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Multiplexed nucleic acid sensing methods with high specificity are vital for clinical diagnostics and infectious disease control, especially in the postpandemic era. Nanopore sensing techniques have developed in the past two decades, offering versatile tools for biosensing while enabling highly sensitive analyte measurements at the single-molecule level. Here, we establish a nanopore sensor based on DNA dumbbell nanoswitches for multiplexed nucleic acid detection and bacterial identification. The DNA nanotechnology-based sensor switches from an "open" into a "closed" state when a target strand hybridizes to two sequence-specific sensing overhangs. The loop in the DNA pulls two groups of dumbbells together. The change in topology results in an easily recognized peak in the current trace. Simultaneous detection of four different sequences was achieved by assembling four DNA dumbbell nanoswitches on one carrier. The high specificity of the dumbbell nanoswitch was verified by distinguishing single base variants in DNA and RNA targets using four barcoded carriers in multiplexed measurements. By combining multiple dumbbell nanoswitches with barcoded DNA carriers, we identified different bacterial species even with high sequence similarity by detecting strain specific 16S ribosomal RNA (rRNA) fragments.

NiCo alloy particles (NiCo-APs)@hydrophilic carbon cloth (HCC) composites were successfully prepared by uniformly decorating magnetic NiCo-APs on the surface of three-dimensional HCC by employing an in-situ hydrothermal method. The NiCo-APs@HCC composites exhibited a unique corncob-like network structure that helped improve the electromagnetic wave (EMW) absorption performance of composites. The EMW absorption properties of the composites could be controlled by altering the Ni/Co molar ratio. The optimal minimum reflection loss (RL

DNA nanotechnology provides a unique opportunity for molecular computation, with strand displacement reactions enabling controllable reorganization of nanostructures. Additional DNA strand exchange strategies with high selectivity for input will enable novel complex systems including biosensing applications. Herein, we propose an autocatalytic strand displacement (ACSD) circuit: initiated by DNA breathing and accelerated by a seesaw catalytic reaction, ACSD ensures that only the correct base sequence starts the catalytic cycle. Analogous to an electronic circuit with a variable resistor, two ACSD reactions with different rates are connected in parallel to mimic a parallel circuit containing branches with different resistances. Finally, we introduce a multiplexed nanopore sensing platform to report the output results of a parallel path selection system at the single-molecule level. By combining the ACSD strategy with fast and sensitive single-molecule nanopore readout, a new generation of DNA-based computing tools is established.

Respiratory infections are the major cause of death from infectious disease worldwide. The clinical presentation of many respiratory viruses is indistinguishable; therefore, diagnostic approaches that can identify multiple pathogens are essential for patient management. We aimed to address this challenge with self-assembled DNA nanobait that can simultaneously identify multiple short RNA targets. The nanobait approach relies on specific target selection via toehold-mediated strand displacement and rapid read-out via nanopore sensing. Here, we show this platform can concurrently identify several common respiratory viruses, detecting a panel of short targets of viral nucleic acids from SARS-CoV-2, respiratory syncytial virus (RSV), rhinovirus, influenza, and parainfluenza. Our nanobait could be reprogrammed to discriminate viral variants, and we identified several key SARS-CoV-2 variants with single-nucleotide resolution. We increased assay specificity with bespoke nanobait that could identify numerous short RNA targets in the same viral sample in a complex background of the human transcriptome. Notably, we found that the sequence position in the viral RNA secondary structure is critical for nanobait design. Lastly, we show that nanobait could discriminate between samples extracted from oropharyngeal swabs from negative and positive SARS-CoV-2 patients using programmable target cleavage without pre-amplification. Our system allows for multiplexed identification of native RNA molecules, providing a new scalable approach for diagnostics of multiple respiratory viruses in a single assay.

