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The European Space Agency Climate Change Initiative Land Cover data (ESA CCI-LC, from 1992 to 2015) is introduced to the National Center for Atmospheric Research Community Earth System Model version 1.2.1 (NCAR CESM1.2.1). In comparison with the original land surface data in the Community Land Model version 4 (ORG), the new data features notable land use and land cover change (LULCC) with increased forests over northeastern Asia and Alaska by decreasing shrublands and grasslands. Overestimated bare land cover over the Tibetan Plateau (TP) and the Rocky Mountains in the ORG are corrected with the replacements by grasslands and shrublands respectively in the new data. The model simulation results show that with the introduction of the ESA CCI-LC, the simulated surface albedo, surface net radiation flux, sensible and latent heat fluxes are relatively improved over the regions where significant LULCC exists, such as northeastern Asia, Alaska, the TP, and Australia. Surface air temperature, precipitation, and atmospheric circulation are improved in boreal winter but degraded in summer. The winter warming over northeastern Asia results from increased longwave downwelling flux and adiabatic heating while the notable winter cooling over Alaska is attributed to strong cold advection followed by reduced longwave downwelling flux. LULCC alters precipitation by influencing water vapor content. In winter, LULCC affects atmospheric circulation via modulating baroclinicity while in summer, it influences land-sea thermal contrast, thus affecting the intensity of East Asian summer monsoon. LULCC also alters the simulated dust burden.

Small interfering RNA (siRNA)-based RNA interference has emerged as a promising therapeutic strategy for the treatment of a wide range of incurable diseases. However, the safe and effective delivery of siRNA therapeutics into the interior of target cells remains challenging. Here, we disclosed novel amphiphilic peptide dendrimers (AmPDs) that composed of hydrophobic two lipid-like alkyl chains and hydrophilic poly(lysine) dendrons with different generations (2C18-KK2 and 2C18-KK2K4) as nanovehicles for siRNA delivery. These AmPDs are able to self-assemble into supramolecular nanoassemblies that are capable of entrapping siRNA molecules into nanoparticles to protect siRNA from enzymatic degradation and promote efficient intracellular uptake without evident toxicity. Interestingly, by virtue of the optimal balance of hydrophobic lipid-like entity and hydrophilic poly(lysine) dendron generations, AmPD 2C18-KK2K4 bearing bigger hydrophilic dendron can package siRNA to form stable, but more ready to disassemble complexes, thereby resulting in more efficient siRNA releasing and better gene silencing effect in comparison with AmPD 2C18-KK2 bearing smaller dendron. Additional studies confirmed that 2C18-KK2K4 can capitalize on the advantages of lipid and peptide dendrimer vectors for effective siRNA delivery. Collectively, our AmPD-based nanocarriers indeed represent a safe and effective siRNA delivery system. Our findings also provide a new perspective on the modulation of self-assembly amphiphilic peptide dendrimers for the functional and adaptive delivery of siRNA therapeutics.

Fragile angular-shaped granular materials, such as calcareous sand, rockfill material, and ballast, show complex stress–strain–volumetric relationships due to the effects of particle breakage. This...

Annual land use land cover (LULC) change information at medium spatial resolution (i.e. at 30 m) is required in numerous subjects, such as biophysical modelling, land management and global change studies. Annual LULC information, however, is usually not available at continental or national scale due to reasons such as insufficient remote sensing data coverage or lack of computational capabilities. Here we integrate high temporal resolution and coarse spatial resolution satellite images (i.e., Moderate Resolution Imaging Spectroradiometer (MODIS) and Global Inventory Modelling and Mapping Studies (GIMMS) normalized difference vegetation index (NDVI)) with high spatial resolution datasets (China’s Land-Use/cover Datasets (CLUDs) derived from 30-meter Landsat TM/ETM+/OLI) to generate reliable annual nominal 30 m LULC maps for the whole of China between 1980 and 2015. We also test the performance of a statistical based change detection algorithm (Breaks for Additive Seasonal and Trend), originally designed for tracking forest change, in classifying all-type LULC change. As a result, a nominal 30 m annual land use/land cover datasets (CLUD-A) from 1980 to 2015 was developed for the whole China. The mapping results were assessed with a change sample dataset, a regional annual validation sample set and a three-year China sample set. Of the detected change years, 75.61% matched the exact time of conversion within ±1 year. Annual mapping results provided a detail process of urbanization, deforestation, afforestation, water and cropland dynamics over the past 36 years. The consistent characterization of land change dynamics for China can be further used in scientific research and to support land management for policy-makers.

Apoptotic peptide (kla), which can trigger the mitochondria-mediated apoptotic programmed cell death, has been widely recognized as a potential anticancer agent. However, its therapeutic potential has been significantly impaired by its poor biostability, lack of tumor specificity, and particularly low cellular uptake. Herein, a linear peptide Arg-Trp-d-Arg-Asn-Arg (RWrNR) was identified as an integrin αvβ3 specific ligand with a nanomolar dissociation constant (Kd = 0.95 nM), which can greatly improve kla antitumor activity (IC50 = 8.81 μM) by improving its cellular uptake, compared to the classic integrin-recognition motif c-RGDyK (IC50 = 37.96 μM). Particularly, the RWrNR-kla conjugate can be entrapped in acidic sensitive nanogels (RK/Parg/CMCS-NGs), composed of poly-l-arginine (Parg) and carboxymethyl chitosan (CMCS, pI = 6.8), which can not only carry out controlled release of RWrNR-kla in response to the tumor acidic microenvironment, and consequently enhance its tumor specificity and cell internalization, but also trigger tumor-associated macrophages to generate nitric oxide, leading to enhanced synergistic anticancer efficacy. Importantly, RK/Parg/CMCS-NGs have been proven to effectively activate the apoptosis signaling pathway in vivo and significantly inhibit tumor growth with minimal adverse effects. To summarize, RK/Parg/CMCS-NGs are a promising apoptotic peptide-based therapeutics with enhanced tumor accumulation, cytosolic delivery, and synergistic anticancer effects, thereby holding great potential for the treatment of malignant tumors.

