30 research outputs found
ONCache: A Cache-Based Low-Overhead Container Overlay Network
Recent years have witnessed a widespread adoption of containers. While
containers simplify and accelerate application development, existing container
network technologies either incur significant overhead, which hurts performance
for distributed applications, or lose flexibility or compatibility, which
hinders the widespread deployment in production.
We design and implement ONCache (\textbf{O}verlay \textbf{N}etwork
\textbf{Cache}), a cache-based container overlay network, to eliminate the
overhead while keeping flexibility and compatibility. We carefully analyze the
difference between an overlay network and a host network, and find that an
overlay network incurs extra packet processing, including encapsulating,
intra-host routing, namespace traversing and packet filtering. Fortunately, the
extra processing exhibits an \emph{invariance property}, e.g., most packets of
the same flow have the same processing results. This property motivates us to
cache the extra processing results. With the proposed cache, ONCache
significantly reduces the extra overhead while maintaining the same flexibility
and compatibility as standard overlay networks. We implement ONCache using eBPF
with only 524 lines of code, and deploy ONCache as a plugin of Antrea.
With ONCache, container communication achieves similar performance as host
communication. Compared to the standard overlay network, ONCache improves the
throughput and request-response transaction rate by 12\% and 36\% for TCP (20\%
and 34\% for UDP), while significant reduces per-packet CPU overhead. Many
distributed applications also benefit from ONCache
Characterization of the parent and hydroxylated polycyclic aromatic hydrocarbons in the soil of the Fildes Peninsula, Antarctica
Polycyclic aromatic hydrocarbons (PAHs) and hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were investigated in the soil of the Fildes Peninsula, Antarctica. Various analytes were detected, and the concentration of OH-PAHs was 0.300–1.847 ng·g−1 dry weight, with the dominant components being danthron and 1-hydroxy-phenanthrene. The relationship between soil total organic matter (TOM), OH-PAHs, and the parent PAHs in the soil was studied. No significant correlation was detected between the spatial distribution of OH-PAHs and the occurrence of PAHs, whereas a positive correlation with TOM was found
Single cell transcriptome profiling reveals cutaneous immune microenvironment remodeling by photodynamic therapy in photoaged skin
BackgroundThe immune microenvironment plays a critical role in maintaining skin homeostasis, which is closely related to the dysfunction in photoaged skin such as autoimmunity and tumorigenesis. Several recent studies have demonstrated the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in alleviating photoaging and skin cancer. However, the underlying immune mechanisms and the immune microenvironment change by ALA-PDT remain largely unknown.MethodsTo illustrate the effects of ALA-PDT on immune microenvironment in photoaged skin, single cell RNA sequencing (scRNA-seq) analysis of photoaged skin on the extensor side of the human forearm before and after ALA-PDT was performed. R-packages of Seurat, clusterProfiler, Monocle, CellChat were used for cell clustering, differentially expressed genes analysis, functional annotation, pseudotime analysis and cell-cell communication analysis. The gene sets related to specific functions were extracted from the MSigDB database, which were used to score the functions of immune cells in different states. We also compared our result with published scRNA-seq data of photoaged skin of the eyelids.ResultsThe increase score of cellular senescence, hypoxia and reactive oxygen species pathway in immune cells and the decrease of immune receptor activity function and proportion of naive T cells were found in skin photoaging. Moreover, the function of T cell ribosomal synthesis was also impaired or down regulated and function of G2M checkpoint was up regulated. However, ALA-PDT showed promising results in reversing these effects, as it improved the above functions of T cells. The ratio of M1/M2 and percentage of Langerhans cells also decreased with photoaging and increased after ALA-PDT. Additionally, ALA-PDT restored the antigen presentation and migration function of dendritic cells and enhanced cell-cell communication among immune cells. These effects were observed to last for 6 months.ConclusionALA-PDT has potential to rejuvenate immune cells, partially reversed immunosenescence and improved the immunosuppressive state, ultimately remodelling the immune microenvironment in photoaged skin. These results provide an important immunological basis for further exploring strategies to reverse skin photoaging, chronological aging and potentially systemic aging
