Ultrasound irradiation effect on morphological properties of a 3D nano zinc(II) supramolecular coordination polymer.

Nano-structures of [Zn(L)(atpt)]n (1) (L=1,2-bis(2-methylbenzimidazol-1-ylmethyl)benzene and H2atpt=2-aminoterephthalic acid) were obtained by hydrothermal and sonochemical approaches, characterized by scanning electron microscopy (SEM), IR, powder X-ray diffraction (PXRD), and elemental analysis. CP 1 features a 2D (4,4) network with the point symbol {44.62}, the 3D supramolecular architecture in CP 1 is controlled through π⋯π stacking interactions. The influence of various concentrations of initial reagents, power of ultrasound irradiation, and ultrasound time on the morphology and size of nano-structured CP 1 were studied in detail. In addition, the luminescence and photocatalytic properties of the nanoparticles of CP 1 for the degradation of methyl blue (MB) have also been investigated.

Ultrasonic green synthesis of an Ag/CP nanocomposite for enhanced photodegradation effectiveness.

A nanoparticle of cobalt(II) coordination polymer (CP), [Co(L)(npht)]n (1) (H2npht=4-nitrophthalic acid, L=1,3-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene) and its nanocomposite (Ag/CP 1) were obtained by the sonochemical approach and characterized by IR, elemental analysis, thermogravimetric analyses (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRPD). CP 1 shows a 1D double chain containing two different helical chains, which is further extended into a two-dimensional supramolecular framework by C-H⋯O hydrogen bonding interactions. The photoluminescence properties and photocatalytic properties of the nanoparticles of CP 1 and Ag/CP 1 on the degradation of methylene blue (MB) were investigated, Ag/CP 1 exhibited excellent photocatalytic activity under UV and visible light, which can be attributed to the strong interactions between Ag nanorods and CP 1, which lead to electron-hole pair separation between Ag nanorods and CP 1. In addition, the photocatalytic mechanism is also carried out by introducing t-butyl alcohol (TBA) as a widely used ·OH scavenger. The influence of ultrasound irradiation time and power on the morphology and size of the nanostructure CP 1 were studied. The results indicated that a decrease in time and an increase in power led to a decrease of particle size.

A new three-dimensional bis(benzimidazole)-based cadmium(II) coordination polymer.

A new coordination polymer (CP), formulated as [Cd(L)(DCTP)]n (1) (L=1,1'-(1,4-butanediyl)bis(2-methylbenzimidazole), H2DCTP=2,5-dichloroterephthalic acid), was synthesized under hydrothermal conditions and the performance as luminescent probe was also investigated. Single-crystal X-ray diffraction reveals CP 1 is a 3D 3-fold interpenetrated dia network with large well-defined pores. It is found that CP 1 revealed highly sensitive luminescence sensing for Fe3+ ions in acetonitrile solution with a high quenching efficiency of KSV=2541.238L·mol-1 and a low detection limit of 3.2µM (S/N=3). Moreover, the photocatalytic efficiency of 1 for degradation of methylene blue could reach 82.8% after 135min. Therefore, this coordination polymer could be viewed as multifunctional material for selectively sensing Fe3+ ions and effectively degrading dyes.

A multifunctional Ni(ii) coordination polymer: synthesis, crystal structure and applications as a luminescent sensor, electrochemical probe, and photocatalyst.

Herein, a nickel coordination polymer (CP 1), {Ni(1,4-bib)1.5(TPA-Cl2)·H2O}n (1,4-bib = 1,4-bis(1H-imidazol-1-yl)benzene, H2TPA-Cl2 = 2,5-dichloro-terephthalic acid), has been synthesized under solvothermal conditions. The structure of CP 1 is a 3D 3-fold interpenetrating framework with the sqc12 topology. The thermal stability and luminescence properties of CP 1 were investigated. Scanning electron microscopy (SEM) images of this material display that it possesses an irregular block 3D structure. Interestingly, CP 1 can serve as a multifunctional material via its luminescence sensing, electrochemical sensing, and photocatalytic properties. The experimental results indicate that CP 1 is an efficient luminescent sensor for the detection of Fe3+ ions in an aqueous solution. In addition, CP 1 exhibits a sensitive and rapid electrochemical response to nitrite ions in water solution. The photocatalytic activities of CP 1 were evaluated in the degradation of different dye contaminants (MB, RhB, and MO), and the results demonstrate that its photocatalytic efficiency for the degradation of MB is highest (92.1% for MB, 85.7% for RhB, and 86.2% for MO). The effects of different dyes, different powers of UV light, and different amounts of catalyst CP 1 on the photocatalytic efficiency were also explored. Finally, the mechanism of the luminescence quenching effect toward Fe3+ ions, electroreduction of nitrite ions, and photocatalytic degradation of different dyes have been investigated in detail.

