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This study reported the involvement of a gene cluster from a conjugative plasmid in the biofilm formation of Escherichia coli. We used a novel EZ-Tn5 transposon technique to generate a transposon l...

Polymer nanocomposites with improved dielectric permittivity and high breakdown strength are extremely desirable for the flexible electronic devices and power systems. The compatibility of fillers and polymer matrix is important in determining the dielectric and breakdown strength properties. The core–shell structure concept is useful to improve the compatibility of fillers with polymer matrix. Herein, an organic thermoplastic urethanes (TPU) polymer shell was successfully grafted on the surface of barium titanate (BaTiO(3), BT) and such a TPU shell improved the permittivity and breakdown strength of TPU@BT/PVDF polymer nanocomposites greatly. The permittivity of TPU@BT/PVDF nanocomposites with 12 wt% fillers at 10^2 Hz was up to 13.5, which was 1.5 times higher than that of pure poly(vinylidene fluoride) (PVDF). The improvement of the dielectric properties could be attributed to the enhanced interfacial polarisation between BT nanoparticles and TPU shell. Besides, the compatibility of BT nanoparticles and PVDF matrix was improved after the introduction of TPU shell. Accordingly, a highest breakdown strength value about 373 MV/m was obtained for the TPU@BT/PVDF nanocomposites with 7 wt% fillers. The core–shell strategy could be extended to a variety of inorganic fillers to improve the dielectric and breakdown strength properties of polymer nanocomposites.

Severe burns may lead to intestinal inflammation and oxidative stress, resulting in intestinal barrier damage and gut dysfunction. Loganin, an iridoid glycoside compound, has been isolated from Cornus officinalis Sieb. et Zucc; however, its role in the treatment of burn injury is yet to be fully elucidated. Therefore, the present study examined the effect of loganin administration on burn-induced intestinal inflammation and oxidative stress after severe burns in male Sprague-Dawley rats. Histological injury was assessed by hematoxylin and eosin staining. Furthermore, cytokine expression in intestinal tissues was measured by ELISA and reverse transcription-quantitative PCR. Antioxidative activities were assessed by determining the levels of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA). Apoptosis was detected by flow cytometry. Apoptosis-related proteins, toll-like receptor 4 (TLR4) protein and NF-κB translocation were examined by western blotting. Immunohistochemical staining was used to observe TLR4 and NF-κB p65 expression in intestinal tissues. The present study suggested that loganin administration significantly reduced burn injury-induced intestinal histological changes, tumor necrosis factor-α, interleukin (IL)-6 and IL-1β production and oxidative stress, evidenced by decreased ROS levels and MDA content (P

Neurodegenerative diseases are irreversible conditions that result in progressive degeneration and death of nerve cells. Although the underlying mechanisms may vary, oxidative stress is considered to be one of the major causes of neuronal loss. Importantly, there are still no comprehensive treatments to completely cure these diseases. Therefore, protecting neurons from oxidative damage may be the most effective therapeutic strategy. Here we report a neuroprotective effects of a novel hybrid compound (dlx-23), obtained by conjugating α-lipoic acid (ALA), a natural antioxidant agent, and 3-n-butylphthalide (NBP), a clinical anti-ischemic drug. Dlx-23 protected against neuronal death induced by both H2O2 induced oxidative stress in Cath.-a-differentiated (CAD) cells and 6-OHDA, a toxin model of Parkinson's disease (PD) in SH-SY5Y cells. These activities proved to be more potent than the parent compound (ALA) alone. Dlx-23 scavenged free radicals, increased glutathione levels, and prevented mitochondria damage. In addition, live imaging of primary cortical neurons demonstrated that dlx-23 protected against neuronal growth cone damage induced by H2O2. Taken together these results suggest that dlx-23 has substantial potential to be further developed into a novel neuroprotective agent against oxidative damage and toxin induced neurodegeneration.

Drag reducers (DRs) have a significant effect on shale hydraulic fracturing. Hence, it is very essential to develop excellent DRs for engineering applications. In this work, a novel nanocomposite drag reducer (PASD-SiO2) was synthesized using acrylamide (AM), sodium 4-styrenesulfonate (SSS), dimethylhexadeylallylammonium bromide (DMAAB) and modified nanosilica by redox free radical copolymerization. Fourier transform infrared spectroscopy (FT-IR), 13C nuclear magnetic resonance spectroscopy (13C NMR), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), elemental analysis, dynamic light scattering spectrophotometer (DLS) and scanning electron microscopy (SEM) were utilized to characterize the copolymer. Then its solution properties were evaluated. The results showed that the nanocomposite exhibited better performances of temperature resistance, salt tolerance, shear resistance and viscoelasticity than those of a pure polymer. The indoor drag reduction measurements were carried out in a closed loop flow system. The maximum drag reduction efficiency of PASD-3%SiO2 was 59.2%, which was 9.7% higher than that of a neat polymer. These improvements in desirable properties were mainly attributed to the dispersion of silica nanoparticles in the polymer matrix. Nanosilica acted as a cross-linker and enhanced the strength of the network structures, which improved the structural stability. In addition, the polymer containing silica nanoparticles exhibited improved structural rigidity. Therefore, the polymer molecules showed more persistent and effective restriction towards vortices under turbulent flows. This novel drag reducer showed good potential for slickwater fracturing applications.

A new kind of CO2 responsive polymeric surfactant (named DEA-SSS) was synthesized by using 2-(diethylamino)ethyl methacrylate (DEA) and sodium styrene sulfonate (SSS) via radical polymerization. Th...

