An integrated urban air quality modeling system was applied to assess the effects of a short-term odd-even day traffic restriction scheme (TRS) on traffic-related air pollution in the urban area of ...Beijing (UAB) before, during and after the 2008 Olympic Games. Using traffic flow data retrieved from an on-line traffic monitoring system, concentration levels of CO, PM
10, NO
2 and O
3 on the 2nd, 3rd, 4th Ring Roads (RR) and Linkage Roads (LRs), the main roads distributed around the UAB, were predicted for the pre- (10th-19th, July), during- (20th July-20th September) and post-TRS (21st-30th, September) periods. A widely used statistical framework for model evaluation was adopted, the dependences of model performance on time-of-the-day and on wind direction were investigated, and the model predictions turned out reasonably satisfactory. Results showed that daily average concentrations on the 2nd, 3rd, 4th RR and LRs decreased significantly during the TRS period, by about 35.8, 38.5, 34.9 and 35.6% for CO, about 38.7, 31.8, 44.0 and 34.7% for PM
10, about 30.3, 31.9, 32.3 and 33.9% for NO
2, and about 36.7, 33.0, 33.4 and 34.7% for O
3, respectively, compared with the pre-TRS period. Hourly average concentrations were also reduced significantly, particularly for the morning and evening peaks for CO and PM
10, for the evening peak for NO
2, and for the afternoon peak for O
3. Consequently, both the daily and hourly concentration level of CO, PM
10, NO
2 and O
3 conformed to the China National Ambient Air Quality Standards Grade II during the Games. In addition, notable reduction of concentration levels was achieved in different regions of Beijing, with the traffic-related air pollution in the downwind northern and western areas relieved most significantly. The TRS policy was therefore effective in alleviating traffic-related air pollution and improving short-term air quality in Beijing during the Games.
►The current modeling study shows that traffic restriction scheme proves effective in reducing short-term traffic-related air pollution. ►A widely accepted statistical framework for model evaluation was used and justified the credibility of the modeling results. ►Daily average, hourly average and peak concentrations of major air pollutants decreased in response to the TRS policy. ►Notable reduction of concentration levels was achieved in different regions of the UAB.
Liquid-liquid phase separation (LLPS) of intrinsically disordered proteins (IDPs) is involved in both intracellular membraneless organelles and extracellular tissues. Despite growing understanding of ...LLPS, molecular-level mechanisms behind this process are still not fully established. Here, we use histidine-rich squid beak proteins (HBPs) as model IDPs to shed light on molecular interactions governing LLPS. We show that LLPS of HBPs is mediated though specific modular repeats. The morphology of separated phases (liquid-like versus hydrogels) correlates with the repeats' hydrophobicity. Solution-state NMR indicates that LLPS is a multistep process initiated by deprotonation of histidine residues, followed by transient hydrogen bonding with tyrosine, and eventually by hydrophobic interactions. The microdroplets are stabilized by aromatic clustering of tyrosine residues exhibiting restricted molecular mobility in the nano-to-microsecond timescale according to solid-state NMR experiments. Our findings provide guidelines to rationally design pH-responsive peptides with LLPS ability for various applications, including bioinspired protocells and smart drug-delivery systems.
•Synthesis of silver nanoparticles using hydroxy propyl methyl cellulose is reported.•HPMC and glucose are used as capping agent and reducing agent respectively.•It is the first time to use HPMC for ...synthesis of silver nanoparticles.•The small, spherical and well-dispersed particle is observed in the range of 3–17nm.•The green method can be extended to other noble metals.
A simple and environmentally friendly method for the synthesis of highly stable and small sized silver nanoparticles with narrow distribution from 3nm to 17nm is reported. Silver nitrate, hydroxy propyl methyl cellulose (HPMC) and glucose, were used as silver precursor, capping agents and reducing agents respectively. The formation of silver nanoparticles was observed by change of color from colorless to wine red. The silver nanoparticles were characterized by transmission electron microscopy (TEM), UV–visible spectroscopy (UV–vis), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The results demonstrated that the obtained metallic nanoparticles were single crystalline silver nanoparticles capped with HPMC. The effects of the reaction time, reaction temperature and the concentration of silver ion and reducing agents on the particle size were investigated. A possible formation mechanism was proposed. The method may be extended to other noble metal for other technological applications such as additional medicinal, industrial applications.