The high-ash tailings produced by flotation contains a large number of minerals that can be recycled. However, as the separation and purification technology for flotation tailings is not mature and separation efficiencies are low, it is generally treated as separation waste, resulting in the waste of mineral resources. In view of this phenomenon, the particle size composition and density composition of high-ash minerals in flotation tailings of coal slime as well as the type and content of mineral elements were measured. It was determined that the main mineral composition is quartz, and there is also a certain amount of chlorite (silicate mineral). A self-spinning hydrocyclone used for flotation tailings separation and purification was designed, and numerical simulation was carried out by fluent software. The internal flow field-, tangential velocity-, and axial velocity-distribution characteristics of the hydrocyclone at different rotational speeds were investigated. The physical model of the hydrocyclone was set up and the separation efficiency improvement test of fine particles was carried out. The results show that the overflow yield of −0.045 mm particles increased gradually with the increase in cylinder rotation speed. When the rotation speed increased to 900 r/min, the overflow yield of −0.045 mm particles can reach more than 90%, which can effectively realize the material classification according to 0.045 mm.

Construction of delicate nanostructures with a facile, mild-condition and economical method is a key issue for building high-performance electrode materials. We demonstrate a facile and novel "reassembling strategy" to hollow MnCoS nanospheres derived from dual-ZIF for supercapacitors. The spherical shell's surface structure, thickness and Mn distribution were controlled by regulating the solvothermal reaction time. The chemical composition, phases, specific surface areas and microstructure were studied and the electrochemical performances were systematically estimated. As the unique low-crystalline and optimized hollow nanosphere structure contributes to increasing active sites, MnCoS nanospheres exhibit excellent electrochemical performance. The test results show that the specific capacitance increases with increasing solvothermal time, and the MCS with a 5 h reaction time exhibits optimal electrochemical properties with a high specific capacity of 957 C g

Cyclophilins, a type of peptidyl-prolyl cis-trans isomerase, function as an important molecular chaperone in series of biological processes. However, the expression pattern and signal transduction pathway of cyclophilins is still unclear. Hereby, it was clarified that the promoter of OsCYP2 is a constitutive expression pattern which by GUS staining in transformants with pOsCYP2:GUS genetic transformation. Simultaneously, it is found that the sequence of promoter had not only core elements but also contained inducible elements. Then, the ABA responsive element was used to cDNA library screening, a transcription factor myc2-like was identified by yeast one hybrid and confirmed though electrophoretic mobility shift assay. Furthermore, the relative expression showed that myc2-like was induced by abscisic acid. In addition, myc2-like overexpression could enhance salt tolerance in transformants and partial restore cyp2-RNAi line. Together, we explored a novel transcriptional signal mediated by myc2-like, a potential regulator of salt stress physiological processes in rice.

The parameters of jet mixing devices have an important influence on the mixing process, particle movement and interface regulation. At present, jet mixing devices are widely used in the coal slime flotation field, and their variable parameters lack systematic optimization. In this paper, the performance of reagent mixing and the distribution characteristics of flow field are taken as the evaluation indexes, and computational fluid dynamics (CFD) software (FLUENT) is used to optimize the variable parameters of the device. The results show that when the area ratio Ar=1.96~3.24, the throat-nozzle distance Le=0.2Dh~0.6Dh, the suction tube is located 1/4~1/2 Lz to the left of the nozzle outlet and is symmetrically arranged, the length of the throat tube L is from 6Dz to 12Dz, the mixing performance of the jet mixing device was optimal. The flow field distribution characteristics showed that the area ratio has a more significant effect. The larger the area ratio is, the more favorable the mixing of the working fluid and the injection fluid is. The throat-nozzle distance has little effect on the flow field distribution, and its optimal value ranges from 0.3Dh to 0.6Dh. The fog droplet size test showed that the dispersion effect was the best when the area ratio Ar=3.24. The diameter size test of the injected bubbles was carried out to verify the performance of the jet mixing device after parameter optimization. The experimental results and the simulation results confirm each other, which proves the correctness of the numerical simulation results.

