Optimum investment strategy for hydrogen-based steelmaking project coupled with multiple uncertainties.

The large-scale application of hydrogen steelmaking technology is expected to substantially accelerate the decarbonization process of the iron and steel industry. However, hydrogen steelmaking projects are still in the experimental or demonstration stage, and scientific investment decision-making methods are urgently needed to support the large-scale development of the technology. When assessing the investment value, existing studies usually only consider the intrinsic project value under a specific pathway, while ignoring the option value under realistic multiple uncertainties in terms of technology, market, and policy, leading to an underestimation of the investment value. To address this issue, this study constructs a real options model to explore the optimal investment timing and revenue of the hydrogen steelmaking project, by taking into account multi-dimensional uncertainties stemming from price fluctuations in the steel market, the development of the carbon market, and technological advances. Additionally, the impacts of various subsidy policies on the investment strategy are also investigated. Least Squares Monte Carlo method is applied to overcome computational challenges posed by dynamic programming under multi-dimensional uncertainties. The results show that: (i) Investment is not recommended based on current crude steel price and hydrogen price. (ii) When the annual reduction rate of hydrogen price reaches 5%, the optimal investment timing would advance to 2036. (iii) On this basis, with the introduction of a 20% green hydrogen subsidy policy, the optimal investment timing would be further brought forward to 2033. The implementation of tax incentives would significantly increase the investment value. The investment value would surge from 170 million CNY to 262 million CNY as the tax rate decreases from 20% to zero. The findings could provide reasonable suggestions for investment decisions under realistic volatile environments, as well as scientific references for policy design, thus facilitating the large-scale and high-level development of hydrogen-based steelmaking technology.

Circular economy strategies for mitigating metals shortages in electric vehicle batteries under China's carbon-neutral target.

Concerns over supply risks of critical metals used in electric vehicle (EV) batteries are frequently underscored as impediments to the widespread development of EVs. With the progress to achieve carbon neutrality by 2060 for China, projecting the critical metals demand for EV batteries and formulating strategies, especially circular economy strategies, to mitigate the risks of demand-supply imbalance in response to potential obstacles are necessary. However, the development scale of EVs in the transport sector to achieve China's carbon neutrality is unclear, and it remains uncertain to what extent circular economy strategies might contribute to the reduction of primary raw materials extraction. Consequently, we explore the future quantity of EVs in China required to achieve carbon neutrality and quantify the primary supply security levels of critical metals with the effort of battery cascade utilization, technology substitutions, recycling efficiency improvement, and novel business models, by integrating dynamic material flow analysis and national energy technology model. This study reveals that although 18%-30% of lithium and 20%-41% of cobalt, nickel, and manganese can be supplied to EVs through the reuse and recycling of end-of-life batteries, sustainable circular economy strategies alone are insufficient to obviate critical metals shortages for China's EV development. However, the supplementary capacity offered by second-life EV batteries, which refers to the use of batteries after they have reached the end of their first intended life, may prove adequate for China's prospective novel energy storage applications. The cumulative primary demand for lithium, cobalt, and nickel from 2021 to 2060 would reach 5-7 times, 23-114 times, and 4-19 times the corresponding mineral reserves in China. Substantial reduction of metals supply risks apart from lithium can be achieved by the cobalt-free battery technology developments combined with efficient recycling systems, where secondary supply can satisfy the demand as early as 2054.

Evaluating rare-earth constraints on wind power development under China's carbon-neutral target.

