Effects of aeration modes and rates on nitrogen conversion and bacterial community in composting of dehydrated sludge and corn straw.

Aeration is an important factor to regulate composting efficiency and nitrogen loss. This study is aimed to compare the effects of different aeration modes (continuous and intermittent) and aeration rate on nitrogen conversion and bacterial community in composting from dehydrated sludge and corn straw. Results showed that the intermittent aeration mode at same aeration volume was superior to the continuous aeration mode in terms of NH3 emission reduction, nitrogen conversion and germination index (GI) improvement. Intermittent aeration mode with 1200 L/h (aeration 5 min, stop 15 min) [K5T15 (V1200)] and 300 L/h of continuous aeration helped to the conservation of nitrogen fractions and accelerate the composting process. However, it was most advantageous to use 150 L/h of continuous aeration to reduce NH3 emission and ensure the effective composting process. The aeration mode K5T15 (V1200) showed the fastest temperature rise, the longer duration of thermophilic stage and the highest GI (95%) in composting. The cumulative NH3 emission of intermittent aeration mode was higher than continuous aeration mode. The cumulative NH3 emission of V300 was 23.1% lower than that of K5T15 (V1200). The dominant phyla in dehydrated sludge and corn straw composting were Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. The dominant phylum in the thermophilic stage was Firmicutes (49.39%~63.13%), and the dominant genus was Thermobifida (18.62%~30.16%). The relative abundance of Firmicutes was greater in the intermittent aeration mode (63.13%) than that in the continuous aeration mode (57.62%), and Pseudomonas was dominant in composting with lower aeration rate and the lowest NH3 emission. This study suggested that adjustment to the aeration mode and rate could affect core bacteria to reduce the nitrogen loss and accelerate composting process.

Optimization of coupling crop and livestock production system's eco-efficiency in northern China based on a life cycle assessment and data envelopment analysis method.

Under the twin pressures of global food security and dual­carbon strategies, improving farm eco-efficiency is critical for achieving China's goal of a 50 Pg increase in grain production, meeting the ambitious climate mitigation targets set by the Paris Agreement, and meeting seven of the seventeen Sustainable Development Goals (SDGs) set by the United Nations. However, there is limited research on eco-efficiency measures supported by localised fine-scale data and coupling mechanisms for the structure, production process, efficiency improvement, and carbon reduction synergies of integrated farming systems in China. This study used the Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) methods to assess eco-efficiency at the farm level in northern China, included in the National Coupling Crop and Livestock Production Pilot Programs, to improve the eco-efficiency of farms to achieve increased production and emission reductions. The results showed that the overall eco-efficiency of farms was in the lower-middle range, with only 20.18 % of the farms having a technical efficiency exceeding 1. Problems included a backward level of pure technical efficiency and a return to scale. Non-integrated farms have the lowest profitability (41.33 %) and the highest carbon emission intensity of 3.03 kg CO2eq/USD. The global warming potential impact of non-integrated farms optimization could be reduced by 25 Pg CO2eq. Implementing the integrated farming mode has a significant advantage in reducing carbon emissions and improving productivity. Overall, farm fodder optimization can be increased by up to 42.41 %. Simultaneously, farms with sufficient farmland are more likely to realise a highly integrated business mode for crop cultivation and livestock breeding. Therefore, constructing a new type of green integrated farming system will help farms achieve increased production and emission reductions, promote the development of sustainable agriculture, and provide a Chinese model for the realisation of global SDGs.

Synergistic effects of chemical additives and mature compost on reducing H2S emission during kitchen waste composting.

Additives could improve composting performance and reduce gaseous emission, but few studies have explored the synergistic of additives on H2S emission and compost maturity. This research aims to make an investigation about the effects of chemical additives and mature compost on H2S emission and compost maturity of kitchen waste composting. The results showed that additives increased the germination index value and H2S emission reduction over 15 days and the treatment with both chemical additives and mature compost achieved highest germination index value and H2S emission reduction (85%). Except for the treatment with only chemical additives, the total sulfur content increased during the kitchen waste composting. The proportion of effective sulfur was higher with the addition of chemical additives, compared with other groups. The relative abundance of H2S-formation bacterial (Desulfovibrio) was reduced and the relative abundance of bacterial (Pseudomonas and Paracoccus), which could convert sulfur-containing substances and H2S to sulfate was improved with additives. In the composting process with both chemical additives and mature compost, the relative abundance of Desulfovibrio was lowest, while the relative abundance of Pseudomonas and Paracoccus was highest. Taken together, the chemical additives and mature compost achieved H2S emission reduction by regulating the dynamics of microbial community.

