Current therapy of malignant glioma in clinic is unsatisfactory with poor patient compliance due to low therapeutic efficiency and strong systemic side effects. Herein, we combined chemo-photothermal ...targeted therapy of glioma within one novel multifunctional drug delivery system. A targeting peptide (IP)-modified mesoporous silica-coated graphene nanosheet (GSPI) was successfully synthesized and characterized, and first introduced to the drug delivery field. A doxorubicin (DOX)-loaded GSPI-based system (GSPID) showed heat-stimulative, pH-responsive, and sustained release properties. Cytotoxicity experiments demonstrated that combined therapy mediated the highest rate of death of glioma cells compared to that of single chemotherapy or photothermal therapy. Furthermore, the IP modification could significantly enhance the accumulation of GSPID within glioma cells. These findings provided an excellent drug delivery system for combined therapy of glioma due to the advanced chemo-photothermal synergistic targeted therapy and good drug release properties of GSPID, which could effectively avoid frequent and invasive dosing and improve patient compliance.
Three‐dimensional (3D) printing has received extensive attention due to its unique multidimensional functionality and customizability and has been recognized as one of the most revolutionary ...manufacturing technologies. Functional 3D printed products represent an important orientation for next‐generation manufacturing and attract a great spotlight for the application in sensors, actuators, robots, electronics, and medical devices. However, the lack of functions of printing polymeric materials dramatically limits the development of functional 3D printing. Different from traditional processing, the physical properties, such as geometry and rheological behavior, of the polymeric materials must match the printing process, making the selection of printable materials limited. More importantly, challenges in large‐scale production of such materials further stifle the development of functional 3D printing industry. In this review, we aim to outline recent advances in polymeric materials and methodologies for the functional 3D printing technology. The reports are classified based on functionalities, including electronic conductive, thermally conductive, electromagnetic interference shielding, energy storage, and energy harvesting materials. This study attempts to provide a comprehensive overview of the challenges and opportunities for 3D printing functional polymeric materials/devices, also seeks to enlighten the orientation of future research in this field.
The idea of harnessing the customization competence of 3D printing technology has recently come under the spotlight, enabling the realization of manifold functional polymeric devices with unprecedented properties to which conventional measures are inaccessible. Recent advances in materials and methodologies to realize functional polymeric devices derived from 3D printing technology are summarized. Specifically, applications categorized according to their specific functionalities are discussed, having areas such as electronic conductive, thermal conductive, electromagnetic interference shielding, energy storage, and energy harvesting applications embodied. In the end, the challenges and opportunities are outlined, which highlights future endeavors that should be directed to this field.
The particulate matter (PM) pollution of Beijing fluctuated significantly before and after precipitation events during the rainy period. The rainwater samples were continually collected at ...five-minute intervals on the roof of a building in downtown Beijing. The PM2.5 was also monitored at same temporal scale. The pH and concentrations of ammonia-N, nitrate-N, phosphorus, sulfur, and heavy metals (Cd, Mn, Fe, Zn, and Cu) in the rainwater samples were measured, and the values were used to assess the effect of washing on PM2.5 and determine the characteristics of the rainwater pollutants. The PM2.5 was negatively correlated to the quantity of accumulated rainfall (R2 value ranged from 0.668 to 0.974), which identified the function of the washing process on PM2.5 pollution. The washing process of rainfall strongly affects PM2.5, which decreased to 10–30μgm−3 with 5mm of rainfall. The analysis of the temporal patterns of ten pollutants in rainwater demonstrated that most of the pollution load was contributed by the first 5 to 10min of the washing process. The event mean concentration (EMC) of nine inorganic pollutants was used to evaluate the pollution load and identify sources of particle pollution. Sulfur was the primary inorganic element detected in PM, and the average EMC of twelve rainfall events was 8.92mgL−1. The EMC of ammonia-N, nitrate-N, and phosphorus after significant PM2.5 pollution was 11.57mgL−1, 1.72mgL−1, and 0.019mgL−1, respectively. The total pollution load of the rainwater collecting area during the rainy reason was also calculated, and the largest heavy metal load of 3.11mg was attributed to Zn. The pollution loads of heavy metals and the stable relationship between the pollutants indicate the potential urban environmental management policies in Beijing.
•Temporal features of PM2.5 in 2013 summer of Beijing downtown were analyzed.•Washing process of rainfall on PM2.5 was quantified with twelve rainfall events.•Ten inorganic rainfall pollution dynamics expressed possible PM2.5 source.•EMC of nine parameters identified the interactions of water and air pollution.