China proposed a target to achieve carbon neutrality before 2060. Wind power is crucial for mitigating climate change and achieving carbon neutrality. However, its development depends on the potential constraints of rare-earth elements. Therefore, first projecting the rare-earth demand for wind power equipment in the context of achieving carbon neutrality and identifying potential obstacles are necessary. However, the carbon-neutral pathway for China's power sector is unclear, let alone the corresponding rare-earth demand. Consequently, this study explores a potential cost-effective carbon-neutral pathway for China's power sector and quantifies the demand for rare-earth elements used for producing wind power equipment under different pathways, by integrating dynamic material flow analysis and a national energy technology model. The results showed that the rare-earth supply may be inadequate for wind power development in terms of achieving carbon neutrality in China, especially for dysprosium and terbium. To neutralise the carbon emissions of China's power sector, the cumulative rare-earth demand during 2021-2060 would be 222-434 kt, of which at most 1/3 could potentially be obtained by circular usage from end-of-life wind turbines. However, the existing low secondary recovery rate of rare-earth elements makes the available circular amounts very small. Shifting to a wind power market dominated by direct-drive turbines may increase the cumulative rare-earth demand by up to 34 %. Without material intensity reduction for the wind power technologies, an additional 38 % demand for rare-earth elements will occur, exacerbating the risk of shortage.

Approaching national climate targets in China considering the challenge of regional inequality.

Achievement of national climate targets and the corresponding costs would entirely depend on regional actions within the country. However, because of substantial inequalities and heterogeneities among regions, especially in developing economies, aggressive or uniform actions may exacerbate inequity and induce huge economic losses, which in turn challenges the national climate pledges. Hence, this study extends prior research by proposing economically optimal strategies that can achieve national climate targets and ensure the greatest local and national benefits as well as regional equality. Focusing on the biggest developing country China, we find this strategy can avoid up to 1.54% of cumulative GDP losses for approaching carbon neutrality, and more than 90% of regions would obtain economic gains compared either with existing independently launched targets or with the uniform strategy that all regions achieve peak carbon emissions before 2030. We also provide optimal carbon mitigation pathways to regional peak carbon, carbon intensity and energy consumption.

An Economy-wide Analysis of the Energy and Environmental Impacts of International Trade Policy Adjustments for Chemical Industry in China.

In China, the proportion of energy consumption and carbon emissions embodied in international trade in chemical industry is high. It is important to consider how international trade policy adjustments in chemical industry will affect the economy and environment so as to achieve the goal of carbon intensity. This study investigates the impact of international trade policy adjustments. We adopt a computable general equilibrium model to simulate the impacts of trade policy adjustment. The result shows all adjustment plans cause economic losses. All plans will promote energy structure toward cleaner. All plans reduce CO2 emissions and energy consumption but cannot realize the carbon intensity and energy intensity target. The adjustment of tariff policy in basic raw materials sector should be smaller than that of other sectors. Raising the export tariff is the best policy choice for achieving the carbon intensity target, but other low-carbon policies should be introduced. In particular, protection measures should be taken for the energy industry.

Life cycle CO2 emissions for the new energy vehicles in China drawing on the reshaped survival pattern.

Promoting new energy vehicles (NEVs) is the key to achieving net-zero emissions in the transportation sector. NEVs' total life cycle CO2 emissions are mainly determined by average vehicle lifespan, annual mileage traveled, energy carbon intensity and energy mix in the production stage. Current studies mainly adopt assumptions about NEVs' average lifespan due to limited available data. This paper expands on the previous studies by examining the NEVs' age and distribution based on the national representative China Compulsory Traffic Accident Liability Insurance for Motor Vehicles (CTALI) database from 2018 to 2020. Then, the survival patterns and lifespan of NEVs are assessed using Weibull distribution. New energy passenger vehicles' life cycle CO2 emissions are further evaluated based on the reshaped representative survival patterns. The results show that there are significant differences in survival patterns between conventional vehicles and NEVs. NEVs generally show a shorter average lifespan compared with conventional vehicles. Among NEVs, the average lifespan of plug-in hybrid electric vehicles (PHEVs) is better than that of battery electric vehicles (BEVs). The survival patterns of several types of electric vehicles (including passenger battery electric vehicles, non-operating light battery electric buses, and light battery electric trucks) do not have a stable period in their first few years of operation. The life cycle assessment results show that the total life cycle CO2 emissions of passenger BEVs and PHEVs are lower than those of conventional vehicles. However, the short lifespan dramatically increases the passenger BEV and PHEV total life cycle CO2 emissions per kilometer, resulting in passenger BEV total life cycle CO2 emissions per kilometer being higher than those of conventional vehicles.