Fabricating and investigating a beveled mesa with a specific inclination angle to improve electrical and optical performances for GaN-based micro-light-emitting diodes.

In this Letter, beveled mesas for 30 × 30 µm2 GaN-based micro-light-emitting diodes (µLEDs) with different inclination angles are designed, fabricated, and measured. We find that µLED with a mesa inclination angle of 28° has the lowest internal quantum efficiency (IQE) and the highest injection current density at which the peak IQE is obtained. This is due to the increased quantum confined Stark effect (QCSE) at the mesa edge. The increased QCSE results from the strong electric field coupling effect. Instead of radiative recombination, more nonradiative recombination and leakage current will be generated in the sidewall regions. Besides, the smallest angle (28°) also produces the lowest light extraction efficiency (LEE), which arises from the optical loss caused by the sidewall reflection at the beveled surface sides. Therefore, the inclination angle for the beveled mesa has to be increased to 52° and 61° by using Ni and SiO2 as hard masks, respectively. Experimental and numerical results show that the external quantum efficiency (EQE) and the optical power can be enhanced for the fabricated devices. Meanwhile, the reduced surface recombination rate also decreases the leakage current.

Macrophage-hitchhiked arsenic/AB bionic preparations for liver cancer.

Macrophage-hitchhiked arsenic/AB bionic preparations were developed to improve the therapeutic effect on liver cancer by means of the tumor-targeting ability of macrophages in vivo. In vitro and in vivo cellular uptake assays demonstrated that arsenic/AB, with negatively charged particles of around 100-200 nm size, could hitchhike to macrophages. Dissolution experiments of arsenic/AB showed that arsenic/AB could delay the release of arsenic and ensure the safety of macrophages during its transport. Histological examination confirmed the safety of the preparations for major organs. In vivo distribution experiment showed that the arsenic/AB bionic preparations could rapidly accumulate in tumors, and in vivo treatment experiment showed a significant tumor inhibition of arsenic/AB. The therapeutic mechanism of liver cancer might be that the arsenic/AB bionic preparations could inhibit tumor growth by reducing inflammatory response and inhibiting CSF1 secretion to block CSF1R activation to induce more differentiation of tumor-associated macrophages (TAMs) towards the anti-tumor M1 phenotype. Therefore, we concluded that the arsenic/AB bionic preparations could improve the distribution of arsenic in vivo by hitchhiking on macrophages as well as make it have tumor targeting and deep penetration abilities, thus increasing the therapeutic effect of arsenic on liver cancer with reduced side effects.

Lattice-matched AlInN/GaN bottom DBR impact on GaN-based vertical-cavity-surface-emitting laser diodes: systematical investigations.

In this paper, by using advanced numerical models, we investigate the impact of the AlN/GaN distributed Bragg reflector (DBR) and AlInN/GaN DBR on stimulated radiative recombination for GaN-based vertical-cavity-surface-emitting lasers (VCSELs). According to our results, when compared with the VCSEL with AlN/GaN DBR, we find that the VCSEL with AlInN/GaN DBR decreases the polarization-induced electric field in the active region, and this helps to increase the electron-hole radiative recombination. However, we also find that the AlInN/GaN DBR has a reduced reflectivity when compared with the AlN/GaN DBR with the same number of pairs. Furthermore, this paper suggests that more pairs of AlInN/GaN DBR will be set, which helps to even further increase the laser power. Hence, the 3 dB frequency can be increased for the proposed device. In spite of the increased laser power, the smaller thermal conductivity for AlInN than AlN results in the earlier thermal droop in the laser power for the proposed VCSEL.

Suppressing optical crosstalk for GaN/InGaN based flip-chip micro light-emitting diodes by using an air-cavity patterned sapphire substrate as a light filter.

