摘要 :
The environmental impact assessment of organic fraction of municipal solid waste (OF/MSW)-to-biofuel structures
is essential prior to scaling them up to identify worrisome impacts on ecosystems, resources, human health,
and clim...
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The environmental impact assessment of organic fraction of municipal solid waste (OF/MSW)-to-biofuel structures
is essential prior to scaling them up to identify worrisome impacts on ecosystems, resources, human health,
and climate. The current article aims to address a sustainable and comprehensive guide for analyzing the
environmental impacts (based on the life cycle analysis (LCA)) of different OF/MSW-to-biofuel structures. To
analyze different structures, three pre-treatment procedures (namely, hot water/acetone organosolv/acid), two
different hydrolysis treatment ways (acidic/enzymatic), and different fermentation alternative methods (ethanolic/
acetone-ethanol-butanol fermentations) were considered. The findings of the research indicated that scenarios
based on acetone-ethanol-butanol fermentation cannot address a favorable environmental performance
(due to the insufficiency of the avoided effects of the output products to compensate the environmental burdens
caused by acetone pre-treatment). In contrast, scenarios based on ethanolic fermentation integrated with hot
water or acid-based pre-treatment process can address superior environmental performances compared to scenarios
based on acetone-ethanol-butanol fermentation and ethanolic (with acetone pre-treatment). Comprehensively,
Scenario S-4 (as most eco-friendly Scenario) yielded the greatest net environmental savings with
reductions of -857.16 potentially disappeared fraction/m~2 per year, -214.3 kg CO_2 equivalent per ton of/MSW,
and -3.33 GJ per ton of/MSW processed.
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The paper presents a three-country stock-flow consistent model, with one fixed exchange rate and two flexible exchange rates, in the tradition of portfolio balance models with imperfect asset substitutabil-ity. The model is applie...
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The paper presents a three-country stock-flow consistent model, with one fixed exchange rate and two flexible exchange rates, in the tradition of portfolio balance models with imperfect asset substitutabil-ity. The model is applied to simulate the impact of the diversification of the foreign reserves of China, away from US dollars and towards euros. The simulation results show that China and the USA both benefit from diversification, while the Euroland economy slows down. An intriguing feature of the model is that it generates path dependence.
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To analyze and predict the mechanical behaviors of deep hard rocks, some key issues concerning rock fracturing mechanics for deep hard rock excavations are discussed. First, a series of apparatuses and methods have been developed ...
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To analyze and predict the mechanical behaviors of deep hard rocks, some key issues concerning rock fracturing mechanics for deep hard rock excavations are discussed. First, a series of apparatuses and methods have been developed to test the mechanical properties and fracturing behaviors of hard rocks under high true triaxial stress paths. Evolution mechanisms of stress-induced disasters in deep hard rock excavations, such as spalling, deep cracking, massive roof collapse, large deformation and rockbursts, have been recognized. The analytical theory for the fracturing process of hard rock masses, including the three-dimensional failure criterion, stress-induced mechanical model, fracturing degree index, energy release index and numerical method, has been established. The cracking-restraint method is developed for mitigating or controlling rock spalling, deep cracking and massive collapse of deep hard rocks. An energy-controlled method is also proposed for the prevention of rockbursts. Finally, two typical cases are used to illustrate the application of the proposed methodology in the Baihetan caverns and Bayu tunnels of China.
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Abstract This paper studies the coordination of the elderly healthcare service supply chain (EHSSC) within a dual-channel setting. A game-theoretic framework is introduced to analyse how best the elderly service integrator (ESI) a...
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Abstract This paper studies the coordination of the elderly healthcare service supply chain (EHSSC) within a dual-channel setting. A game-theoretic framework is introduced to analyse how best the elderly service integrator (ESI) and elderly service provider (ESP) would make decisions and interact amidst cooperation and competition. Three cases including the centralised case, the Bertrand game case and the Stackelberg game case are examined to obtain the optimal relationship structure suitable for the EHSSC coordination. The associated loss due to customer dissatisfaction and the value increment due to the ESI’s service enhancement effort are incorporated in the model. Also, by considering customer’s health status, optimal pricing strategies are investigated for both the ESI and ESP under two different service demand classes. The main results are summarised as follows. First, the value increment due to the ESI’s service enhancement effort may have different impacts on the ESP’s prices in different service demand classes. Second, the whole supply chain would achieve effective coordination when the ESP acts as the Stackelberg leader with an appropriate setting of the wholesale price. Third, a lower wholesale price set by the ESP could benefit both the ESI and ESP in achieving greater demand and profit.
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MicroRNAs (miRNAs) may promote the development and progression of human cancers. Therefore, components of the miRNA biogenesis pathway may play critical roles in human cancer. Single nucleotide polymorphisms (SNPs) or mutations in...
