PM Removal Research Articles

Ultralow-resistance and self-sterilization biodegradable nanofibrous membranes for efficient PM0.3 removal and machine learning-assisted health management

The development of multifunctional nanofibrous membranes (NFMs) that enable anti-viral protection during air purification and respiratory disease diagnosis for health management is of increasing importance. Herein, we unraveled a heterostructure-enhanced electro-induced stereocomplexation (HEIS) strategy to fabrication of poly(lactic acid) (PLA) NFMs enabling a combination of efficient PM removal, respiratory monitoring and self-sterilization. The strategy involved an electro-induced stereocomplexation (EIS) approach to trigger the generation of hydrogen bonds between enantiomeric poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) chains, promoting CO dipole alignment and molecular polarization during electrospinning. This was further enhanced by incorporation of Ag-doped TiO2 (Ag-TIO) nanodielectrics to promote the electroactivity and surface activity, conferring profound refinement of PLA nanofibers (from 460 nm to an ultralow level of 168 nm) and high porosities of over 91 %. Arising from the sustainable generation of plentiful charges based on triboelectric nanogenerator (TENG) mechanisms, the electroactive PLA NFMs exhibited remarkable triboelectric properties even in high-humidity environments (80 %RH), excellent PM0.3 filtration efficiency with an ultralow pressure drop (93.1 %, 31.8 Pa, 32 L/min), and 100 % antimicrobial efficiency against both E. coli and S. aureus. Moreover, a deep-learning algorithm based on convolutional neural network (CNN) was proposed to recognize various respiratory patterns. The proposed strategy confers the biodegradable NFMs an unusual combination of ultralow-resistance air purification and machine learning-assisted health management, signifying promising prospects in environmental protection and personal healthcare.

Hierarchically structured poly(lactic acid) nanofibers by organic–inorganic nanohybridization strategy towards efficient PM removal and respiratory monitoring

Despite the enormous potential in efficient removal of airborne PMs by biodegradable poly(lactic acid) (PLA) nanofiberous membranes (NFMs), current manufacturing methods still have large function gaps in providing reliable control over the fiber microstructure, membrane morphology or electret properties. Herein, the concept of organic–inorganic nanohybridization, strategically involving the combined electrospinning of PLA/TiO2 and electrospray of ZIF-8 nanodielectrics, was conceived to engender PLA NFMs (PLA/TIO@ZIF) featuring largely promoted electroactivity and surface activity, as exemplified by the increased dielectric constant and surface potential (up to 3.47 and 8.5 kV, respectively). This conferred the PLA/TIO@ZIF NFMs remarkable triboelectric nanogenerator (TENG) properties, yielding the output voltage as high as 17.9 V at 10 N and 1 Hz, and output current of 39.6 nA as driven by the humanoid respiration. Given impressive in situ electret performance and charge regeneration capability, the PLA/TIO@ZIF NFMs enabled ultrahigh PM0.3 filtering properties (90.4 %, 175 Pa, 85 L/min), accompanied by increased resistance to humidity (92.1 % removal of PM0.3, RH90 %, 32 L/min). Moreover, perfect 100 % inhibition of E. coli and S. aureus was achieved for PLA/TIO@ZIF, arising mainly from the plentiful surface charges and ROS generation. It is envisioned that the hierarchically nanostructured NFMs, offering the exceptional function integration, are highly appealing for long-term air purification and self-powered respiratory monitoring.

Enhancement and Removal of PM2.5 by Cold and Warm Air Masses Accompanying Certain Synoptic Weather Systems across Hangzhou, China during 2014–2020

Enhancement and Removal of PM2.5 by Cold and Warm Air Masses Accompanying Certain Synoptic Weather Systems across Hangzhou, China during 2014–2020

Highly Reactive Peroxide Species Promoted Soot Oxidation over an Ordered Macroporous Ce0.8Zr0.2O2 Integrated Catalyzed Diesel Particulate Filter.

