Plasmonic metals under photoexcitation can generate energetic hot electrons to directly induce chemical reactions. However, the capability and fundamental insights of the transportation of these hot ...electrons at plasmonic metal‐2D material interfaces remain unclear. Herein, hot‐electron transfer at Au‐graphene interfaces has been in situ studied using surface‐enhanced Raman spectroscopy (SERS) with atomic layer accuracy. Combining in situ SERS studies with density functional theory calculations, it is proved that hot electrons can be injected from plasmonic Au nanoparticles to graphene and directly penetrate graphene to trigger photocatalytic reactions. With increasing graphene layers, the transportation of hot electrons decays rapidly and would be completely blocked after five layers of graphene. Moreover, the transfer of hot electrons can be modulated by applying an external electric field, and the hot‐electron transfer efficiency under electrochemical conditions is improved by over three times in the presence of a monolayer of graphene.
Hot‐electron transfer at Au–graphene interfaces has been investigated in situ with atomic layer accuracy, and it is shown that hot electrons can be injected from plasmonic Au nanoparticles to graphene and penetrate up to four layers of graphene.
Graphdiyne oxide (GDO), the oxidized form of graphdiyne (GDY), exhibits an ultrafast humidity response with an unprecedented response speed (ca. 7 ms), which is three times faster than that of ...graphene oxide (GO) with the same thickness and O/C ratio. The ultrafast humidity response of GDO is considered to benefit from the unique carbon hybridization of GDO, which contains acetylenic bonds that are more electron‐withdrawing than ethylenic bonds in GO, consequently giving rise to a faster binding rate with water. This distinctive structure‐based property enables the fabrication of a novel GDO‐based humidity sensor with an ultrafast response speed and good selectivity against other kinds of gas molecules as well as high sensitivity. These properties allow the sensor to accurately monitor the respiration rate change of human and hypoxic rats.
Hybridization matters: Graphdiyne oxide (GDO), the oxidized form of graphdiyne (GDY), exhibits an ultrafast humidity response with an unprecedented response speed (ca. 7 ms), which is three times faster than that of graphene oxide (GO). The acetylenic bond of GDO is more electron‐withdrawing than the ethylenic bond in GO and gives rise to a faster binding rate with water.
We examine the impact of political risk on firms' payout policy. Using a large international sample across 35 countries over the period from 1990 to 2008, we find that global political crises raise ...the market perceived uncertainty and cost of external financing. Using crisis events as a proxy for political risk, we document that past dividend payers are more likely to terminate dividends and that non-payers are less likely to initiate dividends during periods of high political risk. These findings suggest a precautionary incentive of managers in response to political shocks. Further analysis shows that the effect of political risk on payout policy is stronger for multinational corporations, but can be attenuated by country-specific institutional settings, such as more stable political systems and stronger investor legal protection.
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A multi-functional hybrid hydrogel P(M-Arg/NIPAAm) with temperature response, anti-protein adsorption and antibacterial properties was prepared and applied as wound dressing. The ...hydrogel was carried out by free radical copolymerization of methacrylate arginine (M-Arg) and N-isopropyl acrylamide (NIPAAm) monomers using N,N′-methylene bisacrylamide as a crosslinker, and ammonium persulfate/N,N,N′, N′-tetramethylethylenediamine as the redox initiator. To endow the antimicrobial property, chlorhexidine diacetate (CHX) was preloaded into the hydrogel and polyhexamethylene guanidine phosphate (PHMG) was grafted on the hydrogel surface, respectively. The antimicrobial property of two series of hydrogels was evaluated and compared. The successful synthesis of M-Arg, PHMG and hydrogels was proved by 13C NMR, 1H NMR and FTIR spectroscopy. The hydrogel morphology characterized by scanning electron microscopy confirmed that the homogeneous porous and interconnected structures of the hydrogels. The swelling, protein adsorption property, in vitro release of CHX, antimicrobial assessment, cell viability as well as in vivo wound healing in a mouse model were studied. The results showed the nontoxicity and antimicrobial P(M-Arg/NIPAAm) hydrogel accelerated the full-thickness wound healing process and had the potential application in wound dressing.