In this work, by using three-dimensional finite-difference time-domain (3D FDTD) method, the effect of conventional nano-patterned sapphire substrate (NPSS) on the optical crosstalk and the light extraction efficiency (LEE) for InGaN/GaN-based flip-chip micro light-emitting diodes (µ-LEDs) are systematically studied. We find that the conventional NPSS is not suitable for µ-LEDs. It is because the inclined mesa sidewall for µ-LEDs possesses a good scattering effect for µ-LEDs, but the introduced conventional NPSS causes part of the light be off escape cone between sapphire and air and become the guided light. To suppress the guided light and improve the optical crosstalk, a thick air layer between the n-GaN layer and the sapphire substrate can be used as a light filter to prevent the guided light from propagating into the sapphire. However, in reality, it is challenging to make the aforementioned air layer from point of fabrication view. Therefore, we propose the air-cavity patterned sapphire substrate (AC-PSS) as the light filter. Our results show that the crosstalk ratio can be decreased to the value even lower than 10%. The LEE can also be enhanced simultaneously due to combination effects of the filtering effect of the AC-PSS and the scattering effect of the inclined mesa sidewall.

On the impact of the beveled mesa for GaN-based micro-light emitting diodes: electrical and optical properties.

In this report, the impact of different mesa designs on the optical and electrical characteristics for GaN-based micro-light emitting diodes (µLEDs) has been systematically and numerically investigated by using TCAD simulation tools. Our results show that an enhanced light extraction efficiency can be obtained by using beveled mesas. The inclined mesa angles can more effectively reflect the photons to the substrate, and this helps to extract the photons to free air for flip-chip µLEDs. However, it is found that the current injection is influenced by inclination angles for the investigated µLEDs, such that the beveled mesas make stronger charge-coupling effect and increase the electric field magnitude in the multiple quantum wells at the mesa edge, so that the carriers cannot be effective consumed by radiative recombination. As a result, this gives rise to stronger defect-induced nonradiative recombination at mesa surfaces. Therefore, there are tradeoffs between the LEEs and IQEs when changing the beveled angle, to maximize external quantum efficiency for GaN-based µLEDs, the beveled mesa angle shall be carefully designed and optimized.

Precision Feeding in Ecological Pig-Raising Systems with Maize Silage.

Ecological pig-raising systems (EPRSs) differ from conventional breeding systems, focusing more on environmental consequences, human health, and food safety during production processes. Thus productions from EPRSs have undergone significant development in China. Thus far, adding plant fiber sources (e.g., sweet potato leaves, maize or wheat straw, potato, alfalfa, and vinasse) to feed has become a common practice to reduce the cost during the fattening period. Under such a context, it is necessary to choose the precision EPRS diet components and fattening period with low environmental consequences and high economic benefits. This study set up a database via pig growth models to predict environmental and economic performance based on two trials with 0%, 10%, 40%, 60%, and 80% maize silage (dry weight) added to the feed. A continuous curve about plant fiber concentration was built through the generated database. Our results showed that, with increased plant fiber concentration, the environmental performance of the EPRSs exhibited an "increase-decrease-increase" trend, and the economic performance firstly increased and then decreased. The best maize silage added percentages of emergy yield ratio (EYR), environmental loading ratio (ELR), unit emergy value (UEV), and emergy sustainability index (ESI), and the economic profits were 19.0%, 34.3%, 24.6%, 19.9%, and 18.0%, respectively. Besides, the 19.9% sun-dried maize silage added to the feed with a 360-day raising period had the best balance for environmental impact and economic performance. At the balance point, the performances of EYR, ELR, UEV, ESI, and the economic profit were only 0.04%, 3.0%, 0.8%, 0.0%, and 0.1%, respectively, lower than their maximum values. Therefore, we recommended the feed added 20% sun-dried maize silage is suitable for practical pig raising systems.

Is a thin p-GaN layer possible for making high-efficiency AlGaN-based deep-ultraviolet light-emitting diodes?

In this report, we investigate the impact of a thin p-GaN layer on the efficiency for AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs). According to our results, the light extraction efficiency (LEE) becomes higher with the decrease of the p-GaN layer thickness, which can be ascribed to the decreased absorption of DUV emission by the thin p-GaN layer. Moreover, we also find that the variation trend of external quantum efficiency (EQE) is consistent with that of LEE. Therefore, we can speculate that high-efficiency DUV LEDs can be achieved by using thin p-GaN layer to increase the LEE. However, a thin p-GaN layer can also cause severe current crowding effect and the internal quantum efficiency (IQE) will be correspondingly reduced, which will restrict the improvement of EQE. In this work, we find that the adoption of a current spreading layer for such DUV LED with very thin p-GaN layer can facilitate the current spreading effect. For the purpose of demonstration, we then utilize a well-known p-AlGaN/n-AlGaN/p-AlGaN (PNP-AlGaN) structured current spreading layer. Our experimental and numerical results show that, as long as the current crowding effect can be suppressed, the DUV LED with thin p-GaN layer can significantly increase the EQE and the optical power thanks to the enhanced LEE.