Peregrine and saker falcon genome sequences provide insights into evolution of a predatory lifestyle
As top predators, falcons possess unique morphological, physiological and behavioral adaptations that allow them to be successful hunters: for example, the peregrine is renowned as the world's fastest animal. To examine the evolutionary basis of predatory adaptations, we sequenced the genomes of both the peregrine (Falco peregrinus) and saker falcon (Falco cherrug), and we present parallel, genome-wide evidence for evolutionary innovation and selection for a predatory lifestyle. The genomes, assembled using Illumina deep sequencing with greater than 100-fold coverage, are both approximately 1.2 Gb in length, with transcriptome-assisted prediction of approximately 16,200 genes for both species. Analysis of 8,424 orthologs in both falcons, chicken, zebra finch and turkey identified consistent evidence for genome-wide rapid evolution in these raptors. SNP-based inference showed contrasting recent demographic trajectories for the two falcons, and gene-based analysis highlighted falcon-specific evolutionary novelties for beak development and olfaction and specifically for homeostasis-related genes in the arid environment–adapted saker
Mitigating initial capacity loss for practical lithium-ion battery
Rechargeable lithium-ion batteries (LIBs) with high energy and power density are urgently required for electric vehicles and aerospace industry. For such large-scale industrial applications, the development and industrial conversion of high-performance electrode materials are important considerations for improving practical battery prototype and module performance. Current commercial graphite anode materials have limited active sites for lithium accommodation and extremely low Li+ intercalation voltage (<0.1 V) and thus, have low specific capacity (372 mAh g-1) and lithium dendrite induced safety issues. While numerous promising anode materials with optimized electrochemical performance, such as fast-charging capability and long-term stability have been developed, they still suffer from low initial Coulombic efficiency (ICE) due to solid electrolyte interphase (SEI) formation and lithium trapping, which impede their commercialization. In this thesis, new insights and strategies for the two mechanisms leading to initial capacity loss (ICL) based on different type of anode materials were investigated.Doctor of Philosoph
A figure of merit for fast-charging Li-ion battery materials
Rate capability is characterized necessarily in almost all battery-related reports, while there is no universal metric for quantitative comparison. Here, we proposed the characteristic time of diffusion, which mainly combines the effects of diffusion coefficients and geometric sizes, as an easy-to-use figure of merit (FOM) to standardize the comparison of fast-charging battery materials. It offers an indicator to rank the rate capabilities of different battery materials and suggests two general methods to improve the rate capability: decreasing the geometric sizes or increasing the diffusion coefficients. Based on this FOM, more comprehensive FOMs for quantifying the rate capabilities of battery materials are expected by incorporating other processes (interfacial reaction, migration) into the current diffusion-dominated electrochemical model. Combined with Peukert's empirical law, it may characterize rate capabilities of batteries in the future.National Research Foundation (NRF)Submitted/Accepted versionThe authors are grateful for funding support from the National Research Foundation of Prime Minister’s Office of Singapore (NRF2015_IIP003_004)
New insights into the environmental photochemistry of common-use antibiotics in ice and in water : A comparison of kinetics and influencing factors
