)/kg dry matter (DM) and its CP had a rumen degradability of 74.1 ± 2.7%. Most of the DM and organic matter (OM) were lost during the first 36 h of incubation and the cell wall components after 48 h of incubation. Maximum (120 h) DM, OM, neutral and acid detergent fibre, hemicellulose and cellulose disappearances from the bags incubated in the rumen were 66.3, 57.8, 55.6, 55.2, 56.7 and 44.3%, respectively. Rumen degradation of DM and OM was correlated (r2 = 0.66), but significantly different. It is concluded that, from a nutritional point of view, C. diffusa compares well with many commonly used fodder crops and could be used as protein source for ruminants on smallholder farms. South African Journal of Animal Science Vol. 36(1) 2006: 28-3

In Situ Structure Characterization in Slot-Die-Printed All-Polymer Solar Cells with Efficiency Over 9%

Herein, high-performance printed all-polymer solar cells (all-PSCs) based on a bulk-heterojunction (BHJ) blend film are demonstrated using PTzBI as the donor and N2200 as the acceptor. A slot-die process is used to prepare the BHJ blend, which is a cost-effective, high-throughput approach to achieve large-area photovoltaic devices. The real-time crystallization of polymers in the film drying process is investigated by in situ grazing incidence wide-angle X-ray scattering characterization. Printing is found to significantly improve the crystallinity of the polymer blend in comparison with spin coating. Moreover, printing with 1,8-diiodooctane as the solvent additive enhances the polymer aggregation and crystallization during solvent evaporation, eventually leading to multi-length-scale phase separation, with PTzBI-rich domains in-between the N2200 crystalline fibers. This unique morphology achieved by printing fabrication results in an impressively high power conversion efficiency of 9.10%, which is the highest efficiency reported for printed all-PSCs. These findings provide important guidelines for controlling film drying dynamics for processing all-PSCs

Pathological behaviour of the scalar graviton in Ho\v{r}ava-Lifshitz gravity

We confirm the recent claims that, in the infrared limit of Ho\v{r}ava-Lifshitz gravity, the scalar graviton becomes a ghost if the sound speed squared is positive on the flat de Sitter and Minkowski background. In order to avoid the ghost and tame the instability, the sound speed squared should be negative and very small, which means that the flow parameter $\lambda$ should be very close to its General Relativity (GR) value. We calculate the cubic interactions for the scalar graviton which are shown to have a similar structure with those of the curvature perturbation in k-inflation models. The higher order interactions become increasing important for a smaller sound speed squared, that is, when the theory approaches GR. This invalidates any linearized analysis and any predictability is lost in this limit as quantum corrections are not controllable. This pathological behaviour of the scalar graviton casts doubt on the validity of the projectable version of the theory.Comment: 7 pages, references added; v3: Typos corrected, minor changes to text and precise determination of the strong coupling scale. Replaced to match published version

Inhibitory mechanism of 3-hydroxypropionaldehyde accumulation in 1,3-propanediol synthesis with Klebsiella pneumoniae

3-Hydroxypropionaldehyde accumulation may cause the cessation of 1,3-propanediol sustained production with glycerol by Klebsiella pneumoniae. The impeller tip speed shift from higher to lower speed at glycerol excess or the pulsed glycerol feeding could lead to an abrupt increase of the 3- hydroxypropionaldehyde concentration (up to 10 mmol/l) in 10 min. The intracellular consequence of the 3-hydroxypropionaldehyde accumulation has not yet been elucidated. The rapid accumulation of 3- hydroxypropionaldehyde relying on the impeller tip speed shift was employed to investigate the influences of 3-hydroxypropionaldehyde to the activities of nine key enzymes related to glycerol metabolism, CO2 and O2 levels in off-gas, cell growth and 1,3-propanediol synthesis. Compared with that at 1.19 mmol/l 3-hydroxypropionaldehyde in broth, the residual enzymatic activities of the nine key enzymes ranged from 9.44 to 74.68% in the cultures at 7.5 mmol/l 3-hydroxypropionaldehyde in broth. The inhibitions of cell growth and the 1,3-propanediol synthesis were unnoticeable at the low level of 3- hydroxypropionaldehyde. By contrast, the CO2 and O2 levels changes in off-gas response to the 3- hydroxypropionaldehyde accumulation were less than 15 min. These results suggest that 3- hydroxypropionaldehyde inhibited the growth and metabolism of K. pneumoniae in a more complicated manner.Keywords: Fermentation, glycerol, 3-hydroxypropionaldehyde, Klebsiella pneumoniae, 1,3-propanediol

Agricultural origins and the isotopic identity of domestication in northern China

Stable isotope biochemistry (δ 13C and δ 15N) and radiocarbon dating of ancient human and animal bone document 2 distinct phases of plant and animal domestication at the Dadiwan site in northwest China. The first was brief and nonintensive: at various times between 7900 and 7200 calendar years before present (calBP) people harvested and stored enough broomcorn millet (Panicum miliaceum) to provision themselves and their hunting dogs (Canis sp.) throughout the year. The second, much more intensive phase was in place by 5900 calBP: during this time both broomcorn and foxtail (Setaria viridis spp. italica) millets were cultivated and made significant contributions to the diets of people, dogs, and pigs (Sus sp.). The systems represented in both phases developed elsewhere: the earlier, low-intensity domestic relationship emerged with hunter-gatherers in the arid north, while the more intensive, later one evolved further east and arrived at Dadiwan with the Yangshao Neolithic. The stable isotope methodology used here is probably the best means of detecting the symbiotic human-plantanimal linkages that develop during the very earliest phases of domestication and is thus applicable to the areas where these connections first emerged and are critical to explaining how and why agriculture began in East Asia