In this paper, the cation monomer, N, N’-dimethylhexadeylallylammonium bromide (DMHAAB), was prepared using N, N-dimethylhexadecyl amine and allyl bromide in a laboratory. Acrylamide (AM), sodium 4-styrenesulfonate (SSS) and DMHAAB were utilized to successfully synthesize acrylamide-based terpolymer (denoted as ASD) via redox free-radical polymerization. Surface-modified montmorillonite (O-MMT) was obtained by cation exchange reaction between pristine sodium montmorillonite (Na-MMT) and cetyltrimethyl ammonium bromide (CTAB). O-MMT was added during the copolymerization in order to prepare nanocomposites with the homogeneous dispersion of exfoliated phyllosilicates (denoted as ASD/MMT). The aqueous solution properties were evaluated by viscosimetry and rheological behavior. ASD/MMT exhibited better salt-tolerance, temperature-resistance, shear stability and viscoelasticity in comparison to ASD. In a closed loop system the drag reduction properties were measured where both ASD/MMT and ASD acted as drag reduction agent. The results indicated that drag reduction efficiency (DR) of ASD/2%MMT increased with Reynolds number (Re) rising and reached DR of 58% in high Re region at a concentration of 300 ppm, compared with 49% for ASD. The superior properties of ASD/MMT could be attributed to the contribution of delaminated nanoplatelets in polymer matrix, which improved the interaction strength of physical crosslink network to some extent. The ASD/MMT had a significant potential in slickwater fracturing fluids.

Tigecycline is one of the last-resort antibiotics to treat complicated infections caused by both multidrug-resistant Gram-negative and Gram-positive bacteria1. Tigecycline resistance has sporadically occurred in recent years, primarily due to chromosome-encoding mechanisms, such as overexpression of efflux pumps and ribosome protection2,3. Here, we report the emergence of the plasmid-mediated mobile tigecycline resistance mechanism Tet(X4) in Escherichia coli isolates from China, which is capable of degrading all tetracyclines, including tigecycline and the US FDA newly approved eravacycline. The tet(X4)-harbouring IncQ1 plasmid is highly transferable, and can be successfully mobilized and stabilized in recipient clinical and laboratory strains of Enterobacteriaceae bacteria. It is noteworthy that tet(X4)-positive E. coli strains, including isolates co-harbouring mcr-1, have been widely detected in pigs, chickens, soil and dust samples in China. In vivo murine models demonstrated that the presence of Tet(X4) led to tigecycline treatment failure. Consequently, the emergence of plasmid-mediated Tet(X4) challenges the clinical efficacy of the entire family of tetracycline antibiotics. Importantly, our study raises concern that the plasmid-mediated tigecycline resistance may further spread into various ecological niches and into clinical high-risk pathogens. Collective efforts are in urgent need to preserve the potency of these essential antibiotics. Plasmid-encoded tet(X) genes from Escherichia coli in China confer high-level tigecycline resistance.

Liang Xing,1,2,* Feng Sun,1,2,* Zhendong Wang,1,2 Yan Li,1,2 Zhifang Yang,1,2 Fengshan Wang,1,3 Guangxi Zhai,3 Haining Tan1,2 1National Glycoengineering Research Center, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, Shandong, People’s Republic of China; 2Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250012, Shandong, People’s Republic of China; 3School of Pharmaceutical Sciences, Shandong University, Jinan 250012, Shandong, People’s Republic of China *These authors contributed equally to this work Background: In the past few years, significant progress has been made in inhibiting neovascularization at the tumor site, cutting off the nutrient supply of the tumor, and inhibiting tumor growth and metastasis. However, many proteins/peptides have the disadvantage of poor stability, short half-life, and uncertain targeting ability. Chemical modification can be used to overcome these disadvantages; many polyethylene glycol-modified proteins/peptides have been approved by US FDA. The purpose of this study was to obtain a novel anti-angiogenic chondroitin sulfate (CS)-peptide nanoparticle conjugate with efficient anti-neovascularization and tumor targeting ability and an acceptable half-life. Materials and methods: The CS-ES2-AF nanoparticle conjugate was synthesized and characterized using 1H-nuclear magnetic resonance spectroscopy, transmission electron microscopy, and particle size and zeta potential analyzer. The anti-angiogenic ability was studied using MTT, migration, tube formation, and chick chorioallantoic membrane assays. The targeting ability of CS-ES2-AF was studied by ELISA, surface plasmon resonance, and bioimaging. The pharmacokinetics was also studied.Results: The CS-ES2-AF could self-assemble into stable nanoparticles in aqueous solution, which significantly enhances its anti-neovascularization activity, tumor targeting more explicit, and prolongs its half-life.Conclusion: CS is an effective protein/peptide modifier, and CS-ES2-AF displayed good potential in tumor targeting therapy. Keywords: chondroitin sulfate, ES2-AF, nanoparticles, anti-angiogenesis, targeting &nbsp