Nanopores are powerful single-molecule tools for label-free sensing of nanoscale molecules including DNA that can be used for building designed nanostructures and performing computations. Here, DNA hard drives (DNA-HDs) are introduced based on DNA nanotechnology and nanopore sensing as a rewritable molecular memory system, allowing for storing, operating, and reading data in the changeable three-dimensional structure of DNA. Writing and erasing data are significantly improved compared to previous molecular storage systems by employing controllable attachment and removal of molecules on a long double-stranded DNA. Data reading is achieved by detecting the single molecules at the millisecond time scale using nanopores. The DNA-HD also ensures secure data storage where the data can only be read after providing the correct physical molecular keys. Our approach allows for easy-writing and easy-reading, rewritable, and secure data storage toward a promising miniature scale integration for molecular data storage and computation.

Coal-based activated carbons (CACs) have excellent valuable applications, and have been industrially produced. However, ultra-fine coal-based activated carbons (UCACs) and their removal of methylene blue (MB) have rarely been reported in the present literature. Two kinds of UCACs were obtained in this paper and the adsorption test of MB was carried out. The adsorption performance of MB on UCAC was simulated by Grand Canonical Monte Carlo (GC-MC) method. The experimental results were validated by molecular simulation, and the adsorption mechanism was investigated. The adsorption amount of MB, the d50, and specific surface area values of the UCACnew (obtained by the new method) and UCACcm (obtained by the conventional chemical method) were 746.95 mg/g, 12.54 μm, 1225.36 m2/g and 652.77 mg/g, 12.10 μm, 713.76 m2/g, respectively. The results of the molecular simulation calculations were consistent with the pattern of magnitude of the experimental results. The peak of the adsorption concentration occurred near 6 Å on the pore surface. The interaction energy of MB molecules with carboxyl groups was much larger than with hydroxyl groups. Van der Waals forces dominated the adsorption process, with a contribution of >60% in both cases.

The increasingly electromagnetic wave (EMW) pollution has rendered the study and development of new, high-efficiency EMW absorbers a sought-after topic. In this study, graphite carbon nitride nanotubes/cobalt@carbon (GCNNs/Co@C) composites were fabricated using an in-situ synthesis method, which included facile grinding and carbonization pyrolysis. The synthesized GCNNs/Co@C composites exhibited a unique castor-fruit-like structure, that is, GCNNs formed an entwined three-dimensional (3D) network structure on the surface of cobalt@carbon (Co@C), which improved the EMW absorption properties of composites. The obtained GCNNs/Co@C composites exhibited excellent EMW absorption performance. For the fabricated GCNNs/Co@C composites, the minimum reflection loss (RL

Anion binding by receptor molecules is a central field of modern chemistry which impacts areas of catalysis as well as biological and materials chemistry. As binding often requires high chemical stability under aerobic and aqueous conditions for practical applications, carbon-based anion receptors have dominated this field, with main group element analogues receiving far less attention. The recent observation that the air- and moisture-stable amino-cyclophosph(V)azanes of the type [RN(E)P(μ-NR)]2 (E = O, S, Se) can exhibit halide binding that is competitive with topologically related organic receptors (such as squaramides and thioureas) has motivated us here to explore how the binding properties of phosphazane receptors can be enhanced further. Coordination of transition metals by the two P,N metal coordination sites of the phosph(III)azane dimer [(2-py)NHP(μ-NtBu)]2 not only activates the receptor for anion binding (by fixing the optimum exo-exo conformation and polarizing the endocyclic N-H substituents) but also stabilizes the P2N2 ring to hydrolysis and oxidation. We show how the binding properties of these receptors can be modulated by the coordinated metal fragments and that they can bind chloride 1 to 2 orders of magnitude stronger than the related squaramides and thioureas. These features can be utilized in anion transport through phospholipid bilayers under aqueous conditions for which transport can be improved by 1 order of magnitude compared to the previous best phosphazane and thiourea transporters. This study demonstrates how careful design of inorganic systems can result in potent supramolecular functionality, beyond that observed for organic counterparts.