Despite the zwitterionic characteristic and biocompatible property of arginine based hydrogels, the brittle behavior and non-transparency still remain as a significant problem for wound dressing. Furthermore promoting the antibacterial property of the zwitterionic hydrogel is also necessary to prevent the bacterial colonization and subsequent wound infection. Therefore, we created a hybrid hydrogel combined methacrylate arginine (M-Arg) and N-isopropyl acrylamide (NIPAAm). NIPAAm improves transparency and mechanical property as well as acts as a temperature-response drug release system. Additionally, chlorhexidine (CHX) was preloaded into the hydrogels and polyhexamethylene guanidine phosphate (PHMG) was grafted on the hydrogel surface, respectively, which make the hydrogel useful as a favorable antibacterial dressing. The hybrid hydrogel has a combination effect of biocompatibility, environmentally responsive transformation behavior, biodegradability, anti-protein adsorption and antimicrobial properties. This report proposes the preparation of P(M-Arg/NIPAAm) hydrogel that has a great potential for wound healing.
In this paper, we present new two-stage multiple comparison procedures with the average for location parameters of two-parameter exponential distributions under heteroscedasticity by modifying the ...existing one proposed by Wu and Wu. Not like one-stage procedures, two-stage multiple comparison procedures are design oriented. A simulation comparison study is done for the new two stage procedures, the old two stage procedures in Wu and Wu and the existing one-stage procedures. The results show that the proposed procedures have shorter confidence length with coverage probabilities closer to the nominal ones than the old two-stage one. At last, an example of four drugs for the treatment for leukemia is studied for illustrative aims.
This paper presents an experimental program that includes 78 fiber reinforced polymer (FRP)-confined square concrete columns subjected to eccentric loading. The degradation of the axial strength of ...FRP-confined short concrete columns due to the load eccentricity is investigated in this work. A larger load eccentricity leads to a greater decrease in the axial strength. From the test results, it is found that FRP confinement can cause less strength degradation compared with that of unconfined concrete specimens. For FRP-confined square concrete specimens, the strength enhancement due to FRP confinement increases with increasing load eccentricity. However, the increasing load eccentricity decreases the confinement efficiency for FRP-confined circular concrete specimens. The relationship between the strength of eccentrically loaded FRP-confined square columns and their corner radii is evaluated.
AbstractThe shear strength of RC beams is composed of the strength provided by transverse reinforcement (Vs) and concrete (Vc). According to a literature search, no existing shear strength model ...considers the contribution of compression reinforcement. Only a few discussions on the effect of compression bars on the shear strength of RC members have been conducted in the literature. This study investigated, in detail, the influence of compression reinforcement through experimental testing and finite-element (FE) modeling. First, two groups of beams with different compression reinforcement ratios were designed and tested. After that, a robust FE model was developed, and the effect of compression reinforcement on the shear strength of RC beams was numerically evaluated. The accuracy of the FE model was verified using the test results. The mechanism of the compression reinforcement was analyzed using a conventional truss model. A systematic parametric study was subsequently conducted to investigate the combined effects of compression reinforcement and other critical factors on shear strength. It was concluded that the effect of the compressive reinforcement on the shear strength is comparable to that of the tensile reinforcement. Finally, the research findings were integrated into developing a new model for the additional shear strength of RC members owing to the compression reinforcement.
ABSTRACT
Background
This study aimed to investigate the effect of systemic inflammation, assessed by high sensitivity C‐reactive protein (hs‐CRP) levels, on prediabetes progression and regression in ...middle‐aged and older adults based on the China Health and Retirement Longitudinal Study (CHARLS).
