ABSTRACT
Platform operations are very common in the sharing economy. Nowadays, retailers can sell the end‐of‐season product leftovers to platforms which offer product rental services to the market. ...Motivated by this observed industrial practice, we build stylized supply chain models to explore the platform supported supply chain operations. We uncover that the presence of the platform creates the “triple marginalization” problem in which supply chain coordination cannot be achieved even if the manufacturer is willing to supply at cost using the wholesale pricing contract. We show how the markdown sponsor (MS) contract can deal with the triple marginalization problem and achieve supply chain coordination. However, we illustrate that a moral hazard problem, in which the retailer has incentive to overclaim the amount of markdown sponsor, arises. We reveal that the moral hazard problem brings a loss to the manufacturer, an immoral gain for the retailer, and there is no impact on the platform and consumers. We analytically derive the impact of moral hazard (which means the loss to the manufacturer, and the gain for the retailer) and find that it relates to the markdown sponsor rate, as well as the degree of overclaiming. To overcome the moral hazard problem under MS contract, we propose measures such as the adoption of blockchain technology, and “discounted” markdown sponsor contract, to help. We also explore the implementations of other contracts to overcome the moral hazard, like virtual buyback with inventory reallocation contract, and wholesale pricing contract with side payments.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Selective catalytic reduction with NH3 (NH3–SCR) is the most efficient technology to reduce the emission of nitrogen oxides (NOx) from coal-fired industries, diesel engines, etc. Although ...V2O5–WO3(MoO3)/TiO2 and CHA structured zeolite catalysts have been utilized in commercial applications, the increasing requirements for broad working temperature window, strong SO2/alkali/heavy metal-resistance, and high hydrothermal stability have stimulated the development of new-type NH3–SCR catalysts. This review summarizes the latest SCR reaction mechanisms and emerging poison-resistant mechanisms in the beginning and subsequently gives a comprehensive overview of newly developed SCR catalysts, including metal oxide catalysts ranging from VOx, MnOx, CeO2, and Fe2O3 to CuO based catalysts; acidic compound catalysts containing vanadate, phosphate and sulfate catalysts; ion exchanged zeolite catalysts such as Fe, Cu, Mn, etc. exchanged zeolite catalysts; monolith catalysts including extruded, washcoated, and metal-mesh/foam-based monolith catalysts. The challenges and opportunities for each type of catalysts are proposed while the effective strategies are summarized for enhancing the acidity/redox circle and poison-resistance through modification, creating novel nanostructures, exposing specific crystalline planes, constructing protective/sacrificial sites, etc. Some suggestions are given about future research directions that efforts should be made in. Hopefully, this review can bridge the gap between newly developed catalysts and practical requirements to realize their commercial applications in the near future.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Evidence suggests that fasting exerts extensive antitumor effects in various cancers, including colorectal cancer (CRC). However, the mechanism behind this response is unclear. We investigate the ...effect of fasting on glucose metabolism and malignancy in CRC. We find that fasting upregulates the expression of a cholesterogenic gene, Farnesyl-Diphosphate Farnesyltransferase 1 (FDFT1), during the inhibition of CRC cell aerobic glycolysis and proliferation. In addition, the downregulation of FDFT1 is correlated with malignant progression and poor prognosis in CRC. Moreover, FDFT1 acts as a critical tumor suppressor in CRC. Mechanistically, FDFT1 performs its tumor-inhibitory function by negatively regulating AKT/mTOR/HIF1α signaling. Furthermore, mTOR inhibitor can synergize with fasting in inhibiting the proliferation of CRC. These results indicate that FDFT1 is a key downstream target of the fasting response and may be involved in CRC cell glucose metabolism. Our results suggest therapeutic implications in CRC and potential crosstalk between a cholesterogenic gene and glycolysis.