Rigid versus semi-rigid bis(imidazole) ligands in the assembly of two Co(ii) coordination polymers: structural variability, electrochemical properties and photocatalytic behavior.

The hydrothermal reactions of 1,2,4,5-cyclohexanetetracarboxylic acid (H4L) with CoCl2·2H2O and rigid or semi-rigid bis(imidazole) ligands were able to generate two Co(ii) coordination polymers (CPs), {[Co5(L)2(1,4-bimb)(µ3-OH)2(H2O)8]·2H2O}n (1), {[Co(L)0.5(1,4-bib)]·H2O}n (2) (1,4-bimb = 1,4-bis(imidazol-1-ylmethyl)benzene, 1,4-bib = 1,4-bis(1H-imidazol-1-yl)benzene). CPs 1 and 2 were structurally characterized by elemental analysis, IR spectroscopy, X-ray powder diffraction and single crystal X-ray diffraction. CP 1 features a 3D 3,3,4,4,5-connected framework with an unprecedented {42·8·102·12}{43·6·86}2{43}2{46}2{62·8}2 topology, which represents the first example of CPs with such a topology. CP 2 possesses a three-fold interpenetration 3D framework with mog topology. The distinct structures of the two CPs may result from diverse coordination modes of the (L)4- ligands and different structural characteristics of rigid or semi-rigid N-donor ligands. The thermal stabilities, photoluminescence properties and electrochemical behavior in the solid state for CPs 1 and 2 have been investigated. The photophysical studies indicated that CPs 1 and 2 are potential semiconductive materials. Moreover, both CPs 1 and 2 show high photocatalytic efficiency for the degradation of methylene blue (MB) under UV light irradiation and exhibit good stability and recyclability. A possible photocatalytic mechanism is speculated by introducing t-butyl alcohol (TBA) as a widely used ˙OH scavenger.

Construction of noninterpenetrating and interpenetrating Co(ii) networks with halogenated carboxylate modulated by auxiliary N-donor co-ligands: structural diversity, electrochemical and photocatalytic properties.

Six Co(ii)-based coordination polymers (CPs) with characteristic frameworks and topologies-namely, [Co(L1)(DCTP)]n (1), [Co(L2)(DCTP)]n (2), [Co(L3)(DCTP)]n (3), {[Co3(L4)3(DCTP)3·H2O]·H2O}n (4), [Co(L5)1.5(DCTP)]n (5) and [Co(L6)(DCTP)]n (6)-were successfully hydrothermally synthesized by employing the halogenated linear ligand 2,5-dichloroterephthalic acid (H2DCTP). The interpenetrated structures could be rationally modulated by auxiliary N-donor co-ligands containing 1,1'-(1,4-butanediyl)bis-1H-benzimidazole (L1), 1,4-bis(5,6-dimethylbenzimidazol-1-yl)-2-butylene (L2), 1,2-bis(2-methylbenzimidazol-1-ylmethyl)benzene (L3), 1,4-bis(2-methylbenzimidazol-1-ylmethyl)benzene (L4), 1,2-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene (L5) and 1,4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene (L6). These diaphanous crystals were clearly characterized by elemental analysis, infrared (IR) spectra and X-ray powder diffraction (XRPD) as well as single-crystal X-ray diffraction analysis. With the aid of the flexible N-donor co-ligands, CP 1 occupies a non-interpenetrated 2D sheet with the point symbol {44·62} sql net topology, CP 2 possesses a 3D hexagon-shaped network with the point symbol {66} three-fold interpenetrated sqc6 topology, CP 3 exhibits a 2D layer with the point symbol {44·62} sql net topology, CP 4 reveals an unusual 3D framework with the point symbol {42·63·8} three-fold interpenetrated sra topology, CP 5 has a 3D hexagon-shaped network with the point symbol {66} two-fold interpenetrated sqc6 topology, while CP 6 displays a 3D hexagon-shaped network with the point symbol {66} three-fold interpenetrated sqc6 topology. The diverse structures of CPs 1-6 illustrate that the substitute group and position of the methyl group of the bis(benzimidazole) derivatives play a significant role in the assembly of such interpenetrated frameworks. Moreover, luminescence properties and thermal behavior, as well as the electrochemical and photocatalytic properties of CPs 1-6 on the degradation of methylene blue, are also presented.