Low matching thickness, broad effective absorption bandwidth (EAB, RL -10 dB) and excellent reflection loss (RL) are desirable properties for the advanced microwave absorption materials (MAMs). We synthesized novel interpenetrating structured rod-like nickel cobaltite (NiCo

Hydrothermal carbon (HTC) was prepared by the one-step hydrothermal method for Cr (VI) removal from wastewater, which was considered a “green chemistry” method. The specific surface area (SBET) of HTC was 85 m2/g with the pore size in range of 2.0–24.0 nm. FT-IR spectra analysis showed that the HTC had abundant chemical surface functional groups. The influence of adsorption parameters such as pH, HTC dosage, Cr (VI) concentration, and contact time on the removal efficiency of Cr (VI) had been investigated. When the initial concentration was 50 mg/L, pH = 6, amount of adsorbent was 0.2 g/50 ml, and adsorption time was 90 min; the Cr (VI) absorbed rate of HTC reached 98%. Batch adsorption experiments indicated that Cr (VI) adsorption data of HTC fitted the Freundlich isothermal and pseudo-second-order kinetic models. Overall, our findings provide a promising material in treatment of Cr (VI)-rich wastewater and give a clear picture of its application, which is worthy of further study.

DNA strand displacement reaction is essential for the development of molecular computing based on DNA nanotechnology. Additional DNA strand exchange strategies with high selectivity for input will enable novel complex systems including biosensing applications. Most approaches use bulk readout methods based on fluorescent probes that complicate the monitoring of parallel computations. Herein we propose an autocatalytic strand displacement (ACSD) circuit, which is initiated by DNA breathing and accelerated by seesaw catalytic reaction. The special initiation mechanism of the ACSD circuit enables detection of single base mutations at multiple sites in the input strand with much higher sensitivity than classic toehold-mediated strand displacement. A swarm intelligence model is constructed using the ACSD circuit to mimic foraging behaviour of ants. We introduce a multiplexed nanopore sensing platform to report the output results of a parallel path selection system on the single-molecule level. The ACSD strategy and nanopore multiplexed readout method enhance the toolbox for the future development of DNA computing.

Since the discovery of the G-quadruplex (G4) structure in telomeres in 1980s, studies have established the role it plays in various biological processes. Here we report binding between DNA G4 and a self-assembled tetrahedral metal-organic cage 1 and consequent formation of aggregates, whereby the cage protects the DNA G4 from cleavage by S1 nuclease. We monitor DNA–cage interaction using fluorescence spectroscopy, firstly by quenching of a fluorescent label appended to the 5′ end of G4. Secondly, we detect the decrease in fluorescence of the G4-selective dyes thioflavin-T and Zn-PPIX bound to various DNA G4 sequences following the addition of cage 1. Our results demonstrate that 1 interacts with a wide range of G4s. Moreover, gel electrophoresis, circular dichroism and dynamic light scattering measurements establish the binding of 1 to G4 and indicate the formation of aggregate structures. Finally, we find that DNA G4 contained in an aggregate of cage 1 is protected from cleavage by S1 nuclease., We find FeII4L4 binds to G-quadruplex and forms aggregates. G-quadruplex in the aggregates is protected from digestion by S1 nuclease.

Deoxyribonucleic acid (DNA) nanostructure‐based data encoding is an emerging information storage mode, offering rewritable, editable, and secure data storage. Herein, a DNA nanostructure‐based storage method established on a solid‐state nanopore sensing platform to save and encrypt a 2D grayscale image is proposed. DNA multi‐way junctions of different sizes are attached to a double strand of DNA carriers, resulting in distinct levels of current blockades when passing through a glass nanopore with diameters around 14 nm. The resulting quaternary encoding doubles the capacity relative to a classical binary system. Through toehold‐mediated strand displacement reactions, the DNA nanostructures can be precisely added to and removed from the DNA carrier. By encoding the image into 16 DNA carriers using the quaternary barcodes and reading them in one simultaneous measurement, the image is successfully saved, encrypted, and recovered. Avoiding any proteins or enzymatic reactions, the authors thus realize a pure DNA storage system on a nanopore platform with increased capacity and programmability.

