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This study established a simple, rapid, and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous quantification of contezolid and its major metabolite M2 in human plasma and cerebrospinal fluid (CSF). We used isotope-labeled internal standards (IS) along with protein precipitation to efficiently eliminate impurities. The ion transition was m/z 409.1 → 269.1 for contezolid, m/z 414.1 → 269.0 for contezolid-d5, m/z 445.1 → 385.1 for M2, and m/z 450.2 → 390.1 for M2-d5. The flow rate was 0.4 mL/min with a run time of 2.5 min. Validation results demonstrated that the calibration range was 10–5000 ng/mL for contezolid, and 5–2500 ng/mL for M2 in plasma and CSF. Both analytes exhibit excellent linear relationships (all R2 ≥ 0.99). Intra- and inter-batch accuracy and precision for all quality control (QC) levels were within ± 15%, including the lower limit of quantification (LLOQ). The recoveries of contezolid and M2 were 92.60–100.4% and 92.26–99.61% in plasma and 93.33–99.19% and 91.31–98.21% in CSF, respectively. The matrix effects for contezolid and M2 were 97.20–110.3% and 98.27–105.47% in plasma and 105.25–112.99% and 103.35–109.84% in CSF, respectively. The coefficients of variation (CV%) were ≤ 12.58%. Conteozolid and M2 remained stable in plasma and CSF. This study has established a simple and accurate method for determining contezolid and M2 in human plasma and CSF, making it a valuable tool for monitoring the efficacy of central nervous system (CNS) drugs. [ABSTRACT FROM AUTHOR]

As a complement of production-based accounting (PBA), consumption-based accounting (CBA) provides an alternative perspective to understand national emissions and responsibilities for global climate change. Existing studies assessed historical national emissions under CBA. However, how CBA might guide future mitigation under the Paris Agreement goals has not been well understood. By combining global multi-region input-output analysis and the equity principle of 'equal cumulative per capita emissions' (ECPCE), this study explores potential implications of CBA for future national emissions budgets to limit global warming to below 1.5°C. Historically, consumption-based greenhouse gas (GHG) emissions were higher than production-based emissions in most developed countries while lower in many developing countries. When CBA is used instead of PBA to allocate emissions budgets by ECPCE, future GHG mitigation burdens would become more stringent in 70% of Annex I (mostly developed) countries but slightly smaller in 55% of non-Annex I (mostly developing) countries. In particular, more than half of Annex I countries might need to achieve negative GHG budgets under 1.5°C. Our analysis emphasizes that, as net emission importers, developed countries could strive to pay equal attention to achieving consumption-based and production-based emissions reductions, and strengthen technological and financial support to developing countries that undertake production outsourcing. As net emission exporters, with international support and domestic investment, developing countries could pragmatically promote energy structure optimization and technological innovation to accelerate the decarbonization of production. To support the Paris Agreement goals, mitigation contributions initiated from the perspective of CBA could also be welcomed. Key policy insights Developed countries shift emissions to developing countries through international trade. CBA increases historical responsibilities of developed countries for climate warming from the PBA assessments. Compared to PBA, CBA has clear implications on future national emissions budgets under responsibility-based allocations, but does not change the urgency of national mitigation required to achieve the Paris Agreement goals. Allocated by ECPCE, future GHG budgets for over 50% of the world's countries would be run out before 2040 under 1.5°C at the 2015 emissions rates, using either CBA or PBA. According to different roles in global supply chains, developed countries should step up support to help developing countries improve emissions and energy intensities, which is a key to reducing emissions embodied in trade. [ABSTRACT FROM AUTHOR]

