Genome-wide identification and expression pattern analysis of the GRF transcription factor family in Astragalus mongholicus.

BACKGROUND: Astragalus membranaceus is a plant of the Astragalus genus, which is used as a traditional Chinese herbal medicine with extremely high medicinal and edible value. Astragalus mongholicus, as one of the representative medicinal materials with the same origin of medicine and food, has a rising market demand for its raw materials, but the quality is different in different production areas. Growth-regulating factors (GRF) are transcription factors unique to plants that play important roles in plant growth and development. Up to now, there is no report about GRF in A. mongholicus. METHODS AND RESULTS: This study conducted a genome-wide analysis of the AmGRF gene family, identifying a total of nine AmGRF genes that were classified into subfamily V based on phylogenetic relationships. In the promoter region of the AmGRF gene, we successfully predicted cis-elements that respond to abiotic stress, growth, development, and hormone production in plants. Based on transcriptomic data and real-time quantitative polymerase chain reaction (qPCR) validation, the results showed that AmGRFs were expressed in the roots, stems, and leaves, with overall higher expression in leaves, higher expression of AmGRF1 and AmGRF8 in roots, and high expression levels of AmGRF1 and AmGRF9 in stems. CONCLUSIONS: The results of this study provide a theoretical basis for the further exploration of the functions of AmGRFs in plant growth and development.

Adjustable ultraviolet and white light dual emission phosphor Y2Sr(Ga1-yAly)4SiO12:xPr3+ for health lighting.

Mid-ultraviolet light (290-320 nm) can promote human vitamin D synthesis, which helps in the prevention and treatment of rickets and cartilage disease. For people who lack sufficient ultraviolet radiation all year round, it is significant to supplement the ultraviolet component in daily lighting sources. However, there are few luminous materials showing a combination of mid-ultraviolet light and white light emission on the market. Here, we designed a new material, Y2Sr(Ga1-yAly)4SiO12:xPr3+ (YSGAS:xPr3+), which achieves dual emission of 320 nm ultraviolet and white light from a single substrate with a single doped phosphor. Without Al3+ ions, the emission intensity of the Y2SrGa4SiO12:xPr3+ phosphor shows a contribution-dependent relationship, and concentration quenching due to exchange interaction. The crystal field environment was regulated by partially replacing Ga3+ ions with Al3+ ions. After introducing Al3+, YSGAS:xPr3+ phosphors exhibit dual ultraviolet emission (320 nm) and visible light emission. The emission color of YSGAS:xPr3+ can be adjusted by changing the Al3+ concentration, and Y2Sr(Ga0.6Al0.4)4SiO12:1%Pr3+ emits both ultraviolet light and white light. The LED device prepared by using the YSGAS:Pr3+ phosphor and chips shows a color temperature of 4858 K and appropriate CIE coordinates of (0.3474, 0.3390), indicating wide application prospects in the field of "health lighting" for particular populations.

Speckle wavemeter based on a multi-core fiber and compressive imaging.

Random speckle patterns contain valuable information about the incident light. Researchers have successfully constructed spectrometers and wavemeters by utilizing the speckles generated by inter-mode interferences of a multimode fiber (MMF). However, cameras were often employed to record the speckle data in previous reports. The camera's high cost (especially in the near-infrared range), large size, and low response speed limit the applications in optical communications, metrology, and optical sensing. A seven-core fiber (SCF) was fused with an MMF to capture the speckle pattern, where each core coupled part of the speckle field. Furthermore, we take advantage of the space division multiplexing capability of the SCF by incorporating an optical switch. This allows the variety of speckles generated by the incidence of different cores into the MMF. A convolutional neural network (CNN) regression algorithm was designed to analyze the complicated speckle data. The experimental results show that the proposed wavemeter can resolve adjacent wavelengths of 1 pm with an error of about 0.2 pm. We also discussed how different lengths of MMF influence the wavelength resolution. In conclusion, our research presents a robust and cost-effective approach to a wavelength measurement device by use of a seven-core optical fiber.

Defect Engineering of WO3 by Rapid Flame Reduction for Efficient Photoelectrochemical Conversion of Methane into Liquid Oxygenates.