Methods
Participants with prediabetes from CHARLS were followed up 4 years later with blood samples collected for measuring fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c). The level of hs‐CRP was assessed at baseline and categorized into tertiles (low, middle, and high groups). Prediabetes at baseline and follow‐up was defined primarily according to the American Diabetes Association (ADA) criteria. Logistic regression models were used to estimate the odds ratios (ORs) and confidence intervals (CIs). We also performed stratified analyses according to age, gender, BMI, the presence of hypertension, and the disease history of heart disease and dyslipidemia and sensitivity analyses excluding a subset of participants with incomplete data.
Results
Of the 2,874 prediabetes included at baseline, 834 participants remained as having prediabetes, 146 progressed to diabetes, and 1,894 regressed to normoglycemia based on ADA criteria with a 4 year follow‐up. After multivariate logistics regression analysis, prediabetes with middle (0.67–1.62 mg/L) and high (>1.62 mg/L) hs‐CRP levels had an increased incidence of progressing to diabetes compared with prediabetes with low hs‐CRP levels (<0.67 mg/L; OR = 1.846, 95%CI: 1.129–3.018; and OR = 1.632, 95%CI: 0.985–2.703, respectively), and the incidence of regressing to normoglycemia decreased (OR = 0.793, 95%CI: 0.645–0.975; and OR = 0.769, 95%CI: 0.623–0.978, respectively). Stratified analyses and sensitivity analyses showed consistent results.
Conclusions
Low levels of hs‐CRP are associated with a high incidence of regression from prediabetes to normoglycemia and reduced odds of progression to diabetes.
This study found that low levels of hs‐CRP are associated with a high incidence of regression from prediabetes to normoglycemia and reduced odds of progression to diabetes. Subgroup analyses showed a stronger association between hs‐CRP and type 2 diabetes in women than in men. Thus, prediabetes may need to be closely monitored in middle‐aged and older women with elevated hs‐CRP. In addition, whether a lower cutoff value for hs‐CRP elevation in women should be proposed is a question worthy of future research.
Body Structure Aware Deep Crowd Counting Huang, Siyu; Li, Xi; Zhang, Zhongfei ...
IEEE transactions on image processing,
2018-March, 2018-Mar, 2018-3-00, 20180301, Letnik:
27, Številka:
3
Journal Article
Recenzirano
Crowd counting is a challenging task, mainly due to the severe occlusions among dense crowds. This paper aims to take a broader view to address crowd counting from the perspective of semantic ...modeling. In essence, crowd counting is a task of pedestrian semantic analysis involving three key factors: pedestrians, heads, and their context structure. The information of different body parts is an important cue to help us judge whether there exists a person at a certain position. Existing methods usually perform crowd counting from the perspective of directly modeling the visual properties of either the whole body or the heads only, without explicitly capturing the composite body-part semantic structure information that is crucial for crowd counting. In our approach, we first formulate the key factors of crowd counting as semantic scene models. Then, we convert the crowd counting problem into a multi-task learning problem, such that the semantic scene models are turned into different sub-tasks. Finally, the deep convolutional neural networks are used to learn the sub-tasks in a unified scheme. Our approach encodes the semantic nature of crowd counting and provides a novel solution in terms of pedestrian semantic analysis. In experiments, our approach outperforms the state-of-the-art methods on four benchmark crowd counting data sets. The semantic structure information is demonstrated to be an effective cue in scene of crowd counting.
Traditional media are facing a crisis of declining trust, public disengagement, and declining revenue. More and more people are avoiding and rejecting traditional news because of its depressing ...effect on their feelings. The constructive journalism movement seeks to correct the negative bias of traditional journalism, strengthen the connection between the media industry and its audience, and reestablish the authority and legitimacy of journalism. This new model of journalism can give hope to a life that is "not-yet" and encourage people to move forward to solve social problems with a positive mindset. In the current era of public communications, constructive journalism offers a new option for people to rethink the many possibilities for journalists, the news communication system, and the journalism industry and thus shape their own social roles and positioning.
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