We investigated the prevalence and transmission of NDM-producing Enterobacteriaceae in fecal samples of geese and environmental samples from a goose farm in Southern China. The samples were cultivated on MacConkey agar plates supplemented with meropenem. Individual colonies were examined for blaNDM and blaNDM-positive bacteria were characterized based on WGS data from the Illumina and ONT platforms. Of 117 samples analyzed, the carriage rates for NDM-positive Enterobacteriaceae were 47.1, 18 and 50% in geese, inanimate environments (sewage, soil, fodder and dust) and mouse samples, respectively. Two variants (4 blaNDM-1 and 40 blaNDM-5) were found among 44 blaNDM-positive Enterobacteriaceae, which belonged to 8 species and Escherichia coli was the most prevalent (50%). WGS analysis revealed that blaNDM co-existed with diverse antibiotic resistance genes (ARGs). Population structure analysis showed that most E. coliand Enterobacter sp. isolates were highly heterogeneous while most Citrobacter sp. and P. stuartii isolates possessed extremely high genetic similarity. Additionally, blaNDM-5-positive ST4358/ST48 E. coli isolates were found to be clonally spread between the geese and environment and were highly genetically similar to those reported from ducks, farm environments and humans in China. Plasmid analysis indicated that IncX3 pHNYX644-1-like (n=40) and untypable pM2-1-like plasmids (n=4) mediated blaNDM spread. pM2-1-like plasmids possessed diverse ARGs including blaNDM-1, the arsenical and mercury resistance operons and the maltose operon. Our findings revealed that the goose farm is a reservoir for NDM-positive Enterobacteriaceae. The blaNDM contamination of wild mice and the novel pM2-1-like plasmid described in this study likely adds to the risk for dissemination of blaNDM and associated resistance genes. Importance: The carbapenem-resistant bacteria, in particular NDM-producing Enterobacteriaceae, has become a great threat to global public. These bacteria have been found not only in hospital and community environments, but also among food animal production chains, which are recognized as reservoirs for NDM-producing Enterobacteriaceae. However, the dissemination of NDM-producing bacteria in the waterfowl farm has been less well explored. Our study demonstrated that horizontal spread of blaNDM-carrying plasmids and the partial clonal spread of blaNDM-positive Enterobacteriaceae contributed to widespread contamination of blaNDM in the goose farm ecosystem, including mouse. Furthermore, we found a novel and transferable blaNDM-1-carrying MDR plasmid that possessed multiple environmental adaptation-related genes. The outcomes of this study contribute to a better understanding of the prevalence and transmission of blaNDM-producing Enterobacteriaceae among diverse niches in the farm ecosystem.

Antimicrobial resistance is recognized as one of the major global health challenges of the 21st century. Synergistic combinations for antimicrobial therapies can be a good strategy for the treatment of multidrug resistant infections. We examined the ability of a group of 29 plant essential oils as substances which enhance the antibiotic activity. We used a modified well diffusion method to establish a high-throughput screening method for easy and rapid identification of high-level enhancement combinations against bacteria. We found that 25 essential oils possessed antibacterial activity against Escherichia Coli ATCC 25922 and methicillin-resistant Staphylococcus aureus (MRSA) 43300 with MICs that ranged from 0.01% to 2.5% v/v. We examined 319 (11 × 29) combinations in a checkerboard assay with E. Coli ATCC 25922 and MRSA 43300, and the result showed that high-level enhancement combinations were 48 and 44, low-level enhancement combinations were 214 and 211, and no effects combinations were 57 and 64, respectively. For further verification we randomly chose six combinations that included orange and Petitgrain essential oils in a standard time-killing assay. The results are in great agreement with those of the well diffusion assays. Therefore, the modified diffusion method was a rapid and effective method to screen high-level enhancement combinations of antibiotics and essential oils.

The emergence and spread of the novel mobile Tet(X) tetracycline destructases confer high-level tigecycline and eravacycline resistance in Escherichia coli and Acinetobacter spp. and pose serious threats to human and animal health. Therefore, a rapid and robust Tet(X) detection assay was urgently needed to monitor the dissemination of tigecycline resistance. We developed a rapid and simple assay to detect Tet(X) producers in Gram-negative bacteria based on matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). This MALDITet(X) test was based on the inactivation of tigecycline by a Tet(X)-producing strain after a 3-h incubation of bacterial cultures with tigecycline. Culture supernatants were analyzed using MALDI-TOF MS to identify peaks corresponding to tigecycline (586 ± 0.2 m/z) and a tigecycline metabolite (602 ± 0.2 m/z). The results were calculated using the MS ratio [metabolite/(metabolite + tigecycline)]. The sensitivity of the MALDITet(X) test with all 216 test strains was 99.19%, and specificity was 100%. The test can be completed within 3 h. Overall, the MALDITet(X) test is an accurate, rapid, cost-effective method for the detection of Tet(X)-producing E. coli and Acinetobacter spp. by determining the unique peak of an oxygen-modified derivative of tigecycline.

The recent emergence of plasmid-mediated tigecycline resistance gene tet(X) has challenged the clinical effectiveness of tigecycline as a last-resort treatment option. During 2017-2018, 336 fecal samples from sick ducks, pigs, chickens and geese in Guangdong, China, were screened for tet(X)-positive Acinetobacter baumannii strains. Their activities on tetracyclines were determined by microbiological degradation and mass spectrometry, followed by susceptibility testing, sequence typing, gene transfer, molecular location and genomic DNA sequencing analyses. A total of 10 tet(X)-positive A. baumannii strains were isolated from ducks and chickens, including eight plasmid-borne tet(X5)-positive and two chromosomal tet(X6)-positive isolates. All of them exhibited good degradation activities on tetracyclines by hydroxylation at C11a and were multidrug-resistant to tigecycline, tetracycline, florfenicol, ciprofloxacin and trimethoprim/sulfamethoxazole. Genetically, they belonged to two sequence types (ST355, n = 8; ST1980, n = 2) that were consistent with their pulsotypes, revealing a clonal spread of ST355 A. baumannii. An ISCR2- or IS26-mediated tet(X) transposition structure, homologous to those of clinical A. baumannii strains, was also identified and ISCR2 could transfer tet(X5) into the recipient Acinetobacter baylyi ADP1 at a frequency of (1.8 ± 0.3)×10-6. Therefore, more efforts are needed to evaluate the clinical impact of these tigecycline resistance genes.

