Diaqua­bis­(5-carb­oxy-1H-imidazole-4-carboxyl­ato-κ2 N 3,O 4)iron(II)

In the title compound, [Fe(C5H3N2O4)2(H2O)2], the FeII ion lies on an inversion centre and is coordinated by two N and two O atoms from two 5-carb­oxy-1H-imidazole-4-carboxyl­ate ligands and two water mol­ecules in a distorted octa­hedral geometry. An intra­molecular O—H⋯O hydrogen bond occurs. In the crystal, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds form a three-dimensional network, which consolidates the packing

Diaqua­bis­(hydrogen tartrato)cobalt(II) dihydrate

The title complex, [Co(C4H5O6)2(H2O)2]·2H2O, contains a CoII ion, two single deprotonated tartrate anions, two coordinated water mol­ecules and two lattice water mol­ecules. The coordination geometry of the CoII ion is a distorted octa­hedron with two O atoms from two coordinated water mol­ecules occupying cis positions in the equatorial plane and four O atoms from two hydrogen tartrate ions occupying the remaining positions. In the crystal, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network

5-Carb­oxy-2-isopropyl-1H-imidazol-3-ium-4-carboxyl­ate monohydrate

In the title compound, C8H10N2O4·H2O, the imidazole N atom is protonated and one of the carboxyl­ate groups is deprotoned, forming a zwitterion. An intra­molecular O—H⋯O hydrogen bond occurs. The crystal structure is stabilized by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds. In addition, inter­molecular N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules into two-dimensional networks parallel to (10)

The relationship between perceived organizational support and insomnia in Chinese nurses: The Serial multiple mediation analysis

BackgroundNurses are in high-pressure, high-load, and high-risk environment for a long time, and their insomnia cannot be ignored. Insomnia not only has a negative impact on the physical and mental health of nurses, but also on the efficiency and quality of nursing work.ObjectiveThe purpose of this study was to investigate the multiple mediating effect of psychological capital, effort-reward ratio, and overcommitment in the relationship between perceived organizational support and insomnia among Chinese nurses.MethodsA cross-sectional study has been carried out in a tertiary grade A hospital in Shandong Province, China from March 2021 to May 2021. The demographic questionnaire, Perceived Organization Support Questionnaire, Psychological Capital Questionnaire, Chinese version Effort-Reward Imbalance, Questionnaire and Athens Insomnia Scale were used for data collection. SPSS PROCESS 3.4 macro program developed by Hayes was used to test the serial multiple mediation. Descriptive analysis, independent-samples t-test, one-way analysis of variance, Pearson’s correlation analyses, ordinary least-squares regression, and the bootstrap method were used for data analysis.Results658 valid questionnaires were collected (81.2%). Nurses’ perceived organizational support was positively correlated with psychological capital (r = 0.455, p < 0.001), and was significantly negatively correlated with effort-reward ratio (r = −0.318, p < 0.001), overcommitment (r = −0.328, p < 0.001), and insomnia (r = −0.358, p < 0.001); Psychological capital was negatively correlated with effort-reward ratio (r = −0.275, p < 0.001), overcommitment (r = −0.339, p < 0.001), and insomnia (r = −0.402, p < 0.001), respectively; effort-reward ratio and overcommitment were significantly positively correlated with insomnia (r = 0.379, p < 0.001; r = 0.466, p < 0.001), respectively. In the model of perceived organizational support—psychological capital—effort-reward ratio—insomnia, the overall mediating effect was −0.080 (95%CI: −0.109 ~ −0.058), and the mediating effect of psychological capital was −0.050, accounting for 34.30% of the total effect; the mediating effect of effort-reward ratio was −0.024, accounting for 16.49% of the total effect; the chain mediating effect of psychological capital and effort-reward ratio was −0.007, accounting for 4.49% of the total effect. In the model of perceived organizational support—psychological capital—overcommitment—insomnia, the overall mediating effect was −0.085 (95%CI: −0.109 ~ −0.064), and the mediating effect of psychological capital was −0.042, accounting for 28.64% of the total effect; the mediating effect of overcommitment was −0.029, accounting for 19.81% of the total effect; the chain mediating effect of psychological capital and overcommitment was −0.015, accounting for 10.14% of the total effect.ConclusionPerceived organizational support had direct negative influence on insomnia. Psychological capital and effort-reward ratio/overcommitment acted as chained mediating factor could partially relieve insomnia symptoms related to perceived organizational support. It is suggested to improve the level of organizational support and psychological capital of nurses, and reduce the effort-reward imbalance and overcommitment of nurses, so as to effectively decline and deal with nurses’ insomnia

Composition and Performance of Nanostructured Zirconium Titanium Conversion Coating on Aluminum-Magnesium Alloys

