Wastewater treatment plants (WWTPs) contribute increasing amounts of greenhouse gases (GHGs), due to rapid development and increasingly stringent wastewater discharge limits in China. In this study, ...GHG emissions from 38 WWTPs in Beijing were estimated using the pollutants parameter normalizing method (PPNM) and the effects of various factors were analyzed. The result showed that, the total GHG emissions of Beijing WWTPs in 2017 were 1 045 661.5 t CO2-eq (tons of CO2-equivalent), the direct and indirect emissions were 186 366.0 and 859 295.5 t CO2-eq, respectively. The average emission intensity was 0.603 kg CO2-eq/m3. Direct and indirect GHG emissions were influenced by various factors, such as treatment process, influent parameters and treatment scale. The anaerobic-anoxic-oxic (AAO) process demonstrated low emission intensities (0.092 kg CO2/m3), while biofilm processes (MBBR) obtained relatively high emission intensities (0.277 kg CO2/m3). Direct GHG emission has a positive correlation with the amount of pollutant removed and low influent pollutant concentrations (chemical oxygen demand COD<300 mg/L and total nitrogen TN <20 mg/L) can lead to high indirect GHG emission intensities. The low power utilization efficiency of small-scale WWTPs (<1 × 107 t/a; 6.60 kWh/kg COD; 30.54 kWh/kg TN) contributed to additional GHG emissions. Compared with the GHG emissions in Shanghai in 2016, higher influent pollutant concentrations and stricter discharge limits contributed to higher GHG emission intensity in Beijing for both direct (0.108 kg CO2/m3) and indirect (0.496 kg CO2/m3) emissions. The comparison results between cities indicated that the PPNM method achieved a more accurate account of GHG emissions, and the analysis results provided support for carbon emission reduction.
Display omitted
•Greenhouse gas emissions from wastewater treatment were estimated for Beijing.•Indirect greenhouse gas emission (859 295.5 tCO2-eq) was 4.6 times of direct emission (186 366.0 tCO2-eq).•AAO and MBBR are processes with lowest and highest emission intensities.•Strict discharge limits lead to high greenhouse gas emissions.
Display omitted
•Shape memory effect (SME) is discovered in P(VDF-TrFE) ferroelectric polymers.•The shape recovery speed is much faster than other shape memory polymers.•The SME is realized by a new ...mechanism (ferroelectric-paraelectric transition).•Schiff base crystals with photothermal effect and photoisomerization are designed.•The composites exhibit light-induced SME and deformation.
Polyvinylidene difluoride (PVDF)-based polymers have been extensively investigated as a type of electroactive polymer because of their wide applications in flexible sensors, actuators, and transducers. In this work, we demonstrate a new functionality of the PVDF-based polymer-shape memory effect (SME). We show that this effect mainly originates from the ferroelectric-paraelectric phase transition and that shape recovery can be realized at a high speed (<100 ms), superior to most of the existing shape memory polymers. We synthesize modified Schiff base light-sensitive materials and compound them with the polymer to achieve composites exhibiting light-activated SME in the visible light range by exploiting the photothermal effect of the Schiff base compounds. Furthermore, the composites possess light-induced deformation because of the isomerization-induced volume change of the Schiff base molecules under light illumination. To demonstrate the application potential of the multifunctional composites, flexible actuators and robots were designed by combining the thermal-, light-, and electric field-activated SME or deformation. This study not only proposes new multifunctional composites with good application potential, but also presents a new mechanism to design shape memory polymers and expands the functionality of PVDF-based ferroelectric polymers.
PM
2.5
-related neurological and mental diseases, such as cognitive impairment and stroke, tend to cause disability. Six-week-old male C57BL/6 mice were divided into 6 groups and exposed to ...concentrated PM
2.5
or filtered air for 2, 4, and 6 months, respectively. The neurobehavioral changes of mice were tested. The weight of the whole brain and olfactory bulbs were recorded at the end of exposure, and the brain structure was observed by hematoxylin and eosin (HE) staining. Serum indicators, mRNA, and protein expressions were detected. The spatial learning memory ability was impaired, and the mice were more anxious after PM
2.5
exposure. Relative brain weight decreased with age, and PM
2.5
exposure exceeded the decrease of relative brain weight. Interestingly, superoxide dismutase (SOD) and albumin decreased in the PM
2.5
-exposed groups although neuronal morphology and other serum indicators did not show significant difference between PM and FA groups. Moreover, PM
2.5
induced the increase of plasminogen at 2 months but recovered at 4 months and then increased at 6 months again. The results from protein expression and transcriptomic test demonstrated that PI3K/AKT/FoxO1 pathway might be activated after 6-month PM
2.5
exposure in mice. Indicators albumin, the percentage of albumin over IgG (A/G value), and plasminogen were the main serous changes in mice after early-stage (2 months) and long-term (6 months) PM
2.5
exposure. In addition, early-stage injury induced by PM
2.5
might recover at later time point and display significant injury again with the exposure time. PM
2.5
exposure-induced brain injury might be associated with the activation of PI3K/AKT/FoxO1 pathway.