Long-term predialysis blood pressure variability and outcomes in hemodialysis patients.

Blood pressure variability (BPV) is significantly associated with cardiovascular diseases (CVD) and mortality in hemodialysis patients. However, the relationship between blood pressure and CVD in hemodialysis patients is complex and affected by many factors. The present study aimed to assess the association of long-term predialysis BPV with all-cause mortality and major adverse cardiovascular events (MACE). One thousand seven hundred twenty-seven patients receiving maintenance hemodialysis were recruited in nine hemodialysis centers. Predialysis BPV was assessed over 1-year intervals. Outcomes included all-cause mortality and MACE during follow-up periods. The mean age of the final cohort was 59 years, of which 57% were males. Greater predialysis systolic BPV was associated with an increased risk of all-cause mortality (adjusted hazard ratio, 1.101; 95% confidence intervals 1.064-1.140) and MACE (adjusted hazard ratio, 1.091; 95% confidence intervals 1.059-1.125). Results were similar when systolic BPV was stratified by baseline systolic blood pressure. In conclusion, greater predialysis BPV among hemodialysis patients was associated with all-cause mortality and MACE. Strategies to reduce blood pressure variability might be beneficial for hemodialysis patients.

Are electric vehicles cost competitive? A case study for China based on a lifecycle assessment.

Promoting the development of electric vehicles (EVs) is regarded as an important measure to ensure energy security, mitigate climate change, and solve the transport sector's air pollution problems. Nowadays, compared to gasoline vehicles, whether the EVs are more competitive in terms of cost is still a question. There is no consensus achieved since the total cost depends on the development stage of the automobile industry and power generation structure as well as the cost accounting boundary. Many of existing studies did not include the costs occurred in all the stages. In response to this concern, this study estimates the lifecycle cost covering the whole process of production, use, disposal, and infrastructure construction as well as externalities for passenger battery electric vehicle (BEV), fuel cell vehicle (FCV), and gasoline vehicle (GV) by applying the comprehensive lifecycle cost model to China. The results indicate that in 2018, BEV and FCV were more expensive than GV (1.2-5.3 times), but that BEV will become cheaper after 2025, and its cost advantage will be enlarged to $419 (5%) compared to GV by 2030. The lifecycle cost of FCV will be $527 (or 5%) lower than that of GV by 2030. These results clarify that the costs of vehicle production account for the largest proportion in the total lifecycle cost.

Energy system transformations and carbon emission mitigation for China to achieve global 2 °C climate target.

The Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 2 °C compared to the pre-industrial level. To achieve this, it is essential to accelerate the low-carbon transition of energy system. China is the largest carbon emitter and plays a decisive role in mitigating global climate change. The transition pathways for China to contribute to meeting the global 2 °C target, however, have not been extensively explored. Here we develop a bottom-up national energy technology model (C3IAM/NET), a linear optimization model, to reveal the energy consumption, carbon emissions and technology pathway at the national and sectoral levels in line with the 2 °C climate target. Results show that China's carbon emissions need to peak at the year 2023 and reduce to 3.56 GtCO2 by mid-century. During the 2020-2050 planning horizon, the remaining carbon budget is estimated to be controlled within 234 GtCO2, with a cumulative emission reduction of 165.3 GtCO2, of which the power sector bearing the largest share of responsibility, followed by the industry, transportation and building sectors. We project that China's primary energy consumption needs to peak before 2040 and the proportion of non-fossil energy in energy structure needs to reach 76% by 2050, and about 88.4% of electricity production comes from renewables and nuclear energy.

Review of carbon leakage under regionally differentiated climate policies.