The photochemistry of organic contaminants present in ice is receiving growing attention, given the wide presence of ice during winter in temperate regions as well as Polar and mountain environments. Differences between ice photochemistry and aqueous photochemistry, however, influence the quantitative fate and transformation of organic chemicals present in freshwater, marine and ice-cap environments and these differences need to be explored. Here we comparatively studied the ice and aqueous photochemistry of three antibiotics [levofloxacin (LVX), sulfamerazine (SM), and chlortetracycline (CTC)] under the same simulated sunlight (λ > 290 nm). Their photodegradation in ice/water followed pseudo-first-order kinetics, whereby the photolytic rates of LVX in ice and water were found to be similar, SM photodegraded faster in ice, while CTC underwent slower photodegradation in ice. Whether individual antibiotics underwent faster photodegradation in ice or not depends on the specific concentration effect and cage effect coexisting in the ice compartment. In most cases, the fastest photodegradation occurred in freshwater ice or in fresh water, and the slowest photolysis occurred in pure-water ice or in pure water. This can be attributed to the effects of key photochemical reactive constituents of Cl-, HA, NO3 - and Fe(III), that exist in natural waters. These constituents at certain levels showed significant effects (P < 0.1) on the photolysis, not only in ice but also in water. However, these individual constituents at a given concentration, serve to either enhance or suppress the photoreaction, depending on the specific antibiotic and the matrix type (e.g., ice or aqueous solution). Furthermore, extrapolation of the laboratory findings to cold environments indicate that pharmaceuticals present in ice will have a different photofate compared to water. These results are of particular relevance for those regions that experience seasonal ice cover in fresh water and coastal marine systems
Occurrence, spatiotemporal distribution and risks of macrolide antibiotics in the Weihe River and its tributaries, north-central China
The presence of antibiotics as emerging micropollutants in the aquatic environment has been raising health concerns for a number of years. Macrolides (MLs) are a large class of widely-used antibiotics, but there is a lack of information on their distribution and risks in surface waters across the central and western regions of China. To clearly describe the pollution characteristics and risks of MLs in Weihe River (the largest tributary of the Yellow River), analysis of 5 typical MLs was conducted using a newly developed LC−MS/MS method for 50 water samples collected over three seasons during 2021–2022. The results revealed that the area showed comparable ML concentrations with other regions worldwide. However, the ML concentrations were much lower than those in the river during 2016 from a previous study. Furthermore, concentrations exhibited significant seasonal variation, with highest concentrations in the winter. Along the main stream of the Weihe River, the sampling sites close to the wastewater treatment plants (WWTPs) and livestock farms exhibited higher concentrations of MLs, indicating the significant contribution from WWTPs and animal husbandry to the emission of MLs. The risk quotients (RQs) suggested that the ecological risks associated with MLs were most pronounced in winter among the three seasons, with erythromycin posing a high or medium risk to algae at all sampling sites. The results of this study will be of importance towards the goal of understanding the presence of these emerging contaminants in surface waters and any required risk reduction measures
MoS2 anchored on agar-derived 3D nitrogen-doped porous carbon for electrocatalytic hydrogen evolution reaction and lithium-ion batteries
MoS2 has been explored as a potential material for hydrogen evolution reaction (HER) and lithium-ion batteries (LIBs). However, the limited number of active sites and poor conductivity restrain its applications. Herein, a facile method is reported to construct MoS2 nanosheets (MoS2 NSs) grown on agar-derived 3D nitrogen-doped porous carbon (MoS2-NPC). The as-prepared MoS2-NPC composite exhibits good stability and HER electrocatalytic properties with a low overpotential of 209 mV at 10 mA cm−2 and a small Tafel slope of 41 mV dec−1. Furthermore, as an anode of LIBs, it delivers an initial discharge capacity of 1289 mAh g−1 at 0.1 A g−1 and rate capability of 712 and 419 mAh g−1 at 0.5 and 2.0 A g−1, respectively. This is attributed to the synergistic effects and unique 3D network structure, which avoids the aggregation of MoS2 and results in more exposed active sites. The agar-derived 3D nitrogen-doped porous carbon can act as a support material for MoS2 NSs dispersed on the surface, providing a cheap and efficient strategy to prepare high quality catalysts for electrochemical energy conversion and storage applications.This work was financially supported by the National Natural Science Foundation of China (Nos. U1764254 and 21911530255), 111 Project, China (No. D17003), Graphene Flagship (881603), and the Open Research Fund of the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry (Jilin University, Grant No. 2021-03).Peer reviewe