The inter-satellite link is an important technology to improve the accuracy of clock offset measurement and prediction for BeiDou Navigation Satellite System (BDS). At present, BDS measures clock ...offsets of invisible satellite mainly through the “one-hop” reduction mode based on the satellite-ground clock offset of the node visible satellite and the inter-satellite clock offset between the two satellites. However, there exists a systematic deviation caused by the node satellite reduction, and there is still a large room for improvement in clock offset measurement and prediction. Therefore, this paper firstly proposes a method of whole-network adjustment for clock offset based on the satellite-ground and inter-satellite two-way data. The least square method is used to realize the whole-network adjustment of clock offset based on the observations of two sources, and to obtain optimal estimates of different clock offset reduction. Secondly, the evaluation method combining internal and external symbols are proposed by the fitting residual, prediction error and clock offset closure error. Finally, experimental verification is completed based on BDS measured data. In comparison with the “one-hop” reduction method, the fitting residual and prediction error of the whole-network adjustment method reduces about 45.06% and 52.15%, respectively. In addition, inter-satellite station closure error and three-satellite closure error are reduced from 0.69 ns and 0.23 ns to about 0 ns. It can be seen that the accuracy of BDS time synchronization is significantly improved.
•PI-Zn@PMF membrane prepared by blending Zn@PMF into in-situ crosslinked PI matrix.•PI matrix membrane facilitates the CO2 adsorption and catalyst immobilization.•Mass transport of reactants is ...promoted by flow-through operation.•The membrane shows a TOF of 3362 h−1 for synthesis of carbonates at mild conditions.
Synthesis of cyclic carbonates via cycloaddition of CO2 to epoxides is an important strategy for CO2 valorization. However, efficient and easy-to-handle catalytic system for this type of reaction at mild conditions is still rare. In this work, we present a polyimide-based catalytic membrane with hierarchical pore structure for flow through synthesis of cyclic carbonates at mild conditions. The membrane was fabricated by incorporating a porous and metallized poly-melamine-formaldehyde (Zn@PMF) into phase inversed polyimide (PI) matrix. Upon in-situ crosslinking with tris(2-aminoethyl)amine, the solvent-resistant PI membrane can not only facilitate the CO2 adsorption and immobilize the catalysts, but also promote mixing by flow-through operations. As a result, the nanocomposite membrane exhibited an excellent catalytic performance with a maximum TOF value of 3362 h−1 at ambient conditions. This catalytic activity is not only higher than the Zn@PMF particle but also is the highest among reported catalysts under the similar reaction conditions. Its high catalytic performance was also confirmed in CO2 cycloaddition in a synthetic flue gas stream.
The direct utilization of CH4 and CO2 to simultaneously produce C2+ hydrocarbons (C2 and aromatics) and syngas (CO and H2) on opposite sides of a mixed ionic-electronic conducting ...SrCe0.7Zr0.2Eu0.1O3-δ membrane reactor is demonstrated. On one side (interior) of the membrane reactor, direct non-oxidative methane conversion (DNMC) over an iron/silica catalyst produces C2+ hydrocarbons and H2. On the other side (outer surface) of the membrane, permeated hydrogen (driving the DNMC reaction) reacts with a CO2 sweep gas to form CO and water via the reverse water gas shift (RWGS) reaction. This novel single hydrogen-permeable membrane reactor simultaneously addresses both reduction of greenhouse gas (CO2 and CH4) emissions as well as production of value-added hydrocarbon products (C2+, CO, and H2) with in situ gas separation.