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MicroRNAs (miRNAs) may promote the development and progression of human cancers. Therefore, components of the miRNA biogenesis pathway may play critical roles in human cancer. Single nucleotide polymorphisms (SNPs) or mutations in genes involved in the miRNA biogenesis pathway may alter levels of gene expression, affecting disease susceptibility. Results of previous studies on genetic variants in the miRNA biogenesis pathway and cancer risk were inconsistent. Therefore, a meta-analysis is needed to assess the associations of these genetic variants with human cancer risk. We searched for relevant articles from PubMed, Web of Science, CNKI, and CBM through Jun 21, 2016. In total, 21 case-control articles met all of the inclusion criteria for the study. Significant associations were observed between cancer risk and the DGCR8polymorphism rs417309A (OR 1.22, 95% CI [1.04–1.42]), as well as the DICER1 polymorphism rs1057035 TT (OR 1.13, 95% CI [1.05–1.22]). These SNPs exhibit high potential as novel diagnostic markers. Future studies with larger sample sizes and more refined analyses are needed to shed more light on these findings.
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In a busy railway marshalling station, train and engine traffic management in the receiving/departure yard plays a crucial role in efficient and stable operations. Traditionally, a track assignment problem (TAP) is solved to assig...
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In a busy railway marshalling station, train and engine traffic management in the receiving/departure yard plays a crucial role in efficient and stable operations. Traditionally, a track assignment problem (TAP) is solved to assign tracks to trains for berthing at a receiving/departure yard. However, the TAP does not encompass shunting operations in the yard (e.g., engine replacement and train disassembly), which can result in additional scheduling challenges for dispatchers and route conflicts between operations. This paper investigates a train and engine routing and scheduling problem (TERSP) in a receiving/departure yard of railway marshalling stations, which involves simultaneously assigning routes and scheduling route-setting start times for both train and shunting operations to be conducted in the yard. By introducing the concepts of task, activity, and pattern, we transform the original problem into assigning pre-generated patterns incorporating both route and route-setting start time alternatives to activities. The transformed problem is formulated into a compact binary integer linear programming model with a linear number of constraints and the objective of minimizing the total time deviation of all involved tasks. An improved technique that relies on listing all maximal (bi)cliques in a constructed graph is designed to effectively model the time coherence and track section occupation constraints. A heuristic that gradually expands the patterns for the identified key activities by adding more start time alternatives is applied to remedy an infeasible model caused by potential route conflicts. In addition, a rolling horizon algorithm that decomposes the original problem into consecutive smaller stages using either a time-rolling or a train-rolling rule is developed to efficiently solve instances. Finally, numerical experiments based on the physical layouts and real timetables of a receiving yard and a departure yard of a large marshalling station in China are conducted to assess the performance and applicability of our proposed approaches. The results demonstrate that our approaches typically find (near-)optimal solutions within several minutes for the investigated instances by simultaneously addressing different classes of yard operations and resources.
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In this paper, we address a loaded train combination problem at a heavy-haul marshalling station. This problem lies on assigning/combining loaded inbound trains to/into heavier outbound trains, and determining the actual departure...
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In this paper, we address a loaded train combination problem at a heavy-haul marshalling station. This problem lies on assigning/combining loaded inbound trains to/into heavier outbound trains, and determining the actual departure time of outbound trains. By using a time-discretized modelling technique, we formulate the studied problem as a mixed integer linear programming model, to minimize the weighted sum of the total railcar dwell time and the total railcar extra transfer time. Several variable fixing rules and valid inequalities are designed to strengthen the proposed model. An iterated search algorithm, in which an intensification search and a neighborhood search are executed iteratively, is developed to solve large-scale problems efficiently. In the intensification search, the proposed model is reduced into a simpler assignment model to compute an incumbent solution, by fixing the departure time of outbound trains. In the neighborhood search, a rolling horizon heuristic is designed to improve the incumbent solution, by dividing the departure period of outbound trains into multiple overlapped shorter stages, and re-optimizing the solution in each stage while maintaining that in other stages unchanged. Different scales of instances, randomly generated from a real-world marshalling station in one of the busiest Chinese heavy-haul railways, are used to test the proposed approaches. Computational results demonstrate that our algorithm computes (near-optimal solutions (with a maximum relative gap of 1.73% only) for all the tested instances within a maximum computation time shorter than 13 min. Our approach can also find better solutions (with an average improvement rate of 3.27%) in shorter computation time, when compared to the empirical method used in practice.
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Oxidative stress and neuroinflammation have been demonstrated to be linked with Alzheimer’s disease (AD). In this study, we examined the protective effects of DL0410 in aging rats and explored the underlying mechanism against oxi...
