A new metal–organic framework (MOF), {(H 3 O)Eu (SBDB)(H 2 O) 2 } n (H 4 SBDB = 1,5-disulfo-benzene-2,4-dicarboxylic acid) ( 1 ), was successfully synthesized under solvothermal conditions. Ten ...central Eu 3+ ions are coordinated by the H 4 SBDB ligands and two coordination water molecules. The adjacent Eu 3+ ions are connected by oxygen atoms from carboxyl groups, forming a 1D chain. 1D chains are linked by H 4 SBDB ligands to induce a 2D infinitely extensible planar structure, and then connected by hydrogen bonds to form a 3D supernetwork structure. Complex 1 exhibits excellent thermal and chemical stability. AC impedance analysis shows that the highest proton conductivity of 1 reaches up to 1.0 × 10 −4 S cm −1 (338 K, 98% RH). Furthermore, complex 1 is an excellent luminescence-based sensor with high sensitivity and a low detection limit for ascorbic acid (AA) in aqueous solutions.
In the design and optimisation of marine wireless communication and navigation systems, a thorough investigation of radio wave propagation characteristics under atmospheric ducting conditions is ...essential. The authors aim to enhance the efficiency of radio wave propagation loss prediction in marine atmospheric ducting environments, proposing a prediction model based on Fast Reordered‐Alternate Direction Decomposition (FR‐ADD). By approximating the diffraction term into three independent components, exploiting the commutative properties of the Fourier transform to reduce the spatial dimensions, and incorporating a rapid algorithm for the parabolic equation, the model optimises the stepping process and significantly improves computational efficiency. Simulation experiments demonstrate that, in the long‐distance and complex marine ducting environments, the model not only maintains prediction accuracy but also substantially reduces computational load and prediction time, effectively realising over‐the‐horizon propagation prediction. In the experiment of radio wave propagation characteristics in the Yellow and Bohai Seas, the simulation data from the FR‐ADD model showed significant correlation with actual measurements and simulations from the AREPS software, confirming the method's efficiency and practicality.
The authors introduce a radio wave propagation loss prediction model for marine atmospheric ducting environments, based on Fast Reordered‐Alternate Direction Decomposition (FR‐ADD), for wireless communication and navigation systems. The model improves computational processes, maintaining prediction accuracy while significantly reducing computational load and prediction time, effectively enabling over‐the‐horizon propagation prediction.
Breast cancer preferentially develops osteolytic bone metastasis, which makes patients suffer from pain, fractures and spinal cord compression. Accumulating evidences have shown that exosomes play an ...irreplaceable role in pre-metastatic niche formation as a communication messenger. However, the function of exosomes secreted by breast cancer cells remains incompletely understood in bone metastasis of breast cancer.
Mouse xenograft models and intravenous injection of exosomes were applied for analyzing the role of breast cancer cell-derived exosomes
. Effects of exosomes secreted by the mildly metastatic MDA231 and its subline SCP28 with highly metastatic ability on osteoclasts formation were confirmed by TRAP staining, ELISA, microcomputed tomography, histomorphometric analyses, and pit formation assay. The candidate exosomal miRNAs for promoting osteoclastogenesis were globally screened by RNA-seq. qRT-PCR, western blot, confocal microscopy, and RNA interfering were performed to validate the function of exosomal miRNA.
Implantation of SCP28 tumor cells
leads to increased osteoclast activity and reduced bone density, which contributes to the formation of pre-metastatic niche for tumor cells. We found SCP28 cells-secreted exosomes are critical factors in promoting osteoclast differentiation and activation, which consequently accelerates bone lesion to reconstruct microenvironment for bone metastasis. Mechanistically, exosomal miR-21 derived from SCP28 cells facilitates osteoclastogenesis through regulating PDCD4 protein levels. Moreover, miR-21 level in serum exosomes of breast cancer patients with bone metastasis is significantly higher than that in other subpopulations.
Our results indicate that breast cancer cell-derived exosomes play an important role in promoting breast cancer bone metastasis, which is associated with the formation of pre-metastatic niche via transferring miR-21 to osteoclasts. The data from patient samples further reflect the significance of miR-21 as a potential target for clinical diagnosis and treatment of breast cancer bone metastasis.
