Observation of strong anisotropic forbidden transitions in (001) InGaAs/GaAs single-quantum well by reflectance-difference spectroscopy and its behavior under uniaxial strain

The strong anisotropic forbidden transition has been observed in a series of InGaAs/GaAs single-quantum well with well width ranging between 3 nm and 7 nm at 80 K. Numerical calculations within the envelope function framework have been performed to analyze the origin of the optical anisotropic forbidden transition. It is found that the optical anisotropy of this transition can be mainly attributed to indium segregation effect. The effect of uniaxial strain on in-plane optical anisotropy (IPOA) is also investigated. The IPOA of the forbidden transition changes little with strain, while that of the allowed transition shows a linear dependence on strain

Effect of calcium addition on Mg-AlOx supported Ni catalysts for hydrogen production from pyrolysis-gasification of biomass

Producing hydrogen from catalytic gasification of biomass represents an interesting process to facilitate the development of hydrogen economy. However, the design of catalyst is a key challenge for this technology. In this work, cost-effective Ca added Ni-based catalysts were developed and studied for producing hydrogen with a fixed-bed reactor. The relationship between Ca addition and the performance of catalyst in terms of the yield of hydrogen and catalyst deactivation (metal sintering and coke formation) was studied. The results showed that hydrogen production was largely enhanced when Ca was added, as the yield of hydrogen was enhanced from 10.4 to 18.2 mmol g−1 sample in the presence of Ca-based catalyst. However, the yield and concentration of hydrogen were kept at similar levels with the increase of Ca. By normalizing the yield of hydrogen in relation to the amount of Ni presented inside the catalyst, the hydrogen yield per mole of nickel was increased from 50 g Ni −1(0.1Ca catalyst) to 80 g Ni−1 (0.8Ca catalyst) when the Ca addition was increased from 10 mol% to 80 mol%. TPO-FTIR analysis of the experimented catalysts showed that 0.5 Ca catalyst had the highest amount of coke formation, in particular, most of the deposited carbons were amorphous which could deactivate the catalyst seriously. It is therefore concluded that the addition of cost-effective Ca could enhance the yield of hydrogen from biomass gasification. However, the concentration of Ca in the catalyst needs to be controlled to mitigate the generation of coke on the used catalyst

LNK suppresses interferon signaling in melanoma.

LNK (SH2B3) is a key negative regulator of JAK-STAT signaling which has been extensively studied in malignant hematopoietic diseases. We found that LNK is significantly elevated in cutaneous melanoma; this elevation is correlated with hyperactive signaling of the RAS-RAF-MEK pathway. Elevated LNK enhances cell growth and survival in adverse conditions. Forced expression of LNK inhibits signaling by interferon-STAT1 and suppresses interferon (IFN) induced cell cycle arrest and cell apoptosis. In contrast, silencing LNK expression by either shRNA or CRISPR-Cas9 potentiates the killing effect of IFN. The IFN-LNK signaling is tightly regulated by a negative feedback mechanism; melanoma cells exposed to IFN upregulate expression of LNK to prevent overactivation of this signaling pathway. Our study reveals an unappreciated function of LNK in melanoma and highlights the critical role of the IFN-STAT1-LNK signaling axis in this potentially devastating disease. LNK may be further explored as a potential therapeutic target for melanoma immunotherapy

Enhancing hydrogen production from the pyrolysis-gasification of biomass by size-confined Ni catalysts on acidic MCM-41 supports

Hydrogen, currently produced from the reforming of fossil fuel resources, is a significant source for clean energy and the chemical industry. It is promising to develop a high-efficiency hydrogen production process from renewable biomass for sustainable development. This research reports that catalyst support acidity could strongly enhance the hydrogen production from the biomass gasification of wood sawdust. For minimizing the influence of the Ni particle size for the biomass gasification, the uniform Ni nanoparticles around 2–3 nm were loaded into one type of mesoporous support MCM-41 with various acidity. Ni/H-[Al] MCM-41 with a large amount of Brϕnsted acid sites contributed 2–3 times higher hydrogen yield (21.6 mmol H2 g−1 sample) than that on Ni/H-[Si]MCM-41 with a small amount of very weak acidic surface SiOH groups (9.8 mmol H2 g−1 sample) and that on nonacidic Ni/Na-[Si]MCM-41 (6.7 mmol H2 g−1 sample). The surface acid sites on supports could generate bifunctional catalysts and were proposed to show two functions for enhancing the hydrogen production: 1) help to crack and transfer the pyrolysis chemicals into smaller compounds for more efficient reforming on the Ni surface inside nanopores; 2) enhance the support and Ni interaction for better reduction property and surface activity of Ni nanoparticles and improve the reforming performance. The obtained Ni/MCM-41 catalysts were quite stable and no sintering has been observed after the gasification at 800 °C, and only a low coke deposition has been detected