Artificially formed resistive ITO/p-GaN junction to suppress the current spreading and decrease the surface recombination for GaN-based micro-light emitting diodes.

Due to the increased surface-to-volume ratio, the surface recombination caused by sidewall defects is a key obstacle that limits the external quantum efficiency (EQE) for GaN-based micro-light-emitting diodes (µLEDs). In this work, we propose selectively removing the periphery p+-GaN layer so that the an artificially formed resistive ITO/p-GaN junction can be formed at the mesa edge. Three types of LEDs with different device dimensions of 30 × 30 µm2, 60 × 60 µm2 and 100 × 100 µm2 are investigated, respectively. We find that such resistive ITO/p-GaN junction can effectively prevent the holes from reaching the sidewalls for µLEDs with smaller size. Furthermore, such confinement of injection current also facilitates the hole injection into the active region for µLEDs. Therefore, the surface-defect-caused nonradiative recombination in the edge of mesa can be suppressed. Meantime, a reduction of current leakage caused by the sidewall defects can also be obtained. As a result, the measured and calculated external quantum efficiency (EQE) and optical output power for the proposed LED with small sizes are increased.

Step-type quantum wells with slightly varied InN composition for GaN-based yellow micro light-emitting diodes.

In this work, we propose adopting step-type quantum wells to improve the external quantum efficiency for GaN-based yellow micro light-emitting diodes. The step-type quantum well is separated into two parts with slightly different InN compositions. The proposed quantum well structure can partially reduce the polarization mismatch between quantum barriers and quantum wells, which increases the overlap for electron and hole wave functions without affecting the emission wavelength. Another advantage is that the slightly decreased InN composition in the quantum well helps to decrease the valence band barrier height for holes. For this reason, the hole injection capability is improved. More importantly, we also find that step-type quantum wells can make holes spread less to the mesa edges, thus suppressing the surface nonradiative recombination and decreasing the leakage current.

Lipid/PAA-coated mesoporous silica nanoparticles for dual-pH-responsive codelivery of arsenic trioxide/paclitaxel against breast cancer cells.

Nanomedicine has attracted increasing attention and emerged as a safer and more effective modality in cancer treatment than conventional chemotherapy. In particular, the distinction of tumor microenvironment and normal tissues is often used in stimulus-responsive drug delivery systems for controlled release of therapeutic agents at target sites. In this study, we developed mesoporous silica nanoparticles (MSNs) coated with polyacrylic acid (PAA), and pH-sensitive lipid (PSL) for synergistic delivery and dual-pH-responsive sequential release of arsenic trioxide (ATO) and paclitaxel (PTX) (PL-PMSN-PTX/ATO). Tumor-targeting peptide F56 was used to modify MSNs, which conferred a target-specific delivery to cancer and endothelial cells under neoangiogenesis. PAA- and PSL-coated nanoparticles were characterized by TGA, TEM, FT-IR, and DLS. The drug-loaded nanoparticles displayed a dual-pH-responsive (pHe = 6.5, pHendo = 5.0) and sequential drug release profile. PTX within PSL was preferentially released at pH = 6.5, whereas ATO was mainly released at pH = 5.0. Drug-free carriers showed low cytotoxicity toward MCF-7 cells, but ATO and PTX co-delivered nanoparticles displayed a significant synergistic effect against MCF-7 cells, showing greater cell-cycle arrest in treated cells and more activation of apoptosis-related proteins than free drugs. Furthermore, the extracellular release of PTX caused an expansion of the interstitial space, allowing deeper penetration of the nanoparticles into the tumor mass through a tumor priming effect. As a result, FPL-PMSN-PTX/ATO exhibited improved in vivo circulation time, tumor-targeted delivery, and overall therapeutic efficacy.

Energy consumption, CO2 emissions, and agricultural disaster efficiency evaluation of China based on the two-stage dynamic DEA method.

