27 research outputs found
High-Temperature Oxidation Performance of 4Cr4Mo2NiMnSiV Hot Die Steel
A new type of hot working die steel was designed by using JMatPro, and high-temperature oxidation tests were carried out in the ambient atmosphere at 600 ℃ and 700 ℃. The heat treatment process and oxidation mechanism of the designed 4Cr4Mo2NiMnSiV steel were studied in detail. XRD, SEM and EDS were used to analyze the crystallographic phases, surface and cross-section morphologies of the oxide films. The results show that the main phases in the 4Cr4Mo2NiMnSiV steel were γ and α + δ. During the high-temperature oxidation, oxidation of the Fe outer layer and Cr inner layer occurred. After oxidation at 600℃, the surface oxidation layer comprised a monolayer with an uneven morphology. The surface oxide film had two layers after oxidation at 700℃. The outer oxide layer mainly contained Fe2O3 and Fe3O4, while the inner oxide layer mainly contained Cr2O3. The microstructure was relatively regular and had a significant effect on the protection of the metallic matrix. When oxidized, the 4Cr4Mo2NiMnSiV alloy steel easily formed protective layers, such as Cr2O3 and SiO2, so that the test steel had excellent oxidation resistance at high temperatures
Roadmap on Perovskite Light-Emitting Diodes
In recent years, the field of metal-halide perovskite emitters has rapidly
emerged as a new community in solid-state lighting. Their exceptional
optoelectronic properties have contributed to the rapid rise in external
quantum efficiencies (EQEs) in perovskite light-emitting diodes (PeLEDs) from
<1% (in 2014) to approaching 30% (in 2023) across a wide range of wavelengths.
However, several challenges still hinder their commercialization, including the
relatively low EQEs of blue/white devices, limited EQEs in large-area devices,
poor device stability, as well as the toxicity of the easily accessible lead
components and the solvents used in the synthesis and processing of PeLEDs.
This roadmap addresses the current and future challenges in PeLEDs across
fundamental and applied research areas, by sharing the community's
perspectives. This work will provide the field with practical guidelines to
advance PeLED development and facilitate more rapid commercialization.Comment: 103 pages, 29 figures. This is the version of the article before peer
review or editing, as submitted by an author to Journal of Physics:
Photonics. IOP Publishing Ltd is not responsible for any errors or omissions
in this version of the manuscript or any version derived from i
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Determining RNA Natural Modifications and Nucleoside Analog-Labeled Sites by a Chemical/Enzyme-Induced Base Mutation Principle
The natural chemical modifications of messenger RNA (mRNA) in living organisms have shown essential roles in both physiology and pathology. The mapping of mRNA modifications is critical for interpreting their biological functions. In another dimension, the synthesized nucleoside analogs can enable chemical labeling of cellular mRNA through a metabolic pathway, which facilitates the study of RNA dynamics in a pulse-chase manner. In this regard, the sequencing tools for mapping both natural modifications and nucleoside tags on mRNA at single base resolution are highly necessary. In this work, we review the progress of chemical sequencing technology for determining both a variety of naturally occurring base modifications mainly on mRNA and a few on transfer RNA and metabolically incorporated artificial base analogs on mRNA, and further discuss the problems and prospects in the field
Determining RNA Natural Modifications and Nucleoside Analog-Labeled Sites by a Chemical/Enzyme-Induced Base Mutation Principle
The natural chemical modifications of messenger RNA (mRNA) in living organisms have shown essential roles in both physiology and pathology. The mapping of mRNA modifications is critical for interpreting their biological functions. In another dimension, the synthesized nucleoside analogs can enable chemical labeling of cellular mRNA through a metabolic pathway, which facilitates the study of RNA dynamics in a pulse-chase manner. In this regard, the sequencing tools for mapping both natural modifications and nucleoside tags on mRNA at single base resolution are highly necessary. In this work, we review the progress of chemical sequencing technology for determining both a variety of naturally occurring base modifications mainly on mRNA and a few on transfer RNA and metabolically incorporated artificial base analogs on mRNA, and further discuss the problems and prospects in the field
Microstructure and mechanical properties of aluminum/steel bimetal using compound casting with electroless nickel plating
The surface of steel substrate was pretreated by nickel plating and Aluminum/nickel-plated steel bimetal was prepared by compound casting. After liquid aluminum was casted on the surface of the nickel-plated steel, it was placed in a heat preservation device and temperature set at 760 °C. In the compound casting process of molten aluminum and nickel-plated steel, good metallurgical bonding is formed between aluminum and steel by means of diffusion. Subsequently, the microstructure of the aluminum/nickel-plated steel bimetal was examined using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) techniques. The phase composition of the intermediate layer was analyzed by x-ray diffraction (XRD). Further, the bonding properties and fracture mechanism of the intermediate layer were analyzed by measuring the corresponding Vickers microhardness and shear strength. The results show that the intermediate layer is divided into two layers. In addition, intermetallic compounds appear in the intermediate layer; Al _5 Fe _2 , near the steel side, and Al _8 Fe _2 Si, near the aluminum side. The main phases in the intermediate layer are α -Al, α -Fe, Al _5 Fe _2 , Al _5 FeSi and Al _8 Fe _2 Si. The microhardness of the intermediate layer of the aluminum/steel bimetal is higher than that of both the aluminum matrix and steel matrix. It is observed that the thickness of the intermediate layer of the aluminum/nickel-plated steel bimetal increases with the increase of the holding time. When the holding time was 15 min, the intermediate layer of the aluminum/nickel-plated steel bimetal exhibits the highest shear strength, i.e. 13.4 MPa. The fracture of the aluminum/steel bimetal is a brittle fracture, and starts from the intermediate layer. The results show that nickel plating on steel substrate can obviously improve the casting properties of an aluminum/steel bimetal