A tricomponent catalyst comprising titanium tetrachloride, triisobutyl aluminum and diphenyl ether is developed for the highly cis-1,4-selective polymerization of isoprene. The influence of the content of diphenyl ether and its complexation order on polymerization, microstructure and performance of polyisoprene are studied. The polyisoprene synthesized presents high monomer conversion (91–99%). With the increasing of diphenyl ether content, intrinsic viscosity and viscosity-average molecular weight of polyisoprene increase. The molar percentage of cis-1,4-unit is almost unaffected by diphenyl ether and different complexation sequence. The polyisoprene reveals comparable Tg (–61.31°C) and mechanical strengths (11.14 MPa, 667%) to commercially available LHIR-80 synthesized with neodymium. However, the viscosity and viscosity-average molecular weight of the former are lower than that of the latter, which avails the processability and maintains excellent mechanical properties.

Light scattering has been used for label-free cell detection. The angular light scattering patterns from the cells are unique to them based on the cell size, nucleus size, number of mitochondria, and cell surface roughness. The patterns collected from the cells can then be classified based on different image characteristics. We have also developed a machine learning (ML) method to classify these cell light scattering patterns. As a case study we have used this light scattering technique integrated with the machine learning to analyze staurosporine-treated SH-SY5Y neuroblastoma cells and compare them to non-treated control cells. Experimental results show that the ML technique can provide a classification accuracy (treated versus non-treated) of over 90%. The predicted percentage of the treated cells in a mixed solution is within 5% of the reference (ground-truth) value and the technique has the potential to be a viable method for real-time detection and diagnosis.

The Northeast China Plain is one of the major grain-producing areas of China because of its fertile black soil and large fields adapted for agricultural machinery. It has experienced some land-use changes, such as urbanization, deforestation, and wetland reclamation in recent decades. A comprehensive understanding of these changes in terms of the total cropping land and its heterogeneity during this period is important for policymakers. In this study, we used a series of cropland products at the 30-m resolution for the period 1980–2015. The heterogeneity for dominant cropland decreased slowly over the three decades, especially for the large pieces of cropland, showing a general trend of increased cropland homogeneity. The spatial patterns of the averaged heterogeneity index were nearly the same, varying from 0.5 to 0.6, and the most heterogeneous areas were mainly located in some separate counties. Cropland expansion occurred across most of Northeast China, while cropland shrinking occurred only in the northern and eastern sections of Northeast China and around the capital cities, in the flat areas. Also, changes in land use away from cropland mainly occurred in areas with low elevation (50–200 m) and a gentle slope (less than 1 degree). The predominant changes in cropland were gross gain and homogeneity, occurring across most of the area except capital cities and boundary areas. Possible reasons for the total cropland heterogeneity changes were urbanization, restoration of cropland to forest, and some government land-use policies. Moreover, this study evaluates the effectiveness of cropland policies influencing in Northeast China.

CAM16 colour appearance model has been extended to predict the appearance for stimulus of varying sizes and to provide new scales to evaluate saturation, vividness, whiteness and blackness.

Quantifying the spatiotemporal change of land cover and understanding their ecological, environmental, and socioeconomic impacts are important for sustainable development. Surface mining by the minerals industry is one driver of the changes in land cover, leading to loss of natural vegetation and top soils, and interruption of ecosystem service flows. This study investigates the effectiveness of remote sensing datasets to identify and map land cover changes, with the specific goal of understanding the impact of surface mining activities on land cover globally from 1980s to 2013. Diverse remote sensing datasets with long term observations are analyzed, including high-resolution images in Google Earth, Landsat Thematic Mapper (TM)/Enhanced Thematic Mapper Plus (ETM+)/Operational Land Imager (OLI), the Moderate Resolution Imaging Spectroradiometer (MODIS) Vegetation Index (VI) product and Defense Meteorological Satellites Program (DMSP)/Operational Linescan System (OLS) stable night-time light. The results indicated that after entering 21st century, North America (e.g., the United States and Canada) was the only continent to have more surface mining spots categorized as Shrink type (rehabilitated) rather than Expand type. South America (e.g., Chile and Brazil) and Asia (e.g., India and China) had the highest proportions of Expand Type of surface mining spots. Detailed demonstrations on how those remote sensing datasets could help in mining spot monitoring are presented.

Land use/land cover change is a continuing research focus, not only because of its ecological and environmental effects but also because of the difficulties with accurate change detection and analy...

It is not easy in remote sensing field to distinguish corn and soybean mapping for the similarity of the mixed summer crops. To understand the variations better and generate corn and soybean maps m...

In recent decades, palm oil, which forms one of the world’s major bulk feedstock and oil crops, has been cultivated at an increasing scale to meet new demand. Oil palm expansion has driven not only...

Organozirconiums had been studied as the peroxyl radical scavenger in UV-curing coatings, which had varied performance in overcoming oxygen inhibition. Herein we modified the complex of zirconium with organic fluorides in order to increase its efficiency of peroxyl radical scavenging. A formulation consists of two conventional monomers (Ebercyl 270 and TPGDA) and an oxygen-sensitive photoinitiator TPO was employed in this study. With different content added in the formulation, the UV-cured coatings had different depth conversion profiles, which were measured by confocal Raman microscopy. Moreover, the standing time for the enrichment of fluorinated organozirconium products to the surface of the coatings and two irradiation sources (Hg-Xe lamp and UV-LED lamp) were adopted to emphasize their properties against oxygen inhibition. Finally, it is shown that fluorinated organozirconiums can lead to tack-free coatings, while the cured films from neat formulation remain tacky.

The fabrication of polystyrene-grafted nanosilica (SiO 2 − g −PS) via nitroxide radical coupling (NRC) reaction was presented in this study. First, nanosilica anchored with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-based nitroxide radicals was synthesized by hydrolysis-condensation reaction between TEMPO-based nitroxide radical functional triethoxysilyl coupling agents and nanosilica. Then, the pre-synthesized, well-defined PS with bromide end group which was obtained by atom-transfer radical polymerization (ATRP) was grafted onto the functionalized nanosilica in the presence of CuBr/PMDETA. The structure, surface morphologies and particle size of the obtained hybrid nanoparticles were investigated by characterization methods The grafting yield by this method achieved up to 37.5% in the given conditions, which is approximated to the ones obtained by ‘grafting to’ route. A comprehensive study of UV-curable formula based on acrylates/polymer-grafted nanosilica were also discussed to find a possible correlation among the viscosity, curing kinetics, mechanical and thermal properties of the final hybrid organic-inorganic coatings.