Despite the increasing challenges of coping with global climate change, current climate policy is still implemented unilaterally at national and subnational levels, with different forms and intensities in both time and space dimensions. Such regionally differentiated climate policies inevitably cause carbon leakage phenomenon, that is, reduced carbon emissions in abating areas may be offset to some extent by increased carbon emissions in non-abating areas. The occurrence of carbon leakage could undermine the environmental effectiveness of implemented climate policies and cause extra emission reduction costs. Studying carbon leakage is vital not only to the effective formulation, implementation, and evaluation of climate policy, but also to the fair sharing of international emission reduction responsibilities. To understand how this important issue has been discussed, this paper systematically reviewed the research shedding light on carbon leakage. Taking the questions of how carbon leakage happens, what are the key influencing factors, how to evaluate it and where does the heterogeneity of results come from as the story line, we investigated the main mechanism of carbon leakage and the factors influencing it, the distribution of carbon leakage across countries, measurement methods and results through the bibliometric analysis and meta-analysis. On the basis of this, three aspects of improvements worthy of further study were proposed.

PPM1A suppresses the proliferation and invasiveness of RCC cells via Smad2/3 signaling inhibition.

BACKGROUND: Cytokine therapies show promise in treating renal cell carcinoma (RCC). Transforming growth factor beta 1 (TGF-ß1) is a cytokine whose downstream Smad2/3 signaling activity is inhibited by the protein phosphatase Mg2+/Mn2+-dependent 1 A (PPM1A). Here, we hypothesized that PPM1A may be involved in suppressing RCC cell aggressiveness through its negative regulation of Smad2/3. METHODS: We quantified PPM1A expression from RCC tumors and matching healthy tissue and performed a Kaplan-Meier survival analysis. In silico analysis on PPM1A was performed using Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma and Clinical Proteomic Tumor Analysis Consortium RCC cohort data. We tested four RCC cell lines and selected the ACNH and A498 cells lines as expressing the greatest PPM1A levels. We assayed the effects of RNAi-mediated PPM1A silencing on invasiveness, proliferation, colony formation, and Smad2/3 phosphorylation in untreated and TGF-ß1-stimulated ACNH and A498 cells. A nude mouse A498 xenograft tumor model was constructed to validate PPM1A's effects in vivo. RESULTS: PPM1A levels are reduced in RCC tumors and are negatively correlated with RCC grade and stage. Below-median PPM1A expression is associated with reduced overall survival in RCC patients. PPM1A silencing promoted cellular invasiveness, proliferation, colony formation, and Smad2/3 phosphorylation under TGF-ß1-stimulated conditions but not under untreated conditions. These effects of PPM1A were shown to be dependent on Smad2/3. Intratumor PPM1A overexpression inhibited A498 xenograft tumor growth. CONCLUSIONS: This study establishes a direct link between PPM1A's suppression of Smad2/3 signaling and RCC cell aggressiveness. PPM1A could potentially serve as a biomarker for RCC cell aggressiveness.

Co-current analysis among electricity-water-carbon for the power sector in China.

China's power sector consumes large amounts of water for its cooling every year, which has increased water stress in many regions and caused the vulnerability in electricity generation. Current plans for power sector mainly focus on the clean and low-carbon development, while it is unclear how to reconcile CO2-reduction target with water-saving target. In this paper, an optimization model named NET-Power (National Energy Technology-Power) is developed to simulate the deployment of power generation technologies, and to further answer whether there is a conflict or not between water-saving target and CO2-reduction target in the power sector. The result shows that peaking carbon emissions before 2030 in the power sector may increase the water consumption by 34.85Gt. In addition, to further meeting the water constraint on the basis of peaking carbon emissions would lead to a higher carbon intensity of thermal power. These findings indicate that low-carbon transition will cause significant water-carbon contradiction, which mainly lies in nuclear power technology and dry-cooling technology. Finally, the optimal technology layout path that can meet the dual constraints of water and carbon for the power sector in China is proposed.

Self-preservation strategy for approaching global warming targets in the post-Paris Agreement era.