Particulate matter, represented by soot particles, poses a significant global environmental threat, necessitating efficient control technology. Here, we innovatively designed and elaborately fabricated ordered hierarchical macroporous catalysts of Ce0.8Zr0.2O2 (OM CZO) integrated on a catalyzed diesel particulate filter (CDPF) using the self-assembly method. An oxygen-vacancy-enriched ordered macroporous Ce0.8Zr0.2O2 catalyst (VO-OM CZO) integrated CDPF was synthesized by subsequent NaBH4 reduction. The VO-OM CZO integrated CDPF exhibited a markedly enhanced soot oxidation activity compared to OM CZO and powder CZO coated CDPFs (T50: 430 vs 490 and 545 °C, respectively). The well-defined OM structure of the VO-OM CZO catalysts effectively improves the contact efficiency between soot and the catalysts. Meanwhile, oxygen vacancies trigger the formation of a large amount of highly reactive peroxide species (O22-) from molecular oxygen (O2) through electron abstraction from the three adjacent Ce3+ (3Ce3+ + Vö + O2 → 3Ce4+ + O22-), contributing to the efficient soot oxidation. This work demonstrates the fabrication of the ordered macroporous CZO integrated CDPF and reveals the importance of structure and surface engineering in soot oxidation, which sheds light on the design of highly efficient PM capture and removal devices.

PVC waste-derived nanofiber: Simple fabrication with high potential performance for PM removal in air filtration

The utilization of polymer waste in nanofiber membranes is still limited. This study successfully fabricated nanofiber membranes for air filtration using polyvinyl chloride (PVC) waste through electrospinning. The feed solution properties were observed by measuring viscosity and conductivity parameters at varying concentrations of PVC 10–30%, which, indeed, the concentration of PVC greatly affects the microstructure. The smallest fiber diameter was obtained with the addition of 10% PVC. However, it was found that the fiber has beads. Furthermore, the fiber diameter increased with a higher concentration of PVC without the formation of beads, in particular for the PVC concentration > 20%. The ultimate tensile strength was 3.36, 3.97, and 3.67 MPa for 20, 25, and 30% of PVC, respectively. Due to the PVC hydrophobic nature (contact angle value of 100–120°), the PVC waste nanofiber successfully reached the filtration efficiency of 94.35% for PM2.5 and 94.60% for PM0.3 filtration, with a relatively low-pressure drop of 119.12 Pa for fiber membrane with 20% of PVC waste. It implies that the quality factor (QF) is comparable to that of pure-polymer nanofibers or commercial air filters. Thus, the utilization of PVC waste-based nanofiber holds great promise for advancing air filtration systems.

An Assessment Framework for Mapping the Air Purification Service of Vegetation at the Regional Scale

Efficiently mitigating the severe air pollution resulting from rapid progress is crucial for the sustainable development of the socio-ecological system. Recently, concerns about nature-based solutions have emerged in the research on the treatment of air pollution. Studies on the purification of PM2.5 using vegetation currently concentrate on the individual scale of tree species or urban vegetation, ignoring the regional scale, which could better assist ecological governance. Therefore, taking the Fenwei Plain of China as the study area, an assessment framework of the air purification service’s spatial distribution reflecting regional vegetation was constructed. The dry deposition model and GeoDetector were used to quantify the spatial-temporal pattern and explore natural driving factors on the removal of PM2.5. The results showed that (1) the PM2.5 purification services offered by various types of vegetation exhibit notable variations. The average removal rates of PM2.5 by vegetation were 0.186%, 0.243%, and 0.435% in 2000, 2010, and 2021, respectively. (2) Meanwhile, a wide range of spatial mismatch exists between the PM2.5 concentration and PM2.5 removal. Insufficient supply regions of PM2.5 purification services account for 50% of the Fenwei Plain. (3) PM2.5 removal was strongly influenced by the types of vegetation and the Normalized Vegetation Index (NDVI), followed by the Digital Elevation Model (DEM), and less affected by meteorological factors; a strong joint effect was shown among the factors. The findings in this research provide a new perspective on regional air pollution management at the regional scale.

