The establishment of either forest or grassland on degraded cropland has been proposed as an effective method for climate change mitigation because these land use types can increase soil carbon (C) ...stocks. This paper synthesized 135 recent publications (844 observations at 181 sites) focused on the conversion from cropland to grassland, shrubland or forest in China, better known as the ‘Grain‐for‐Green’ Program to determine which factors were driving changes to soil organic carbon (SOC). The results strongly indicate a positive impact of cropland conversion on soil C stocks. The temporal pattern for soil C stock changes in the 0–100 cm soil layer showed an initial decrease in soil C during the early stage (<5 years), and then an increase to net C gains (>5 years) coincident with vegetation restoration. The rates of soil C change were higher in the surface profile (0–20 cm) than in deeper soil (20–100 cm). Cropland converted to forest (arbor) had the additional benefit of a slower but more persistent C sequestration capacity than shrubland or grassland. Tree species played a significant role in determining the rate of change in soil C stocks (conifer < broadleaf, evergreen < deciduous forests). Restoration age was the main factor, not temperature and precipitation, affecting soil C stock change after cropland conversion with higher initial soil C stock sites having a negative effect on soil C accumulation. Soil C sequestration significantly increased with restoration age over the long‐term, and therefore, the large scale of land‐use change under the ‘Grain‐for‐Green’ Program will significantly increase China's C stocks.
Peptide‐based materials are one of the most important biomaterials, with diverse structures and functionalities. Over the past few decades, a self‐assembly strategy is introduced to construct ...peptide‐based nanomaterials, which can form well‐controlled superstructures with high stability and multivalent effect. More recently, peptide‐based functional biomaterials are widely utilized in clinical applications. However, there is no comprehensive review article that summarizes this growing area, from fundamental research to clinic translation. In this review, the recent progress of peptide‐based materials, from molecular building block peptides and self‐assembly driving forces, to biomedical and clinical applications is systematically summarized. Ex situ and in situ constructed nanomaterials based on functional peptides are presented. The advantages of intelligent in situ construction of peptide‐based nanomaterials in vivo are emphasized, including construction strategy, nanostructure modulation, and biomedical effects. This review highlights the importance of self‐assembled peptide nanostructures for nanomedicine and can facilitate further knowledge and understanding of these nanosystems toward clinical translation.
The recent progress in peptide‐based nanomaterials from building block peptides and self‐assembly driving forces to application‐directed ex situ and in situ construction of nanomaterials is systematically summarized. The advantages of intelligent in situ construction of peptide‐based nanomaterials in vivo are emphasized. The importance of self‐assembled peptide nanostructures for nanomedicine is highlighted.
Metal nanoparticles are being extensively used in biomedical fields due to their small size-to-volume ratio and extensive thermal stability. Gold nanoparticles (AuNPs) are an obvious choice for ...biomedical applications due to their amenability of synthesis, stabilization, and functionalization, low toxicity, and ease of detection. In the past few decades, various chemical methods have been used for the synthesis of AuNPs, but recently, newer environment friendly green approaches for the synthesis of AuNPs have gained attention. AuNPs can be conjugated with a number of functionalizing moieties including ligands, therapeutic agents, DNA, amino acids, proteins, peptides, and oligonucleotides. Recently, studies have shown that gold nanoparticles not only infiltrate the blood vessels to reach the site of tumor but also enter inside the organelles, suggesting that they can be employed as effective drug carriers. Moreover, after reaching their target site, gold nanoparticles can release their payload upon an external or internal stimulus. This review focuses on recent advances in various methods of synthesis of AuNPs. In addition, strategies of functionalization and mechanisms of application of AuNPs in drug and bio-macromolecule delivery and release of payloads at target site are comprehensively discussed.
An assembly‐induced retention effect for enhanced tumor photoacoustic (PA) imaging and therapeutics is described. A responsive small‐molecule precursor is prepared that simultaneously self‐assembles ...into nanofibers in tumor sites that exhibit an assembly‐induced retention effect, which results in an improved PA imaging signal and enhanced therapeutic efficacy. This successful proof‐of‐concept study paves the way to develop novel supramolecular biomaterials for cancer diagnostics and therapeutics.
Pollution by heavy metals limits the area of land available for cultivation of food crops. A potential solution to this problem might lie in the molecular breeding of food crops for phytoremediation ...that accumulate toxic metals in straw while producing safe and nutritious grains. Here, we identify a rice quantitative trait locus we name cadmium (Cd) accumulation in leaf 1 (CAL1), which encodes a defensin-like protein. CAL1 is expressed preferentially in root exodermis and xylem parenchyma cells. We provide evidence that CAL1 acts by chelating Cd in the cytosol and facilitating Cd secretion to extracellular spaces, hence lowering cytosolic Cd concentration while driving long-distance Cd transport via xylem vessels. CAL1 does not appear to affect Cd accumulation in rice grains or the accumulation of other essential metals, thus providing an efficient molecular tool to breed dual-function rice varieties that produce safe grains while remediating paddy soils.