The free availability of decametre global satellite images and high-performance supercomputing provides opportunities for the development of many global products, including land cover, forest change, water, and cropland. However, some regions are particularly hard to map. Identification of these regions aids the understanding of map accuracy issues. In this study, we analysed seven maps produced with different algorithms/approaches but using the same classification system and training samples. A common validation dataset was used to identify regions incorrectly classified by all maps. These were defined as difficult to map regions (DMRs). They covered around 16% of the world’s ice-free terrestrial areas. Our analysis indicated that (1) grassland, shrubland, forest, and cropland were the most common land-cover types that could not be correctly classified, but impervious surfaces had the greatest proportion of misclassification; (2) incorrect classification mainly occurred in tropical/subtropical gr...

A series of UV-curable flexible hyperbranched polyurethane acrylate (F-HBPUA) with various generation numbers and soft chains are successfully developed by modifying different generations of hydroxyl terminated hyperbranched polyurethane (HBPU-OH) with diverse soft chains contained semiadduct urethane monoacrylate. The influence of generation number and soft chain on the performances of F-HBPUA and its UV-cured freestanding film is studied. The degree of branching of F-HBPUA from the second to the fifth generation is proved to be 0.74, 0.79, 0.82 and 0.94, respectively. The glass transition temperature of F-HBPUA increases with increasing generation number but it decreases with the increase of soft chain length. The thermal stability of F-HBPUA improveswith higher generations while the longer soft chain is only beneficial to the heat resistance at below 300 °C. As the increase of generation number and chain length, the UV-curing time of F-HBPUA film is significantly shortened from 12 s to 3 s, the flexibility of the UV-cured film is greatly increased from 4 mm to 1 mm, adhesion is improved to 3 grades. This novel flexible hyperbranched polyurethane acrylates can be applied to coatings, membranes and 3D print parts with excellent flexibility.

The aim of this study was to investigate the chemical components, antimicrobial, antioxidative, anti-inflammatory and antitumor activities of essential oils from Curcuma aromatica Salisb. rhizomes collected from 12 different habitats in China. The chemical composition analysis of the 12 essential oils by gas chromatography-mass spectrometer (GC–MS) led to the identification of 78 components, and the dominant compounds were 8,9-dehydro-9-formyl-cycloisolongifolene (2.66–36.83%), germacrone (4.31–16.53%), ar -turmerone (2.52–17.69%), turmerone (2.62–18.38%), ermanthin (0.75–13.26%), β-sesquiphyllandrene (0.33–11.32%) and ar -curcumene (0.29–10.52%). Furthermore, the 12 essential oils displayed different 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities (IC 50 , 1.57–21.36 μg/ml), and most of them were superior to Trolox C (IC 50 , 8.82 μg/ml). Their antimicrobial activities against fungus were far higher than against bacteria, and essential oils of rhizomes collected from Guangxi, Zhejiang or Sichuan showed the better activities against different microorganisms. They also exhibited antitumor activities (IC 50 , 30.66–259.62 μg/ml) against melanoma cells (B16) and prostate cancer cells (LNCaP), and anti-inflammatory action by significantly down-regulating expression of tumor necrosis factor-α (TNF-α) and cyclo-oxygenase-2 (COX-2) in vivo . On the whole, the compositions and bioactivities of these essential oils were different from each other. Hence, it is hoped that, from these results, C. aromatica rhizomes from different habitats should be used more rationally and effectively as natural pharmaceutical, culinary and cosmetic additives in the future.

Despite being a mainstay of clinical cancer treatment, chemotherapy is limited by its severe side effects and inherent or acquired drug resistance. Nanotechnology-based drug-delivery systems are widely expected to bring new hope for cancer therapy. These systems exploit the ability of nanomaterials to accumulate and deliver anticancer drugs at the tumor site via the enhanced permeability and retention effect. Here, we established a novel drug-delivery nanosystem based on amphiphilic peptide dendrimers (AmPDs) composed of a hydrophobic alkyl chain and a hydrophilic polylysine dendron with different generations (AmPD KK2 and AmPD KK2K4). These AmPDs assembled into nanoassemblies for efficient encapsulation of the anti-cancer drug doxorubicin (DOX). The AmPDs/DOX nanoformulations improved the intracellular uptake and accumulation of DOX in drug-resistant breast cancer cells and increased permeation in 3D multicellular tumor spheroids in comparison with free DOX. Thus, they exerted effective anticancer activity while circumventing drug resistance in 2D and 3D breast cancer models. Interestingly, AmPD KK2 bearing a smaller peptide dendron encapsulated DOX to form more stable nanoparticles than AmPD KK2K4 bearing a larger peptide dendron, resulting in better cellular uptake, penetration, and anti-proliferative activity. This may be because AmPD KK2 maintains a better balance between hydrophobicity and hydrophilicity to achieve optimal self-assembly, thereby facilitating more stable drug encapsulation and efficient drug release. Together, our study provides a promising perspective on the design of the safe and efficient cancer drug-delivery nanosystems based on the self-assembling amphiphilic peptide dendrimer.

Biodiversity conservation is the cornerstone for sustainable development. Bold conservation targets provide the last opportunities to halt the human-driven mass extinction. Recently, bold conservation targets have been proposed to protect 30% or 50% of Earth. However, little is known about its potential impacts on cropland. We identify potential cropland losses when 30% and 50% of global terrestrial area is given back to nature by 2030/2050, at three spatial scales (global, biome and country) and using two approaches (“nature-only landscapes” and “shared landscapes”). We find that different targets, applied scales and approaches will lead to different cropland losses: (1) At the global scale, it is possible to protect 50% of the Earth while having minimum cropland losses. (2) At biome scale, 0.64% and 8.54% cropland will be lost globally in 2030 and 2050 under the nature-only approach while by contrast, the shared approach substantially reduces the number of countries confronted by cropland losses, demanding only 0% and 2.59% of global cropland losses in 2030 and 2050. (3) At the national scale, the nature-only approach causes losses of 3.58% and 10.73% of global cropland in 2030 and 2050, while the shared approach requires 0.77% and 7.55% cropland in 2030 and 2050. Our results indicate that bold conservation targets could be considered, especially when adopting the shared approach, and we suggest adopting ambitious targets (protecting at least 30% by 2030) at the UN Biodiversity Conference (COP 15) to ensure a sustainable future for Earth.