Source apportionment of fine particulate matter at different underground sites in the Chengdu metro system in summer

With the popularization of subway systems, subway air quality has gradually begun to attract public attention. The removal of PM2.5 based solely on concentration may not be sustainable or effective. Targeted measures directed at the emission sources of PM2.5 are therefore needed to improve removal efficiency. The quantification of the chemical composition of PM2.5 is the basis for source apportionment analysis. In this study, PM2.5 samples were collected from tunnels, carriages, platforms, and outdoor environments. The composition of PM2.5 was detected. PM2.5 sources were determined using positive matrix factorization. The average PM2.5 concentrations at subway sites followed the decreasing sequence of tunnel > carriage > platform, and were higher than those outdoors. Iron was the most abundant element in PM2.5 in the subway system. The five PM2.5 sources at subway sites, included train movement, vehicle emission, mixed source (secondary sulfate and coal combustion), secondary nitrate, and industrial emission. After analyzing the differences in PM2.5 sources at various subway sites, train movement and vehicle emission were identified as priority sources to control if we are to improve subway air quality. They are selected in particular mainly owing to their important contributions to PM2.5 release (20.4 %–33.3 % and 18.9 %–32.9 %, respectively). Overall, these findings provide unique insights for the development of targeted strategies to control subway air pollutants, thus helping to achieve healthy and sustainable subway environments.

Performance evaluation of particulate matter removal by surfactant foams

Surfactant foams can be repeatedly formed and ruptured, providing an extensive surface area which can be utilized for the contaminant removal. In order to mitigate the expenses associated with filter maintenance in the filter-equipped device, the particulate matter removal was attempted by the surfactant foam in this study, aiming to assess the feasibility as an alternative technology for improving air quality. Two types of particulate matter (Arizona test dust (ATD) and incense stick) and two types of surfactants (SLS-30 and LAO) were adopted to evaluate the removal efficiency of particulate matter under different surfactant concentrations (0.05, 0.1, and 0.2 wt%) and different flow systems (with and without internal airflow). Overall, ATD were better removed than incense stick due to the larger size which resulted in the greater sedimentation and subsequent contact with foams. Also, SLS-30 showed better removal performance than LAO as the surfactant concentration increased from 0.05 wt% to 0.2 wt%. These findings can be attributed to foam generation properties, in which SLS-30 demonstrated superior foam generation capabilities as the surfactant concentration increased, providing a larger surface area for PM adsorption as well as suppressing the remaining headspace in the chamber. The findings in this study presents the advantageous utilization of foams as an adsorbent for PM as well as a filling material in the limited space, thereby enabling enhanced PM removal capabilities.

Study on Multi-Pollutant Test and Performance Index Determination of Wet Electrostatic Precipitator

A wet electrostatic precipitator (WESP) is typically installed downstream of wet flue gas desulfurization (WFGD) to remove fine particles and sulfuric acid mists from flue gases in coal-fired power plants. The emission reduction characteristics of multiple pollutants and the energy consumption data of 214 sets of WESPs (94 sets of metal plate WESPs, 111 sets of conductive Fiber Reinforced Plastic WESPs, and 9 sets of flexible plate WESPs) were tested and analyzed, and the results showed that: WESPs had a high removal efficiency on PM, PM2.5, SO3, droplets and Hg, and mostly concentrated in ≥75%, ≥70%, ≥60%, ≥70% and ≥40%, respectively. The outlet pollutant concentrations were mostly concentrated in ≤5 mg/m3, ≤3 mg/m3, ≤5 mg/m3, ≤15 mg/m3 and ≤5 μg/m3, respectively. Specific power consumption and specific water consumption were concentrated in the range of 0.5~2.5 × 10−4 kWh/m3 and ≤10 × 10−6 t/m3. The correlation analysis of multiple pollutant’s removal performance was studied and the quantitative evaluation index requirements of high efficiency WESPs were determined in this paper. The high efficiency indexes of WESPs, such as PM emission concentration, SO3 emission concentration, PM removal efficiency, SO3 removal efficiency, pressure drop, air leakage rate and specific power consumption, were ≤2.50 mg/m3, ≤2.50 mg/m3, ≥90%, ≥85%, ≤200 Pa, ≤0.5% and ≤1.3 × 10−4 kWh/m3, respectively. The high efficiency indexes of specific water consumption for metal plate WESPs and FRP WESPs were ≤2.50 and ≤0.66 × 10−6 t/m3, respectively. This study can provide valuable reference for the following energy conservation and efficiency improvement of ultra-low emission units.