Enhancing hydrogen production from the pyrolysis-gasification of biomass by size-confined Ni catalysts on acidic MCM-41 supports

Hydrogen, currently produced from the reforming of fossil fuel resources, is a significant source for clean energy and the chemical industry. It is promising to develop a high-efficiency hydrogen production process from renewable biomass for sustainable development. This research reports that catalyst support acidity could strongly enhance the hydrogen production from the biomass gasification of wood sawdust. For minimizing the influence of the Ni particle size for the biomass gasification, the uniform Ni nanoparticles around 2–3 nm were loaded into one type of mesoporous support MCM-41 with various acidity. Ni/H-[Al] MCM-41 with a large amount of Brϕnsted acid sites contributed 2–3 times higher hydrogen yield (21.6 mmol H2 g−1 sample) than that on Ni/H-[Si]MCM-41 with a small amount of very weak acidic surface SiOH groups (9.8 mmol H2 g−1 sample) and that on nonacidic Ni/Na-[Si]MCM-41 (6.7 mmol H2 g−1 sample). The surface acid sites on supports could generate bifunctional catalysts and were proposed to show two functions for enhancing the hydrogen production: 1) help to crack and transfer the pyrolysis chemicals into smaller compounds for more efficient reforming on the Ni surface inside nanopores; 2) enhance the support and Ni interaction for better reduction property and surface activity of Ni nanoparticles and improve the reforming performance. The obtained Ni/MCM-41 catalysts were quite stable and no sintering has been observed after the gasification at 800 °C, and only a low coke deposition has been detected

Effect of providing near glasses on productivity among rural Indian tea workers with presbyopia (PROSPER) a randomised trial

BACKGROUND: Presbyopia, age-related decline in near vision, is the most common cause of vision impairment globally, but no trials have assessed its workplace effects. We aimed to study the effect of near glasses on the productivity of tea workers with presbyopia.METHODS: This randomised trial was done in tea pickers aged 40 years or older in Assam, India, with unaided near visual acuity (NVA) lower than 6/12 in both eyes, correctable to 6/7·5 with near glasses; unaided distance vision 6/7·5 or greater; and no eye disease. Participants were randomly assigned (1:1) to receive free glasses optimising NVA at working distance (cost including delivery US$10·20 per person), either immediately (intervention group) or at closeout (control group). Participants were stratified by age, sex, and productivity. The primary outcome (investigator-masked) was the difference between groups in the change in mean daily weight of tea picked (productivity), between the 4-week baseline period (June, 2017) and the 11-week evaluation period (July 24, 2017, to Oct 7, 2017). Workers' income was tied to their productivity. Compliance with study glasses was assessed at seven unannounced visits. Results were analysed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT03228199.FINDINGS: Between July 3, 2017, and July 15, 2017, 1297 (48·1%) of 2699 permanent workers met the age criteria and consented for eye examinations. 751 (57·9%) fulfilled vision criteria and were randomly assigned to the intervention (n=376) or control (n=375) groups. Groups did not differ substantially in baseline characteristics. No participants owned glasses at baseline, 707 (94·1%) received the allocated intervention, and all were followed up and analysed. Between the baseline and evaluation periods, mean productivity in the intervention group increased from 25·0 kg per day to 34·8 kg per day (an increase of 9·84 kg per day), a significantly higher increase than in the control group (from 26·0 kg per day to 30·6 kg per day; an increase of 4·59 kg per day), corresponding to a between-group difference of 5·25 kg per day (95% CI 4·50-5·99; 21·7% relative productivity increase; effect size 1·01 [95% CI 0·86-1·16]; p&lt;0·0001). Intervention-group compliance with study glasses reached 84·5% by closeout. Regression model predictors of greater productivity increase included intervention group membership (5·25 kg per day [95% CI 4·60-5·91], p&lt;0·0001) and, among intervention participants, older age (p=0·039) and better compliance with the intervention (p&lt;0·0001).INTERPRETATION: A substantial productivity increase was achieved in this rural cohort by providing glasses to correct presbyopia, with little cost and high intervention uptake.FUNDING: Clearly.</p

Covariant anomaly and Hawking radiation from the modified black hole in the rainbow gravity theory

Recently, Banerjee and Kulkarni (R. Banerjee, S. Kulkarni, arXiv:0707.2449 [hep-th]) suggested that it is conceptually clean and economical to use only the covariant anomaly to derive Hawking radiation from a black hole. Based upon this simplified formalism, we apply the covariant anomaly cancellation method to investigate Hawking radiation from a modified Schwarzschild black hole in the theory of rainbow gravity. Hawking temperature of the gravity's rainbow black hole is derived from the energy-momentum flux by requiring it to cancel the covariant gravitational anomaly at the horizon. We stress that this temperature is exactly the same as that calculated by the method of cancelling the consistent anomaly.Comment: 5 page