A water-soluble self-assembled supramolecular FeII4L4 tetrahedron binds to single stranded DNA, mismatched DNA base pairs, and three-way DNA junctions. Binding of the coordination cage quenches fluorescent labels on the DNA strand, which provides an optical means to detect the interaction and allows the position of the binding site to be gauged with respect to the fluorescent label. Utilizing the quenching and binding properties of the coordination cage, we developed a simple and rapid detection method based on fluorescence quenching to detect unpaired bases in double-stranded DNA.

This paper proposes a fuzzy comprehensive evaluation of ultrafine powders, namely, yield and quality value-based feature selection. Three indicators reflecting product yield and quality were selected to construct a simple and practical fuzzy comprehensive evaluation protocol. The weight set of the indices and the fuzzy evaluation set were calculated based on the analytic hierarchy process (AHP) method. The fuzzy comprehensive evaluation value was worked out as the only comprehensive index for the evaluation of product. The best ultrafine comminution condition will be established through the comparison of the fuzzy comprehensive evaluation values. Single-factor experiments and orthogonal experiments of the main influencing factors of ultrafine comminution were conducted. It was concluded that the importance of each factor is sequentially the concentration, specific surface area (SSA) of the media, and percentage of critical speed (PCS). Moreover, the concentration and SSA of the media were equally important. Ultrafine comminution by ball mill had the best overall performance under the PCS of 85%, the SSA of the media of 0.24 m2/kg, and the concentration of 75%.

Background: The impact of Lauren type, namely intestinal and diffuse types, on prognosis and lymph node metastasis (LNM) for gastric cancer (GC), requires further exploration, since current samples are deficient and the results are inconsistent.We aimed to translate the widely used WHO classifications into Lauren types and analyze the impact with the largest sample size available.Methods: Corresponding Lauren types of the WHO classification system in the Surveillance, Epidemiology, and End Results (SEER) database were included to identify all patients with histological diagnoses of intestinal-type or diffuse-type GC.Results: 4,338 intestinal-type and 22,990 diffuse-type GC were included in our study. Compared with intestinal-type, diffuse-type had a relatively poor prognosis after adjustment for other risk factors (HR, 1.236; PConclusion: Intestinal-type GC carries a better prognosis but a higher risk of LNM than diffuse-type. Patients with intestinal-type GC are likely to gain a greater benefit from receiving surgical treatment, but it is worth noting that clinicians should pay more attention to their lymphatic metastasis.*Contributed equally.The first author: Chanqiong Zhang, Guangyu Chen

DNA is emerging as a novel material for digital data storage. The two main challenges are efficient encoding and data security. Here, we develop an approach that allows for writing and erasing data by relying solely on Watson-Crick base pairing of short oligonucleotides to single-stranded DNA overhangs located along a long double-stranded DNA hard drive (DNA-HD). Our enzyme-free system enables fast synthesis-free data writing with predetermined building blocks. The use of DNA base pairing allows for secure encryption on DNA-HDs that requires a physical key and nanopore sensing for decoding. The system is suitable for miniature integration for an end-to-end DNA storage device. Our study opens a novel pathway for rewritable and secure data storage with DNA.One Sentence SummaryStoring digital information on molecules along DNA hard drives for rewritable and secure data storage.