Holey Ti3C2Tx nanosheets membrane with high PM removal efficiency for air pollution

Developing air filters with high efficiency, low airflow resistance, good chemical and thermal stability is a great challenge for PM purification applications. MXene membranes with controlled interlayer nano-channels and abundant hydrophilic groups exhibit excellent separation potential. However, the easy stacking between neighboring nanosheets in two-dimensional lamellar membranes increases the resistance during the separation process. In this study, metal oxides were assembled with Ti3C2Tx nanosheets by electrostatic interaction, and holey Ti3C2Tx (H-Ti3C2Tx) nanosheets with abundant through-hole structures were prepared by calcination and etching with a specific surface of 13.2 m2g−1, 6 times higher than that of Ti3C2Tx (2.2 m2g−1). H-Ti3C2Tx nanosheet membranes with transverse and longitudinal channels were produced using vacuum filtering. The membrane has excellent PM filtration performance, with filtration efficiency higher than 94.59% for PM 0.3 and 99.97% for PM 2.5 and 99.99% for PM 10.0, respectively, and the pressure drop of 120 Pa after 12 h of operation, which is better than that of pure Ti3C2Tx membrane (>1300 Pa). Excellent PM filtration was also demonstrated under high humidity conditions. Our findings provide a scalable strategy for the synthesis of holes MXene materials as well as demonstrate their potential in air purification.

Portable botanical biofilters to address internal combustion engine exhaust exposure

Previous research has identified the capacity of active botanical biofiltration to provide significant benefits for indoor air quality, however existing systems are large and require integration into the building. Thus, a “Portable Botanical Biofilter” (PBB) has been developed, however, its pollutant filtration capacity is unknown and may be constrained due to the limited dimensions of practical portable systems. This study thus aimed to quantify a PBB's removal efficiency under controlled conditions for CO2, PM (Total Suspended Particles (TSP) along with particle size distribution) and total volatile organic compounds (TVOCs). Testing was conducted in a purpose-built 15.6 m3 chamber at two light intensities, regular lighting (79.4 μmol∙m−2 s−1) as commercially supplied to the system and with elevated supplementary lighting (167 μmol∙m−2 s−1). CO2 removal testing was conducted with the plant species Peperomia obtusifolia, Gibasis pellucida, and a no plant control. TVOC and PM removal testing was conducted with systems containing the known pollutant removing plants: Gibasis pellucida, Spathiphyllum wallisii and mixed modules containing Peperomia obtusifolia and Nematanthus glabra at the two lighting levels. All treatments removed CO2 significantly faster than the control, with supplementary lighting allowing CO2 removal at a significantly faster rate than regular lighting (0.232–0.673 g h−1). However, CO2 net removal rates were likely to be insufficient to have valuable effects in a realistically sized room. TSP removal differed significantly between treatments for plant species, but not between light levels. The system removed particles of all sizes, with promising results for the smallest particle size (PM0.3), with highly effective reduction in comparison to the control (up to ∼72%). We conclude that in its delivered, prototype state, the PBB was unlikely to be an effective air purifying device for the removal of indoor CO2, however promising results for the removal of TVOCs and PM were recorded. To improve both CO2 and other pollutant removal, further improvements to lighting, system sealing, and module design are required, along with further testing to allow comparison with other systems.