Objectives: There is an urgent need for accurate and fast diagnostic tests to identify carbapenemase-producing bacteria. Here we used Bacillus stearothermophilus as an indicator strain in the format of the carbapenem inactivation method (CIM) procedure to develop a rapid carbapenemase phenotype detection method: CIMB.S. Methods: The CIMB.S test was derived from the mCIM, where B. stearothermophilus replaced Escherichia coli as the indicator strain. The test bacteria were incubated in the presence of imipenem for 30 min, and then, aliquots were placed on colorimetric plates, and incubation was continued for 3.5 h at 60°C. We examined 134 clinical strains to evaluate the CIMB.S performance. Results: The CIMB.S can be completed in 4 h, and we successfully identified 38/39 (97.4%) carbapenemase-producing Enterobacteriaceae, including 17/18 (94.4%) carbapenemase-producing Pseudomonas aeruginosa and 18/19 (94.7%) carbapenemase-producing Acinetobacter baumannii. All non-carbapenemase producers we tested were negative and included Enterobacteriaceae (n = 36), P. aeruginosa (n = 17), and A. baumannii (n = 5). Conclusions: The CIMB.S test is a rapid carbapenemase phenotype detection method requiring only 4 h of total work time and displays high sensitivity and specificity.

In this research, a novel amphiphilic hydrophobically associative polymer nanocomposite (ADOS/OMMT) was prepared using acrylamide (AM), sodium 4-vinylbenzenesulfonate (SSS), N, N′-dimethyl octadeyl allyl ammonium bromide (DOAAB) and organo-modified montmorillonite (OMMT) through in situ polymerization. Both X-ray diffraction patterns and transmission electron microscopy images verified the dispersion morphology of OMMT in the copolymer matrix. Then, the effect of the introduction of OMMT layers on the copolymer properties was studied by comparing with pure copolymer AM/SSS/DOAAB (ADOS). The thermal degradation results demonstrated that the thermal stability of the ADOS/OMMT were better than pure copolymer ADOS. During the solution properties tests, ADOS/OMMT nanocomposite was superior to ADOS in viscosifying ability, temperature resistance, salt tolerance, shear resistance and viscoelasticity, which was because OMMT contributed to enhance the hydrophobic association structure formed between polymer molecules. Additionally, the ADOS/OMMT nanocomposite exhibited more excellent interfacial activity and crude oil emulsifiability in comparison to pure copolymer ADOS. These performances indicated ADOS/OMMT nanocomposite had good application prospects in tertiary recovery.

The cfr gene associated with linezolid resistance has attracted wide attention. However, little is known about its prevalence and mode of transmission in Enterococcus faecalis. In this study, we investigate the prevalence and genetic environment of the cfr gene in 91 E. faecalis isolates collected from swine faecal swabs in 30 farms in Guangdong Province, China in 2012. A relatively high prevalence of cfr was identified in E. faecalis isolates (11/91, 12.1%) by PCR. All the cfr-positive E. faecalis strains had a multidrug-resistance phenotype including erythrocin, tetracycline, gentamicin, kanamicin and ciprofloxacin, except vancomycin and linezolid. Molecular typing indicated that ST475 and ST16 were the most common types in cfr-positive E. faecalis strains. In addition, we demonstrated that all the cfr genes were located on plasmids by S1-PFGE and Southern blotting. A 12 kb cfr-positive plasmid (pE30) was identified in most (9/11) E. faecalis strains, but it couldn't mediate resistance to linezolid in the transconjugant. Sequence analysis showed that the pE30 was a pCPPF5-like plasmid and the region surrounding the cfr gene was the same as a cfr-carrying ISEnfa5-composite element in Streptococcus plasmid pStrcfr with 4 bp direct repeat (GTAT) on both sides. In conclusion, the cfr gene which had no linezolid resistance phenotype was present in multidrug-resistance E. faecalis strains, and the clonal spread of ST475 and ST16 strains and the horizontal transfer of the pCPPF5-like plasmids have contributed to the dissemination of cfr.

Objectives The emergence and spread of plasmid-encoded tet(X3/X4) genes that confer high-level tigecycline and eravacycline resistance in Escherichia coli and Acinetobacter spp. pose serious threats to human and animal health. We developed a rapid and robust assay to detect Tet(X3/X4) in Gram-negative bacteria based on eravacycline degradation by the presence of the Tet(X) enzyme in the test strain. Methods This tetracycline inactivation method (TIM) is based on the degradation of eravacycline by the Tet(X3/X4)-producing strain, which results in reduced eravacycline activity against an acid-producing thermophile Bacillus stearothermophilus indicator strain. For Tet(X)-negative strains, eravacycline retains its antimicrobial activity. Coupled with a pH-sensitive dye (bromocresol purple), the reduced colorimetric inhibition zone can be measured to determine the production of Tet(X3/X4). One hundred and eighteen isolates, including 30 tet(X4)-positive E. coli, 30 tet(X3)-positive Acinetobacter spp. and 58 tet(X)-negative E. coli and Acinetobacter spp., were examined to evaluate the performance of this TIM. Results The sensitivity and specificity for E. coli carrying tet(X4) was 96.7% and 100%, respectively, and for Acinetobacter spp. carrying tet(X3) both were 100%. The TIM assay can be completed within 6.5 h. Conclusions The TIM is a simple, rapid and cost-effective method for the detection of plasmid-mediated high-level tigecycline resistance in E. coli and Acinetobacter spp.

Virginiamycin (VM), a streptogramin antibiotic, has been used to promote healthy growth and treat illnesses in farm animals in the United States and other countries. The combination streptogramin Quinupristin-Dalfopristin (QD) was approved in the United States in 1999 for treating patients with vancomycin-resistant Enterococcus faecium (VREF) infections. Many chickens and swine test positive for QD-resistant E. faecium, raising concerns that using VM in food animals might select for streptogramin-resistant strains of E. faecium that could compromise QD effectiveness in treating human VREF infections. Such concerns have prompted bans and phase-outs of VM as growth promoters in the United States and Europe. This study quantitatively estimates potential human health risks from QD-resistant VREF infections due to VM use in food animals in China. Plausible conservative (risk-maximizing) quantitative risk estimates are derived for future uses, assuming 100% resistance to linezolid and daptomycin and 100% prescription rate of QD to high-level (VanA) VREF-infected patients. Up to one shortened life every few decades to every few thousand years might occur in China from VM use in animals, although the most likely risk is zero (e.g., if resistance is not transferred from bacteria in food animals to bacteria infecting human patients). Sensitivity and probabilistic uncertainty analyses suggest that this conclusion is robust to several data gaps and uncertainties. Potential future human health risks from VM use in animals in China appear to be small or zero, even if QD is eventually approved for use in human patients.