With a large agricultural sector, China is greatly affected by natural disasters caused by extreme weather events. Because the occurrence of natural disasters is closely related to the sharp increased consumption of energy and the massive emissions of carbon dioxide, this research examines relevant data from 2013 to 2017 in four major regions of China that cover 30 provincial administrative regions. Using the two-stage dynamic DEA model, we evaluate total efficiency value, two-stage efficiency value, and the efficiencies of energy consumption, CO2 emissions, and crop disaster areas, setting CO2 as the link between the production stage (first stage) and the crop damage stage (second stage). The research findings show that overall efficiency in China is generally low, whereby the total efficiencies of eastern and northeastern China are higher than those of central and western China. The efficiency value of the first stage (production stage) is greater than that of the second stage (crop damage stage), and the efficiency of most administrative regions' second stage is below 0.3, which is the main reason for the country's low overall efficiency. There is little difference between China's CO2 and energy consumption efficiency scores, but the efficiency values of crop disaster areas fluctuate greatly. The efficiency scores of various indicators in the eastern region are generally higher and more balanced, and the total efficiency scores exhibit a decreasing trend from east to west. Therefore, it is necessary to implement the environmental policy of controlling energy consumption and early warning of natural disasters in the central and western regions, and promote the R&D industry and technological innovation of carbon dioxide emission reduction and disaster control in the economically developed eastern regions.

Alternative Strategy to Reduce Surface Recombination for InGaN/GaN Micro-light-Emitting Diodes-Thinning the Quantum Barriers to Manage the Current Spreading.

Owing to high surface-to-volume ratio, InGaN-based micro-light-emitting diodes (µLEDs) strongly suffer from surface recombination that is induced by sidewall defects. Moreover, as the chip size decreases, the current spreading will be correspondingly enhanced, which therefore further limits the carrier injection and the external quantum efficiency (EQE). In this work, we suggest reducing the nonradiative recombination rate at sidewall defects by managing the current spreading effect. For that purpose, we properly reduce the vertical resistivity by decreasing the quantum barrier thickness so that the current is less horizontally spreaded to sidewall defects. As a result, much fewer carriers are consumed in the way of surface nonradiative recombination. Our calculated results demonstrate that the suppressed surface nonradiative recombination can better favor the hole injection efficiency. We also fabricate the µLEDs that are grown on Si substrates, and the measured results are consistent with the numerical calculations, such that the EQE for the proposed µLEDs with properly thin quantum barriers can be enhanced, thanks to the less current spreading effect and the decreased surface nonradiative recombination.

Clinical usefulness of bronchoalveolar lavage in patients with interstitial lung diseases: a pilot study.

BACKGROUND: Bronchoalveolar lavage (BAL) is a useful tool in the diagnostic work-up of patients with interstitial lung diseases (ILDs). In this prospective study, we investigated the clinical usefulness of BAL in patients with ILD radiographically. METHODS: The enrolled patients were classified into outpatient department (OPD), and inpatients groups who was admitted to general ward (GW) or intensive care unit (ICU) groups based on the time when BAL done. The clinical usefulness of BAL was defined as a new diagnosis established and/or treatment significantly changed. The clinical usefulness of BAL among the three groups of patients and the patients divided by underlying diseases was compared using the χ2 test with or without Fisher's exact test. RESULTS: Among our 184 patients, there were 37 in OPD group, 86 in GW group and 61 in ICU group. The final diagnoses were infectious in 23, non-infectious in 102, mixed etiologies in 19, and non-diagnostic in 40 patients. The diagnostic yields (revised diagnosis after BAL) of BAL among ICU patients, GW patients and OPD patients were 60.6%, 69.7% and 21.6%, respectively (P<0.001), and was 57.1% in total patients. The diagnostic yields of BAL among patients with cancer, organ transplantation and collagen vascular disease were statistically different (P=0.009). CONCLUSIONS: BAL is of use in establishing a diagnosis of ILD and is mandatary especially in the admitted patients with ILD because diagnostic yield was relatively higher in admitted patients than in OPD patients. In addition, BAL should be done more early in the admitted patients with malignancy, stem cell and/or organ transplantation and collagen vascular disease especially when they showed poor response to initial medications.

Enhancing the lateral current injection by modulating the doping type in the p-type hole injection layer for InGaN/GaN vertical cavity surface emitting lasers.

In this report, we propose GaN-based vertical cavity surface emitting lasers with a p-GaN/n-GaN/p-GaN (PNP-GaN) structured current spreading layer. The PNP-GaN current spreading layer can generate the energy band barrier in the valence band because of the modulated doping type, which is able to favor the current spreading into the aperture. By using the PNP-GaN current spreading layer, the thickness for the optically absorptive ITO current spreading layer can be reduced to decrease internal loss and then enhance the lasing power. Furthermore, we investigate the impact of the doping concentration, the thickness and the position for the inserted n-GaN layer on the lateral hole confinement capability, the lasing power, and the optimization strategy. Our investigations also report that the optimized PNP-GaN structure will suppress the thermal droop of the lasing power for our proposed VCSELs.