Synergistic enhancement of external electrical energy in PM filtration with Cu-HHTP@CuO nanowire arrays coated copper mesh

Developing multifunctional purification systems that combine air filtration and antibacterial functionality is a challenging task. However, in designing air filtration materials, achieving a balance between filtration efficiency and pressure drop remains a significant challenge. In this study, we developed a novel filtration material composed of hierarchically 3D Cu-HHTP nanowiskers coated CuO nanowires that were grown in-situ on a copper mesh. Benefitted from the intrinsically electrical conductivity of Cu-HHTP, we combined the composite material with external electrical energy for air filtration. By applying lower electric potential directly (voltage of 5 V), the 3D conductive mesh filter exhibited excellent performances in terms of the PM2.5 removal efficiency (∼99.7%), pressure drop (∼32 Pa at 2 cm s -1), and quality factor (0.187 at 2 cm s -1). Furthermore, after ten cycles of filtration and cleaning, the material maintained a high PM removal rate. In addition to its excellent filtration performance, the composite metal mesh also exhibited outstanding antibacterial activity against both E. coli and S. aureus. The electro-mechanical stability and recyclability of the composite filter make it a cost-effective and environmentally friendly solution for air purification, with promising potential for improving air quality.

Bifunctional Activated Carbon Ultrathin Fibers: Combining the Removal of VOCs and PM in One Material

Bifunctional Activated Carbon Ultrathin Fibers: Combining the Removal of VOCs and PM in One Material

Simulation of Dynamic Rearrangement Events in Wall-Flow Filters Applying Lattice Boltzmann Methods

Wall-flow filters are applied in the exhaust treatment of internal combustion engines for the removal of pm. Over time, the pressure drop inside those filters increases due to the continuously introduced solid material, which forms pm deposition layers on the filter substrate. This leads to the necessity of regenerating the filter. During such a regeneration process, fragments of the pm layers can potentially rearrange inside single filter channels. This may lead to the formation of specific deposition patterns, which affect a filter’s pressure drop, its loading capacity and the separation efficiency. The dynamic formation process can still not consistently be attributed to specific influence factors, and appropriate calculation models that enable a quantification of respective factors do not exist. In the present work, the dynamic rearrangement process during the regeneration of a wall-flow filter channel is investigated. As a direct sequel to the investigation of a static deposition layer in a previous work, the present one additionally investigates the dynamic behaviour following the detachment of individual layer fragments as well as the formation of channel plugs. The goal of this work is the extension of the resolved particle methodology used in the previous work via a discrete method to treat particle–particle and particle–wall interactions in order to evaluate the influence of the deposition layer topology, pm properties and operating conditions on dynamic rearrangement events. It can be shown that a simple mean density methodology represents a reproducible way of determining a channel plug’s extent and its average density, which agrees well with values reported in literature. The sensitivities of relevant influence factors are revealed and their impact on the rearrangement process is quantified. This work contributes to the formulation of predictions on the formation of specific deposition patterns, which impact engine performance, fuel consumption and service life of wall-flow filters.

High temperature resistant polyimide/polyethersulfone nano-fibers membrane for removal of PM

Air pollution is a recently global environmental problem due to rapidly industrial and economical activities, which results of serious threats to human's living environment and natural ecosystem. Fibrous membrane is a useful method to filter air pollution particles. Therefore, this study used Taguchi method to determine factors influence, while four factors included ratio of PI and PES, flow rate, voltage, and spinning time, for testing filter efficiency of electrospinning fiber. Spinning time of 20 min was defined as the best condition to generate the fibrous membrane with filter efficiency and quality of 99.54% and 5.56, and flow rate of 0.15 ml/h was the best condition to form the fibrous membrane with filter efficiency and quality of 93.84% and 0.88. Thermogravimetry and differential scanning calorimetry were used to conduct thermal analysis of nano-fiber membrane, and decomposed temperature of PI/PES was about 500 °C. Temperature of hot gas filtration usually occurred at the temperature of above 260 °C, such as 200–350 °C for waste incineration, 150–300 °C for concrete producing, and 171–210 °C for crematorium operation, so the PI/PES acquired potential advantage on application of hot gas filtration because of its high temperature resistance and high filter efficiency.