The growth, migration and spread of malignant tumors requires a large number of new blood vessels to supply nutrients. In our previous study, it was found that the hyaluronic acid (HA) modified novel antiangiogenic peptide ES2-AF has better solubility, longer half-life, stronger targeting than non-modified ES2-AF, and it significantly inhibited the formation of new blood vessels. In the current work, we studied the stability of ES2-AF after HA modification, including heat stability, longterm stability, and pH stability. After treatment with HA-ES2-AF, cell apoptosis and the cell cycle were analyzed using flow cytometry. The inhibitory effect of HA-ES2-AF on tumors was investigated in vivo in HepG2 tumor-bearing nude mice. All the above results showed that HA-ES2-AF significantly improved stability, effectively induced apoptosis of endothelial cells, caused G1 phase arrest of endothelial cells, and decreased the percentage of cells in G2 and S phases. In vivo, HA-ES2-AF exhibited an inhibitory effect on tumors growth. In addition, the results provide a reliable basis for studying the inhibition of neovascularization and anti-tumor drugs in the future.

Horizontal transfer of plasmid-encoded multidrug-resistant determinants is a major health problem and has attracted much public attention. We studied the dissemination of the efflux pump gene oqxAB located on transferable plasmid pHXY0908 between Salmonella Typhimurium and Escherichia coli in the gut of chickens. After an inoculation with Salmonella Typhimurium harboring oqxAB-bearing plasmid pHXY0908, chickens were treated with enrofloxacin and florfenicol. Inoculated, but non-treated chickens were included as a control group. Our results revealed that commensal E. coli isolates from the gut of chickens acquired the oqxAB-bearing plasmid in both treated and non-treated groups. Additionally, in the florfenicol treatment group, the average isolation rate of oqxAB-positive E. coli was significantly higher than that in the non-treated group. PFGE analysis showed that oqxAB-positive E. coli strains belonged to different patterns with one predominating. Moreover, multilocus sequence typing analysis revealed that E. coli ST533 was closely associated with the spread of oqxAB gene. qPCR analysis indicated that antibiotic administration provided selective advantages for sustaining a significantly high level of oqxAB gene from the DNA extracted from the feces. There was also a fluctuation in the intestinal microbiota with antibiotic therapy. In conclusion, the present study indicates that the oqxAB gene could be readily spread within the intestinal microflora. This could be enhanced by administrated with clinical doses of florfenicol and enrofloxacin, resulting in the enlargement of resistance gene reservoirs. In addition, ST533 E. coli isolates were found to contribute to transfer of the oqxAB gene.

Contactin-associated protein-like 2 (CNTNAP2 or CASPR2) is a neuronal transmembrane protein of the neurexin superfamily which is correlated with pain related hypersensitivity. Recent results indicated that the hyperactive phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway may be a promising therapeutic target for pain-related hypersensitivity in patients with dysfunction of CNTNAP2. Resveratrol is one of the most widely studied polyphenols with several beneficial properties. In the present study, we investigated the effects of resveratrol on the pain related hypersensitivity. And we found that the up-regulated phosphorylation of S6 could be suppressed by resveratrol. The nocifensive behavior duration time to heat and chemical algogens stimulation in Cntnap2-deficiency (Cntnap2−/−) mice could be attenuated by resveratrol. Our results indicated that resveratrol could rescue the pain related hypersensitivity for Cntnap2−/− mice may be via mTOR signaling pathway.

Most solid tumors require neovascularization during their growth. In our previous study, ES2 (IVRRADRAAVP) was covalently conjugated to soluble chitooligosaccharide chloride (HTCOSC) to form one novel HTCOSC-ES2 conjugate, which displayed better anti-angiogenic activity. In this work, the intracellular distribution and endocytosis of the conjugate in endothelial cells, as well effects on endothelial cell cycle and apoptosis were investigated. In addition, pharmacokinetic and antitumor studies were conducted. HTCOSC-ES2 entered the cell via clathrin and lipid valve pathway and was transported to the nucleus via lysosomal transport mechanism. Unlike ES2, HTCOSC-ES2 effectively inhibited the growth of endothelial cells and promoted apoptosis; thus, it could inhibit tumor angiogenesis, resulting in strong anti-tumor activity in vivo. The half-life of HTCOSC-ES2 was also prolonged, and its clearance was delayed. Immunohistochemistry assays showed that HTCOSC-ES2 obviously reduced the microvessel density, decreased the expression of VEGF, and increased the expression of caspase-3.

We sequenced a novel conjugative multidrug resistance IncF plasmid, p42-2, isolated from Escherichia coli strain 42-2, previously identified in China. p42-2 is 106,886 bp long, composed of a typical IncFII-type backbone (∼54 kb) and one distinct acquired DNA region spanning ∼53 kb, harboring 12 antibiotic resistance genes [ bla CTX-M-55 , oqxA , oqxB , fosA3 , floR , tetA (A), tetA (R), strA , strB , sul2 , aph(3′)-II , and Δ bla TEM-1 ]. The spread of these multidrug resistance determinants on the same plasmid is of great concern and, because of coresistance to antibiotics from different classes, is therapeutically challenging.