The thiol-epoxy click chemistry is promising for microelectronic packaging due to its outstanding properties, while there is little knowledge on silicone/epoxy composite fabricated via this approach. Herein, a thiol-functionalized silicone resin (MDT-SH) is synthesized and compounded with epoxy resin to form silicone/epoxy composite. The thermal-curing behaviors, mechanical properties and LED encapsulation of the developed composite are studied detailedly. The thermal-curing kinetics indicate that the thiol-epoxy polymerization in silicone/epoxy composite tends more to the first-order reaction and its active energy is about 60.3 kJ/mol. The mechanical properties of the composite are varied with the molecular structure of MDT-SH and thiol/epoxy ratio. Moreover, the composite has excellent transparency in visible region, and its transparency is little affected by thermal and UV ageing. More importantly, the transparency is only slightly decreased after the composite is serviced at normal temperature and pressure for 2 years. The light output power of LEDs encapsulated by this composite is comparable to the commercial counterparts like Dow Corning OE-6550, but its thermal-curing time and temperature are much lower than the latter, contributing to cost reduction. Therefore, this silicone/epoxy composite based on thiol–epoxy click chemistry would greatly improve the microelectronic packaging.

An excellent biocompatible nitrogen-doped carbon dots (N-CDs) was successfully synthesized from orange juice and ethylenediamine by hydrothermal decomposition method. The as-prepared N-CDs were mono-dispersed spherical nanoparticles with a narrow size distribution of 0.5–3.0 nm and showed a good dispersion and stability in aqueous solution with the pH value ranging from 3.0 to 13.0. Photoluminescence spectra of as-prepared N-CDs demonstrated that the fluorescence intensity of N-CDs was increased with the doped nitrogen atoms and the FL-QY (fluorescence quantum yield) of N-CDs was up to 31.7%. Compared with Gly-CQDs(CQDs synthesied by Gly), which were prepared from chemical carbon source via hydrothermal decomposition method, the as-prepared N-CDs showed much lower cytotoxicity for Human THP-1 macrophage cells. These results indicated N-CDs prepared by our proposed method have excellent compatibility and more suitable for the application in biolabeling and bioimage. Due to the fluorescence quenching of N-CDs by mercury (II) ion (Hg2+), a sensitive and selective method was developed for detecting Hg2+. The results indicated that the fluorescence intensity ratio of N-CDs was proportional to the concentration of Hg2+ in the range from 4.0 μg/mL to 32.0 μg/mL and the recovery of spiked samples was ranged from 102.0% to 103.0%, which hinted our proposed method has a good sensitivity and accuracy and was suitable for detecting Hg2+ with satisfactory in tap water.

We report the world’s first all-season training and validation sample sets for global land cover classification with Landsat-8 data. Prior to this, such samples were only available at a single date primarily from the growing season. It is unknown how much limitation such a single-date sample has to mapping global land cover in other seasons of the year. To answer this question, we selected available Landsat-8 images from four seasons and collected training and validation samples from them. We compared the performances of training samples in different seasons using Random Forest algorithm. We found that the use of training samples from any individual season would result in the best overall classification accuracy when validated by samples in the same season. The global overall accuracy from combined best seasonal results was 67.2% when classifying the 11 Level-1 classes in the Finer Resolution Observation and Monitoring of Global Land Cover (FROM-GLC) classification system. The use of training samples from all seasons (named all-season training sample set hereafter) produced an overall accuracy of 67.0%. We also tested classification within 10° latitude 60° longitude zones using all-season training subsample within each zone and obtained an overall accuracy of 70.2%. This indicates that properly grouped subsamples in space can help improve classification accuracies. All the results in this study seem to suggest that it is possible to use an all-season training sample set to reach global optimality with universal applicability in classifying images acquired at any time of a year for global land cover mapping.

In this study, we prepared a novel triblock copolymer, PDMS-b-(PMAEBB-co-PDMAEMA)2 (tri-PI) bearing side-chain benzophenone (BP) and coinitiator amine, as a macro-photoinitiator via reversible addition-fragmentation chain transfer (RAFT) copolymerization of the polymerizable photoinitiator 2-(methacryloyloxy)ethyl-2-benzoylbenzoate (MAEBB) and the unsaturated coinitiator amine 2-(dimethylamino)ethyl methacrylate (DMAEMA) with a bifunctional polydimethylsiloxane (PDMS) macro-chain transfer agent (macro-CTA). The structure of synthesized copolymer was confirmed by Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). The effects of the photoinitiator/coinitiator ratio, concentration, and photoinitiator systems on the photopolymerization kinetics of tri(propylene glycol) diacrylate (TPGDA) were investigated by real-time FT-IR. The mobility of the tri-PI chain segments was proven by X-ray photoelectron spectroscopy (XPS), and the surface morphology of TPGDA curing coatings was studied by scanning electron microscopy (SEM). Results showed that tri-PI strongly suppressed the effect of oxygen inhibition on the photopolymerization system. Tri-PI was also used in the curing of UV-curable waterborne polyurethane acrylate (UV-WPUA) resin to determine its versatility.

A new xanthone, 2,8-dihydroxy-9-oxo-9H-xanthene-6-carboxylic acid (1), together with six known compounds, 2,8-dihydroxy-1-methoxycarbonyl-9-oxo-9H-xanthene-6-carboxylic acid (2), 8-hydroxy-3-methyl-9-oxo-9Hxanthene-1-carboxylic acid methyl ether (3), 1,3,6-trihydroxy-8-methylxanthone (4), 1,6-dihydroxy-3-methoxy-8-methylxanthone (5), decarboxycitrinone (6), and formoic acid A (7), were isolated from an endophytic fungus Arthrinium arundinis of Anoectochilus roxburghii. Compounds 2, 3, 5–7 were also isolated from this genus for the first time.