Photoelectrochemical (PEC) conversion is a promising way to use methane (CH4) as a chemical building block without harsh conditions. However, the PEC conversion of CH4 to value-added chemicals remains challenging due to the thermodynamically favorable overoxidation of CH4. Here, we report WO3 nanotube (NT) photoelectrocatalysts for PEC CH4 conversion with high liquid product selectivity through defect engineering. By tuning the flame reduction treatment, we carefully controlled the oxygen vacancies of WO3 NTs. The optimally reduced WO3 NTs suppressed overoxidation of CH4 showing a high total C1 liquid selectivity of 69.4% and a production rate of 0.174 µmol cm-2 h-1. Scanning electrochemical microscopy revealed that oxygen vacancies can restrain the production of hydroxyl radicals, which, in excess, could further oxidize C1 intermediates to CO2. Additionally, band diagram analysis and computational studies elucidated that oxygen vacancies thermodynamically suppress overoxidation. This work introduces a strategy for understanding and controlling the selectivity of photoelectrocatalysts for direct conversion of CH4 to liquids.

Trollius chinensis Bunge: A Comprehensive Review of Research on Botany, Materia Medica, Ethnopharmacological Use, Phytochemistry, Pharmacology, and Quality Control.

Trollius chinensis Bunge, a perennial herb belonging to the Ranunculaceae family, has been extensively used in traditional Chinese medicine. Documented in the Supplements to the Compendium of Materia Medica, its medicinal properties encompass a spectrum of applications, including heat clearance, detoxification, alleviation of oral/throat sores, earaches, eye pain, cold-induced fever, and vision improvement. Furthermore, T. chinensis is used in clinical settings to treat upper respiratory infections, pharyngitis, tonsillitis, esoenteritis, canker, bronchitis, etc. It is mainly used to treat inflammation, such as inflammation of the upper respiratory tract and nasal mucosa. This comprehensive review explores the evolving scientific understanding of T. chinensis, covering facets of botany, materia medica, ethnopharmacological use, phytochemistry, pharmacology, and quality control. In particular, the chemical constituents and pharmacological research are reviewed. Polyphenols, mainly flavonoids and phenolic acids, are highly abundant among T. chinensis and are responsible for antiviral, antimicrobial, and antioxidant activities. The flower additionally harbors trace amounts of volatile oil, polysaccharides, and other bioactive compounds. The active ingredients of the flower have fewer side effects, and it is used in children because of its minimal side effects, which has great research potential. These findings validate the traditional uses of T. chinensis and lay the groundwork for further scientific exploration. The sources utilized in this study encompass Web of Science, Pubmed, CNKI site, classic monographs, Chinese Pharmacopoeia, Chinese Medicine Dictionary, and doctoral and master's theses.

Identification of the lateral organ boundary domain gene family and its preservation by exogenous salicylic acid in Cerasus humilis.

The gene family known as the Lateral Organ Boundary Domain (LBD) is responsible for producing transcription factors unique to plants, which play a crucial role in controlling diverse biological activities, including their growth and development. This research focused on examining Cerasus humilis'ChLBD gene, owing to its significant ecological, economic, and nutritional benefits. Examining the ChLBD gene family's member count, physicochemical characteristics, phylogenetic evolution, gene configuration, and motif revealed 41 ChLBD gene family members spread across 8 chromosomes, with ChLBD gene's full-length coding sequences (CDSs) ranging from 327 to 1737 base pairs, and the protein sequence's length spanning 109 (ChLBD30)-579 (ChLBD35) amino acids. The molecular weights vary from 12.068 (ChLBD30) to 62.748 (ChLBD35) kDa, and the isoelectric points span from 4.74 (ChLBD20) to 9.19 (ChLBD3). Categorizing them into two evolutionary subfamilies: class I with 5 branches, class II with 2, the majority of genes with a single intron, and most members of the same subclade sharing comparable motif structures. The results of collinearity analysis showed that there were 3 pairs of tandem repeat genes and 12 pairs of fragment repeat genes in the Cerasus humilis genome, and in the interspecific collinearity analysis, the number of collinear gene pairs with apples belonging to the same family of Rosaceae was the highest. Examination of cis-acting elements revealed that methyl jasmonate response elements stood out as the most abundant, extensively dispersed in the promoter areas of class 1 and class 2 ChLBD. Genetic transcript analysis revealed that during Cerasus humilis' growth and maturation, ChLBD developed varied control mechanisms, with ChLBD27 and ChLBD40 potentially playing a role in managing color alterations in fruit ripening. In addition, the quality of calcium fruit will be affected by the environment during transportation and storage, and it is particularly important to use appropriate means to preserve the fruit. The research used salicylic acid-treated Cerasus humilis as the research object and employed qRT-PCR to examine the expression of six ChLBD genes throughout storage. Variations in the expression of the ChLBD gene were observed when exposed to salicylic acid, indicating that salicylic acid could influence ChLBD gene expression during the storage of fruits. This study's findings lay the groundwork for additional research into the biological role of the LBD gene in Cerasus humilis. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01438-5.