The sandblasting-acid-etched (SLA) technique and hydroxyapatite (HA) deposition are the two methods widely used to improve surface characteristics of titanium implants. In the current study, a layer of HA was deposited on SLA-treated titanium (SLA-Ti) by a simple deposition method. The surface topography and surface roughness of SLA-Ti and HA-coated titanium (HA-Ti) were evaluated using scanning electron microscope (SEM) and atomic force microscope (AFM). Protein adsorption, osteoblast chemotaxis as well as osteoblast attachment on both Ti surfaces were additionally analyzed. The results show that SLA-Ti surface is covered with uniform, multiple micropores, whereas HA-Ti surface is covered with a large number of uniform microparticles under multiple microporous background. In comparison to SLA-Ti, the surface roughness of HA-Ti surface is lower. The protein adsorption on SLA-Ti and HA-Ti surfaces is generally even, and the chemotaxis of osteoblast have no differences. After 12 and 24 h of incubation, more osteoblasts are adhered to the HA-Ti surface and more osteoblast-osteoblast connection is observed on HA-Ti surface compared to SLA-Ti surface. These findings demonstrate that HA coating deposited on SLA-Ti surface improves SLA-Ti surface morphology and promotes osteoblast attachment in vitro.

To mimick the natural enzymes [FeFe]-hydrogenases, some new porphyrin and metalloporphyrin moiety-containing model complexes, namely 5-[p-Fe2(CO)6(μ-SCH2)2CHO2CC6H4],10,15,20-triphenylporphyrin (2), 5-[p-Fe2(CO)6(μ-SCH2)2CHO2CC6H4],10,15,20-triphenylporphyrinozinc (3), 5-[p-Fe2(CO)6(μ-SCH2)2NC2H4SC6H4],10,15,20-triphenylporphyrin (7), and 5-[p-Fe2(CO)5(μ-SCH2)2NC2H4SC6H],10,15,20-triphenylporphyrin (8), have been successfully prepared by our designed synthetic routes involving the corresponding precursor compounds [(μ-SCH2)2CHO2CC6H4CHO-p]Fe2(CO)6 (1), p-Boc-NHC2H4SC6H4CHO (4), 5-(p-Boc-NHC2H4SC6H4),10,15,20-triphenylporphyrin (5), and 5-(p-NH2C2H4 SC6H4),10,15,20-triphenylporphyrin (6). All these new compounds 1–8 have been characterized by elemental analysis and various spectroscopic methods, and particularly for 1–3 and 7 by X-ray crystallography. In addition, the density functional theory computations on 8 were performed to assist its structural characterization.

In order to achieve the goal of purifing the waste water and recycling of copper, use the electrodeposition to treat the copper-containing wastewater. The experiment studies the effects of electrode materials, cell voltage, plate distance, pH and other experimental conditions in the process of deposition and the effect of blowing nitrogen in the process of deposition. The results show that the best condition is using graphite-aluminum electrode, cell voltage is 7V, plate distance is 10mm and pH is 3 under the condition of blowing nitrogen. From which the removal rate of copper can reach more than 93%. Nitrogen can effectively reduce the concentration of dissolved oxygen in the water, reduce the degree of corrosion of the metal and eliminate the concentration polarization and electrochemical polarization in the deposition process to obtain a higher electrodeposition efficiency and current efficiency.

A 6061 aluminium rectangular tube extrusion using porthole dies was simulated by finite element software DEFORM-3D. The speed, stress, strain and temperature in the extrusion was given and analyzed. Using the original porthole die, the speed at the bearing entrance is not uniform. Bearing length at the rectangular corners should be increased. The stress, strain and temperature near the bearing are the largest, so the region of the die should be treated and enhanced.

The first phosphinobenzaldehyde- and phosphinoporphyrin-functionalized model complexes (1–4) have been synthesized and structurally characterized. Thus, reaction of diiron complex [(μ-SCH2)2CH2]Fe2(CO)6 or [(μ-SCH2)2NC6H4CO2Me-p]Fe2(CO)6 with p-Ph2PC6H4CHO in the presence of Me3NO gave the phosphinobenzaldehyde-functionalized model complexes [(μ-SCH2)2CH2]Fe2(CO)5(p-Ph2PC6H4CHO) (1) and [(μ-SCH2)2NC6H4CO2Me-p]Fe2(CO)5(p-Ph2PC6H4CHO) (2) in 61% and 71% yields, respectively. Further reaction of 1 or 2 with PhCHO, pyrrole, and BF3·OEt2 followed by treatment with p-chloranil resulted in formation of the phosphinoporphyrin-functionalized model complexes 5-{[(μ-SCH2)2CH2]Fe2(CO)5(p-Ph2PC6H4)}-10,15,20-triphenylporphyrin (3) and 5-{[(μ-SCH2)2NC6H4CO2Me-p]Fe2(CO)5(p-Ph2PC6H4)}-10,15,20-triphenylporphyrin (4) in 19% and 18% yields, respectively. While the new complexes 1–4 were characterized by elemental analysis and spectroscopy, the structures of 1, 3, and 4 were confirmed by X-ray crystallography. Particularly ...

Zhou X, Chen X, Cai JJ, et al. Drug Des Devel Ther. 2015;9: 4599–4611. On page 4600, the product type and source of the relaxin used in these experiments was missed from the ‘Materials and methods’ section. Under the subheading ‘Rat model of cardiac fibrosis’ the second paragraph should read: Rats were randomly divided into five groups (ten per group) for treatment: control; myocardial fibrosis (isoproterenol [Iso]); and low-, middle-, and high-dose RLX (0.2, 2, and 20 μg⋅kg-1⋅day-1, respectively). RLX was obtained from Peprotech, Rocky Hill, NJ, USA (product number 130-15). For the Iso-model, on days 1–6, Iso (5 mg⋅kg-1⋅d-1; Sigma-Aldrich Co., St Louis, MO, USA) was injected subcutaneously in the rats. In the therapeutic groups, Iso administration was the same as in the Iso-model group, and RLX at different concentrations (0.2, 2.0, and 20 μg⋅kg-1⋅day-1) were injected at the same time as Iso injection and lasted for 6 days, then RLX injection was continued for another 8 days. The same volume of saline was injected for controls.Read the original article.