For the first time, we are reporting a novel type of dual fluorescence temperature-sensitive DNA-templated silver nanocluster (AgNC) pair, which contains two pieces of single-stranded AgNC in proximity through hybridization. Both the chameleon AgNC pairs, A-NCP and B-NCP, possess two bright fluorescence peaks that achieve sensitive variations corresponding to temperature change from 15 to 45 °C. With the increase in temperature, one of the fluorescence emissions of A-NCP (A-FL570) increases, while the other (A-FL640) decreases. However, both the emissions of B-NCP (B-FL685 and B-FL620) decrease simultaneously. Therefore, A-NCP shows a remarkable fluorescence color variation from orange to yellow, while the fluorescence color of B-NCP changes from orange to colorless, with increase in temperature. Moreover, the temperature responding linear range of A-NCP can be regulated by adjusting the structures and sequences of assistant DNA templates. It is assumed that the two single-stranded segmental AgNCs are integrated together as they are assembled into AgNC pairs, leading to a dramatic variation in fluorescence properties. The temperature-sensitive phenomenon is due to the dehybridization-induced separation of two pieces of segmental AgNC, caused by temperature increase. The temperature-sensitive AgNC pairs have been successful in indicating the temperature of living cells, showing the potential for a new application of silver nanocluster as a nanothermometer with adjustable response range, bringing novel insight into the regulatory mechanism of AgNC fluorescence variation.

The application of coal fly ash magnetic spheres (MSs) in water treatment is limited due to their complex mineral compositions, low magnetism, and large diameters. In this study, MSs were carefully ball milled and magnetically separated to improve their related properties. After the processing, the resultant magnetic ball-milled MSs (MBMSs) show a substantial change in composition, magnetism, and surface property in addition to a decrease in diameter. Compared with those of the original MSs, the Fe percentage, magnetism, and specific surface area of MBMSs are increased by 25.87%, 54.60%, and 810%, respectively. Dispersive spectrometer mapping investigation shows segregated high- and low-Fe areas with different structures in MS. These different structures enable purification. Highly turbid clay water flocculation experiments using MSs as flocculants indicate that MBMSs can cause fast flocculation whereas the compared samples exert less or slight flocculation effect. Zeta potential investigation suggests that the different flocculation effects are due to the change in the point of zero charge (pHPZC). The pHPZC increases from 3.91 for the original MS to 4.96 for MBMS. The reduction in the diameter, as well as the increase in magnetism, surface area, and pHPZC, makes MSs applicable to water treatment.

Metal-organic anion channels based on Zn10 L15 pentagonal prisms have been prepared by subcomponent self-assembly. The insertion of these prisms into lipid membranes was investigated by ion-current and fluorescence measurements. The channels were found to mediate the transport of Cl- anions through planar lipid bilayers and into vesicles. Tosylate anions were observed to bind and plug the central channels of the prisms in the solid state and in solution. In membranes, dodecyl sulfate blocked chloride transport through the central channel. Our Zn10 L15 prism thus inserts into lipid bilayers to turn on anion transport, which can then be turned off through addition of the blocker dodecyl sulfate.

G-quadruplexes (Gq) are guanine-rich DNA structures formed by single-stranded DNA. They are of paramount significance to gene expression regulation, but also drug targets for cancer and human viruses. Current ensemble and single-molecule methods require fluorescent labels, which can affect Gq folding kinetics. Here we introduce, a single-molecule Gq nanopore assay (smGNA) to detect Gqs and kinetics of Gq formation. We use ~5 nm solid-state nanopores to detect various Gq structural variants attached to designed DNA carriers. Gqs can be identified by localizing their positions along designed DNA carriers establishing smGNA as a tool for Gq mapping. In addition, smGNA allows for discrimination of (un-)folded Gq structures, provides insights into single-molecule kinetics of G-quadruplex folding, and probes quadruplex-to-duplex structural transitions. smGNA can elucidate the formation of G-quadruplexes at the single-molecule level without labelling and has potential implications on the study of these structures both in single-stranded DNA and in genomic samples.

