Soil carbon transformation and sequestration have received significant interest in recent years due to a growing need for quantitating its role in mitigating climate change. Even though our ...understanding of the nature of soil organic matter has recently been substantially revised, fundamental uncertainty remains about the quantitative importance of microbial necromass as part of persistent organic matter. Addressing this uncertainty has been hampered by the absence of quantitative assessments whether microbial matter makes up the majority of the persistent carbon in soil. Direct quantitation of microbial necromass in soil is very challenging because of an overlapping molecular signature with nonmicrobial organic carbon. Here, we use a comprehensive analysis of existing biomarker amino sugar data published between 1996 and 2018, combined with novel appropriation using an ecological systems approach, elemental carbon–nitrogen stoichiometry, and biomarker scaling, to demonstrate a suit of strategies for quantitating the contribution of microbe‐derived carbon to the topsoil organic carbon reservoir in global temperate agricultural, grassland, and forest ecosystems. We show that microbial necromass can make up more than half of soil organic carbon. Hence, we suggest that next‐generation field management requires promoting microbial biomass formation and necromass preservation to maintain healthy soils, ecosystems, and climate. Our analyses have important implications for improving current climate and carbon models, and helping develop management practices and policies.
We reprocessed existing amino sugar data, published between 1996 and 2018 from global agricultural, grassland, and forest ecosystems in temperate zones, by scaling them up to microbial necromass carbon. On average, microbial necromass abundance increased in the order agricultural < grassland < forest, while its contribution to soil organic carbon (SOC) storage was lowest in the forest ecosystem. Fungal necromass abundance and its contribution to SOC were consistently higher than bacterial necromass. Microbial necromass can make up more than half of SOC pool, suggesting the need to understand microbial necromass conservation in the context of soil management and climate change mitigation.
A therapeutic strategy that can eliminate primary tumours, inhibit metastases, and prevent tumour relapses is developed herein by combining adjuvant nanoparticle-based photothermal therapy with ...checkpoint-blockade immunotherapy. Indocyanine green (ICG), a photothermal agent, and imiquimod (R837), a Toll-like-receptor-7 agonist, are co-encapsulated by poly(lactic-co-glycolic) acid (PLGA). The formed PLGA-ICG-R837 nanoparticles composed purely by three clinically approved components can be used for near-infrared laser-triggered photothermal ablation of primary tumours, generating tumour-associated antigens, which in the presence of R837-containing nanoparticles as the adjuvant can show vaccine-like functions. In combination with the checkpoint-blockade using anti-cytotoxic T-lymphocyte antigen-4 (CTLA4), the generated immunological responses will be able to attack remaining tumour cells in mice, useful in metastasis inhibition, and may potentially be applicable for various types of tumour models. Furthermore, such strategy offers a strong immunological memory effect, which can provide protection against tumour rechallenging post elimination of their initial tumours.
Hypoxia, a common feature within many types of solid tumors, is known to be closely associated with limited efficacy for cancer therapies, including radiotherapy (RT) in which oxygen is essential to ...promote radiation‐induced cell damage. Here, an artificial nanoscale red‐blood‐cell system is designed by encapsulating perfluorocarbon (PFC), a commonly used artificial blood substitute, within biocompatible poly(d,l‐lactide‐co‐glycolide) (PLGA), obtaining PFC@PLGA nanoparticles, which are further coated with a red‐blood‐cell membrane (RBCM). The developed PFC@PLGA‐RBCM nanoparticles with the PFC core show rather efficient loading of oxygen, as well as greatly prolonged blood circulation time owing to the coating of RBCM. With significantly improved extravascular diffusion within the tumor mass, owing to their much smaller nanoscale sizes compared to native RBCs with micrometer sizes, PFC@PLGA‐RBCM nanoparticles are able to effectively deliver oxygen into tumors after intravenous injection, leading to greatly relieved tumor hypoxia and thus remarkably enhanced treatment efficacy during RT. This work thus presents a unique type of nanoscale RBC mimic for efficient oxygen delivery into solid tumors, favorable for cancer treatment by RT, and potentially other types of therapy as well.
Artificial nanoscale red blood cells (RBCs) are fabricated by coating perfluorocarbon‐loaded nanoparticles with an RBC membrane. Upon intravenous injection, such nanoparticles, with efficient oxygen‐loading function, prolonged blood‐circulation time, and great extravascular diffusion ability, are able to effectively deliver oxygen into tumors, leading to greatly relieved tumor hypoxia and thus remarkably enhanced treatment efficacy during radiotherapy.