Forming conditions of the shale gas reservoir of the Weixin Sag in the Dianqianbei Depression are studied and preferable sweet spots for shale gas exploration are proposed based on the results of geologic survey, drilling and seismic survey in the shale gas region. The black shale of Cambrian Niutitang Formation and Silurian Longmaxi Formation are the two principal exploration targets in the Weixin Sag, having the characteristics of big net thickness (>50m) and abundant organic matter, low porosity and permeability. Those two formations have favorable conditions for the formation of shale gas reservoirs and also can be easily hydraulic fractured in the later stages of production. The coexistence of the clastic rock layer on the top, shallow entire seal, and the absence of exposed faults are the three desirable factors for the preservation of shale gas reservoir. The shale core analysis shows that the major composition is methane, the content of which increases as the preservation conditions become better and the shale TOC content and formation pressure increase. After integrated evaluation and optimized selection of shale gas exploration zones, it is determined that the Junlian-Luobu zone located in the north of the sag is the most favorable sweet spot for shale gas exploration in the overlapping target layer of the Longmaxi Formation and Niutitang Formation, and the Huani-Weixin zone in the middle of the sag is proposed to be the sweet spot for shale gas exploration in the Niutitang Formation. It is recommended that importance be attached to the evaluation of shale gas exploration in the Lower Carboniferous Jiusi Formation and Upper Permian Leping formation. 摘要: 根据页岩气区域地质调查研究、钻探和地震勘探成果 研究滇黔北坳陷威信凹陷页岩气成藏条件 优选页岩气勘探“甜点”。寒武系牛蹄塘组和志留系龙马溪组黑色页岩是威信凹陷页岩气两套重点勘探评价层系 单层厚度达50 m以上 有机质丰度高 具有低孔、低渗和富硅质特征 具备形成页岩气藏的有利地质条件并易于后期储集层压裂改造。上覆碎屑岩盖层、无通天断层、浅层整体封闭3大因素并存利于页岩气藏保存。岩心解吸显示页岩气成分以甲烷为主 页岩气含量随保存条件变好、页岩TOC丰度增大和地层压力加大而增加。页岩气勘探甜点综合评价优选认为 凹陷北部的筠连—罗布地区为龙马溪组和牛蹄塘组页岩气目的层叠合的最有利甜点勘探区 -部的花坭—威信地区为牛蹄塘组页岩气有利甜点区。建议重视下石炭统旧司组、上二叠统乐平组的页岩气勘探评价。图7表3参14 关键词滇黔北坳陷 威信凹陷 页岩气 成藏条件 区带优选-图分类号TE132.2 文献标识码A Key words: Dianqianbei Depression, Weixin Sag, shale gas, reservoir forming conditions, optimized exploration zone election

This paper explores the brazing process of SiCp/A356 composites and aluminum alloy using semisolid metal. The two substrates were heated up to the semisolid temperature range of Zn-Al filler metal in the joint region by a resistance heating plate. In order to mix the filler metal with the base metal of both sides to be a single uniform joint, a stirrer was introduced into the weld seam. After stirring, specimens were sectioned for analysis of macro- and micro-structures along the weld region. The research shows that SiCp/A356 composites and aluminum can be local joined with semi-solid filler metal. It can be found that part of the oxide film on the interface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds can be formed between the filler metal and the base materials. Moreover, the oxide film of surface of aluminum alloy disrupted and removed was easier than that of surface of composites with existing of Sic particle. The joint microstructure with globular α-Al grain enclosed by rich-Zn phase can be obtained after stirring brazing.

Osteoclasts are primary bone resorption cells and intervention in osteoclast activation is considered an effective therapeutic approach to treatment of bone diseases involving osteoclasts. TRPV5 was detected in osteoclasts and it has been thought to take part in the transportation of the degraded calcium in the resorption lacuna, which is essential for bone resorption. The aim of the present study was to examine the effects of a modulator of calcium dynamics, econazole, on the expression of TRPV5 and bone resorption activity in rat osteoclast-like cells (OLCs). OLCs were obtained by co-culturing rat bone marrow cells with osteoblasts and then culturing with different concentrations of econazole (0.01, 0.1, 1.0, 10.0 μmol/L). Cell counting and staining protocols were used to determine whether econazole influenced the survival of OLCs. Expression of TRPV5 in response to econazole treatment was assessed by western blotting. Bone resorption activity of OLCs was determined by measuring the resorption area of dentin slices with a microscope and a digital image analysis system. Additionally, Ca(2+) inside OLCs was tested. We found that econazole inhibited expression of TRPV5 in a dose dependent manner while it had no influence on the survival of OLCs and it therefore inhibited bone resorption activity in rat OLCs. Ca(2+) inside OLCs increased, suggesting a limited compensatory mechanism to make up for inhibition of TRPV5 effects.

Synthetic nanoparticles often bear wide distribution in size and shape. However, it is critical to have nanoparticles with the lowest size and shape dispersion possible in many experiments for their unique size- and/or shape-dependent physiochemical properties. Therefore, quick and handy separation methods of nanoparticles have brought considerable attention in many scientific areas recently. Electrophoresis has been extensively used in the separation and purification of biological molecules such as nucleic acids and proteins with a remarkable resolution. The charged nanoparticles are very close in size to protein complexes, organelles and microorganisms, and share similarity in motion behavior with biological molecules in an electric field. It is a new idea to use electrophoresis technology for nanoparticles’ identification, separation and purification, which has achieved favorable results. This review presents recent advances in the separation of nanoparticles by agarose gel electrophoresis, capillary electrophoresis and some other electrophoretic techniques.