Population growth and industrial development have exacerbated environmental pollution of both land and aquatic environments with toxic and harmful materials. Luminescence-based chemical sensors ...crafted for specific hazardous substances operate on host-guest interactions, leading to the detection of target molecules down to the nanomolar range. Particularly, the luminescence-based sensors constructed on the basis of metal-organic frameworks (MOFs) are of increasing interest, as they can not only compensate for the shortcomings of traditional detection techniques, but also can provide more sensitive detection for analytes. Recent years have seen MOFs-based fluorescent sensors show outstanding advantages in the field of hazardous substance identification and detection. Here, we critically discuss the application of MOFs for the detection of a broad scope of hazardous substances, including hazardous gases, heavy metal ions, radioactive ions, antibiotics, pesticides, nitro-explosives, and some harmful solvents as well as luminous and sensing mechanisms of MOF-based fluorescent sensors. The outlook and several crucial issues of this area are also discussed, with the expectation that it may help arouse widespread attention on exploring fluorescent MOFs (LMOFs) in potential sensing applications.
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•MFe2O4@PC was used in visible light enhanced heterogeneous H2O2 process.•MFe2O4@PC can treat wastewater with a pH in the range of 3–7.•The surface-OH functional groups of MFe2O4@PC ...improve the adsorption properties.•The adsorption property synergizes with photocatalysis to enhance the photo-Fenton.
Nanoscale magnetic spinel ferrite composites with the general formula MFe2O4@PC (M = Fe, Cu, Co, and Mn; PC = biochar) were prepared by a facile impregnation and pretreatment method. MFe2O4@PC particles were deliberated by X-ray Diffractometer (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), Brunauer–Emmett–Teller adsorption–desorption isotherm (BET), X-ray Photoelectron Spectroscopy (XPS) and Vibrating Sample Magnetometer. The results showed that MFe2O4 coating, which is evenly distributed on the surface of HNO3-pretreated biochar, can provide more active sites to enable MFe2O4@PC to be activated by visible light. The XRD confirmed that the crystallite sizes of MFe2O4 ranged from 10.0 to 27.9 nm. With the help of surface-OH, PCoF has a rapid adsorption performance on metronidazole (MNZ) and can degrade 99% of MNZ within 20 minutes at an optimal pH of 3.0. Meanwhile, the PCuF composites showed excellent photo-Fenton catalytic performance for the degradation of MNZ under neutral pH conditions, and 96.0% of MNZ (300 mg/L) could be removed within 120 min. This study confirmed OH is the main reactant, while O2− and h+ contributed to the degradation of MNZ during photocatalysis. MFe2O4@PC composite can be separated easily by an external magnetic field. The synthesized PCoF was reused for 5 cycles and it was clear that it had no significant loss, indicating its excellent ability to remove MNZ from wastewater.
Ruthenium-doped amorphous molybdenum dioxide coupled with a reduced graphene oxide hybrid (Ru-MoO
2
@PC/rGO) is synthesized using polyoxometalate-based MOFs/GO as a precursor. Benefitting from the ...synergistic effect of numerous exposed active sites, Ru dopants and the introduction of GO, the designed catalyst shows exceptional electrocatalytic performance toward the HER in alkaline media.
Ruthenium-doped amorphous molybdenum dioxide coupled with a reduced graphene oxide hybrid (Ru-MoO
2
@PC/rGO) is synthesized using polyoxometalate-based MOFs/GO as a precursor.