Exogenous antigens processed in the cytosol and subsequently cross-presented on major histocompatibility complex class I (MHC-I) molecules activate cytotoxic CD8+ lymphocytes (CTL), which are crucial in cancer immunotherapy. Here, we reported a nanovaccine, which was produced by encapsulating OVA (ovalbumin, a model antigen) chemically modified with MPGΔNLS (MPGΔNLS-OVA conjugate) into poly(lactide-co-glycolide) acid (PLGA) nanoparticles. We hypothesized that after the uptake of the nanovaccine into immune cells, MPGΔNLS, a cell-penetrating peptide (CPP), would assist the escape of the antigens from lysosomes into the cytosol, increase the amount of antigens processed in the cytosol and subsequently enhance antigen cross-presentation via MHC-I molecules to elicit cytotoxic CD8+ T cell responses. The results of the in vitro experiments demonstrated that the MPGΔNLS-OVA-loaded PLGA NPs not only elevated the release of OVA into the cytosol of dendritic cells (BMDCs), but also promoted the maturation and activation of BMDCs. It was also observed in mice vaccinated with MPGΔNLS-OVA-loaded PLGA NPs that the MPGΔNLS modification could stimulate the expansion of OVA-specific T-cells, generation of OVA-specific IgG antibodies and proliferation of OVA-specific memory T cells. Moreover, the treatment of E·G7-OVA tumor-bearing mice with MPGΔNLS-OVA-loaded PLGA NPs resulted in significantly suppressed tumor growth and prolonged survival periods of the mice compared to the treatment with unmodified OVA-PLGA NPs or free OVA. In summary, cell-penetrating peptides linked with antigens encapsulated in nanovaccines can spatiotemporally affect the intracellular localization of antigens, promote antigen cross-presentation and stimulate antigen-specific immune responses, especially CTL responses. Therefore, the CPP modification on antigens is an innovative approach to enhance the efficacy of nanovaccines for cancer immunotherapy.

Northeast China is a major grain production area, an ecological important forest area, and the largest old industrial base which is now suffering from economic growth slowdown and brain drain. Accurate and long-term dynamic land cover maps are highly demanded for many regional applications. In this study, we developed a set of continuous annual land cover mapping product at 30 m resolution using multi-temporal Landsat images. The maps in year 2000 and 2015 were tested using another independent validation dataset and the overall accuracies were 80.69% and 88.38%, respectively. The accuracies of the maps were improved by the integration of multi-temporal Landsat images and post-classification strategies. We found a general trend that the total area of land that experienced a change in land cover each year increased over time. The area change of each land cover type is also detected. The area of forests was 3.92 × 10 5 km 2 in 1986, fluctuated under fire disturbance, but declined in a quite high rate over the period of 1989 to 2006, and finally stayed relatively stable in area around 3.58 × 10 5 km 2 . The expansion of croplands was the leading land cover change from 1986 to 2000, and then the total area of croplands slightly declined under the Grain to Green Project of China, while shrublands, grasslands and wetlands began to increase. The area of impervious surfaces increased by more than 502% during the last three decades, and about 73% of the new built-up area was converted from croplands. We also demonstrated the our maps could capture the important land cover conversion processes, such as urbanization, forest logging activities, and agricultural expansion.

Superhydrophobic sponge as potential absorbing material for oil/water separation is attracting great attention recently. However, there are still some challenges to feasibly fabricate superhydrophobic sponge with large scale and low cost. Herein, a novel photochromic superhydrophobic melamine sponge (PDMS-SP sponge) is fabricated by facilely dip-coating and thermocuring of hydroxyl-terminated polydimethylsiloxanes mixed with photochromic spiropyran. FT-IR, EDS, and XPS results confirm the successful coating of PDMS-SP upon melamine sponge. The resultant sponge not only possesses excellent water repellency with a contact angle of 154.5° and oil-water separation efficiency with an oil absorption capacity of 48–116 folds of itself weight, but also shows photochromic phenomenon between colorless and purple when it is successively exposed to UV irradiation and visible light.

The precursor zirconium oxychloride octahydrate (ZrOCl2·8H2O) was firstly used to prepare clear and transparent zirconia sol via an auto-hydrolysis sol-gel method without the water. Triethylamine (TEA) and dimethylaminoethyl methacrylate (DMAM) were used as acid binding agents to control the pH value in the sol-gel process. Silane coupling agent, acetylacetone (acac) and isopropyl tri(dioctyl)pyrophosphato titanate (titanate coupling agent, NDZ-201) were utilized to protect the zirconia nanoparticles and improve the interaction between the organic network and inorganic component in UV-curing hybrid coatings. The hydrolysis and condensation processes were monitored by FT-IR. The particle size and distribution of zirconia sol with different coupling agents were evaluated by the transmission electron microscopy (TEM). The Scanning electron microscopy (SEM) indicated that the particle size was smaller and had a more uniformity dispersion when NDZ-201 was used. An organic/inorganic interpenetrating network (IPN), which was based on polyacrylate and zirconia nanoparticles, was probably formed by the proper ratio of acrylates to zirconia sol during the UV-curing process. Thermal Mechanical Analysis (TMA) results showed that the IPN structure had a higher Tg. Notably, the hardness and flexibility of the UV-curing hybrid coatings were simultaneously improved compared with the UV-curing pure organic polymer.

A kind of spiropyran derivatives, 1-chloro-3-(3′,3′-dimethyl-6-nitrospiro[chromene-2,2′-indolin]-1′-yl)propan-2-ol (CSP), was synthesized and characterized by FT-IR, 1H NMR, EI-MS, which contained the spiropyran moiety. The photochromism and solvatochromism in the diverse solvents were investigated in details. The polarity of the solvent played a crucial effect on the absorbance of the ring open form (MC) for CSP, characterized by using the relative polarity and Reichardt's empirical solvent polarity parameter (ET(30)). The fatigue resistance was evaluated by the number of cycles required to reduce the initial absorbance at λmax by 50% (Z50). Entrapment of the radical-scavengers such as butylated hydroxyl toluene (BHT) and 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) practically enhanced the duration of CSP and protected most of the molecules from further oxidation in acetone. The parameter Z50 in ethyl acetate was 534 and was much higher than the others. However, it reached to more than 1200 when CSP was doping in the epoxy resin on OPP film. It indicated that the CSP could be applied in the flexible substrate for foods and medicine package.