High-breathable, antimicrobial and water-repellent face mask for breath monitoring.

Face masks with multiple functionalities and exceptional durability have attracted increasing interests during the COVID-19 pandemic. How to integrate the antibacterial property, comfortability during long-time wearing, and breath monitoring capability together on a face mask is still challenging. Here we developed a kind of face mask that assembles the particles-free water-repellent fabric, antibacterial fabric, and hidden breath monitoring device together, resulting in the highly breathable, water-repellent, and antibacterial face mask with breath monitoring capability. Based on the rational design of the functional layers, the mask shows exceptional repellency to micro-fogs generated during breathing while maintaining high air permeability and inhibiting the passage of bacteria-containing aerogel. More importantly, the multi-functional mask can also monitor the breath condition in a wireless and real-time fashion, and collect the breath information for epidemiological analysis. The resultant mask paves the way to develop multi-functional breath-monitoring masks that can aid the prevention of the secondary transmission of bacteria and viruses while preventing potential discomfort and face skin allergy during long-period wearing.

A novel approach for studying mast cell-driven disorders: Mast cells derived from induced pluripotent stem cells.

BACKGROUND: Mast cells (MCs) are considered the main effectors in allergic reactions and well known for their contribution to the pathogenesis of various inflammatory diseases, urticaria, and mastocytosis. To study their functions in vitro, human primary MCs are isolated directly from several tissues or differentiated from hematopoietic progenitors. However, these techniques bear several disadvantages and challenges including low proliferation capacity, donor-dependent heterogeneity, and the lack of a continuous cell source. OBJECTIVE: To address this, we developed a novel strategy for the rapid and efficient differentiation of MCs from human-induced pluripotent stem cells (hiPSCs). METHODS: A 4-step protocol for the generation of hiPSC-derived MCs, based on the use of 3 hiPSC lines, was established and validated by comparison with human skin MCs and peripheral hematopoietic stem cell-derived MCs. RESULTS: hiPSC-MCs share phenotypic and functional characteristics of human skin MCs and peripheral hematopoietic stem cell-derived MCs. They display stable expression of the MC-associated receptors CD117, FcεRIα, and Mas-related G protein-coupled receptor X2 and degranulate in response to IgE/anti-IgE and substance P. CONCLUSIONS: This novel hiPSC-based approach provides a sustainable and homogeneous source for a rapid and highly productive generation of phenotypically mature, functional MCs, and its principle allows for the investigation of disease- and patient-specific MC populations.

Mast cells, cortistatin, and its receptor, MRGPRX2, are linked to the pathogenesis of chronic prurigo.

BACKGROUND: Chronic prurigo (CPG) is characterized by intensive itch and interactions among nerves, neuropeptides, and mast cells (MCs). The role of some neuropeptides such as cortistatin (CST) and its receptor, Mas-related G protein-coupled receptor X2 (MRGPRX2), in CPG remains poorly investigated. OBJECTIVES: We evaluated first whether CST activates human skin MCs, and second whether CST and MRGPRX2 are expressed in the skin of CPG patients, and by which cells. METHODS: Skin prick tests and microdialysis with CST were performed in 6 and 1 healthy volunteers, respectively. Degranulation of human skin MCs was assessed using ß-hexosaminidase and histamine release assays. Skin samples from 10 patients with CPG and 10 control subjects were stained for CST, MCs, and MRGPRX2 (protein and mRNA) using immunohistochemistry, immunofluorescence, and/or in situ hybridization. Flow cytometry was used to assess CST in human skin MCs. MRGPRX2 levels were measured in serum by ELISA. RESULTS: CST induced concentration-dependent degranulation of human skin MCs in vivo and ex vivo. Skin lesions of CPG patients exhibited markedly higher numbers of CST-expressing cells, CST-expressing MCs, MRGPRX2-expressing cells, and MRGPRX2 mRNA-expressing cells than nonlesional skin. MCs were the main MRGPRX2 mRNA-expressing cells in the lesions of most CPG patients (70%). Stimulation of human skin MCs with anti-IgE led to a release of CST. The number of MRGPRX2-expressing cells correlated with disease severity (r = 0.649, P = .04). MRGPRX2 serum levels in CPG patients correlated with disease severity (r = 0.704, P = .023) and quality-of-life impairment (r = 0.687, P = .028). CONCLUSIONS: CST and MRGPRX2 may contribute to the pathogenesis of CPG and should be evaluated in further studies as potential biomarkers and novel therapeutic targets.