Display omitted
•Capability of the SrCe0.7Zr0.2Eu0.1O3-δ membrane reactor for utilization of CH4 and CO2 was shown.•On the feed side, CH4 upgrading to C2+ hydrocarbons was via DNMC reaction.•On the sweep side, CO2 reacts with H2 to form CO and H2O via the RWGS reaction.•Coke formation is reduced with CO2 as sweep gas.•Stable performance (CH4 conversion and product selectivity) for at least 50 h.
Abstract
Many of the currently available COVID-19 vaccines and therapeutics are not effective against newly emerged SARS-CoV-2 variants. Here, we developed the metallo-enzyme domain of angiotensin ...converting enzyme 2 (ACE2)—the cellular receptor of SARS-CoV-2—into an IgM-like inhalable molecule (HH-120). HH-120 binds to the SARS-CoV-2 Spike (S) protein with high avidity and confers potent and broad-spectrum neutralization activity against all known SARS-CoV-2 variants of concern. HH-120 was developed as an inhaled formulation that achieves appropriate aerodynamic properties for rodent and monkey respiratory system delivery, and we found that early administration of HH-120 by aerosol inhalation significantly reduced viral loads and lung pathology scores in male golden Syrian hamsters infected by the SARS-CoV-2 ancestral strain (GDPCC-nCoV27) and the Delta variant. Our study presents a meaningful advancement in the inhalation delivery of large biologics like HH-120 (molecular weight (MW) ~ 1000 kDa) and demonstrates that HH-120 can serve as an efficacious, safe, and convenient agent against SARS-CoV-2 variants. Finally, given the known role of ACE2 in viral reception, it is conceivable that HH-120 has the potential to be efficacious against additional emergent coronaviruses.
Transfer RNA-derived fragments (tRFs) are a new class of small non-coding RNAs whose biological roles in cancers are not well understood. Emerging evidence suggests that tRFs are involved in gene ...regulation at multiple levels. In this study, we constructed an integrative database, OncotRF (
http://bioinformatics.zju.edu.cn/OncotRF
), for
in silico
exploration of tRF functions, and identification of diagnostic and prognostic biomarkers in cancers. The database contains an analysis pipeline for tRF identification and characterization, analysis results of 11,211 small RNA sequencing samples and 8,776 RNA sequencing samples, and clinicopathologic annotation data from The Cancer Genome Atlas (TCGA). The results include: tRF identification and quantification across
33
cancers, abnormally expressed tRFs and genes, tRF-gene correlations, tRF-gene networks, survival analyses, and tRF-related functional enrichment analyses. Users are also able to identify differentially expressed tRFs, predict their functions, and assess the relevance of the tRF expression levels to the clinical outcome according to user-defined groups. Additionally, an online Kaplan-Meier plotter is available in OncotRF for plotting survival curves according to user-defined groups. OncotRF will be a valuable online database and functional annotation tool for researchers studying the roles, functions, and mechanisms of tRFs in human cancers.
Display omitted
•CH4 reactor/H2 separator recycle system is studied for non-oxidative CH4 conversion.•CH4 reactor/H2 separator recycle circumvents thermodynamic limit in CH4 reaction.•High purity of ...H2 product and high performance membrane separator are achieved.•>90 % selectivity and >50 % yield in aromatic product are achieved in recycle system.•Economic feasibility of CH4 reactor/H2 separator recycle system is simulated.
Direct non-oxidative methane conversion (DNMC) is one of the most promising options to convert methane (CH4) in natural gas in remote extraction sites to liquid aromatics, which is easier to transport compared to CH4 gas. The main constraint of the DNMC is low CH4 conversion, and thus aromatics product yield due to thermodynamic limitation. This work reports a gas recycle CH4 reactor/hydrogen (H2) membrane separator to achieve high CH4 conversion and aromatics yield by circumventing the thermodynamic limitation. The DNMC took place over an iron/silica (Fe/SiO2) catalyst in a packed-bed reactor to produce C2 (i.e. ethane, ethylene and acetylene) and aromatics, along with reaction product H2. The product stream passed through a condenser to collect aromatic products and then a H2-permeable membrane separator to remove H2. The unreacted CH4, C2 products and H2 residual in the product stream were sent to the recycle loop for the next round of DNMC reaction and H2 removal. The results demonstrated that >90 % product selectivity toward aromatics and >50 % aromatics yield are achieved in the gas recycle CH4 reactor/ H2 membrane separator system.
PDF