Two types of photoactive polymers with an alkoxyphenyl ketone moiety at their backbone centers were synthesized through atom transfer radical polymerization. A facile protocol for preparing α,ω-heterotelechelic polymers was developed, employing nitroxide with different functional groups (e.g., hydroxyl, propargyl, glycidyl, and polyethylene glycol) coupled with macromolecular radicals generated via the Norrish-type I photoreaction under mild UV irradiation from the said polymers. Experimental conditions such as solvent effects and irradiaton time were investigated to optimize the efficiency of reaction functionality. The number-average molecular weights of the photoactive polymers and α,ω-heterotelechelic polymers were determined by gel permeation chromatography. Material structures were further confirmed by 1H NMR and FT-IR spectroscopy. The end group activity of α,ω-heterotelechelic polymers obtained from this reaction was further demonstrated using the Cu-catalyzed azide–alkyne click reactions between PS-N3 and polystyrene capped with a propargyl group.

4-Acryloyl-1,2,2,6,6-pentamethyl-piperidinol (APMP) is a reactive hindered amine that prolongs the service life of the polymeric materials and exhibits high stability, good resistance to extraction, and low toxicity. In this paper, a photoinduced free radical copolymerization of APMP and methyl methacrylate (MMA) is accomplished at ambient temperature in solution. APMP plays a key role in the copolymerization, owing to the nitroxides generated in situ from the moiety of 1,2,2,6,6-pentamethyl-piperidine under UV irradiation, and mediates the copolymerization, which is confirmed by the linear kinetics. With the increment of initial monomer feed ratios of APMP/MMA, both the copolymerization rate and the average molecular weight increase. According to the reactivity ratios from the extended Kelen-Tüdos (KT) method at high conversion by1H NMR spectroscopy, a nonlinear model is established and the sequential distribution in the copolymers is also investigated. The dispersion of APMP units is regulated by the feed ratios and reactivity ratios.

Various intrinsic self-healing silicone elastomers have been developed by incorporating different dynamic noncovalent or covalent bonds into elastomeric crosslinked networks. However, these self-healable silicone elastomers are either nontransparent or nonresistant to hydrolysis. In this study, a transparent and hydrolysis-resistant silicone elastomer with self-healability, reprocessability and 3D printability is facilely fabricated by successively thiol-ene UV-curing between thiol and vinyl functionalized polysiloxanes, and thermocuring between carboxyl and amido functionalized polysiloxanes. These obtained elastomers show an excellent healing efficiency of 97%, and the healing processes are repeatable for many times. Moreover, these elastomers can be repeatedly reprocessed with a recovery of 90% of virgin mechanical strengths, and the reprocessed elastomers can still repair damages with an efficiency over 90%. These self-healing and reprocessing behaviors mainly derive from the rearrangement of crosslinked networks via reversible breakage and reformation of ionic bonds. Importantly, the silicone elastomers are transparent with a transmittance of over 90% in visible light and hydrolysis-resistant to hydro-thermal treatment. Besides, the silicone elastomers can be fabricated into various self-healable architectures via 3D printing. Therefore, a feasible approach is provided to impart reversible ionic association induced self-healing and reprocessing to 3D printable silicone elastomers.

The combination of organic and inorganic components has become an challenging for the generation of new materials with preeminent properties over pure constituents. In the present work, a novel hybrid photoinitiator for free radical photopolymerization, belonging to the thioxanthone derivatives, was obtained via chemical joint between silica and 2-chlorothioxanthone (CTX) under a mild preparation condition. This multifunctional supported photoinitiator (silica-s-CTX) can not only initiate the photopolymerization with higher efficiency than traditional photoinitiator CTX, but also prominently improve the dispersion of nanoparticles in the epoxy acrylates resin which brings to the preeminent mechanical properties of UV-cured coatings. Importantly, the amount of residual-free PIs in silica-s-CTX curing system shows a significant decrease comparing with the filled and unfilled CTX curing system. After endowing the silica nanoparticles with photo-initiated performance, it may offer new scientific and technological opportunities for the preparation of high performance UV-curing coatings.

Drug resistance is a major hindrance in the anticancer treatment, which encourages the development of effective therapeutic strategies. For the first time, MDM2-mediated p53 degradation was identified as a critical factor for developing acquired resistance of doxorubicin (DOX) in HepG2 tumor spheroids, which could be effectively reversed by MDM2 inhibitor MI-773, thereby improving anticancer effects. Therefore, a pH-sensitive liposomal formulation of DOX and MI-773 (LipD/M@CMCS) were developed for recovering p53-mediated DOX resistance in hepatocellular carcinoma. LipD/M@CMCS were composed of cationic liposomes covered with carboxymethyl chitosan (pI = 6.8), and were stable in the physiological condition (pH 7.4), but rapidly converted to cationic liposomes in tumor acidic microenvironment (pH 6.5), endowing them with tumor specificity and enhanced cellular uptake. We showed that LipD/M@CMCS could not only effectively induce cell apoptosis in HepG2 tumor spheroids, but significantly inhibit tumor growth with minimal adverse effects. In summary, selective regulation of MDM2 in cancer cells is a promising strategy to overcome DOX resistance, and may provide a perspective on the management of malignant tumors.

In this study, spiropyran (SP)-containing fluorinated polyacrylate (F-PA–SP) latex was prepared by emulsion polymerization using fluorinated and SP-based acrylic monomers as raw materials. Fourier transform infrared and 1H NMR demonstrate that the F-PA–SP copolymer has been successfully synthesized, and dynamic light scattering and transmission electron microscopy analyses indicate that the synthesized latex has presented a uniform particle size of approximately 200 nm. X-ray photoelectron spectroscopy, atomic force microscopy, and water contact angle (WCA) analyses were used to investigate the surface properties of the F-PA–SP coating and demonstrate that its hydrophobicity is enhanced by the addition of a fluorinated acrylic monomer. The photochromic properties of the coating were investigated by UV/vis spectroscopy, and the results reveal that the F-PA–SP coating possesses better photoresponsiveness, fatigue resistance, and photoreversibility under UV/vis irradiation than the coating prepared using flu...

Long-term time series of spatially explicit cropland maps are essential for global crop modelling and climate change studies. The spatial resolution and temporal continuity of global cropland maps ...