Deep learning for emergency ascites diagnosis using ultrasonography images.

PURPOSE: The detection of abdominal free fluid or hemoperitoneum can provide critical information for clinical diagnosis and treatment, particularly in emergencies. This study investigates the use of deep learning (DL) for identifying peritoneal free fluid in ultrasonography (US) images of the abdominal cavity, which can help inexperienced physicians or non-professional people in diagnosis. It focuses specifically on first-response scenarios involving focused assessment with sonography for trauma (FAST) technique. METHODS: A total of 2985 US images were collected from ascites patients treated from 1 January 2016 to 31 December 2017 at the Shenzhen Second People's Hospital. The data were categorized as Ascites-1, Ascites-2, or Ascites-3, based on the surrounding anatomy. A uniform standard for regions of interest (ROIs) and the lack of obstruction from acoustic shadow was used to classify positive samples. These images were then divided into training (90%) and test (10%) datasets to evaluate the performance of a U-net model, utilizing an encoder-decoder architecture and contracting and expansive paths, developed as part of the study. RESULTS: Test results produced sensitivity and specificity values of 94.38% and 68.13%, respectively, in the diagnosis of Ascites-1 US images, with an average Dice coefficient of 0.65 (standard deviation [SD] = 0.21). Similarly, the sensitivity and specificity for Ascites-2 were 97.12% and 86.33%, respectively, with an average Dice coefficient of 0.79 (SD = 0.14). The accuracy and area under the curve (AUC) were 81.25% and 0.76 for Ascites-1 and 91.73% and 0.91 for Ascites-2. CONCLUSION: The results produced by the U-net demonstrate the viability of DL for automated ascites diagnosis. This suggests the proposed technique could be highly valuable for improving FAST-based preliminary diagnoses, particularly in emergency scenarios.

ARID1B/SUB1-activated lncRNA HOXA-AS2 drives the malignant behaviour of hepatoblastoma through regulation of HOXA3.

It has been becoming increasingly evident that long non-coding RNAs (lncRNAs) play important roles in various human cancers. However, the biological processes and clinical significance of most lncRNAs in hepatoblastoma (HB) remain unclear. In our previous study, genome-wide analysis with a lncRNA microarray found that lncRNA HOXA-AS2 was up-regulated in HB. Stable transfected cell lines with HOXA-AS2 knockdown or overexpression were constructed in HepG2 and Huh6 cells, respectively. Our data revealed knockdown of HOXA-AS2 increased cell apoptosis and inhibited cell proliferation, migration and invasion in HB. Up-regulation of HOXA-AS2 promoted HB malignant biological behaviours. Mechanistic investigations indicated that HOXA-AS2 was modulated by chromatin remodelling factor ARID1B and transcription co-activator SUB1, thereby protecting HOXA3 from degradation. Therefore, HOXA-AS2 positively regulates HOXA3, which might partly demonstrate the involvement of HOXA3 in HOXA-AS2-mediated HB carcinogenesis. In conclusion, HOXA-AS2 is significantly overexpressed in HB and the ARID1B/HOXA-AS2/HOXA3 axis plays a critical role in HB tumorigenesis and development. These results might provide a potential new target for HB diagnosis and therapy.

The role of comorbid hypertriglyceridemia and abdominal obesity in the severity of acute pancreatitis: a retrospective study.