On the origin for the hole confinement into apertures for GaN-based VCSELs with buried dielectric insulators.

A better lateral current confinement is essentially important for GaN-based vertical-cavity-surface-emitting lasers (VCSELs) to achieve lasing condition. Therefore, a buried insulator aperture is adopted. However, according to our results, we find that the current cannot be effectively laterally confined if the insulator layer is not properly selected, and this is because of the unique feature for GaN-based VCSELs grown on insulating substrates with both p-electrode and n-electrode on the same side. Our results indicate that the origin for the current confinement arises from lateral energy band bending in the p-GaN layer rather than the electrical resistivity for the buried insulator. The lateral energy band in the p-GaN layer can be more flattened by using a buried insulator with a properly larger dielectric constant. Thus, less bias can be consumed by the buried insulator, enabling better lateral current confinement. On the other hand, the bias consumption by the buried insulator is also affected by the insulator thickness, and we propose to properly decrease the insulator layer thickness for reducing the bias consumption therein and achieving better lateral current confinement. The improved lateral current confinement will correspondingly enhance the lasing power. Thanks to the enhanced lateral current confinement, the 3dB frequency will also be increased if proper buried insulators are adopted.

[Spatial pattern and evolutionary trend of sustainable development index of crop-livestock system: A case study in Shandong Province, China.] / ç§å »ç³»ç»Ÿå¯æŒç»­å‘å±•æŒ‡æ•°çš„ç©ºé—´æ ¼å±€åŠå ¶æ¼”å˜è¶‹åŠ¿­­ä»¥å±±ä¸œçœä¸ºä¾‹.

The intensification and industrialization of agricultural production leads to more and more serious separation of crop and livestock, which causes serious contradiction between livestock excrement and environment, and major challenges for agricultural sustainable development. Here, we quantitatively investigated the spatial pattern and evolutionary trend of the sustainable development index (ESI) of the crop-livestock system using the emergy analysis and the input/output data in Shandong Province (1999-2015). The results showed that the sustainability of the crop-livestock system in Shandong Province decreased from 1999 to 2015 by 22.0%. The net emergy yield ratio (EYR), environmental load ratio (ELR), and the benefits of unit economic inputs significantly increased. The environmental pressure from the crop and livestock production increased obviously, which was closely related to the increase of industrial resources input including electricity, compound fertilizer, and agricultural machinery. There were differences in the sustainable development level of the crop-livestock system among administrative prefectures in Shandong Province. The ESI level of crop-livestock system in most regions was relatively high, while that in the coastal regions (e.g., Weihai, Yantai) and industrial region (e.g., Zibo) was relatively low. The trends of the sustainable development of crop-livestock system varied in different cities. The sustainability of central and southern Shandong was decreasing, while that of northern Shandong was increasing year by year. In 2015, the ESI of the expected crop-livestock system (100% livestock manure replaced fertilizer) could reach 8.4, which was 2.6 times of that of the current crop-livestock system (30% livestock manure replaced fertilizer).

[Preparation and in vitro evaluation of arsenic trioxide glioma targeting drug delivery system loaded by PAMAM dendrimers co-modified with RGDyC and PEG].

Arsenic trioxide (ATO) is an effective component of traditional Chinese medicine arsenic. The existing studies have shown its good inhibition and apoptosis ability on a variety of tumours. However, its toxicity and difficulties in the permeability into the blood brain barrier (BBB) has the limitation in the application of glioma treatment. Polyamide-amine dendrimer (PAMAM) is a synthetic polymer with many advantages, such as a good permeability, stability and biocompatibility. Additionally, the 5th generation of PAMAM is an ideal drug carrier due to its three-dimensional structure. In this study, the 5th generation of PAMAM co-modified with RGDyC and PEG, then confirmed by ¹H-NMR. The average particle size of nanoparticles was about 20 nm according to the nanoparticle size-potential analyser and transmission electron microscopy. in vitro release showed that the nanocarrier not only has the sustained release effect, but also some pH-sensitive properties. The cell results showed that PAMAM co-modified with RGDyC and PEGAM has a lower cytotoxicity than the non-modified group in vitro. Accordingly, the drug delivery system has a better anti-tumour effect across the blood brain barrier (BBB) in vitro, which further proves the tumour targeting of RGDyC.