A biocompatible silicone elastomer that can be UV-cured and 3D printed via thiol-ene photopolymerization between vinyl and thiol functionalized polysiloxanes is explored in this study. The in-situ photo-rheology demonstrates that the photo-crosslinking of silicone elastomer occurs instantaneously upon exposure to UV radiation and its gelation time is influenced synergically by thiol-ene molar ratio, photoinitiator dosage and UV irradiation intensity. Differential scanning photo-calorimeter results indicate that UV-initiated thiol-ene photoreaction preferably follows a second-order reaction kinetics and its activation energy is approximately 23.3 kJ/mol. Moreover, antibacterial assay shows thiol-ene UV-cured silicone elastomer can inhibit the growth of Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria to some extent. Cytotoxicity and biocompatibility results reveal that this silicone elastomer also has good biocompatibility, and it used as wound dressing is conducive to the recovery of wounds. Furthermore, due to excellent spatiotemporal controllability of thiol-ene photoreaction, various elaborate architectures are fabricated by photo-patterning. On the other hand, this UV-curable formulation can also be 3D printed into various structures with smooth surface and good accuracy. These results propose that thiol-ene UV-curable silicone elastomer will be a promising material in biomedical applications as wound dressings or customized soft tissue scaffolds through 3D printing.

In the title compound, the symmetry-unique terminal CuII ion is O,N,N′-coordinated by a 2-{[(2,2,6,6-tetra­methyl­piperidin-4-yl)imino]­meth­yl}phenolate ligand and an O atom from an acetate group in a slightly distorted tetra­hedral coordination environment. The symmetry-unique central CuII ion is coordinated by a different O atom of the same acetate group and by four bridging acetate ligands, which connect the asymmetric unit into a dimeric complex and form a slightly distorted square-pyramidal coordination environment., The title compound, [Cu4(CH3COO)6(C16H23N2O)2], lies across a twofold rotation axis. The asymmetric unit contains two independent CuII ions. The symmetry-unique terminal CuII ion is O,N,N′-coordinated by a 2-{[(2,2,6,6-tetra­methyl­piperidin-4-yl)imino]­meth­yl}phenolate ligand and an O atom from an acetate group in a slightly distorted square-planar coordination environment. The symmetry-unique central CuII ion is coordinated by a different O atom from the same acetate group and by four bridging acetate ligands, which connect the asymmetric unit into a dimeric complex and form a distorted square-pyramidal coordination environment. Within the complex there are two symmetry-equivalent intra­molecular N—H⋯O hydrogen bonds. In the crystal, weak C—H⋯O hydrogen bonds link the complex mol­ecules, forming a three-dimensional network.

A novel UV-curable hyperbranched polyurethane acrylate (FHBPUA) with excellent flexibility is successfully synthesized based on a reaction of hydroxyl terminated hyperbranched polyurethane (regarded as core) with flexible semiadduct urethane monoacrylate (regarded as arms). The structure and property of FHBPUA is firstly analyzed and then utilized as functional additives to ameliorate the UV-curing and mechanical properties of epoxy acrylate resin. The degree of branching of FHBPUA turns out to be 0.82. Its thermal decomposition process consists of three different stages, and the glass transition temperature is around 65 °C. The freestanding FHBPUA film (~30 μm thickness) can be UV-cured within 3 s, and its flexibility is up to 1 mm. With the increase of FHBPUA content to 10 wt %, the UV-curing time of UV1000 film decreases from 6 to 3 s, flexibility strikingly increases from 10 to 1 mm, and adhesive force also improves from 5 to 3 grades, meanwhile its glossiness is not influenced by FHBPUA. In addition, a certain amount of FHBPUA can improve the tensile strength and elongation at break of UV1000 film. This novel FHBPUA can be used not only to develop flexible UV-curable freestanding films but also as functional additives to perfect other UV-curable compositions like coatings, inks and 3D printed parts.

A facile strategy for detecting xanthine in serum samples by copper nanocluster (CuNCs) with high intrinsic peroxidase-like activity was reported. Firstly, a simple, mild and time-saving method for preparing CuNCs was developed, in which dithiothreitol (DTT) and bovine serum albumin (BSA) were used as reductant and stabilizer, respectively. The as-prepared CuNCs exhibited a fluorescence emission at 590 nm with a quantum yield (QY) of approximately 5.29%, the fluorescence intensity of the as-prepared CuNCs exhibited no considerable change when stored under ambient condition with the lifetime is 1.75 μs. Moreover, the as-prepared CuNCs exhibited high intrinsic peroxidase-like activity with lower K m (K m = 8.90 × 10−6 mol L−1) for H2O2, which indicated that CuNCs have a higher affinity for H2O2. Compared with natural enzyme, the as-synthesized CuNCs are more catalytic stable over a wide range of pH (4.0~13.0) and temperature (4~80 °C). Finally, an indirect method for sensing xanthine was established because xanthine oxidase can catalyse the oxidation of xanthine to produce H2O2. Xanthine could be detected as low as 3.8 × 10−7 mol L−1 with a linear range from 5.0 × 10−7 to 1.0 × 10−4 mol L−1. These results proved that the proposed method is sensitive and accurate and could be successfully applied to the determination of xanthine in the serum sample with satisfaction.

In this study, the potential climate change impacts on rice growth and rice yield under 1.5 and 2.0 &deg, C warming scenarios, respectively, are simulated using the Ceres-Rice Model based on high-quality, agricultural, experimental, meteorological and soil data, and the incorporation of future climate data generated by four Global Climate Models (GCMs) in the Pearl River Delta, China. The climatic data is extracted from four Global Climate Models (GCMs) namely: The Community Atmosphere Model 4 (CAM4), The European Centre for Medium-Range Weather Forecasts-Hamburg 6 (ECHAM6), Model for Interdisciplinary Research On Climate 5 (MIROC5) and the Norwegian Earth System Model 1 (NorESM1). The modeling results show that climate change has major negative impacts on both rice growth and rice yields at all study sites. More specifically, the average of flowering durations decreases by 2.8 days (3.9 days), and the maturity date decreases by 11.0 days (14.7 days) under the 1.5 &deg, C and (2.0 &deg, C) warming scenarios, respectively. The yield for early mature rice and late mature rice are reduced by 292.5 kg/ha (558.9 kg/ha) and 151.8 kg/ha (380.0 kg/ha) under the 1.5 &deg, C (2.0 &deg, C) warming scenarios, respectively. Adjusting the planting dates of eight days later and 15 days earlier for early mature rice and late mature rice are simulated to be adaptively effective, respectively. The simulated optimum fertilizer amount is about 240 kg/ha, with different industrial fertilizer and organic matter being applied.