High efficiency video coding (HEVC), which is the newest video coding standard currently, achieves the best coding efficiency compared with all the other existing video coding standards. However, the ...computational complexity of the typical HEVC encoder dramatically increases because of the recursive searching scheme for finding the best coding unit (CU) partitions. In this paper, an adaptive fast CU size decision algorithm for HEVC Intra prediction is proposed based on CU complexity classification (CC) by using machine learning (ML) technology. Firstly, certain image features are extracted to characterize the CU complexity, which has a strong relationship with CU partitions, and then, the support vector machine is employed to analyze and construct the classification model according to the CU complexity. Finally, the proposed adaptive fast CU size decision algorithm, named as CCML, is released based on the complexity classification. The experimental results show that the proposed algorithm could achieve around 60% encoding time reduction for various test video sequences on average with only 1.26% Bjontegaard delta bit rate increase compared with the reference test model HM15.0 of HEVC.
Plant uptake is an important process in determining the transfer of pesticides through a food chain. Understanding how crops take up and translocate pesticides is critical in developing powerful ...models to predict pesticide accumulation in agricultural produce and potential human exposure. Herein, wheat was selected as a model plant species to investigate the uptake and distribution of eleven widely used pesticides in a hydroponic system as a function of time for 144 h. The time-dependent uptake kinetics of these pesticides were fitted with a first-order 1-compartment kinetic model. During 144 h, flusilazole and difenoconazole, with relative high log Kow (3.87 and 4.36, respectively), displayed higher root uptake rate constants (k). To clarify the role of root lipid content (flip) in plant accumulation of pesticides, we conducted a lipid normalization meta-analysis using data from this and previous studies, and found that the flip value was an important factor in predicting the root concentration factor (RCF) of pesticides. An improved correlation was observed between log RCF and log flipKow (R2 = 0.748, N = 26, P < 0.001), compared with the correlation between log RCF and log Kow (R2 = 0.686, N = 26, P < 0.001). Furthermore, the hydrophilic pesticides (e.g. log Kow < 2) were found to reach partition equilibrium faster than lipophilic pesticides (e.g. log Kow > 3) during the uptake process. The quasi-equilibrium factor (αpt) was inversely related to log Kow (R2 = 0.773, N = 11, P < 0.001) suggesting a hydrophobicity-regulated uptake equilibrium. Findings from this study could facilitate crop-uptake model optimization.
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•Time-dependent uptake of 11 pesticides in wheat-water system was evaluated.•Pesticides uptake kinetics were fitted with first-order 1-compartment kinetic model.•Root lipid content was an important factor in predicting RCF of pesticides in plants.•Hydrophilic pesticides reached equilibrium faster than lipophilic pesticides.•Quasi-equilibrium factor (αpt) was inversely related to the log Kow.
Integrating the pesticide Kow with plant root lipid content (flipKow) is better for predicting the root concentration factors of pesticides than just Kow.
This paper presents the pollution levels, variation characteristics, chemical reactivity, source apportionment and potential source regions of 102 volatile organic compounds (VOCs) observed from ...2017.4.26 to 2017.6.6 in urban Wuhan. The concentration of total VOCs (TVOCs) was 28.92 ± 20.10 ppbv, and the VOC composition was dominated by alkanes (51.14%). Propane, ethane and acetone were the most abundant VOC species. The results for the OH radical loss rate (LOH) and ozone formation potential (OFP) indicated that alkenes were responsible for much of the chemical reactivity and O3 formation, accounting for 47.02% and 49.52%, respectively, and the dominant VOC species were mainly associated with anthropogenic sources, such as vehicle emissions, the use of natural gas (NG) and liquefied petroleum gas (LPG), solvent usage and fuel evaporation. Ambient ratio data showed that VOCs were greatly affected by the pollution sources (such as emissions of NG and LPG, liquid gasoline and fuel evaporation sources, vehicle exhaust emissions, and biogenic sources), photochemical reaction processes and regional transport. Industrial sources (11.84%), industrial sources + coal burning (13.09%), LPG/NG usage + solvent usage in painting/coating (37.28%), fuel evaporation (12.04%), vehicle exhaust (13.65%), biogenic sources (5.95%) and biomass burning (6.15%) were determined by positive matrix factorization (PMF). Furthermore, LPG/NG usage, solvent usage in painting/coating and vehicle exhaust were the most important VOC sources, and their various contributions were affected by a combination of factors, including the emission strength of pollution sources, meteorological conditions and photochemical reaction processes. Backward trajectory analysis showed that VOC pollution was mainly derived from the south via short-distance transport. The potential source contribution function (PSCF) results indicated that the main sources affecting VOC pollution were the potential sources to the south and local sources within the city. This study provides evidence for local governments to formulate VOC control strategies during the transition from spring to summer.
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•Alkenes were the key components of chemical reactivity and O3 formation.•The effects of sources, photochemical reactions and air mass on VOCs were analysed.•LPG/NG usage, solvent usage in painting/coating and vehicle exhaust were important.•Potential sources from the south and local sources within the city were important.