BACKGROUND: The effect of comorbid hypertriglyceridemia (HTG) and abdominal obesity (AO) on acute pancreatitis (AP) remains unclear. The aim of this study was to explore the effect of comorbid HTG and AO and discuss which is the dominant disorder. METHODS: In this study, 1219 AP patients who presented with HTG or AO were stratified into four groups: non-HTG + non-AO, HTG + non-AO, non-HTG + AO, and HTG + AO. RESULTS: The 328 patients with comorbid HTG + AO were much younger (42.29 ± 11.77), mainly male (79.57%), and had higher TG levels, larger waist circumferences, and more past medical histories than the patients in the other three non-comorbid groups (P < 0.001). The comorbidity group developed more incidences of persistent organ failure and local complications (P < 0.05). Multivariate logistic regression analysis showed that AO (OR = 3.205, 95% CI = 1.570-6.544), mild HTG (OR = 2.746, 95% CI = 1.125-6.701), and moderate to very severe HTG (OR = 3.649, 95% CI = 1.403-9.493) were independent risk factors for persistent respiratory failure (P < 0.05). Age > 60 years (OR = 1.326, 95% CI = 1.047-1.679), AO (OR = 1.701, 95% CI = 1.308-2.212), diabetes mellitus (OR = 1.551, 95% CI = 1.063-2.261), mild HTG (OR = 1.549, 95% CI = 1.137-2.112), and moderate to very severe HTG (OR = 2.810, 95% CI = 1.926-4.100) were independent risk factors associated with local complications (P < 0.05). Moreover, HTG seemed to be more dangerous than AO. The higher the serum TG level was, the greater the likelihood of persistent respiratory failure and local complications. CONCLUSIONS: Comorbid HTG and AO will aggravate the severity and increase the incidence of local complications of AP. HTG may play a dominant role of risk in the condition of comorbidity. CHINESE CLINICAL TRIAL REGISTRY: ChiCTR2100049566 . Registered on 3rd August, 2021. Retrospectively registered, https://www.chictr.org.cn/edit.aspx?pid=127374&htm=4 .

Bearing Fault Diagnosis via Improved One-Dimensional Multi-Scale Dilated CNN.

Bearings are the key and important components of rotating machinery. Effective bearing fault diagnosis can ensure operation safety and reduce maintenance costs. This paper aims to develop a novel bearing fault diagnosis method via an improved multi-scale convolutional neural network (IMSCNN). In traditional convolutional neural network (CNN), a fixed convolutional kernel is often employed in the convolutional layer. Thus, informative features can not be fully extracted for fault diagnosis. In the proposed IMSCNN, a 1D dimensional convolutional layer is used to mitigate the effect of noise contained in vibration signals. Then, four dilated convolutional kernels with different dilation rates are integrated to extract multi-scale features through the inception structure. Experimental results from the popular CWRU and PU datasets show the superiority of the proposed method by comparison with other related methods.

Cost Analysis of Carbon Capture and Sequestration of Process Emissions from the U.S. Industrial Sector.

The industrial sector represents roughly 22% of U.S. emissions. Unlike emissions from fossil-fueled power plants, the carbon footprint of the industrial sector represents a complex mixture of stationary combustion and process emissions produced as a reaction byproduct of cement, iron and steel, glass, and oil production. This study quantifies the potential opportunities for low-cost carbon capture and storage (CCS) scenarios with process emissions from the U.S. industrial sector by analyzing the variabilities in point-source capture and geographic proximity to relevant sinks, specifically enhanced oil recovery (EOR) and geologic sequestration opportunities. Using a technology-agnostic cost model developed from mature CO2 capture technologies, costs of CCS are calculated for each of the 656 facilities considered, with application of the U.S. federal tax credit 45Q to qualifying facilities. Capture of these targeted industrial process emission streams may lead to the avoidance of roughly 195 MtCO2/yr (188 MtCO2/yr qualifying for 45Q). A total of 123 facilities have the potential to avoid roughly 68.5 MtCO2/yr at costs below $40/tCO2 delivered. This could be competitive for using CO2 for EOR depending on the price of oil. At regional CO2 collection hubs, emissions of 40 MtCO2/yr can be avoided within 100 miles of the existing Louisiana-Mississippi and Texas-New Mexico pipelines.

Cost Analysis of Carbon Capture and Sequestration from U.S. Natural Gas-Fired Power Plants.