Removal of PM and oil mist from automobile exhaust by a “hamburger” structured conjugated microporous polymers membrane

The purification treatment of automobile exhaust has attracted great attention because of the severe harm of automobile exhaust to the global environment and human health. Herein, inspired by capillarity, we adopted a very simple face-to-face constrained growth method to prepare a conjugated microporous polymers membrane (C-CMPs-M) with a “Hamburger” structure through Sonogashira-Hagihara (S-H) coupling reaction for purification and filtration of gaseous, solid and liquid pollutants in automobile exhaust. Thanks to such a special structure, the C-CMPs-M−1 membrane shows an extremely high efficiency of capture and interception of PM2.5 and PM10 (greater than99.5 %) and PM0.3 (greater than95%) in the exhaust gas obtained at different engine speeds. Unlike those hydrophilic filtration materials which suffer the drawback of less tolerance in high humidity conditions, the unique superhydrophobic chemistry of the CMPs membrane makes it possible to efficiently intercept PM under high humidity conditions, and the filtration efficiency basically remains unchanged within 10 h. More interestingly, the super lipophilicity of the membrane endows it excellent oil absorption performance, e.g., high absorption of 907.61 % of its own weight for engine oil was detected and consequently good oil retention performance was also obtained. It also has a strong absorption performance for the unburned oil mist ejected from the exhaust. Based on its ideal porous structure, high interception efficiency, and good physicochemical stability at high humidity and high temperatures conditions, therefore, our C-CMPs-M−1 shows great potential in automobile exhaust purification applications.

Mechanically robust conjugated microporous polymer membranes prepared using polyvinylpyrrolidone (PVP) electrospun nanofibers as a template for efficient PM capture

Air pollution has become a challenging environmental problem worldwide due to rapid industrial development and excessive emissions of vehicle exhaust. Herein, we report a preparation of conjugated microporous polymer membranes (CMPM) with a hierarchical porous structure by electrospun polyvinylpyrrolidone (PVP) nanofibers as a template for effective removal of PM from airborne and vehicle exhaust. CMP membranes have hierarchical holes, where the macropores are from electrospun nanofiber membranes and the mesopores are from polymer synthesis. Taking advantage of its inherent physicochemical and thermal stability and hierarchical hole characteristics, the CMPM-based filter can work continuously for up to 36 h and still maintains a high removal efficiency (>99.56%), and also has a high filtration efficiency in the treatment of vehicle exhausts, with 95.18% for PM0.3, 98% for PM0.5 and >99% for PM2.5-10.0. The superior mechanical properties of CMPM allow the filter to be cleaned and reused. After three cycles, the filtration effectiveness of CMPM is still 94.83% for respirable particulate matter. Under high humidity (RH ≥ 95%) conditions, the CMPM-based filter showed higher than 95.37% filtration of PM0.3-10, and the oil adsorption rate could be maintained at 284% at high speed, proving the great potential of CMPM to clean air in complex situations.