Herein, we report a light-enhanced hypoxia-responsive nanoparticle for synergic treatment of solid tumors. The conversion of oxygen in the tumor exterior induced ROS and the continuous consumption of ...oxygen amplified the hypoxia conditions in the tumor, which enhanced the surface-to-core penetration of nanoparticles into the hypoxia central tissue.
Immunotherapy, the most promising strategy of cancer treatment, has achieved promising outcomes, but its clinical efficacy in pancreatic cancer is limited mainly due to the complicated tumor ...immunosuppressive microenvironment. As a highly inflammatory form of immunogenic cell death (ICD), pyroptosis provides a great opportunity to alleviate immunosuppression and promote systemic immune responses in solid tumors. Herein, membrane‐targeted photosensitizer TBD‐3C with aggregation‐induced emission (AIE) feature to trigger pyroptosis‐aroused cancer immunotherapy via photodynamic therapy (PDT) is applied. The results reveal that pyroptotic cells induced by TBD‐3C could stimulate M1‐polarization of macrophages, cause maturation of dendritic cells (DCs), and activation of CD8+ cytotoxic T‐lymphocytes (CTLs). Pyroptosis‐aroused immunological responses could convert immunosuppressive “cold” tumor microenvironment (TME) to immunogenic “hot” TME, which not only inhibits primary pancreatic cancer growth but also attacks the distant tumor. This work establishes a platform with high biocompatibility for light‐controlled antitumor immunity and solid tumor immunotherapy aroused by cell pyroptosis.
A single effective light‐induced pyroptosis activates cascade amplification of anti‐tumor immunity for pancreatic cancer therapy by membrane anchoring photosensitizer with aggregation‐induced emission feature.
In order to probe the seasonal variation, formation mechanisms as well as geographical origins of fine particles and its chemical components in two cities (Zhengzhou, ZZ and Xinxiang, XX) in Central ...Plains Urban Agglomeration, daily PM2.5 aerosol samples were collected for four consecutive seasons during 2017–2018. The annual average concentrations of PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 μm) were calculated at 70.5 ± 50.8 and 69.0 ± 46.3 μg m−3 at ZZ and XX, respectively. Daily ambient PM2.5 concentrations ranged from 18.2 to 303.0 μg m−3, among which >81% of the total sampling days exceeded the National Ambient Air Quality Standard of China (NAAQS, 35 μg m−3 as an annual average). Additionally, concentrations of PM2.5 and its major chemical components were seasonally dependent, usually with the highest mass concentration in winter. Compared with previous studies, higher NO3−/SO42− were observed in this study depicted that air pollution caused by motor vehicle exhaust cannot be ignored. OC concentration was higher at ZZ than XX during sampling campaign likely partially caused by larger number of motor vehicles, chemical pesticide and solvent used in ZZ. Both homogeneous and heterogeneous reactions played an important role in the formation of nitrate, while heterogeneous reactions dominated the formation of sulfate. We also found a faster increase in nitrate than in sulfate during the evolution of haze. The characteristics of long-range transportation of PM2.5 and its major chemical components and gaseous precursors were observed at both sites through back trajectories and WPSCF analysis, suggesting the complexity of air pollution and the multi-influence among cities.
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•Seasonal variation characteristics of PM2.5 and its chemical components are explored.•A faster increase in nitrate than in sulfate during the evolution of haze periods.•Severe pollution in winter has alleviated obviously compared with previous years.•Discrepancies of individual compositions of PM2.5 at both sites are significant.•Long-range transportation of PM2.5 is observed at both sites with WPSCF analysis.
The primary objective of this study is to investigate the formation and evolution mechanism of the regional haze in Beijing by analyzing the process of a severe haze episode that occurredfrom1 to 31 ...January 2013. The mass concentration of PM2.5 and its chemical components were simultaneously measured at the Beijing urban atmospheric environmental monitoring station. The haze was characterized by a high frequency, a long duration, a large influential region and an extremely high PM2.5 values (>500μg/m3). The primary factors driving the haze formation were stationary atmospheric flows (in both vertical and horizontal directions), while a temperature inversion, a lower planetary boundary layer and a higher RH accelerated the formation of the regional haze. In one incident, the temperature inversion layer occurred at a height of 130m above ground level, which prevented the air pollutants from being dispersed vertically. The regional transport of pollutants also played an important role in the formation of the haze. Wind from the south of Beijing increased from 58% in January 2012 to 63% in January 2013. Because the area to the south of Beijing is characterized by high industrial development, the unusual wind direction favored the regional transport of pollutants and severely exacerbated the haze. SO42−, NO3− and NH4+ are the three major water-soluble ions that contributed to the formation of the haze. The high variability in Cl− and K+ indicated that large quantities of coal combustion and biomass burning occurred during the haze.
•Characteristics of continuous extreme haze episodes are clarified.•Formation mechanism of regional haze is investigated in detail.•Haze events were grouped into three classes.•Relationship between PBL and haze formation was clarified
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