In the process of cutting silicon by natural diamond tools, groove wear happens on the flank face of cutting tool frequently.Scholars believe that one of the wear reasons is mechanical scratching effect by hard particles like SiC. To reveal the mechanical scratching mechanism, it is essential to study changes in the mechanical properties of hard particles and diamond, especially the effect of cutting temperature on hardness of diamond and hard particles. Molecular dynamics (MD) model that contact-zone temperature between tool and workpiece was calculated by dividing zone while nano-cutting monocrystalline silicon was established, cutting temperature values in different regions were computed as the simulation was carried out.On this basis, the models of molecular dynamics simulation of SiC and diamond were established separately with setting the initial temperature to room temperature. The laws of length change of C-C bond and Si-C bond varing with increase of simulation temperature were studied. And drawing on predecessors' research on theoretical calculation of hardness of covalent crystals and the relationship between crystal valence electron density and bond length, the curves that the hardness of diamond and SiC varing with bond length were obtained. The effect of temperature on the hardness was calculated. Results show that, local cutting temperature can reach 1300K.The rise in cutting temperature leaded to a decrease in the diamond local atomic clusters hardness,SiC local atomic clusters hardness increased. As the cutting temperature was more than 1100K,diamond began to soften, the local clusters hardness was less than that of SiC.

The preparation of the high cis−1,4-polyisoprene by Ziegler-Natta catalysis system was studied. The effect of Al-Ti catalysts modified by ethers with different structures which are different electron donor reagent on polymerization of isoprene has been mainly investigated. By the measurement method of the monomer conversion, FTIR, and 1H NMR spectroscopy, the influence of, respectively, added diphenyl ether, anisole, dibutyl ether, or methyl tert-butyl methyl ether as a third active component on the heterogeneous TiCl4-Al(i-Bu)3-ether catalyst activity and microstructure of synthetic polyisoprene was analyzed. By the adding of diphenyl ether or dibutyl ether, the process of prefabricated heterogeneous catalyst is quickly and catalyst particle quantity is large. The polymerization conversion is high and the microstructure cis−1,4 content of the resulting polymer can reach 92%. But Al(i-Bu)3 added anisole or methyl tert-butyl methyl ether hard to cooperate with TiCl4. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44357.

International audience; Self-assembly is a fundamental concept and a powerful approach in molecular science. However, creating functional materials with the desired properties through self-assembly remains challenging. In this work, through a combination of experimental and computational approaches, the self-assembly of small amphiphilic dendrons into nanosized supramolecular dendrimer micelles with a degree of structural definition similar to traditional covalent high-generation dendrimers is reported. It is demonstrated that, with the optimal balance of hydrophobicity and hydrophilicity, one of the self-assembled nanomicellar systems, totally devoid of toxic side effects, is able to deliver small interfering RNA and achieve effective gene silencing both in cells - including the highly refractory human hematopoietic CD34(+) stem cells - and in vivo, thus paving the way for future biomedical implementation. This work presents a case study of the concept of generating functional supramolecular dendrimers via self-assembly. The ability of carefully designed and gauged building blocks to assemble into supramolecular structures opens new perspectives on the design of self-assembling nanosystems for complex and functional applications.

Photosensitive alkoxyamine 2,2,6,6-tetramethyl-1-(1-phenylethoxy)piperidin-4-yl quinoline-2-carboxylate (PE-TEMPO-Q) was synthesized. Photochemical properties of PE-TEMPO-Q were studied to develop photoinduced nitroxide-mediated polymerization of methyl methacrylate (MMA). Rapid and facile polymerization at ambient temperature with PE-TEMPO-Q as an initiator was confirmed to proceed in a controlled mechanism based on the linear growth in molecular weight combined with relative narrow polydispersity index (1.4–1.8) of the resulting polymers. The stereochemistry of obtained polymers was also investigated, and the syndiotacticity slightly increased compared with the typical photopolymerization. Dual-controlled photopolymerization of MMA was achieved in the presence of synthesized alkoxyamine.

International audience; Functional materials capable of responding to stimuli intrinsic to diseases are extremely important for specific drug delivery at the disease site. However, developing on-demand stimulus-responsive vectors for targeted delivery is highly challenging. Here, a stimulus-responsive fluorinated bola-amphiphilic dendrimer is reported for on-demand delivery of small interfering RNA (siRNA) in response to the characteristic high level of reactive oxygen species (ROS) in cancer cells. This dendrimer bears a ROS-sensitive thioacetal in the hydrophobic core and positively charged poly(amidoamine) dendrons at the terminals, capable of interacting and compacting the negatively charged siRNA into nanoparticles to protect the siRNA and promote cellular uptake. The ROS-sensitive feature of this dendrimer boosts specific and efficient disassembly of the siRNA/vector complexes in ROS-rich cancer cells for effective siRNA delivery and gene silencing. Moreover, the fluorine tags in the vector enable F-19-NMR analysis of the ROS-responsive delivery process. In addition, this ingenious and distinct bola-amphiphilic dendrimer is also able to combine the advantageous delivery features of both lipid and dendrimer vectors. Therefore, it represents an innovative on-demand stimulus-responsive delivery platform.

Mass spectrometry was used in conjunction with ion mobility experiments and molecular modeling to study any conformational changes of two PAMAM dendrimers of different structure as a function of their protonation degree. Changes of molecular conformation conjectured from peculiar charge state distribution in the electrospray mass spectra were confirmed by collision cross section values derived from ion mobilograms and supported by theoretical calculations. Shape extension was significant for triply charged molecules of both dendrimers, but the extent of this swelling phenomenon was shown to strongly depend on the PAMAM dendrimers architecture.

International audience; With the aim of developing dendrimer nanovectors with a precisely controlled architecture and flexible structure for DNA transfection, we designed PAMAM dendrimers bearing a triethanolamine (TEA) core, with branching units pointing away from the center to create void spaces, reduce steric congestion, and increase water accessibility for the benefit of DNA delivery. These dendrimers are shown to form stable nanoparticles with DNA, promote cell uptake mainly via macropinocytosis, and act as effective nanovectors for DNA transfection in vitro on epithelial and fibroblast cells and, most importantly, in vivo in the mouse thymus, an exceedingly challenging organ for immune gene therapy. Collectively, these results validate our rational design approach of structurally flexible dendrimers with a chemically defined structure as effective nanovectors for gene delivery, and demonstrate the potential of these dendrimers in intrathymus gene delivery for future applications in immune gene therapy.