Study on the Seismic Response of Shield Tunnel Structures with the Preload Loss of Bolts
Shield tunnels can experience preload loss in their connecting bolts during the operational phase, leading to changes in tunnel structure stiffness, which, in turn, affect the seismic performance of shield tunnels. A refined three-dimensional model of shield tunnel was established using the finite element method to study the impact of preload loss in connecting bolts on the seismic dynamic response of shield tunnels. An artificial viscoelastic boundary was used to simulate the propagation of seismic waves from an infinitely distant field. This study investigated the effects of different levels of preload loss on the seismic response of shield tunnels. In addition, the Arias intensity, which can reflect the degree of seismic impact on structures, was used to analyse the extent of damage to the tunnel. The conclusions drawn from the study are as follows: As the level of preload loss increases, the tightness of the segments during the static phase gradually deteriorates, and the maximum joint opening during the seismic loading phase continues to increase. Post-earthquake non-recoverable ellipticity and radial deformation progressively increase with an increase to preload loss level. Overall tunnel damage becomes more significant with the degree of preload loss increases depending on the Arias intensity. Preload loss leads to a decrease in the overall structural stiffness and an increase in longitudinal relative displacement. In conclusion, preload loss also affects structural failure mode and seismic performance. These research findings are of reference value for enhancing the seismic performance of shield tunnel structures and ensuring engineering safety
The barriers and strategies of conducting on-site sorting of construction waste: a case study of Suzhou
With the rapid development of economy and society in the past two decades, China is confronted with unprecedented pressure from the public demanding for sustainability. Construction waste, as a chief culprit undermining the sustainability has received increasing attention. Construction waste issues in China are particularly severe due to the massive construction waste generated on the one hand and poor construction waste management on the other hand. On-site sorting of construction waste is an effective measure of construction waste management to increase the reuse and recycling rate of construction waste. However, the implementation level of on-site sorting of construction waste is rather low. There is a pressing need to investigate the barriers against it. Therefore, this study analyzes the barriers of conducting on-site sorting of construction waste with a case study of Suzhou. The results indicate that the barriers include (1) lack of on-site management of sorting, and (2) low level of environmental awareness for construction company, (1) lack of on-site management, and (2) lack of advanced demolition technologies for demolition and transport company, and (1) lack of a mature market for recycled materials, and (2) insufficient technologies for construction waste recycling company. Based on the barriers identified, three targeted strategies are also proposed in this study, including improving environmental awareness, enhancing supervision of on-site sorting of construction waste, and providing some economic incentives. The research deliverables of this study are of benefit to researchers, practitioners and government to devise more evidence-based strategies to holistically improve construction waste management performance in China and beyond
Elimination of the yellow pigment gene PSY-E2 tightly linked to the Fusarium head blight resistance gene Fhb7 from Thinopyrum ponticum
Fhb7 is a major gene that was transferred from Thinopyrum ponticum to chromosome 7D of wheat (Triticum aestivum) and confers resistance to both Fusarium head blight (FHB) and Fusarium crown rot (FCR). However, Fhb7 is tightly linked to the PSY-E2 gene, which causes yellow flour, limiting its application in breeding. To break this linkage, marker K-PSY was developed for tagging PSY-E2 and used with Fhb7 markers to identify recombination between the two genes. Screening 21,000 BC1F2 backcross progeny (Chinese Spring ph1bph1b*2/SDAU 2028) revealed two Fhb7+ wheat-Tp7el2L lines, Shannong 2–16 and Shannong 16–1, that carry a desired truncated Fhb7+ translocation segment without PSY-E2. The two lines show levels of resistance to FHB and FCR similar to those of the original translocation line SDAU 2028, but have white flour. To facilitate Fhb7 use in wheat breeding, STS markers were developed and used to isolate Fhb7 on a truncated Tp7el2 translocation segment. Near-isogenic lines carrying the Fhb7+ segment were generated in the backgrounds of three commercial cultivars, and Fhb7+ lines showed increased FHB and FCR resistance without yield penalty. The breakage of the tight linkage between Fhb7 and PSY-E2 via homoeologous recombination provides genetic resources for improvement of wheat resistance to FHB and FCR and permit the large-scale deployment of Fhb7 in breeding using marker-assisted selection