Compressive Strength Prediction of Rubber Concrete Based on Artificial Neural Network Model with Hybrid Particle Swarm Optimization Algorithm.

Conventional neural networks tend to fall into local extremum on large datasets, while the research on the strength of rubber concrete using intelligent algorithms to optimize artificial neural networks is limited. Therefore, to improve the prediction accuracy of rubber concrete strength, an artificial neural network model with hybrid algorithm optimization was developed in this study. The main strategy is to mix the simulated annealing (SA) algorithm with the particle swarm optimization (PSO) algorithm, using the SA algorithm to compensate for the weak global search capability of the PSO algorithm at a later stage while changing the inertia factor of the PSO algorithm to an adaptive state.

Selective and recyclable tandem sensing of PO and Al by a water-stable terbium-based metal-organic framework.

Herein, a luminescent water-stable terbium-based metal-organic framework (MOF) {[Tb(Cmdcp)(HO)](NO)·5HO} (1, HCmdcpBr = N-carboxymethyl-(3,5-dicarboxyl)pyridinium bromide) has been synthesized and used for the recyclable sensing of PO and Al in tandem. MOF 1 acts as a fluorescent sensor for PO by the luminescence "turn-off" mechanism with high selectivity over other anions, such as F, Cl, Br, I, NO, HPO, HSO, HCO, HSO, SO, CO and HPO. The formed PO@1 complex further acts as the Al sensor with the luminescence "turn-on" mechanism, also with high selectivity over diverse inorganic cations of Fe, Mn, Co, Ni, Hg, Na, K, Li, Ag, Mg, Ca, Cd, Pb, Cu, and Zn.

Facile and recyclable dopamine sensing by a label-free terbium(III) metal-organic framework.

Herein, we present a facile strategy for dopamine (DA) sensing by a water-stable MOF of {[Tb(Cmdcp)(HO)](NO)·5HO} (1, HCmdcpBr = N-carboxymethyl-(3,5-dicarboxyl)pyridinium bromide). Without any post-modification, MOF 1 functions as an effective fluorescent sensor for the label-free detection of DA with the detection limit of 0.41 μM (S/N = 3).

Experimental and theoretical validations of a one-pot sequential sensing of Hg and biothiols by a 3D Cu-based zwitterionic metal-organic framework.

A zwitterionic three-dimensional (3D) metal-organic framework (MOF) of {[Cu(Cdcbp)(bipy)]·4HO} (1) has been synthesized and characterized (HCdcbpBr = 3-carboxyl-(3,5-dicarboxybenzyl)-pyridinium bromide; bipy = 4,4'-bipyridine). MOF 1 exhibits a variety of structural traits, such as ligand conjugated, positively charged pyridinium center, and Cu(II) cations that collectively enable its efficient hybridization with the flexible, negatively charged, single-stranded, and thymine-rich (T-rich) DNA. The T-rich DNA is labeled with carboxyfluorescein (FAM) fluorescent probe (characterized as P-DNA), but the resultant MOF 1 - P-DNA hybrid (characterized as P-DNA@1) is non-emissive (off-state) because of the fluorescent quenching by MOF 1.

Sequential and recyclable sensing of Fe and ascorbic acid in water with a terbium(iii)-based metal-organic framework.

A water-stable three-dimensional (3D) metal-organic framework (MOF) of {[Tb(Cmdcp)(HO)](NO)·5HO} (1, HCmdcpBr = N-carboxymethyl-(3,5-dicarboxyl)pyridinium bromide) has been synthesized and characterized. MOF 1 is highly emissive, giving rise to green luminescence that can be quenched by Fe due to the partial overlap of its excitation spectrum with the absorption spectrum of Fe. The subsequent introduction of ascorbic acid (AA) leads to the reduction of Fe into Fe, accompanied by the near-entire recovery of MOF 1 emission.

Experimental and computational investigation of a DNA-shielded 3D metal-organic framework for the prompt dual sensing of Ag and S.