Despite increasing efforts to decarbonize the power sector, the utilization of natural gas-fired power plants is anticipated to continue. This study models existing solvent-based carbon capture technologies on natural gas-fired power plants, using site-specific emissions and regionally defined cost parameters to calculate the cost of CO2 avoided for two scenarios: delivery to and injection within reliable sequestration sites, and delivery and injection for the purpose of CO2-enhanced oil recovery (EOR). Despite the application of credits from the existing federal tax code 45Q, a minimum incentive gap of roughly $38/tCO2 remains for the geologic sequestration of CO2 and $56/tCO2 for CO2-EOR (before consideration of revenue generated from delivered CO2 contracts). At full escalation of 45Q, delivered CO2 costs from this sector for geologic sequestration could reach as low as $22/tCO2. However, given the capital investment required in the near-term, it would be beneficial if the credit provided the greatest economic benefit early on and decreasing over time as deployment continues to ramp up. Additionally, due to the high qualifying limit of 45Q for the power sector, e.g., 500 ktCO2/yr, the tax credit incentivizes the capture of roughly 397 MtCO2/yr at a 90% capture efficiency or 75% of the emissions in this sector, with missed opportunities equating to roughly 118 MtCO2. Advancing the scale of carbon capture and sequestration (CCS) will require both technological advances in the capture technology, cost reductions through the leveraging of existing infrastructure, and increased policy incentives in terms of cost along with the reduction of qualifying limits.

Cost Analysis of Direct Air Capture and Sequestration Coupled to Low-Carbon Thermal Energy in the United States.

Negative emissions technologies will play an important role in preventing 2 °C warming by 2100. The next decade is critical for technological innovation and deployment to meet mid-century carbon removal goals of 10-20 GtCO2/yr. Direct air capture (DAC) is positioned to play a critical role in carbon removal, yet remains under paced in deployment efforts, mainly because of high costs. This study outlines a roadmap for DAC cost reductions through the exploitation of low-temperature heat, recent U.S. policy drivers, and logical, regional end-use opportunities in the United States. Specifically, two scenarios are identified that allow for the production of compressed high-purity CO2 for costs ≤$300/tCO2, net delivered with an opportunity to scale to 19 MtCO2/yr. These scenarios use thermal energy from geothermal and nuclear power plants to produce steam and transport the purified CO2 via trucks to the nearest opportunity for direct use or subsurface permanent storage. Although some utilization pathways result in the re-emission of CO2 and cannot be considered true carbon removal, they would provide economic incentive to deploying DAC plants at scale by mid-century. In addition, the federal tax credit 45Q was applied for qualifying facilities (i.e., producing ≥100 ktCO2/yr).

Lithiation-Aided Conversion of End-of-Life Lithium-Ion Battery Anodes to High-Quality Graphene and Graphene Oxide.

In the past two decades, lithium-ion (Li-ion) batteries have transformed the appearance of the world. Along with the ever-increasing production and usage are the tremendous number of retired batteries, which have created social and environmental issues, making battery recycling an urgent task. Graphene has exhibited outstanding electronic and mechanical properties but it is still difficult to fabricate high-quality graphene with feasible procedures at low cost. Here, a strategy of smartly converting retired Li-ion battery anodes to graphene and graphene oxide is proposed. The graphite powders collected from end-of-life Li-ion batteries exhibited irregular expansion because of the lithium-ion intercalation and deintercalation in the anodegraphite during battery charge/discharge. Such prefabrication process facilitated both chemical and physical exfoliations of the graphite. Comparing with the graphene oxide derived from pristine, untreated graphite, the graphene oxide from anodegraphite exhibited superlative homogeneity and electrochemical properties. The lithiation aided pre-expansion enabled 4 times enhancement of graphene productivity by shear mixing. Furthermore, the graphene fabrication was seamlessly inserted into the currently used battery recycling streamline in which the acid treatment was found to further swell the graphite lattice, pushing up the graphene productivity to 83.7% (10 times higher than that of pristine graphite powders). The findings create new opportunities for capitalizing on waste batteries to produce high-quality graphene and its derivatives.

Surface Interaction of Water-in-Oil Emulsion Droplets with Interfacially Active Asphaltenes.