Macrophages are highly heterogeneous and exhibit a diversity of functions and phenotypes. They can be divided into pro‐inflammatory macrophages (M1) and anti‐inflammatory macrophages (M2). Diabetic ...wounds are characterized by a prolonged inflammatory phase and difficulty in healing due to the accumulation of pro‐inflammatory (M1) macrophages in the wound. Therefore, hydrogel dressings with macrophage heterogeneity regulation function hold great promise in promoting diabetic wound healing in clinical applications. However, the precise conversion of pro‐inflammatory M1 to anti‐inflammatory M2 macrophages by simple and biosafe approaches is still a great challenge. Here, an all‐natural hydrogel with the ability to regulate macrophage heterogeneity is developed to promote angiogenesis and diabetic wound healing. The protocatechuic aldehyde hybridized collagen‐based all‐natural hydrogel exhibits good bioadhesive and antibacterial properties as well as reactive oxygen species scavenging ability. More importantly, the hydrogel is able to convert M1 macrophages into M2 macrophages without the need for any additional ingredients or external intervention. This simple and safe immunomodulatory approach shows great application potential for shortening the inflammatory phase of diabetic wound repair and accelerating wound healing.
An all‐natural hydrogel composed of small molecules pro‐catechol and collagen is developed to promote diabetic wound healing by modulating macrophage heterogeneity. The hydrogel exhibits good bioadhesive, antibacterial, and reactive oxygen species scavenging abilities. In vitro and in vivo experiments show that the hydrogel is able to promote the conversion of pro‐inflammatory (M1) macrophages to anti‐inflammatory (M2) macrophages and the expression of anti‐inflammatory factors.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Summary
Vulnerability curves (VCs) describe the loss of hydraulic conductance against increasing xylem tension, providing valuable insights about the response of plant water transport to water ...stress. Techniques to construct VCs have been developed and modified continuously, but controversies continue.
We compared VCs constructed using the bench‐top dehydration (BD), air‐injection‐flow (AI), pneumatic‐air‐discharge (PAD), optical (OP) and X‐ray‐computed microtomography (MicroCT) methods for tropical trees and lianas with contrasting vessel lengths.
The PAD method generated highly vulnerable VCs, the AI method intermediate VCs, whereas the BD, OP and MicroCT methods produced comparable and more resistant VCs. Vessel‐length and diameter accounted for the overestimation ratio of vulnerability estimated using the AI but not the PAD method. Compared with directly measured midday embolism levels, the PAD and AI methods substantially overestimated embolism, whereas the BD, MicroCT and OP methods provided more reasonable estimations.
Cut‐open vessels, uncertainties in maximum air volume estimations, sample‐length effects, tissue cracks and shrinkage together may impede the reliability of the PAD method. In conclusion, we validate the BD, OP and MicroCT methods for tropical plants, whereas the PAD and AI need further mechanistic testing. Therefore, applications of VCs in estimating plant responses to drought need to be cautious.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Hydraulic failure caused by severe drought contributes to aboveground dieback and whole‐plant death. The extent to which dieback or whole‐plant death can be predicted by plant hydraulic traits has ...rarely been tested among species with different leaf habits and/or growth forms. We investigated 19 hydraulic traits in 40 woody species in a tropical savanna and their potential correlations with drought response during an extreme drought event during the El Niño–Southern Oscillation in 2015. Plant hydraulic trait variation was partitioned substantially by leaf habit but not growth form along a trade‐off axis between traits that support drought tolerance versus avoidance. Semi‐deciduous species and shrubs had the highest branch dieback and top‐kill (complete aboveground death) among the leaf habits or growth forms. Dieback and top‐kill were well explained by combining hydraulic traits with leaf habit and growth form, suggesting integrating life history traits with hydraulic traits will yield better predictions.