We report a two-dimensional spectroscopic analysis of massive red spiral galaxies (M* > 1010.5 M ) and compare them to blue spiral and red elliptical galaxies above the same mass limit based on the ...public SDSS DR15 MaNGA observations. We find that the stellar population properties of red spiral galaxies are more similar to those of elliptical galaxies than to blue spiral galaxies. Red spiral galaxies show a shallow mass-weighted age profile, and they have higher stellar metallicity and Mgb/ 〈 Fe 〉 across the whole 1.5Re as compared to blue spirals, but all these properties are close to those of elliptical galaxies. One scenario to explain this is that red spirals form as remnants of very-gas-rich major mergers that happened above z ∼ 1.
In the upcoming internet of things (IoT) era, spin transfer torque magnetic tunnel junction (STT-MTJ) based non-volatile (NV) memory and circuits for IoT nodes and normally-off electronics will need ...to meet constraints in speed, energy and robustness. This study focuses on NV logic-in-memory (LIM) architecture. Supply voltage (V dd ) scaling in MTJ based NV-LIM is evaluated on FD-SOI 28 nm node. In order to overcome V dd scaling bottleneck, an efficient framework for V dd scaling in NV circuits is proposed with design strategies, e.g., back-bias (BB), poly biasing (PB), and approximate computing. The design vector (V dd ,V BB ,PB) generated power-delay curves can provide user-defined LIM circuit aiming for dynamic/leakage power saving, power/speed efficiency and process variation resilient. The design space is explored in near-threshold regime around 0.5 V supply. Simulations of NV-logic, full adder (NV-FA) and flip-flop (NV-FF) are performed, along with insights for circuit design and practical implementation of NV-LIM circuits with FD-SOI technology.
To improve the response rate of immune checkpoint inhibitors such as anti-PD-L1 antibody in immunosuppressive cancers like triple-negative breast cancer (TNBC), induction of immunogenic cell death ...(ICD) at tumor sites can increase the antigenicity and adjuvanticity to activate the immune microenvironment so that tumors become sensitive to the intervention of immune checkpoint inhibitors. Herein, a self-amplified biomimetic nanosystem, mEHGZ, was constructed by encapsulation of epirubicin (EPI), glucose oxidase (Gox) and hemin in ZIF-8 nanoparticles and coating of the nanoparticles with calreticulin (CRT) over-expressed tumor cell membrane. EPI acts as an ICD inducer, Gox and hemin medicate the cascade generation of reactive oxygen species (ROS) to strengthen the ICD effect, and CRT-rich membrane as “eat me” signal promote presentation of the released antigens by dendritic cells (DCs) to invoke the tumor-immunity cycle. The biomimetic delivery system displays an amplified ICD effect via Gox oxidation, hydroxyl radical generation and glutathione (GSH) depletion. The induced potent ICD effect promotes DCs maturation and cytotoxic T lymphocytes (CTLs) infiltration, reversing an immunosuppressive tumor microenvironment to an immunoresponsive one. Treatment with the nanosystem in combination with anti-PD-L1 antibody results in distinctive inhibition of tumor growth and lung metastasis, supporting that a potent ICD effect can significantly boost the therapeutic efficacy of the anti-PD-L1 antibody. This self-amplified biomimetic nanoplatform offers a promising means of raising the response rate of immune checkpoint inhibitors.
A biomimetic nanosystem encapsulates epirubicin (EPI), glucose oxidase (Gox) and hemin in the core of ZIF-8 nanoparticles and coats with calreticulin (CRT) over-expressed tumor cell membranes as the outermost layer (mEHGZ), which induces cascade-amplified ICD effect to promote dendritic cells (DCs) maturation and cytotoxic T lymphocytes (CTLs) infiltration into tumor site. These create an immunoactivated tumor microenvironment to boost anti-PD-L1 antibody therapeutic effect. Display omitted
•To improve the response rate of immune checkpoint inhibitor in triple-negative breast cancer, a self-amplified biomimetic nanosystem was prepared.•The nanosystem displayed an amplified immunogenic cell death (ICD) effect via hydroxyl radical generation and glutathione depletion.•The potent ICD effect has promoted dendritic cells maturation and cytotoxic T lymphocytes infiltration into tumor sites to boost the anti-PD-L1 antibody therapeutic effect.
Abstract.
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