The H
O
+ HO → HO
+ H
O reaction is an important reservoir for both radicals of HO and HO
catalyzing the destruction of O
. Here, this reaction assisted by NH
and HCOOH catalysts was explored using ...the CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ method and canonical variational transition state theory with small curvature tunneling. Two possible sets of mechanisms, (i) one-step routes and (ii) stepwise processes, are possible. Our results show that in the presence of both NH
and HCOOH catalysts under relevant atmospheric temperature, mechanism (i) is favored both energetically and kinetically than the corresponding mechanism (ii). At 298 K, the relative rate for mechanism (i) in the presence of NH
(10, 2900 ppbv) and HCOOH (10 ppbv) is respectively 3-5 and 2-4 orders of magnitude lower than that of the water-catalyzed reaction. This is due to a comparatively lower concentration of NH
and HCOOH than H
O which indicates the positive water effect under atmospheric conditions. Although NH
and HCOOH catalysts play a negligible role in the reservoir for both radicals of HO and HO
catalyzing the destruction of O
, the current study provides a comprehensive example of how acidic and basic catalysts assisted the gas-phase reactions.
Self-supervised learning (SSL) holds promise in leveraging large amounts of unlabeled data. However, the success of popular SSL methods has limited on single-centric-object images like those in ...ImageNet and ignores the correlation among the scene and instances, as well as the semantic difference of instances in the scene. To address the above problems, we propose a Unified Self-supervised Visual Pre-training (UniVIP), a novel self-supervised framework to learn versatile visual representations on either single-centric-object or non-iconic dataset. The framework takes into account the representation learning at three levels: 1) the similarity of scene-scene, 2) the correlation of scene-instance, 3) the discrimination of instance-instance. During the learning, we adopt the optimal transport algorithm to automatically measure the discrimination of instances. Massive experiments show that Uni-VIP pre-trained on non-iconic COCO achieves state-of-the-art transfer performance on a variety of downstream tasks, such as image classification, semi-supervised learning, object detection and segmentation. Furthermore, our method can also exploit single-centric-object dataset such as ImageNet and outperforms BYOL by 2.5% with the same pre-training epochs in linear probing, and surpass current self-supervised object detection methods on COCO dataset, demonstrating its universality and potential.
•Affordable clean household energy is an important part of sustainable development•Multiple energy sources are used to meet different needs in daily lives•Most rural Chinese had 3-4 different types ...of energy for cooking•Energy stacking has substantial impacts on the proportion of different household energy user•Only 32% rural population extensively used gas or electricity for cooking in 2012•The proportion of clean cooking population was increasing despite of the declined rural population
The household energy mix, especially the sustainable use of affordable clean energy, is an important part of society and is closely related to many sustainable development goals. The proportion of the population mainly using solid fuels or clean energy is widely considered, but multiple energy carriers (energy stacking) used in the real world result in considerable biases in the results in which only primary energy was counted. From a nationwide survey on the household energy mix in rural China, the present study revealed that in 2012, nationally, the average numbers of cooking energy carriers and heating energy sources were 3.4 and 2.5 per household, increasing from 2.0 and 2.2 per household in 1992, respectively. Within the country, the spatial difference in the household number of household energy carriers was negatively associated with the family income level and explained by the affordability and faster clean energy transition. In 2012, the proportion of people extensively using gas or electricity for cooking was 32% and 27% for heating, respectively. The proportion increased substantially over time from 1992 to 2012, indicating an obvious switch to cleaner household energy sources. The absolute number of rural people using clean-household energy was increasing, despite the reduced rural population under urbanization. The proportion of people using clean-household energy for more than half of the time per year for cooking and heating was 56% and 32% , respectively. The results were higher than the proportion of people extensively using clean-household energy, and the difference was larger with more types of different energy sources used in households, particularly for cooking. It is imperative to consider multiple energy uses in household surveys and to call for more field work regarding household energy mix transitions as an integral part of sustainable development research.
β-elemene, a natural drug extracted from Curcuma wenyujin, strongly inhibits glioblastoma growth. However, the mechanism of β-elemene antitumor action remains unclear. Glia maturation factor β (GMFβ) ...regulates cellular growth, fission, differentiation and apoptosis. It has been reported that overexpression of GMFβ inhibits the growth of glioblastoma cells and decreases tumor volume. To illustrate the role of GMFβ in the anti-proliferative effect of β-elemene in glioblastoma, U87 cells were treated with β-elemene at various doses and for different periods of time, and levels of phospho-GMFβ (p-GMFβ) and total GMFβ were determined by immunoprecipitation and western blot analysis. Upon GMFβ silencing using RNA interference, the antitumor action of β-elemene was evaluated in a methyl thiazolyl tetrazolium assay and by semi-quantitative western blot analysis of MKK3/6 and p-MKK3/6 expression. Finally, chemosensitization to cisplatin by β-elemene was examined using a cell counting array, and the cell growth inhibitory rate was calculated. The results showed that β-elemene inhibits U87 cell viability through the activation of the GMFβ signaling pathway. Conversely, silencing the expression of GMFβ reversed the antitumor effect of β-elemene and impaired the phosphorylation of MKK3/6. Furthermore, β-elemene increased the sensitivity of U87 glioblastoma cells to the chemotherapeutic agent cisplatin. Taken together, these results suggest that activation of the GMFβ pathway mediates the antitumor effect of β-elemene in glioblastoma. GMFβ is a putative molecular target for glioblastoma therapy.