Understanding the drivers of CO2 emissions changes is useful in supporting future mitigation. This study applies a log-mean divisia index decomposition to assess four drivers of CO2 emissions changes – population, income, energy intensity and carbon intensity – in 138 countries worldwide over the period 2000–2017. At the global level, income and population are the main drivers of increased emissions over time, with contributions of 116% and 60% to global CO2 emissions changes, respectively. Energy intensity is the key mitigation driver, with a contribution of −80%. Although carbon intensity increased CO2 emissions overall over the period 2000–2017 with a contribution of 4%, it has started to reduce emissions in recent years. China, the United States of America, the European Union, India and Russia are the five regions responsible for most changes in global emissions. The five regions together contribute −73% of the energy intensity effect, and China's income contribution is 83% in relation to the total of 116%. At the national level, in 2017, CO2 emissions returned to below 2000 levels in 62% of Annex I (developed) countries but increased in 88% of non-Annex I (mostly developing) countries. Among the 35 countries realizing CO2 emissions reductions, 24 were driven primarily by energy intensity, six by carbon intensity, three by economic recession, and one by population decrease. Among the 103 countries with increasing CO2 emissions, 63 were driven primarily by income, 26 by population, nine by carbon intensity increase, and five by energy intensity increase. Our analysis emphasizes the necessity of considering differences in national development stages when formulating climate change mitigation policies. Key policy insights Over the period 2000–2017, at the global and national levels, CO2 emissions increases were driven mainly by economic development and population growth, and mitigation was driven mainly by energy intensity improvement. Improving energy intensity and carbon intensity is the key to mitigating CO2 emissions. Carbon intensity is expected to play an increasing role in the future. In over one-third of Annex I countries, CO2 emissions increased from 2000 to 2017. To meet the Paris Agreement goals, Annex I countries will need to enhance mitigation ambition by further tapping the mitigation potentials of energy and carbon intensity. In accordance with national circumstances, development needs and international support, non-Annex I countries should achieve low-carbon economic and energy transitions and peak CO2 emissions as early as possible. [ABSTRACT FROM AUTHOR]

One of the most significant problems of wide expressway in permafrost regions is how to protect the thermal stability of permafrost under an embankment. The composite embankment consisting of perforated pipe and blocky stone has been used in the construction of common roadways. However, its effectiveness for highway is poorly concerned. Based on the cooling effect shown by the field test results of embankment with the common width, the composite embankment was investigated as a potential reasonable cooling system for embankments of wide expressways. The three-dimensional numerical model was established based on local thermal non-equilibrium theory. The temperature field characteristics were analyzed, and three main influencing factors affecting the cooling effect (different pipe diameters, blocky stone layer thicknesses and the pipe spacing) were also examined. The results show that the composite embankment works a considerable protective effect on the permafrost. Meanwhile, the increases of pipe diameter and blocky stone thickness provide an increase in cooling effect, as opposed to the increase of pipe spacing. The validity of the application of a composite embankment for wide expressways is verified and useful parameters optimized from analysis are recommended. The results may be useful in the design of embankments in permafrost regions. [ABSTRACT FROM AUTHOR]

This article proposes a practical technique for designing cellular structures with the configuration of spatially varying structures of unit cells for additive manufacturing processes. At the macroscale, global structures are optimized based on an element-wise topology optimization method to generate an overall layout involving solid, void and lattice materials. At the mesoscale, the effective properties of planar unit cells with graded geometric feature parameters are evaluated via a numerical homogenization method. Communication between unit cells and global structures is established based on a set of property-fitting functions to approximate intermediate element properties. To enhance the manufacturing of the resulting designs, the minimum feature size is constrained and an additional solid layer is attached to the structural boundaries. The design of a cantilever beam is presented to demonstrate the effectiveness of the proposed technique. The effects on mechanical performance of lattice materials with different topologies are numerically analysed and experimentally validated. [ABSTRACT FROM AUTHOR]

Asbestos fiber has been associated with mesothelioma and lung cancer. However, the carcinogenic risks of other fiber nanomaterials with morphological similarities to asbestos have not been fully studied. Ultra-long silver nanowires (AgNWs) are increasingly used fiber-shaped nanomaterials with a high aspect ratio, but very few studies have investigated their health risks. Here, proliferation abnormalities of lung epithelial cells induced by ultra-long AgNWs were investigated. Ultra-long AgNW treatment induced dose- and diameter-dependent increase in the ratio of multinucleated cells. Further, proteins involved in mitosis and cytokinesis, including Aurora A, p-Histone 3 (ser10), RhoA, p-MLC, and myosin IIb, were significantly upregulated after an ultra-long AgNW treatment, leading to mitotic abnormalities and cytokinetic failure. Meanwhile, exposure to ultra-long AgNWs induced cell cycle arrest. Interestingly, a series of experiments demonstrated that ROS generation and Ag+ release were not responsible for the multinucleation induced by ultra-long AgNWs, but ultra-long AgNWs in the intercellular bridge might obstruct the contractile ring and inhibit abscission of the cytokinetic furrow by direct physical contact. Altogether, our findings indicate that ultra-long AgNWs can induce chromosomal instability, which has important consequences for the safety of ultra-long AgNWs to human health. [ABSTRACT FROM AUTHOR]