Comparison of the Cumulative Incidence Rates of Coal Workers' Pneumoconiosis between 1970 and 2013 among Four State-Owned Colliery Groups in China.

The purpose of this study was to identify differences in the incidence characteristics of coal workers' pneumoconiosis (CWP) based on data from four large state-owned colliery groups of China, by comparing the cumulative incidence rates of CWP. We investigated 87,904 coal workers from the Datong, Kailuan, Fuxin, and Tiefa Colliery Groups, who were exposed to dust for at least 1 year. The cumulative incidence rate of CWP was calculated with the life-table method and stratified analysis among coal workers with different occupational categories during different years of first dust exposure. Our results showed the cumulative incidence rate of Datong was higher than that of any other colliery group among workers with different occupational categories during different years of first dust exposure. For Datong workers who started their dust exposure in the 1970s, the cumulative incidence rates of CWP among tunneling, mining, combining, and helping workers were 34.77%, 10.20%, 34.59%, and 4.91% during the observed time of 34 years, respectively. For those in the 1980s, the cumulative incidence rates were 32.29%, 13.51%, 2.98%, and 0.47%, respectively. The cumulative incidence rates of Fuxin and Tiefa were the lowest. In conclusion, the Datong colliery has the highest cumulative incidence rate of CWP among the four studied collieries, followed by Kailuan. The cumulative incidence rates of Fuxin and Tiefa were the lowest. Additional dust-proofing measures for decreasing dust concentrations are still necessary.

Cost-Effectiveness of Coal Workers' Pneumoconiosis Prevention Based on Its Predicted Incidence within the Datong Coal Mine Group in China.

We aimed to estimate the economic losses currently caused by coal workers' pneumoconiosis (CWP) and, on the basis of these measurements, confirm the economic benefit of preventive measures. Our cohort study included 1,847 patients with CWP and 43,742 coal workers without CWP who were registered in the employment records of the Datong Coal Mine Group. We calculated the cumulative incidence rate of pneumoconiosis using the life-table method. We used the dose-response relationship between cumulative incidence density and cumulative dust exposure to predict the future trend in the incidence of CWP. We calculate the economic loss caused by CWP and economic effectiveness of CWP prevention by a step-wise model. The cumulative incidence rates of CWP in the tunneling, mining, combining, and helping cohorts were 58.7%, 28.1%, 21.7%, and 4.0%, respectively. The cumulative incidence rates increased gradually with increasing cumulative dust exposure (CDE). We predicted 4,300 new CWP cases, assuming the dust concentrations remained at the levels of 2011. If advanced dustproof equipment was adopted, 537 fewer people would be diagnosed with CWP. In all, losses of 1.207 billion Renminbi (RMB, official currency of China) would be prevented and 4,698.8 healthy life years would be gained. Investments in advanced dustproof equipment would be total 843 million RMB, according to our study; the ratio of investment to restored economic losses was 1:1.43. Controlling workplace dust concentrations is critical to reduce the onset of pneumoconiosis and to achieve economic benefits.

Effects of chitosan on cell proliferation and collagen production of tendon sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the proliferation and collagen production of tendon sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes; and the effects of chitosan on cell proliferation and collagen production in the 3 cell types of rabbit flexor tendon.</p><p><b>METHODS</b>Three cell lines of tendon sheath, epitenon, and endotenon were isolated from rabbit flexor tendon and cultured. Cell culture media was added with chitosan. The cell number and production of collagens I, II, and III were measured and compared with those cultured without chitosan. The expression of type I collagen in tendon sheath fibroblasts was determined by quantitative analysis of reverse-transcription polymerase chain reaction.</p><p><b>RESULTS</b>All 3 cell lines produced collagens I, II, and III. Adding chitosan to cell media resulted in a significant decrease in cell number in all 3 cell lines. In addition, there was a significant decrease in collagens I, II, and III production in all 3 cell lines as well as the expression levels of type I collagen in tendon sheath fibroblasts (P<0.05).</p><p><b>CONCLUSIONS</b>Chitosan can inhibit cell proliferation and collagen production of the tendon sheath, epitenon, and endotenon, and may provide a promising approach to obviating tendon adhesion formation clinically.</p>