Er3+,Yb3+ co‐doped LaF3‐TiO2 nanocomposites (UC‐TiO2) are inserted as a middle layer in a novel tri‐layer photoanode design (see Figure) of a dye‐sensitized solar cell (DSSC). The Er3+,Yb3+ co‐doped ...LaF3 part of the nanocomposite helps capture near‐infrared (NIR) light by converting it into visible light absorbable by the dye hence opening the road for the development of DSSCs with higher conversion efficiency and photocurrent output.
A pathology‐adaptive nanosystem, in which nest‐like hosts are built based on nanofibers that are transformed from i.v. injected nanoparticles under the acidic tumor microenvironment. The solid tumor ...is artificially modified by nest‐like hosts readily and firmly, resulting in highly efficient accumulation and stabilization of guest theranostics. This strategy shows great potential for the theranostics delivery to tumors.
Modulating the surface charge transport behavior of hole transport materials (HTMs) would be as an potential approach to improve their hole mobility, while yet realized for fabricating efficient ...photovoltaic devices. Here, an oxygen bridged dimer‐based monoamine FeIII porphyrin supramolecule is prepared and doped in HTM film. Theoretical analyses reveal that the polaron distributed on dimer can be coupled with the parallel arranged polarons on adjacent dimers. This polaron coupling at the interface of supramolecule and HTM can resonates with hole flux to increase hole transport efficiency. Mobility tests reveal that the hole mobility of doped HTM film is improved by 8‐fold. Doped perovskite device exhibits an increased efficiency from 19.8 % to 23.2 %, and greatly improved stability. This work provides a new strategy to improve the mobility of HTMs by surface carrier modulation, therefore fabricating efficient photovoltaic devices.
Modulating the charge‐transport behavior of hole‐transport materials (HTMs) is a path toward improved hole mobility and enhanced device properties when used in solar cells. Here, we design a porphyrin supramolecule to modulate the surface properties of the commonly used Spiro‐OMeTAD HTM in perovskite solar cells. Upon doping monoamine FeIII porphyrin into Spiro‐OMeTAD, the porphyrins self‐assemble into oxygen‐bridged dimer‐based supramolecules located at the grain boundaries of the HTM. The doped perovskite devices exhibit an increased efficiency from 19.8 % to 23.2 %, and greatly improved stability.
Safe disposal of solid wastes containing heavy metals is a significant task for environment protection. Immobilization treatment is an effective technology to achieve this task. Cementitious material ...treatments and thermal treatments are two types of attractive immobilization treatments due to that the heavy metals could be encapsulated in their dense and durable wasteforms. This paper discusses the heavy metal immobilization mechanisms of these methods in detail. Physical encapsulation and chemical stabilization are two fundamental mechanisms that occur simultaneously during the immobilization processes. After immobilization treatments, the wasteforms build up a low permeable barrier for the contaminations. This reduces the exposed surface of wastes. Chemical stabilization occurs when the heavy metals transform into more stable and less soluble metal bearing phases. The heavy metal bearing phases in the wasteforms are also reviewed in this paper. If the heavy metals are incorporated into more stable and less soluble metal bearing phases, the potential hazards of heavy metals will be lower. Thus, converting heavy metals into more stable phases during immobilization processes should be a common way to enhance the immobilization effect of these immobilization methods.
•The mechanisms of heavy metal immobilization are classified and summarized.•Chemical stabilization: converting heavy metal into less soluble or less toxic form.•Physical encapsulation: encapsulating heavy metals into low permeability wasteforms.•The phase transformation of heavy metal should be the focus of research on mechanism.
Folate (FA) receptor is a cell surface glycoprotein overexpressed on many cancer cells. It is a high affinity ligand for cancer cell targeting. However, delivery of siRNA directly through folate ...receptor mediated endocytosis for gene silencing has not, if any, been successful in clinical trial. We have reported the application of RNA nanotechnology to construct FA-displaying exosomes for efficient cell targeting, siRNA delivery and cancer regression (Pi et.al Nature Nanotechnology, 2018:13, 82–89; Li et al., Scientific Report, 2018:8, 14,644). However, the mechanism underlying the efficient therapeutic behavior through folate/exosome complex remains elusive. Here we demonstrate that the efficient cancer suppression with the FA-displaying exosome was due to the receptor-mediated cytosol delivery of the siRNA payload without endosome trapping, as attested by fluorescence colocalization analysis, gene knockdown assay and animal tumor regression. It is expected that the high potency of FA-displaying exosome in cytosolic siRNA delivery will renew the concept and interest in using FA as cancer targeting ligand in human cancer therapy.
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•Folate-displaying exosomes to avoid endosome trapping was demonstrated utilizing fluorescence microscopic techniques.•New evidence that FA-exosome fused with the cell membrane to release its payload into the cytosol was provided.•Displaying folate on exosome surface promoted the targeted delivery to tumors and enhanced the siRNA efficacy.
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