55 ARE TWO PACEMAKERS BETTER THAN ONE? SYNCOPE WITHOUT PRODROMES IN A YOUNG PM-DEPENDENT SUBJECT: A CASE STUDY

Abstract Patient presentation and follow-up A 33-year-old woman was admitted to the ER of our hospital because of syncope without prodromes during her routine cycling training. The patient's clinical history is characterized by congenital heart disease, interventional and cardiac surgical procedures in 1992-2021: percutaneous aortic valve (AoV) reconstruction for severe aortic stenosis in bicuspid AoV; conservative surgical Ao valvuloplasty and mitral valve (MV) commissuroplasty; MV substitution surgery; surgical AoV and MV replacement; surgical iatrogenic IVD closure. Atrial fibrillation became chronic and, following repeated interventions, an iatrogenic AV block developed requiring pacemaker implantation. In Dec. 2019, a submuscular PM (epicardial leads) was implanted (Medtronic Adapta DDDRR programmed in VVIRR for permanent atrial fibrillation). 2 years later, a transvenous-lead PM was implanted (Biotronik Evity 8 SR-T VVI-RR MRI conditional) without extracting the Medtronic PM (re-programmed in “back-up” VVI 30 bpm). Patient management and treatment A conservative strategy was adopted by programming the Biotronik/endocardial device in VOO-R mode stimulation only, while waiting for the total discharge of the old (Medtronic/epicardial) device. An alternative strategy could have been the removal of the epicardial PM. PM follow-up was performed via “remote” control and clinical checks in our Congenital Heart Disease Center. The complex clinical history and the choice of up-grading to an endocardial device without removing the epicardial device, has caused a predictable condition that was overlooked. The entry into operation of the ERI VOO 65 bpm mode of the epicardial device, in addition to causing a physiological increase in the pacing threshold of the epicardial catheter itself, produced the inhibition of the endocardial device whenever there was a pacing capture failure of the epicardial system. This situation set asystole off and consequent patient's loss of consciousness. Conclusions

Sex-Dependent Responses to Maternal Exposure to PM2.5 in the Offspring.

Objective: Particulate matter (PM) with a diameter of 2.5 μm or less (PM2.5) can cross the blood-placental barrier causing adverse foetal outcomes. However, the impact of maternal exposure to low-levels of PM2.5 on liver health and the metabolic profile is unclear. This study aimed to investigate hepatic responses to long-term gestational low-dose PM2.5 exposure, and whether the removal of PM after conception can prevent such effects. Method: Female Balb/c mice (8 weeks) were exposed to PM2.5 (5 μg/day) for 6 weeks prior to mating, during gestation and lactation to model living in a polluted environment (PM group). In a sub-group, PM2.5 exposure was stopped post-conception to model mothers moving to areas with clean air (pre-gestation, Pre) group. Livers were studied in 13-week old offspring. Results: Female offspring in both PM and Pre groups had increased liver triglyceride and glycogen levels, glucose intolerance, but reduced serum insulin and insulin resistance. Male offspring from only the Pre group had increased liver and serum triglycerides, increased liver glycogen, glucose intolerance and higher fasting glucose level. Markers of oxidative stress and inflammation were increased in females from PM and Pre groups. There was also a significant sex difference in the hepatic response to PM2.5 with differential changes in several metabolic markers identified by proteomic analysis. Conclusions: Maternal PM exposure exerted sex-dependent effects on liver health with more severe impacts on females. The removal of PM2.5 during gestation provided limited protection in the offspring's metabolism regardless of sex.

Hierarchical fiber with granular-convex structure for highly efficient PM2.5 capture

Air pollution has seriously affected human health and the atmospheric environment. Preparation of fiber membrane with hierarchical structure provides an advanced method for high-performance air filtration. However, indistinctive secondary structure and complicated preparation present constantly in the formation of fiber with hierarchical structure, inevitably limited in the application of air filtration. In this work, a typical granular-convex structure was created in the surface of thermal-crosslinked sodium phytate/polyvinyl alcohol (T-PANa/PVA) fiber via green preparation. Unique secondary structure endowed fiber with efficient physical interception and polar adsorption, which exhibited excellent the removal of air pollutants (removal of PM2.5 high than 99.9% while low air resistance of 36.5 Pa). In addition, due to the exist of crosslinked network, T-PANa/PVA fiber membrane expresses water-resistant and mechanical properties. This work provides a positive strategy to fabricate hierarchical fiber membranes via green preparation for high-performance air filtration, which is expected to substitute traditional air filtration materials and adapt to the sustainable development of future.