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Oxidative stress and neuroinflammation have been demonstrated to be linked with Alzheimer’s disease (AD). In this study, we examined the protective effects of DL0410 in aging rats and explored the underlying mechanism against oxidative damage and neuroinflammation, which was then validated in LPS-stimulated BV2 microglia. We firstly investigated the improvement effects of DL0410 on learning and memory abilities and explored the potential mechanisms in D-gal-induced aging rats. An 8-week treatment with DL0410 significantly improved the learning and cognitive function of D-gal-stimulated Alzheimer’s-like rats in the Morris water maze test, step-down test, and novel object recognition test, and the therapeutic effect of DL0410 at 10 mg/kg was even better than that of donepezil. What is more, the results showed that DL0410 alleviated neuron injury, increased the number of synapses, and improved the level of postsynaptic density protein 95 (PSD95) in the hippocampus and cortex. Next, we examined the protective effects of DL0410 against oxidative damage and neuroinflammation. Our observations indicated that DL0410 reduced the production of harmful oxidation products and promoted the antioxidative system, decreased the levels of proinflammatory cytokines, including tumor necrosis factor α (TNF- α ), interleukin 1 β (IL-1 β ), and interleukin 6 (IL-6), and increased anti-inflammatory cytokines IL-10. Moreover, DL0410 inhibited the activation of astrocytes and microglia and suppressed the activation of the TLR4/MyD88/NF- κ B signaling pathway. The anti-inflammation effect of DL0410 was further confirmed in LPS-stimulated BV2 cells, and the results showed that DL0410 reduced the level of inflammatory factors and inhibited the activation of the TLR4/MyD88/TRAF6/NF- κ B signaling pathway in BV2 microglia. Molecular docking results indicated that DL0410 occupied the LPS recognition site in the TLR4/MD2 complex. Furthermore, the enhanced expression of claudin-1, claudin-5, occludin, CX43, and ZO-1 indicated that DL0410 protected the blood-brain barrier (BBB) integrity. Together, these results suggest that DL0410 exerts neuroprotective effects against hippocampus and cortex injury induced by D-galactose, and the possible mechanisms include antioxidative stress, antineuroinflammation, improving synaptic plasticity, and maintaining BBB integrity, which is mediated by the TLR4/MyD88/NF- κ B signaling pathway inhibition. We suggest that DL0410 is a promising candidate for AD treatment.
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Nanomaterials' unique structures at the nanometer level determine their incredible functions, and based on this, they can be widely used in the field of nanomedicine. However, nanomaterials do possess disadvantages that cannot be ...
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Nanomaterials' unique structures at the nanometer level determine their incredible functions, and based on this, they can be widely used in the field of nanomedicine. However, nanomaterials do possess disadvantages that cannot be ignored, such as burst release, rapid elimination, and poor bioadhesion. Hydrogels are scaffolds with three-dimensional structures, and they exhibit good biocompatibility and drug release capacity. Hydrogels are also associated with disadvantages for biomedical applications such as poor anti-tumor capability, weak bioimaging capability, limited responsiveness, and so on. Incorporating nanomaterials into the 3D hydrogel network through physical or chemical covalent action may be an effective method to avoid their disadvantages. In nanocomposite hydrogel systems, multifunctional nanomaterials often work as the function core, giving the hydrogels a variety of properties (such as photo-thermal conversion, magnetothermal conversion, conductivity, targeting tumor, etc.). While, hydrogels can effectively improve the retention effect of nanomaterials and make the nanoparticles have good plasticity to adapt to various biomedical applications (such as various biosensors). Nanocomposite hydrogel systems have broad application prospects in biomedicine. In this review, we comprehensively summarize and discuss the most recent advances of nanomaterials composite hydrogels in biomedicine, including drug and cell delivery, cancer treatment, tissue regeneration, biosensing, and bioimaging, and we also briefly discussed the current situation of their commoditization in biomedicine.
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We investigate the one-block train formation problem (TFP) in the railway freight transportation industry. The input to this problem is a railway network and a set of demands for transportation. Each demand is a request for shippi...
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We investigate the one-block train formation problem (TFP) in the railway freight transportation industry. The input to this problem is a railway network and a set of demands for transportation. Each demand is a request for shipping a number of rail cars from one station to another. The one-block TFP now addresses two subproblems in the tactical level: Which pairs of stations are directly connected via a block (or: train service); and which demands are transported by each block. The aim is to service all demands against minimal costs. Moving beyond current researches on service network design, the unitary rule and the intree rule are taken into account in this study based on the Chinese railway background. We develop a linear binary programming formulation to minimize the total sum of train accumulation costs and car classification costs, subject to limitations on the classification capacity and the number of sort tracks at each station. Furthermore, we propose a novel solution methodology that applies a tree-based decomposition algorithm. Here, we first decompose the whole network into a series of rooted trees for each destination separately. Then, we divide the trees further into sufficiently small subtrees, whose size is regulated by a node size parameter. Finally, we construct a restricted linear binary model for each subtree and solve these models sequentially to find their optimal solutions. The algorithm ensures that an overall feasible solution is obtained if one exists. Our computational results on a realistic network from the Chinese railway system with 83 stations, 158 links and 5700 randomly generated demands show that the proposed algorithm can derive high-quality solutions within a few hours of computation time. These solutions are on average 48.05% better than those obtained after solving the linear binary program with a commercial solver for 1 day.
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