An emerging Internet application, IPTV, has the potential to flood Internet access and backbone ISPs with massive amounts of new traffic. Although many architectures are possible for IPTV video ...distribution, several mesh-pull P2P architectures have been successfully deployed on the Internet. In order to gain insights into mesh-pull P2P IPTV systems and the traffic loads they place on ISPs, we have undertaken an in-depth measurement study of one of the most popular IPTV systems, namely, PPLive. We have developed a dedicated PPLive crawler, which enables us to study the global characteristics of the mesh-pull PPLive system. We have also collected extensive packet traces for various different measurement scenarios, including both campus access networks and residential access networks. The measurement results obtained through these platforms bring important insights into P2P IPTV systems. Specifically, our results show the following. 1) P2P IPTV users have the similar viewing behaviors as regular TV users. 2) During its session, a peer exchanges video data dynamically with a large number of peers. 3) A small set of super peers act as video proxy and contribute significantly to video data uploading. 4) Users in the measured P2P IPTV system still suffer from long start-up delays and playback lags, ranging from several seconds to a couple of minutes. Insights obtained in this study will be valuable for the development and deployment of future P2P IPTV systems.
Hollow Bi2Se3 nanoparticles prepared by a cation exchange method are loaded with perfluorocarbon as an oxygen carrier. With these nanoparticles, a promising concept is demonstrated to enhance ...radiotherapy by not only using their X‐ray‐absorbing ability to locally concentrate radiation energy in the tumor, but also employing near‐infrared light to trigger burst release of oxygen from the nanoparticles to overcome hypoxia‐associated radio‐resistance.
The recent years have witnessed the blooming of cancer immunotherapy, as well as their combinational use together with other existing cancer treatment techniques including radiotherapy. However, ...hypoxia is one of several causes of the immunosuppressive tumor microenvironment (TME). Herein, we develop an innovative strategy to relieve tumor hypoxia by delivering exogenous H2O2 into tumors and the subsequent catalase-triggered H2O2 decomposition. In our experiment, H2O2 and catalase are separately loaded within stealthy liposomes. After intravenous (iv) preinjection of CAT@liposome, another dose of H2O2@liposome is injected 4 h later. The sustainably released H2O2 could be decomposed by CAT@liposome, resulting in a long lasting effect in tumor oxygenation enhancement. As the result, the combination treatment by CAT@liposome plus H2O2@liposome offers remarkably enhanced therapeutic effects in cancer radiotherapy as observed in a mouse tumor model as well as a more clinically relevant patient-derived xenograft tumor model. Moreover, the relieved tumor hypoxia would reverse the immunosuppressive TME to favor antitumor immunities, further enhancing the combined radio-immunotherapy with cytotoxic T lymphocyte-associated antigen 4 (CTLA4) blockade. This work presents a simple yet effective strategy to promote tumor oxygenation via sequential delivering catalase and exogenous H2O2 into tumors using well-established liposomal carriers, showing great potential for clinical translation in radio-immunotherapy of cancer.
Although silicon (Si) is ubiquitous in soil and plant, evidence is still lacking that Si is essential for higher plants. However, it has been well documented that Si is beneficial for healthy growth ...of many plant species. Si can promote plant mechanical strength, light interception, as well as resistance to various forms of abiotic and biotic stress, thus improving both yield and quality. Indeed, application of Si fertilizer is a rather common agricultural practice in many countries and regions. As the beneficial effects provided by Si are closely correlated with Si accumulation level in plant, elucidating the possible mechanisms of Si uptake and transport in plants is extremely important to utilize the Si-induced beneficial effects in plants. Recently, rapid progress has been made in unveiling molecular mechanisms of Si uptake and transport in plants. Based on the cooperation of Si influx channels and efflux transporters, a model to decipher Si uptake, transport and distribution system in higher plants has been developed, which involves uptake and radial transport in root, xylem and inter-vascular transport and xylem unloading and deposition in leaf. In this paper, we overviewed the updated knowledge concerning Si uptake, transport and accumulation and its significance for the major crops of agricultural importance and highlighted the further research needs as well.
Multiple pedestrian tracking (MPT) has gained significant attention due to its huge potential in a commercial application. It aims to predict multiple pedestrian trajectories and maintain their ...identities, given a video sequence. In the past decade, due to the advancement in pedestrian detection algorithms, Tracking-by-Detection (TBD) based algorithms have achieved tremendous successes. TBD has become the most popular MPT framework, and it has been actively studied in the past decade. In this paper, we give a comprehensive survey of recent advances in TBD-based MPT algorithms. We systematically analyze the existing TBD-based algorithms and organize the survey into four major parts. At first, this survey draws a timeline to introduce the milestones of TBD-based works which briefly reviews the development of the existing TBD-based methods. Second, the main procedures of the TBD framework are summarized, and each stage in the procedure is described in detail. Afterward, this survey analyzes the performance of existing TBD-based algorithms on MOT challenge datasets and discusses the factors that affect tracking performance. Finally, open issues and future directions in the TBD framework are discussed.
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