We herein report an efficient Ag and S dual sensing scenario by a three-dimensional (3D) Cu-based metal-organic framework [Cu(Cdcbp)(bpea)] (MOF 1, HCdcbpBr = 3-carboxyl-(3,5-dicarboxybenzyl)-pyridinium bromide, bpea = 1,2-di(4-pyridinyl)ethane) shielded with a 5-carboxytetramethylrhodamine (TAMRA)-labeled C-rich single-stranded DNA (ss-probe DNA, P-DNA) as a fluorescent probe. The formed MOF-DNA probe, denoted as P-DNA@1, is able to sequentially detect Ag and S in one pot, with detection limits of 3.8 nM (for Ag) and 5.

Rapid sequential detection of Hg and biothiols by a probe DNA-MOF hybrid sensory system.

A one-dimensional (1D) metal-organic framework (MOF) of [Cu(Cdcbp)(HO)·2HO] (1, HCdcbpBr = 3-carboxyl-(3,5-dicarboxybenzyl)-pyridinium bromide) has been synthesized and characterized. MOF 1 features a cationic Cu center, conjugated tricarboxylate ligand bearing positively charged pyridinium and uncoordinated carboxylate groups within its skeleton. These features enable MOF 1 to tightly adsorb thymine rich (T-rich) single-stranded DNA (ss-DNA) probe labeled with carboxyfluorescein (FAM) (denote as P-DNA) through π-stacking, electrostatic interactions and/or hydrogen bonding to give a hybrid complex (denote as P-DNA@1), and quenches its fluorescence via a photo-induced electron transfer (PET) process.

Phenanthroline-linked berberine dimer and fluorophore-tagged DNA conjugate for the selective detection of microRNA-185: Experimental and molecular docking studies.

A phenanthroline (phen) tethered berberine dimer 1 is synthesized and further conjugated with carboxyfluorescein (FAM)-labeled single-stranded probe DNA (P-DNA) to give P-DNA@1. The mutual interaction of these two components triggers the fluorescence quenching of FAM, and the non-emissive P-DNA@1, in turn, functions as a sensor to detect cancer-associated microRNA-185 (miRNA-185), characterized by the FAM fluorescence recovery. The results show that P-DNA@1 is capable of detecting miRNA-185 in 2 min with the detection limit of 0.

Successive and Specific Detection of Hg and I by a DNA@MOF Biosensor: Experimental and Simulation Studies.

A 2D metal-organic framework (MOF) of {[Cu(Dcbb)(Bpe)]·Cl} (1, HDcbbBr = 1-(3,5-dicarboxybenzyl)-4,4'-bipyridinium bromide, Bpe = trans-1,2-bis(4-pyridyl)ethylene)) has been prepared. MOF 1 associates with the thymine-rich (T-rich), single-stranded probe DNA (ss-DNA, denoted as P-DNA) labeled with fluorophore FAM (FAM = carboxyfluorescein) and quenches the FAM emission to give a nonemissive P-DNA@1 hybrid (off state). The P-DNA in the hybrid subsequently captures the Hg to give a rigid double-stranded DNA featuring T-Hg-T motif (ds-DNA@Hg) and detach from MOF 1, triggering the recovery of the FAM fluorescence (on state).

Lanthanum-Based Metal-Organic Frameworks for Specific Detection of Sudan Virus RNA Conservative Sequences down to Single-Base Mismatch.

Reactions of La(NO)·6HO with the polar, tritopic quaternized carboxylate ligands N-carboxymethyl-3,5-dicarboxylpyridinium bromide (HCmdcpBr) and N-(4-carboxybenzyl)-3,5-dicarboxylpyridinium bromide (HCbdcpBr) afford two water-stable metal-organic frameworks (MOFs) of {[La(Cmdcp)(HO)]} (1, 3D) and {[La(Cbdcp)(HO)]} (2, 2D). MOFs 1 and 2 absorb the carboxyfluorescein (FAM)-tagged probe DNA (P-DNA) and quench the fluorescence of FAM via a photoinduced electron transfer (PET) process. The nonemissive P-DNA@MOF hybrids thus formed in turn function as sensing platforms to distinguish conservative linear, single-stranded RNA sequences of Sudan virus with high selectivity and low detection limits of 112 and 67 pM, respectively (at a signal-to-noise ratio of 3).