Low-rank coal is difficult to upgrade using conventional flotation methods due to its high hydrophilic properties. Thus, it is necessary to explore new methods for upgrading and utilizing low-rank coal. In this investigation, a gaseous dodecane pretreatment method was used to enhance the flotation performance of low-rank coal. Pore distribution analysis, FTIR (Fourier Transform Infrared Spectroscopy), and contact angle measurements were used to study the surface properties of the coal sample. Size distribution and float-sink test results indicated that the coal sample contained a lot of clean coal with low ash content, which could be used as a high quality raw material for making coal water slurry. FTIR, pore distribution analysis, and contact angle results showed that the coal was very hydrophilic due to the high concentration of -OH group and the large number of pores and cracks on the coal surface. The hydrophobicity of the coal sample was significantly improved by the gaseous dodecane pretreatment method. Clean coal with 67.2% combustible matter recovery and 10.5% ash content was obtained by gaseous dodecane pretreatment flotation method. Coal water slurry with 60% concentration was prepared using the flotation clean coal.

A water-soluble self-assembled supramolecular FeII4L4 tetrahedron binds to single stranded DNA, mismatched DNA base pairs, and three-way DNA junctions. Binding of the coordination cage quenches fluorescent labels on the DNA strand, which provides an optical means to detect the interaction and allows the position of the binding site to be gauged with respect to the fluorescent label. Utilizing the quenching and binding properties of the coordination cage, we developed a simple and rapid detection method based on fluorescence quenching to detect unpaired bases in double-stranded DNA.

The binding and sensing of anions is an important cross-disciplinary field, which impacts broad areas such as biology, supramolecular chemistry and catalysis. To date, however, this area has been dominated by organic architectures which function as H-bonding, anion receptor molecules. Inorganic anion receptors have largely been based on Lewis acidic metals, with very few examples of H-bonding counterparts of organic systems having been systematically studied. This paper develops strategies for enhancing the anion binding properties of phosphazanes of the type [(RNH)(E)P(μ-N tBu)]2 (E = O, S, Se) which are bench-stable, H-bond receptors that can be regarded as inorganic analogues of squaramides (a key class of organic anion receptor). The distinct advantages of these inorganic receptors over organic counterparts is the ease by which their functionality and electronic character can be altered (by means of the R group, chalcogenide, or metal present). Se substitution at the P centers, the presence of electron-withdrawing R groups, and metal coordination to the soft donor centers can be used to modulate and enhance anion binding. The water stability and superior anion binding properties of the seleno-phosph(V)azanes give them applications as synthetic anion transporters through phospholipid layers.

Using a downflow flotation column, we comparatively investigated the effects of two frother addition modes on clean coal production and bubble characteristics. These modes are traditional frother mode, which involves the direct addition of liquid Sec-Octyl alcohol (2-octanol) to slurry, and a novel addition mode, which injects 2-octanol vapor into the bubbles. Compared with the traditional mode, the vapor addition mode produced a higher concentrate yield, lower ash content, and higher combustible matter recovery. This result suggests that the vapor addition mode facilitates the larger product yield, producing a cleaner coal product. The consumption of 2-octanol under the liquid addition mode was reduced by 53.57% compared with that under the vapor mode to achieve 83% recovery of combustible matter. In the first 0.5 min and last 1.0 min of the 3 min flotation time, the vapor addition mode showed a slower flotation rate, whereas in the middle 1.5 min, the rate was faster. In addition, the vapor addition mode led to a smaller bubble size, critical coalescence concentration (CCC), and 23.21% reduction in 2-octanol consumption to achieve a constant bubble size. The higher capture probability of hydrophobic coal particles presented by the vapor addition mode is considered the fundamental cause for the enhanced clean coal yield and combustible matter recovery. With the increase in frother dosage, the particle–bubble collision probability was identified as the main factor determining the increase in the ash content of the concentrate at a concentration below the CCC. At a concentration above the CCC, the viscosity of bubble surfaces became the main factor.