Nanostructured conversion coating of Al-Mg alloy was obtained via the surface treatment with zirconium titanium salt solution at 25°C for 10 min. The zirconium titanium salt solution is composed of tannic acid 1.00 g·L−1, K2ZrF6 0.75 g·L−1, NaF 1.25 g·L−1, MgSO4 1.0 g/L, and tetra-n-butyl titanate (TBT) 0.08 g·L−1. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrum (FT-IR) were used to characterize the composition and structure of the obtained conversion coating. The morphology of the conversion coating was obtained by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results exhibit that the zirconium titanium salt conversion coating of Al-Mg alloy contains Ti, Zr, Al, F, O, Mg, C, Na, and so on. The conversion coating with nm level thickness is smooth, uniform, and compact. Corrosion resistance of conversion coating was evaluated in the 3.5 wt.% NaCl electrolyte through polarization curves and electrochemical impedance spectrum (EIS). Self-corrosion current density on the nanostructured conversion coating of Al-Mg alloy is 9.7×10-8A·cm-2, which is only 2% of that on the untreated aluminum-magnesium alloy. This result indicates that the corrosion resistance of the conversion coating is improved markedly after chemical conversion treatment

The impact of onshore wind power projects on ecological corridors and landscape connectivity in Shanxi, China

The wind power industry has developed rapidly in China, but the effect of wind power projects on the ecosystem is far from being clearly understood. The objective of this study is to evaluate the negative impact of wind power plants on the ecosystem. In this research, least-cost distance and least-cost path models were employed to establish potential ecological corridors based on the resistance at the site of the wind power projects––which is located in the ecological function area in Qinyuan, South Shanxi Province, China. The landscape connectivity was evaluated using a set of connectivity indices. In addition, the impact on the corridor patency, length, and the connectivity between ecological corridors were analyzed. The results showed that the wind power projects could not only significantly increase the migration resistance that hampers the formation of ecological corridors of the species at the landscape scale, but also had an obvious cutting effect on the landscape––resulting in an increase in the length of the ecological corridors and a decrease in corridor patency and landscape connectivity. There was also a positive relationship between the increase in length and the distance between the source patches. In addition, the connectivity was enhanced with the increase in distance threshold. This study evaluated the ecological impact of onshore wind power projects at the landscape level, filling the gap in research on landscape ecology, especially in the protected area with key ecological function. Meanwhile, the results are beneficial to guide the location selection for wind power projects and minimize their negative impact on the key ecological corridors

Genetic variation and forensic efficiency of 30 indels for three ethnic groups in Guangxi: relationships with other populations

Aim In this study, we used a series of diallelic genetic marker insertion/deletion polymorphism (indel) to investigate three populations of Yao, Kelao, and Zhuang groups in the Guangxi region of China and to evaluate their efficiency in forensic application. Result No deviations for all 30 loci were observed from the Hardy–Weinberg equilibrium after Bonferroni correction (p > 0.05/30 = 0.0017). The allele frequencies of the short allele (DIP-) for the above three populations were in the range of 0.0520–0.9480, 0.0950–0.8780, and 0.0850–0.915, respectively. The observed heterozygosity of the 30 loci for the three populations was in the ranges 0.0802–0.5802, 0.1908–0.6053, and 0.1400–0.5600, respectively. The cumulative power of exclusion and combined discrimination power for Yao, Kelao, and Zhuang groups were (0.9843 and 0.9999999999433), (0.9972 and 0.9999999999184), and (0.9845 and 0.9999999999608), respectively. The DA distance, principal component analysis, and cluster analysis indicated a clear regional distribution. In addition, Zhuang groups had close genetic relationships with the Yao and Kelao populations in the Guangxi region. Conclusion This study indicated that the 30 loci were qualified for personal identification; moreover, they could be used as complementary genetic markers for paternity testing in forensic cases for the studied populations

SPEEK Membrane of Ultrahigh Stability Enhanced by Functionalized Carbon Nanotubes for Vanadium Redox Flow Battery

Proton exchange membrane is the key factor of vanadium redox flow battery (VRB) as their stability largely determine the lifetime of the VRB. In this study, a SPEEK/MWCNTs-OH composite membrane with ultrahigh stability is constructed by blending sulfonated poly(ether ether ketone) (SPEEK) with multi-walled carbon nanotubes toward VRB application. The carbon nanotubes disperse homogeneously in the SPEEK matrix with the assistance of hydroxyl group. The blended membrane exhibits 94.2 and 73.0% capacity retention after 100 and 500 cycles, respectively in a VRB single cell with coulombic efficiency of over 99.4% at 60 mA cm−2 indicating outstanding capability of reducing the permeability of vanadium ions and enhancing the transport of protons. The ultrahigh stability and low cost of the composite membrane make it a competent candidate for the next generation larger-scale vanadium redox flow battery