Tuberculosis of pancreas and peripancreatic lymph nodes in immunocompetent patients: Experience from China

Aim: To determine the clinical, radiographic and laboratory characteristics, diagnostic methods, and therapeutic variables in immunocompetent patients with tuberculosis (TB) of the pancreas and peripancreatic lymph nodes. Methods: The records of 16 patients (6 male, 10 female; mean age 37 years, range 18-56years) with tuberculosis of the pancreas and peripancreatic lymph nodes from 1983 to 2001 in the Southwest Hospital were analyzed retrospectively. In addition, 58 similar cases published in Chinese literature were reviewed and summarized. We reviewed the clinical, radiographic and laboratory findings, diagnostic methods, therapeutic approaches, and outcome in the patients. Criteria for the diagnosis of pancreatic tuberculosis were the presence of granuloma in histological sections or the presence of Mycobacterium tuberculosis DNA by polymerase chain reaction (PCR). Results: Predominant symptoms consisted of abdominal nodule and pain (75 %), anorexia/weight loss (69 %), malaise/weakness (64 %), fever and night sweats (50 %), back pain (38 %) and jaundice (31 %). Swelling of the head of the pancreas with heterogeneous attenuation echo was detected with ultrasound in 75 % (12/16). CT scan showed pancreatic mass with heterogeneous hypodensity focus in all patients, with calcification in 56 % (9/16) patients, and peripancreatic nodules in 38 % (6/16) patients. Anemia and lymphocytopenia were seen in 50 % (8/16) patients, and pancytopenia occurred in 13 % (2/ 16) patients. Hypertransaminasemia, elevated alkaline phosphatase (AP) and GGT were seen in 56 % (9/16) patients. The erythrocyte sedimentation rate (ESR) was elevated in 69 % (11/16) cases. Granulomas were found in 75 % (12/16) cases, and in 38 % (6/16) cases caseous necrosis tissue was found. Laparotomy was performed in 75 % (12/16) cases, and ultrasound-guided fine needle aspiration (FNA) was done in 63 % (10 of 16). The most commonly used combinations of medications were isoniazid/rifampin/streptomycin (63 %, n=10) and isoniazid/rifampin pyrazinamide/streptomycin or ethambutol (38 %, n=6). The duration of treatment lasted for half or one year and treatment was successful in all cases. The characteristics of 58 cases from Chinese literature were also summarized. Conclusion: Tuberculosis of the pancreas and peripancreatic lymph nodes should be considered as a diagnostic possibility in patients presenting with a pancreatic mass, and diagnosis without laparotomy is possible if only doctors are aware of its clinical features and investigate it with appropriate modalities. Pancreatic tuberculosis can be effectively cured by antituberculous drugs.published_or_final_versio

Two independent frontal midline theta oscillations during conflict detection and adaptation in a Simon-type manual reaching task

© 2017 the authors. One of the most firmly established factors determining the speed of human behavioral responses toward action-critical stimuli is the spatial correspondence between the stimulus and response locations. If both locations match, the time taken for response production is markedly reduced relative to when they mismatch, a phenomenon called the Simon effect. While there is a consensus that this stimulus-response (S-R) conflict is associated with brief (4-7 Hz) frontal midline theta (fmθ) complexes generated in medial frontal cortex, it remains controversial (1) whether there are multiple, simultaneously active theta generator areas in the medial frontal cortex that commonly give rise to conflict-related fmθ complexes; and if so, (2) whether they are all related to the resolution of conflicting task information. Here, we combined mental chronometry with high-density electroencephalographic measures during a Simon-type manual reaching task and used independent component analysis and time-frequency domain statistics on source-level activities to model fmθ sources. During target processing, our results revealed two independent fmθ generators simultaneously active in or near anterior cingulate cortex, only one of them reflecting the correspondence between current and previous S-R locations. However, this fmθ response is not exclusively linked to conflict but also to other, conflict-independent processes associated with response slowing. These results paint a detailed picture regarding the oscillatory correlates of conflict processing in Simon tasks, and challenge the prevalent notion that fmθ complexes induced by conflicting task information represent a unitary phenomenon related to cognitive control, which governs conflict processing across various types of response-override tasks

Genes encoding Pir51, Beclin 1, RbAp48 and aldolase b are up or down-regulated in human primary hepatocellular carcinoma

Aim: To reveal new tumor markers and target genes from differentially expressed genes of primary tumor samples using cDNA microarray. Methods: The 33P labeled cDNAs were synthesized by reverse transcription of message RNA from the liver cancerous tissue and adjacent non-cancerous liver tissue from the same patient and used to hybridize to LifeGrid 1.0 cDNA microarray blot containing 8400 known and unique human cDNA gene targets, and an expression profile of genes was produced in one paired human liver tumor tissue. After a global analysis of gene expression of 8400 genes, we selected some genes to confirm the differential expression using Northern blot and RT-PCR. Results: Parallel analysis of the hybridized signals enabled us to get an expression profile of genes in which about 500 genes were differentially expressed in the paired liver tumor tissues. We identified 4 genes, the expression of three (Beclin 1, RbAp48 and Pir51) were increased and one (aldolase b) was decreased in liver tumor tissues. In addition, the expression of these genes in 6 hepatoma cell lines was also showed by RT-PCR analysis. Conclusion: cDNA microarray permits a high throughput identification of changes in gene expression. The genes encoding Beclin 1, RbAp48, Pir51 and aldolase b are first reported that may be related with hepatocarcinoma. Copyright © 2004 by The WJG Press ISSN 1007-9327.published_or_final_versio