Recently, considerable attention has been paid to European eggs that were found to contain the poisonous insecticide fipronil. Excessive consumption of fipronil can harm the human body, in ...particular, the liver, thyroid, nervous system and kidneys. As a consequence, there is an urgent need to develop a method to detect fipronil. In this work, a lanthanide coordination polymer Eu(SIP)(H2O)4n (1) (NaH2SIP = 5-sulfoisophthalic acid monosodium salt) was synthesized and characterized by single-crystal X-ray crystallography, elemental analysis, infrared spectrum and powder X-ray diffractions. The X-ray studies show that 1 is a two-dimensional layered structure, which is constructed of fused {Eu(H2O)43(SIP)3} pseudo-hexagonal grids. The luminescence properties of 1 exhibit effective recognition for fipronil in methanol solution. Furthermore, a wide linear range (10-6-10-4 M), a low detection limit of 0.8 μM, high selectivity and excellent recyclability, reveal that 1 can potentially act as a luminescence-based sensor for quantitative and highly sensitive detection of fipronil. To the best of our knowledge, it is the first time that a metal-organic coordination polymer, as a fluorescent-based probe, has been used for the detection of fipronil. Moreover, fluorescent-based test papers of 1 have also been prepared, which can be regarded as a simple and practical method for detecting fipronil.
Gas diffusion is considered a rate-limiting step in the formation of gas hydrates, yet its molecular mechanisms remain unclear. In this work, we present the molecular mechanisms of the CO2 ...cage-to-cage transport in gas hydrates, as directly observed from molecular dynamics simulations performed at elevated temperatures. We found that at least one water vacancy is required for the CO2 molecules to pass through five-membered water rings, while only the distortion of the local ring structure is required for the CO2 molecules to pass through the six-membered water rings. We used the transition-state theory to estimate the relevant kinetic parameters associated with the CO2 diffusion in gas hydrates. The calculated free energy of activation is about 44 ± 6 kJ/mol, and the diffusion coefficient is in the range of 1.0 × 10–16∼2.0 × 10–14 m2/s, for the CO2 diffusion at 270 K, in close agreement with previous experiments. This work suggests that the presence of empty cages is crucial for the CO2 cage-to-cage transport in gas hydrates.
This study systematically investigates the organic fouling behavior of a superhydrophilic polyvinylidene fluoride (PVDF) ultrafiltration membrane functionalized via post-fabrication tethering of ...surface-tailored silica nanoparticles to poly(methacrylic acid)-grafted PVDF membrane surface. Sodium alginate (SA), Suwannee River natural organic matter (SRNOM), and bovine serum albumin (BSA) were used as model organic foulants to investigate the antifouling behavior of the superhydrophilic membrane with combined-fouling (mixture of foulants) and individual-fouling (single foulant) tests. A membrane bioreactor (MBR) plant supernatant was also used to verify the organic antifouling property of the superhydrophilic membrane under realistic conditions. Foulant size distributions and foulant–membrane interfacial forces were measured to interpret the observed membrane fouling behavior. Molecular weight cutoff measurements confirmed that membrane functionalization did not adversely affect the intrinsic membrane selectivity. Both filtration tests with the synthetic foulant-mixture solution (containing SA, SRNOM, and BSA) and MBR plant supernatant demonstrated the reliability and durability of the antifouling property of the superhydrophilic membrane. The conspicuous reduction in foulant–membrane interfacial forces for the functionalized membrane further verified the antifouling properties of the superhydrophilic membrane, suggesting great potential for applications in wastewater treatment.
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•Superhydrophilic PVDF UF membrane exhibits fouling resistance with a mixture of model organic foulants.•Superhydrophilic PVDF UF membrane exhibits fouling resistance with a wastewater (MBR) plant effluent.•Antifouling resistance correlates with reduction of foulant–membrane adhesion forces.•Surface functionalization does not degrade membrane selectivity.