A strategy that informs on countries' potential losses due to lack of climate action may facilitate global climate governance. Here, we quantify a distribution of mitigation effort whereby each country is economically better off than under current climate pledges. This effort-sharing optimizing approach applied to a 1.5 °C and 2 °C global warming threshold suggests self-preservation emissions trajectories to inform NDCs enhancement and long-term strategies. Results show that following the current emissions reduction efforts, the whole world would experience a washout of benefit, amounting to almost 126.68-616.12 trillion dollars until 2100 compared to 1.5 °C or well below 2 °C commensurate action. If countries are even unable to implement their current NDCs, the whole world would lose more benefit, almost 149.78-791.98 trillion dollars until 2100. On the contrary, all countries will be able to have a significant positive cumulative net income before 2100 if they follow the self-preservation strategy.

Association between predialysis hypermagnesaemia and morbidity of uraemic restless legs syndrome in maintenance haemodialysis patients: a retrospective observational study in Zhejiang, China.

OBJECTIVE: The aim of the present study was to determine whether the predialysis serum magnesium level was associated with morbidity of uraemic restless legs syndrome (RLS) in maintenance haemodialysis patients. DESIGN: A retrospective observational study of morbidity of uraemic RLS was conducted. SETTING: Patients on maintenance haemodialysis three times a week. PARTICIPANTS: We reviewed 578 patients receiving maintenance haemodialysis for >1 year as our cohort. OUTCOME MEASURES: Uraemic RLS was diagnosed according to International RLS Study Group criteria, and hypermagnesaemia was defined as serum magnesium level >1.02 mmol/L. RESULTS: The prevalence of uraemic RLS was 14.4% in our study cohort. Univariate analysis indicated that patients with uraemic RLS differed significantly from non-RLS ones in certain demographic and clinical characteristics, including younger age, longer dialysis duration, higher serum parathyroid hormone level and higher prevalence of predialysis hyperphosphataemia and hypermagnesaemia. Binary logistic-regression model analysis indicated that predialysis hypermagnesaemia was independently associated with uraemic RLS and conferred an increase in morbidity of the syndrome (OR=2.024; 95% CI 1.160 to 3.532; p=0.013). Moreover, we found that dialysis duration and predialysis hyperphosphataemia were independently associated with morbidity of uraemic RLS. CONCLUSIONS: Our data indicated that the predialysis serum magnesium level was associated with morbidity of uraemic RLS in maintenance haemodialysis patients and that predialysis hypermagnesaemia might serve as an independent risk factor for the syndrome.

miR-4429 Inhibits Tumor Progression and Epithelial-Mesenchymal Transition Via Targeting CDK6 in Clear Cell Renal Cell Carcinoma.

Background: Clear cell renal cell carcinoma (ccRCC), as the commonest type among renal cell cancers, is featured with easy relapse and metastasis. Despite mounting achievements on its treatment and diagnosis, the identification of new biomarkers remains urgent. Purposes: Present study aimed to explore the role of microRNA-4429 (miR-4429) in ccRCC. Methods: The expression of miR-4429 and cyclin-dependent kinase 6 (CDK6) was evaluated by real-time polymerase chain reaction and Western blot. Cell proliferation, migration and invasion was evaluated by MTT and transwell assays. The interaction between miR-4429 and CDK6 was assessed by luciferase reporter assay. Prognostic significance of miR-4429 was evaluated by Kaplan-Meier analysis. Correlation between miR-4429 and CDK6 was determined by Spearman's correlation analysis. Results: Firstly, the downregulation of miR-4429 and upregulation of CDK6 in ccRCC tissues and cells were uncovered by quantitative real-time polymerase chain reaction. The prognostic significance of miR-4429 in ccRCC patients was proved by Kaplan-Meier analysis. Gain- and loss-of-function assays validated the suppressive effect of miR-4429 on cell proliferation, migration, invasion, as well as epithelial-mesenchymal transition (EMT) progression. The interaction between miR-4429 and CDK6 was predicted by bioinformatics tool and confirmed by luciferase reporter assay. And the negative expression correlation between miR-4429 and CDK6 was verified by Spearman's correlation analysis. Rescue assays confirmed the role of miR-4429/CDK6 in proliferation, metastasis and EMT progression in ccRCC. Conclusions: Present study revealed that miR-4429 suppressed ccRCC tumor progression and EMT by targeting CDK6.