PtatSiO sub(2)atTiO sub(2) composites with an average diameter of about 120 nm were synthesized by an aqueous method. Morphology, microstructure, and light absorption performance of as-prepared ...samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-Vis diffuse reflectance spectroscopy. The results indicate that 5-nm-thick SiO sub(2) interlayer coated on the Pt nanoparticles were used to separate the Pt from the TiO sub(2). The covering SiO sub(2) layer between Pt nanoparticles and TiO sub(2) layer present a wide spectral response. The enhanced photocatalytic efficiency under both the full spectrum and visible light can be attributed to the existence of Pt nanoparticles and interlayer SiO sub(2). The coupling processes between TiO sub(2) and plasmon were presented and the mechanism was discussed. The localized surface plasmon resonance effect of Pt nanoparticles is the main reason for the enhanced photocatalytic activity of the composite PtatSiO sub(2)atTiO sub(2).
The human influenza A (H3N2) virus dominated the 2014–2015 winter season in many countries and caused massive morbidity and mortality because of its antigenic variation. So far, very little is known ...about the antigenic patterns of the recent H3N2 virus. By systematically mapping the antigenic relationships of H3N2 strains isolated since 2010, we discovered that two groups with obvious antigenic divergence, named SW13 (A/Switzerland/9715293/2013-like strains) and HK14 (A/Hong Kong/5738/2014-like strains), co-circulated during the 2014–2015 winter season. HK14 group co-circulated with SW13 in Europe and the United States during this season, while there were few strains of HK14 in mainland China, where SW13 has dominated since 2012. Furthermore, we found that substitutions near the receptor-binding site on hemagglutinin played an important role in the antigenic variation of both the groups. These findings provide a comprehensive understanding of the recent antigenic evolution of H3N2 virus and will aid in the selection of vaccine strains.
Adamantane-derived drugs have been used for treatment and prophylaxis of influenza A virus infection for many years worldwide. Rapid surveillance of antiviral drug resistance is important for ...appropriate clinical guideline development. Here, we retrospectively assessed adamantane resistance among different influenza A subtypes (H1N1, H3N2 and H5N1) over 53 years (1956-2009) in mainland China.
A total of 1,451 viruses, including 773 H3N2 viruses, 647 H1N1 viruses and 31 human H5N1 viruses, were analysed by matrix gene sequencing and assayed for drug resistance.
Our results show that the prevalence of adamantane-resistant H3N2 viruses was low between 1956 and 2002, but substantially increased in 2003 to the extent that since 2006 all H3N2 viruses have been drug resistant. The percentage of adamantane-resistant H1N1 viruses also increased from 50.0% in 2004 to 98.7% in 2007; however, this decreased to 46.7% in 2009. Only three adamantane-resistant H5N1 viruses have been detected since 2003, when the first case of human H5N1 virus infection was detected in mainland China. Phylogenetic analysis demonstrated that the increase of adamantane-resistant isolates was caused by point mutations or intrasubtype reassortment instead of intersubtype reassortment.
Because of the high percentage of adamantane-resistant H3N2 and H1N1 viruses in mainland China, the use of amantadine and rimantadine drugs for prophylaxis and treatment of current seasonal influenza A infection is not recommended.
The third national land survey is based on orthoimages with the results of the second national land survey to investigate the land classification, area and ownership of the national land in order to ...comprehensively understand the status of land use and land resources changes, and to improve the level of delicacy management for national nature resources. Therefore, an important task to ensure the completion of the third national land survey is to the develop a set of technical methods applicable to the quality inspection on orthoimage of the third national land survey.In view of the inapplicability of the existing inspection standards and technical methods of traditional basic surveying and mapping results on the orthoimage quality inspection of the third national land survey, The paper analyzes the orthoimage production characteristics and quality need of the third national land survey, improves the inspection quality elements, sampling strategy, inspection methods, evaluation methods and quality problem handling based on the existing inspection standards and technical methods by pilot, and puts forward the corresponding inspection standards and technical methods to promote the quality inspection of orthoimage on the third national land survey.Compared with the traditional method, the application of this method in 2865 inspection of county-level’s orthoimage of the third national land survey which covers the whole china, shows that, its inspection index is more reasonable, the inspection process is more scientific, the inspection efficiency is more efficient, and the direct cost of inspection is saved by 31%.
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