Rapid Detection of Bacterial Pathogens Causing Lower Respiratory Tract Infections via Microfluidic-Chip-Based Loop-Mediated Isothermal Amplification.

Respiratory tract infections (RTIs) are among the most common problems in clinical settings. Rapid and accurate identification of bacterial pathogens will provide practical guidelines for managing and treating RTIs. This study describes a method for rapidly detecting bacterial pathogens that cause respiratory tract infections via multi-channel loop-mediated isothermal amplification (LAMP). LAMP is a sensitive and specific diagnostic tool that rapidly detects bacterial nucleic acids with high accuracy and reliability. The proposed method offers a significant advantage over traditional bacterial culturing methods, which are time-consuming and often require greater sensitivity for detecting low levels of bacterial nucleic acids. This article presents representative results of K. pneumoniae infection and its multiple co-infections using LAMP to detect samples (sputum, bronchial lavage fluid, and alveolar lavage fluid) from the lower respiratory tract. In summary, the multi-channel LAMP method provides a rapid and efficient means of identifying single and multiple bacterial pathogens in clinical samples, which can help prevent the spread of bacterial pathogens and aid in the appropriate treatment of RTIs.

Metal-carboxylate coordination polymers with redox-active moiety of tetrathiafulvalene (TTF).

Though numerous metal-organic frameworks or polymers have been reported, the organic building blocks are usually not redox-active. On the other hand, some mono-, di- or tri-nuclear compounds with tetrathiafulvalene (TTF) have been prepared, although little is known about the coordination polymers combined with paramagnetic metals and organic TTF ligands. We report herein a series of coordination polymers of copper(II) and manganese(II) with TTF dicarboxylate ligand (L). Compound 1, [CuL(2,2-bpy)](n), is a one-dimensional (1-D) coordination polymer with five-coordinated square-pyramidal Cu(II) centers. Mn(II) complex 2, [MnL(2,2-bpy)](n), also takes a 1-D structure, showing a double-bridged mode by carboxylate groups. The 4,4-bipyridine compound 3, [MnL(4,4-bpy)(H(2)O)](n)·CH(3)CN, takes a 2-D grid network. A zinc(II) compound 4, [ZnL(4,4-bpy)(H(2)O)](n)·CH(3)CN, isomorphous structure with 3, is also presented. The electrochemical properties of the solid-state compounds were investigated by cyclic voltammetry using surface-modified electrodes. As usually observed in TTF derivatives, two sets of redox-waves were observed. The values of E(1/2)(1) of compounds 1-4 are in the order of 2(Mn) ≈ 3(Mn) < 1(Cu) < 4(Zn), indicating that the metal coordination can affect the potential shift of the TTF ligand. Weak antiferromagnetic exchanges are observed for compounds 1, 2, and 3.

Tetrathiafulvalene-tetracarboxylate: an intriguing building block with versatility in coordination structures and redox properties.

The synthesis of the transition metal coordination polymers containing a tetrathiafulvalene (TTF) moiety substituted with a tetracarboxylate group of the formulas [Mn(L)(0.5)(phen)(H(2)O)(2)](n).nH(2)O (1), [Mn(L)(0.5)(bpy)](n).nH(2)O (2), [Mn(L)(0.5)(bpy)(CH(3)OH)](n).2nH(2)O (3), and [Cu(L)(0.5)(bpy)(DMF)](n).n(DMF) (4) (L(4-) = TTF-tetracarboxylate; phen = 1,10-phenanthroline; bpy = 2,2'-bipyridine) is reported. Complex 1 is a two-dimensional (2-D) coordination polymer constructed of infinite carboxylate bridged Mn(II) chains and TTF moiety linkages. Complex 2 possesses a 3-D polymeric structure formed by infinite -Mn-(O-C-O)(2)-Mn- bridged one-dimensional (1-D) chains, which are further coordinated by TTF-tetracarboxylate ligands of two different orientations. Both complexes 3 and 4 show 1-D extended chain structures but are constituted by different dinuclear metal(II) units with a -Mn-(O-C-O)(2)-Mn- bridge in 3 and a -Cu-(O)(2)-Cu- bridge in 4. Electrochemical study of the solid-state compounds attests to the redox activity of the coordination system. Magnetic investigations reveal the existence of antiferromagnetic interactions between magnetic centers in complexes 3 and 4, while in 1, the paramagnetic metallic centers are isolated, in agreement with the solid-state structure.

Cu(II) and Ni(II) dioxotetraamine complexes integrated with tetrathiafulvalene moiety; structures and solution chemistry.

A new bifunctional tetrathiafulvalene (TTF) derivative has been designed and synthesized, in which the TTF moiety (a redox functional group) is integrated with a dioxotetraamine (a coordination functional group) structure. Like other dioxotetraamine compounds, it is capable of acting as an ion leaving and accepting ligand for protons and Cu(II) and Ni(II) ions in solution. Experiments of pH titration have shown that the TTF unit adds new redox properties to the traditional ligand. Oxidation of the ligand increases the acidity of the imido group and the coordination of metal ions is also sensitive to the oxidation state of the ligand. The ligand forms either a square coordinated Ni(II) complex with two deprotonated imido groups and two amino groups, or a pentacoordinated Cu(II) complex with an additional solvent molecule. The compounds form a belt structure with strong N-H...O hydrogen bonds, which is a basic character for this type of compound in the crystalline form.

Triadic intramolecular charge transfer compound of tetrathiafulvalene exhibiting multicolor solvatochromism.

An A-D-A triad compound comprising a tetrathiafulvalene (TTF) moiety and two pyridyl groups, py-TTF-py (1), has been studied in view of intramolecular charge transfer (ICT). The compound shows a sharp and multicolor change in different solvents and at different pH values, exhibiting good solvatochromism. The results of electronic absorption spectroscopy, cyclic voltammetry, and theoretical calculations confirm that there exists predominantly a monoprotonated A-D-A triad that displays a strong ICT effect, which is tunable as a function of pH. The equilibrium of protonation of 1 has been further studied by means of pH titration, and the result confidently supports the conclusion that only one equivalent H(+) combines with py-TTF-py in dilute solution, even when excessive acid is added. However, unlike the state in dilute solution, the crystal structure of the protonated 1 is a diprotonated A-D-A triad, (1.2H(+)).(CF(3)SO(3)(-))(2).H(2)O (2), that has been structurally characterized.