Adsorption of interfacially active components at the water/oil interface plays critical roles in determining the properties and behaviors of emulsion droplets. In this study, the droplet probe atomic force microscopy (AFM) technique was applied, for the first time, to quantitatively study the interaction mechanism between water-in-oil (W/O) emulsion droplets with interfacially adsorbed asphaltenes. The behaviors and stability of W/O emulsion droplets were demonstrated to be significantly influenced by the asphaltene concentration of organic solution where the emulsions were aged, aging time, force load, contact time, and solvent type. Bare water droplets could readily coalesce with each other in oil (i.e., toluene), while interfacially adsorbed asphaltenes could sterically inhibit droplet coalescence and induce interfacial adhesion during separation of the water droplets. For low asphaltene concentration cases, the adhesion increased with increasing asphaltene concentration (≤100 mg/L), but it significantly decreased at relatively high asphaltene concentration (e.g., 500 mg/L). Experiments in Heptol (i.e., mixture of toluene and heptane) showed that the addition of a poor solvent for asphaltenes (e.g., heptane) could enhance the interfacial adhesion between emulsion droplets at relatively low asphaltene concentration but could weaken the adhesion at relatively high asphaltene concentration. This work has quantified the interactions between W/O emulsion droplets with interfacially adsorbed asphaltenes, and the results provide useful implications into the stabilization mechanisms of W/O emulsions in oil production. The methodology in this work can be readily extended to other W/O emulsion systems with interfacially active components.

Hierarchical N-Doped Carbon as CO2 Adsorbent with High CO2 Selectivity from Rationally Designed Polypyrrole Precursor.

Carbon capture and sequestration from point sources is an important component in the CO2 emission mitigation portfolio. In particular, sorbents with both high capacity and selectivity are required for reducing the cost of carbon capture. Although physisorbents have the advantage of low energy consumption for regeneration, it remains a challenge to obtain both high capacity and sufficient CO2/N2 selectivity at the same time. Here, we report the controlled synthesis of a novel N-doped hierarchical carbon that exhibits record-high Henry's law CO2/N2 selectivity among physisorptive carbons while having a high CO2 adsorption capacity. Specifically, our synthesis involves the rational design of a modified pyrrole molecule that can co-assemble with the soft Pluronic template via hydrogen bonding and electrostatic interactions to give rise to mesopores followed by carbonization. The low-temperature carbonization and activation processes allow for the development of ultrasmall pores (d < 0.5 nm) and preservation of nitrogen moieties, essential for enhanced CO2 affinity. Furthermore, our described work provides a strategy to initiate developments of rationally designed porous conjugated polymer structures and carbon-based materials for various potential applications.

Molecular simulations of nitrogen-doped hierarchical carbon adsorbents for post-combustion CO2 capture.

A present challenge in the mitigation of anthropogenic CO2 emissions involves the design of less energy- and water-intensive capture technologies. Sorbent-based capture represents a promising solution, as these materials have negligible water requirements and do not incur the heavy energy penalties associated with solvent regeneration. However, to be considered competitive with traditional technologies (i.e., MEA capture), these sorbents must exhibit a high CO2 loading capacity and high CO2/N2 selectivity. It has been reported that ultramicroporous character and surface nitrogen functionality are of great importance to the enhancement of CO2 capacity and CO2/N2 selectivity. However, the role of pore size in combination with surface functionality in the enhancement of these properties remains unclear. To investigate these effects, grand canonical Monte Carlo (GCMC) simulations were carried out on pure and N-functionalized 3-layer graphitic slit-pore models and compared to experimental results for two high performing materials reported elsewhere. We show that the quaternary, pyridinic, and especially the oxidized pyridinic group lend to enhanced performance, with the latter providing exceptional CO2 loading (4.31 mmol g-1) and CO2/N2 selectivity (138.3 : 1). Increasing surface nitrogen content resulted in enhanced loading and excellent CO2/N2 selectivity (45.8 : 1-55.9 : 1), provided that the sorbent has significant ultramicroporous character. Additionally, we elucidate a threshold pore width, under which N-functionalization becomes increasingly influential on performance parameters, and show how this threshold changes with application (PC vs. NGCC capture). Finally, we propose that an alternative functionality - the nitroso group - may be responsible for the enhanced performance of some recent materials reported in the literature.