Association between circulating mononuclear cell mitochondrial DNA copy number and in-hospital mortality in septic patients: A prospective observational study based on the Sepsis-3 definition.

PURPOSE: To explore the association between circulating mononuclear cell mitochondrial DNA copy number and the prognosis of sepsis patients based on the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3 definition). METHODS: A total of 200 adult patients who had recently devoloped sepsis were prospectively recruited as the study cohort. Demographic and clinical data were recorded along with a 28-day outcome. Mononuclear cell mtDNA copy number was assessed by quantitative PCR. RESULTS: The 28-day outcome of sepsis patients was significantly associated with circulating mononuclear cell mtDNA copy number. The median mononuclear cell relative mtDNA copy number of survivors was significantly higher than that of nonsurvivors (406.68, range 196.65-625.35 vs. 320.57, range 175.98-437.33, p = 0.001). The Cox proportional hazard survival model analysis indicated that mononuclear cell relative mtDNA copy number was significantly negative associated with the 28-day outcome. For every additional unit of mononuclear cell mtDNA relative copy number, the risk of death falls by 0.1% (HR = 0.999, 95% CI = 0.998 to 1.000, p = 0.017). CONCLUSIONS: Our data indicate first that circulating mononuclear cellular mtDNA copy number might be helpful for outcome predictions in sepsis patients, and second that lower mtDNA copy number implied poor prognosis.

Visualizing and Quantifying the Effect of the Inhibition of HSP70 on Breast Cancer Cells Based on Laser Scanning Microscopy.

Heat shock protein 70 has been recognized as a target for anticancer therapy. The overexpression of heat shock protein 70 is observed frequently in several types of tumors, including breast cancer. It is involved with increased cell proliferation, poor prognosis, and drug resistance in breast cancer. VER-155008 is an effective inhibitor of heat shock protein 70 that targets the adenosine triphosphatase-binding domain of heat shock protein 70. In this study, the effects of VER-155008, heat shock (43°C, 1 hour), and the combination treatment of VER-155008 and heat shock on the mitochondria of the MCF-7 breast cancer cells were investigated through a laser scanning microscope combined with mitochondrial membrane potential fluorescence probe. We observed broken mitochondria networks, decreased mitochondrial membrane potential, and cell size. The mitochondrial contents were reduced with the VER-155008 treatment and the combination treatment of VER-155008 and heat shock. The effects of the inhibition presented treatment time dependence. Moreover, the effect of the inhibition of the sole VER-155008 was alleviated when it was combined with heat shock although there was no obvious change with the sole heat shock treatment. The results indicated that VER-155008, the inhibitor of heat shock protein 70, induced apoptosis in MCF-7 breast cancer cells whatever it was in the sole or the combined manner, and its promoting apoptosis effect could be alleviated by heat shock. Our findings demonstrated that HSP70 can be a good target for developing breast cancer therapy.

Nonlinear optical microscopy of the bronchus.

Because of frequent exposure to carcinogens, the bronchus is prone to early pathologic alterations. The assessment of these early changes is of key significance in physiological studies and disease diagnosis of the bronchus. We utilize nonlinear optical microscopy (NLOM) to image mouse bronchial tissue based on intrinsic nonlinear optical contrast. Our results show that NLOM is effective for imaging the bronchial intact microstructural components, providing quantitative information about the biomorphology and biochemistry of tissue. Our findings also display that NLOM can provide a two-photon ratiometric redox fluorometry, based on mitochondrial signals and reduced pyridine nucleotide (NADH and NADPH) and oxidized flavoproteins (Fp) signals, to assess the metabolic state of the epithelial cells and chondrocytes. It was found that NLOM can offer a sensitive tool, based on the second-harmonic signal depth-dependent decay, to obtain quantitative information on the optical property of the stroma associated with normal and diseased tissue states. Our results suggest that with the advent of the clinical portability of typical nonlinear optical endoscopy, the NLOM technique has the potential to be applied in vivo to the clinical diagnosis and monitoring of bronchial disease.