The floor of inclined coal seams during mining is prone to seepage instability, resulting in water loss and even water inrush. The production of inclined coal seams occupies a certain proportion in ...China. Therefore, it is necessary to carry out the research on the floor structure stability in response to underground mining. Firstly, a four-side solid support inclined laminate model was established by analyzing the stress state and deformation failure law of inclined floor under the action of bidirectional linear load. Then, by studying the relationship between permeability coefficient and deformation, the method and conditions for determining seepage stability are obtained, and the influencing factors and sensitivity of water protection mining in inclined coal seams are determined through engineering cases. The inclined floor deflection curve is not symmetrical; the maximum deflection of the inclined coal seam floor is located at a distance of 0.5864 times the length of the working face in the middle and lower part of the working face, and at a distance of 0.5864 times the advance distance of the working face in the advancing direction. Through an orthogonal experimental analysis, the significance order of the factors affecting the deflection of the bottom plate is as follows: working face length > water pressure > advance distance > dip angle. The boundary of the upper layer in the laminated plate is a compressive stress area, while the middle layer is a tensile stress area. The opposite is true for the middle and lower layers, where shear stress is concentrated in different regions. The maximum stress values in the lower area of the working face are greater than those in the upper area, showing an obvious asymmetry. Finally, the evaluation indicators and stability conditions for seepage stability were determined: the ratio of the ultimate permeability coefficient (
K
li
) to the equivalent permeability coefficient (
K
eq
) should not be less than 1, that is,
K
li
/
K
eq
≥1. The significance of the factors affecting seepage stability is as follows: water pressure>working face length>dip angle, which can provide guidance for water protection mining in similar mines.
A novel nickel(
ii
) complex, Ni(2,2′-bpy)
3
(H
2
SBTC)(H
2
O)
5
(
1
) (2,2′-bpy = 2,2′-bipyridyl), was synthesized based on Ni(2,2′-bpy)
3
2+
discrete units and a partially deprotonated ...sulfonate-carboxylate ligand of H
4
SBTC (5-sulfonyl-1,2,4-benzentricarboxylic acid). The adjacent Ni(2,2′-bpy)
3
2+
cationic units were connected to H
2
SBTC
2−
anions by hydrogen bonds to form a one-dimensional (1-D) chain. The 1-D chains were further linked using hydrogen bonds from free water molecules and H
2
SBTC
2−
anions to generate a two-dimensional (2-D) plane structure. The proton conductivity of
1
reaches 1.3 × 10
−4
S cm
−1
at 318 K, 98% RH. Furthermore, hybrid membranes composed of polyvinyl alcohol (PVA) and
1
as fillers were prepared with different mass percentages. The proton conductivity of
1
@PVA-5 was found to be 1.6 × 10
−3
S cm
−1
at 313 K and 98% RH. The large number of alcoholic hydroxyl groups in PVA promote the resulting conductivity.
A novel 2D nickel(
ii
) complex (
1
) has been successfully synthesized using a 2,2′-bipyridyl, polycarboxylsulfonate ligand H
4
SBTC and Ni
2+
ions. Owing to the presence of abundant water molecules, hydrogen bond networks and other protons,
1
and its hybrid membranes demonstrate high proton conductivity.
Membrane fouling remains a notorious problem in microfiltration (MF) and ultrafiltration (UF), and a systematic understanding of the fouling mechanisms is fundamental for solving this problem. Given ...a wide assortment of fouling studies in the literature, it is essential that the numerous pieces of information on this topic could be clearly compiled. In this review, we outline the roles of membrane-foulant and foulant-foulant intermolecular interactions in MF/UF organic fouling. The membrane-foulant interactions govern the initial pore blocking and adsorption stage, whereas the foulant-foulant interactions prevail in the subsequent build-up of a surface foulant layer (e.g., a gel layer). We classify the interactions into non-covalent interactions (e.g., hydrophobic and electrostatic interactions), covalent interactions (e.g., metal-organic complexation), and spatial effects (related to pore structure, surface morphology, and foulants size for instance). They have either short- or long-range influences on the transportation and immobilization of the foulant toward the membrane. Specifically, we profile the individual impacts and interplay between the different interactions along the fouling stages. Finally, anti-fouling strategies are discussed for a targeted control of the membrane-foulant and foulant-foulant interactions.
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