Continuously reducing the CO2 intensity of GDP is the core strategy for developing countries to realize the dual targets of economic growth and CO2 emissions reduction. The measures are twofold: one is to strengthen energy saving and decrease energy intensity of GDP and the other is to promote energy structural decarbonization and reduce CO2 intensity of energy consumption. In order to control global temperature rise no more than 2°C, the decrease in CO2 intensity of GDP needs surpass 4% before 2030, but it could be merely about 2% based on the current trend. Therefore, all countries ought to speed up the low-carbon transition in energy and economy. As for China, keeping a continuous decline in CO2 intensity of GDP of 4%-5% will ensure the realization of the NDC objectives, and also promotes the early peaking of CO2 emissions before 2030. China will play a positive leading role in realizing a win-win low-carbon development coordinating sustainable development and climate change mitigation. [ABSTRACT FROM AUTHOR]

Comparing and evaluating the Nationally Determined Contribution (NDC) is an important element in global stocktake in the post-Paris climate negotiations, aimed at closing the emissions gap with the Paris Agreement goals. To date, however, there has still been no explicit guideline or method. By applying emissions allowance allocated by 16 schemes as benchmarks, this paper tries to compare and evaluate the NDCs of the top six emitters, which jointly account for about 70% of the world’s CO2 emissions. Results show that the four developed countries’ NDCs lack ambition with respect to most allocations under 2°C and all under 1.5°C, indicating they need to substantially ratchet up their NDCs and lead elevating mitigation. Evaluating cumulative emissions is more likely to clarify the ambition and fairness of China’s NDC. If considering cumulative emissions, China’s NDC is aligned with the median of cumulative allowances under 2°C and within the 1.5°C range. The Paris Agreement invited the Parties to communicate the mid-century low emissions strategies. This paper also tries to explore the mid-century mitigation in the perspective of allocations, which might provide decision-makers with some useful information when envisaging the post-NDC mitigation. [ABSTRACT FROM AUTHOR]

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Thirteen ichnogenera and seventeen ichnospecies were recognised in carbonate rocks from the Lower Permian Taiyuan Formation in North China Basin. Based on the composition, occurrence and diversity of ichnofossils, intensity of bioturbation, lithologic characteristics, especially on the variation of individual size and the filling colour diversities of theZoophycosburrows, four types of ichnofabrics were recognised, that is (1) epigenic tiering ichnofabric – mainly appeared on or near the bedding plane and formed in restricted bay or lagoon sedimentary environments; (2) shallow tiering ichnofabric – developed less than 15 cm under the bedding plane and occurred in the upper shallow-marine environment; (3) medium tiering ichnofabric – mainly distributed from 15 to 20 cm under the bedding plane and generated in the mid-upper shallow sea (restricted–open platform); (4) deep tiering ichnofabric – distributed from 25 to 30 cm under the bedding plane and occurred in lower shallow sea (open platform) far from shore. Based on ichnological and sedimentological analyses above four types of ichnofabrics, the sedimentary environment model of the ichnofabrics in carbonate rocks from the Taiyuan Formation in North China Basin is proposed in this paper. [ABSTRACT FROM AUTHOR]

A series of polymethylacrylic acid (PMAA) standard samples were prepared from fractionated PMMA samples followed by a two-step hydrolysis. The six PMMA standard samples with narrow molecular weight distributions were produced by free radical polymerization and fractionated with toluene-petroleum ether. Their average molecular weights ranged from 3.1 × 103to 4.3 × 104, dispersion coefficients were less than 1.5, and their gel permeation chromatography (GPC) peak shapes were symmetrical. The PMMA standard samples were dissolved in dioxane, and then hydrolyzed in a saturated NaOH-methanol solution for 24 h, the methanol then evaporated, and after that the PMMA samples were hydrolyzed in a 2 mol ·L−1NaOH aqueous solution for 24 h. The1H-NMR results showed that the two-step hydrolysis degree was higher than 98.70%. The PMAA standard samples were obtained after acidifying the hydrolysates, namely polymethacrylic acid sodium salt, and their molecular weights were constant during the separation process. The acid–base titration results showed the purities of the PMAA samples were greater than 98.6%, and their molecular weight distributions were symmetrical and narrow. The molecular weights of the PMAA were determined by the stoichiometric relationship of the hydrolysis reaction. Compared with viscosimetry, the results of both methods were basically the same, and their errors were less than 10%. [ABSTRACT FROM AUTHOR]