Our study show plant hydraulic trait variation partitioned substantially by leaf habit but not by growth‐form along a trade‐off axis between traits that support hydraulic‐tolerance versus drought‐avoidance. Semi‐deciduous species, and shrubs had the highest branch die‐back and whole‐plant mortality among all leaf‐habit or growth‐forms. The mortality ratio could be well explained by hydraulic traits, while largely affected by both leaf‐habit and growth‐form.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
It is an intractable issue to improve the low-temperature SO2-tolerant selective catalytic reduction (SCR) of NOx with NH3 because deposited sulfates are difficult to decompose below 300 oC. Herein, ...we established a low-temperature self-prevention mechanism of mesoporous-TiO2@Fe2O3 core-shell composites against sulfate deposition using experiments and density functional theory. The mesoporous TiO2-shell effectively restrained the deposition of FeSO4 and NH4HSO4 because of weak SO2 adsorption and promoted NH4HSO4 decomposition on the mesoporous-TiO2. The electron transfer at the Fe2O3 (core)-TiO2 (shell) interface accelerated the redox cycle, launching the "Fast SCR" reaction, which broadened the low-temperature window. Engineered from the nano- to macro-scale, we achieved one-pot self-installation of mesoporous-TiO2@Fe2O3 composites on the self-tailored AlOOH@Al-mesh monoliths. After the thermal treatment, the mesoporous-TiO2@Fe2O3@Al2O3 monolith catalyst delivered a broad window of 220-420 oC with NO conversion above 90% and had superior SO2 tolerance at 260 oC. The effective heat removal of Al-mesh monolith catalysts restrained NH3 oxidation to NO and N2O while suppressing the decomposition of NH4NO3 to N2O, and this led to much better high-temperature activity and N2 selectivity. This work supplies a new point for the development of low-temperature SO2-tolerant monolithic SCR catalysts with high N2 selectivity, which is of great significance for both academic interests and practical applications.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
A viologen‐based Borromean entangled porous framework was found to be sensitive to both CuKα and MoKα X‐ray sources, showing rapid photochromic response and recovery within one minute. The ...X‐ray‐induced photochromic process is accompanied by a reversible single‐crystal‐to‐single‐crystal (SC‐SC) structural transformation, an unprecedented phenomenon for X‐ray sensitive materials. The complex can be further processed into portable thin films for detecting the dose of the X‐ray exposure. Moreover, the photochromism can occur over a broad temperature range of 100–333 K, both in the form of single crystals and thin films, making it a potential candidate for practical indoor and outdoor applications.
X‐ray specs: A viologen‐based Borromean‐entangled porous framework was found sensitive to X‐rays and undergo a rapid photochromic response and recovery. This process is accompanied by a reversible single‐crystal‐to‐single‐crystal transformation. The material can be further processed into a thin film for detecting the dose of X‐ray exposure.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Lianas exhibit peak abundance in tropical forests with strong seasonal droughts, the eco‐physiological mechanisms associated with lianas coping with water deficits are poorly understood. We examined ...soil water partitioning, sap flow, and canopy eco‐physiological properties for 99 individuals of 15 liana and 34 co‐occurring tree species in three tropical forests that differed in soil water availability. In the dry season, lianas used a higher proportion of deep soil water in the karst forest (KF; an area with severe seasonal soil water deficit (SSWD)) and in the tropical seasonal forest (TSF, moderate SSWD), permitting them to maintain a comparable leaf water status than trees in the TSF or a better status than trees in the KF. Lianas exhibited strong stomatal control to maximize carbon fixation while minimizing dry season water loss. During the dry period, lianas significantly decreased water consumption in the TSF and the KF. Additionally, lianas had a much higher maximum photosynthetic rates and sap flux density in the wet season and a lower proportional decline in photosynthesis in the dry season compared with those of trees. Our results indicated that access to deep soil water and strong physiological adjustments in the dry season together with active wet‐season photosynthesis may explain the high abundance of lianas in seasonally dry forests.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
As Charles Darwin anticipated, living fossils provide excellent opportunities to study evolutionary questions related to extinction, competition, and adaptation. Ginkgo (Ginkgo biloba L.) is one of ...the oldest living plants and a fascinating example of how people have saved a species from extinction and assisted its resurgence. By resequencing 545 genomes of ginkgo trees sampled from 51 populations across the world, we identify three refugia in China and detect multiple cycles of population expansion and reduction along with glacial admixture between relict populations in the southwestern and southern refugia. We demonstrate multiple anthropogenic introductions of ginkgo from eastern China into different continents. Further analyses reveal bioclimatic variables that have affected the geographic distribution of ginkgo and the role of natural selection in ginkgo's adaptation and resilience. These investigations provide insights into the evolutionary history of ginkgo trees and valuable genomic resources for further addressing various questions involving living fossil species.
PDF