A carbon ionic liquid electrode (CILE) was modified with a polythionine (PTh)/multi-walled carbon nanotubes (MWCNTs) composite and used for the detection of reduced nicotinamide adenine dinucleotide (NADH). The electrode was prepared by electrochemical polymerization of thionine on the MWCNTs in neutral medium. Cyclic voltammetry indicated that the electrode was capable of mediating the oxidation of NADH at an overpotential as low as 0.03 V. Amperometric experiments showed that a sensitive and stable response towards NADH is obtained within 5 s. The linear range for the determination of NADH is from 0.8 μmol L−1 to 422 μmol L−1, with a detection limit of 0.26 μmol L−1 (S/N = 3). The wide linear range, lower detection limit and faster response towards NADH suggests that the new method potentially is useful for developing NAD+-dependent enzyme-based biosensors.

A series of novel light-driven-type models, which contain a single diiron- ADT(azadithiolate) unit or two and four diiron-ADT units covalently bonded to a photosensitizer porphyrin or metalloporphy...

A new type of recyclable chiral catalyst system was developed by absorption of pyrene-modified Pyrphos rhodium catalyst onto carbon nanotubes via π-π stacking interaction. This modified catalyst was successfully applied in the asymmetric hydrogenation of α-dehydroamino esters for nine cycles without obvious deterioration of activity and enantioselectivity.

As the new H-cluster models, a series of N-functionalized azadithiolatodiiron complexes containing mono- and diphosphine ligands 1–7 have been prepared by various methods from complexes [(μ-SCH2N(F...

A series of N-acylated diiron azadithiolate complexes as H-cluster models was synthesized and structurally characterized. Treatment of parent complex [{(μ-SCH 2 ) 2 NH)-Fe 2 (CO) 6 ] (A) with 2-chloroacetic acid in the presence of dicyclohexylcarbodiimide or with 2-chloroacetyl chloride in the presence of Et 3 N gave N-chloroacetyl complex [{(p-SCH 2 ) 2 -NC(O]CH 2 Cl]Fe 2 (CO) 6 ] (1). Further treatment of 1 with MeC(O)SK afforded N-acetylthioacetyl complex [{(μ-SCH 2 ] 2 -NC(O)CH2SC(O)Me)Fe 2 (CO) 6 ] (2). N-Ethoxylcarbonylacetyl complex [{(μ-SCH 2 ) 2 NC(O)CH 2 CO 2 Et}Fe 2 (CO) 6 ] (3) and N-heterocyclic complexes [{(μ-SCH 2 ) 2 NC(O)C 4 H 3 Y-2}Fe 2 (CO) 6 ] (4, Y = 0; 5, Y = S) were produced by reactions of A with EtO 2 CCH 2 C(O]Cl, 2-furancarbonyl chloride, and 2-thio-phenecarbonyl chloride in the presence of pyridine or Et 3 N. Similarly, N-malonyl complex [{Fe2(CO)6(μ-SCH2)2NC-(O)) 2 CH 2 ] (6) and N-carbonylbenzaldehyde complex [{(μ-SCH2)2NC(O)C 6 H 4 CHO-p}Fe 2 (CO) 6 ] (7) could be obtained by reaction of A with malonyl dichloride in the presence of pyridine and with p-CHOC 6 H 4 C(O)Cl in the presence of Et 3 N. More interestingly, further reaction of 7 with PhCHO and pyrrole in a 1:3:4 molar ratio in the presence of BF 3 -OEt 2 followed by p-chloranil yielded the first light-driven type of model complex containing an N-carbonylphenylporphyrin moiety [{(μ-SCH 2 ) 2 NC(O)(TPP)]Fe 2 (CO) 6 ] (8, TPP = tetraphenylporphyrin group). Whereas the molecular structures of 2, 5, and 7 were established by X-ray crystallography, the electrochemical properties of 2-5 as well as the proton reduction to hydrogen gas catalyzed by 2 and 3 were studied by CV techniques.

Lead-free piezoelectric ceramics with the composition of (Na0.53K0.435Li0.035)Nb0.94-x SbxTa0.06O3 (NKLNST) are synthesized by a conventional solid-state sintering process. An MPB-like region between orthorhombic and pseudocubic phases is found in this system. The density, piezoelectric and dielectric properties are enhanced greatly in this region. A composition (Na0.53K0.435Li0.035) (Nb0.86Sb0.08Ta0.06)O3 is found to have excellent electrical properties: d33 = 320pC/N, kp = 49% and kt = 43%, as well as relatively low loss, tan δ = 4.2%, and high relative density higher than 96%, which indicate that this ceramics is a promising lead-free piezoceramics replacing for lead zirconate titanate.

In order to be applied in heterogeneous asymmetric hydrogenation, a series of Single-Walled Carbon Nanotubes (SWNTs)-supported Pt nanoparticle catalysts with different controlled Pt loadings, i.e. 5%, 10% and 20%, were prepared, and characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). By modification with (−)-cinchonidine (Cd), these Pt/SWNTs catalysts were found to be efficient for the asymmetric hydrogenation of ethyl pyruvate, providing (R)-ethyl lactate in high activity and moderate enantioselectivity. Kinetic study showed that the Pt/SWNTs-catalyzed asymmetric hydrogenation of ethyl pyruvate was a “ligand-accelerated” reaction.

Hydrogen is a clean energy carrier. Converting abundant coal sources and green biomass energy into hydrogen effectively and without any pollution promotes environmental protection. The co-gasification performance of coal and a model compound of biomass, carboxymethylcellulose (CMC) in supercritical water (SCW), were investigated experimentally. The influences of temperature, pressure and concentration on hydrogen production from co-gasification of coal and CMC in SCW under the given conditions (20–25 MPa, 650°C, 15–30 s) are discussed in detail. The experimental results show that H2, CO2 and CH4 are the main gas products, and the molar fraction of hydrogen reaches in excess of 60%. The higher pressure and higher CMC content facilitate hydrogen production; production is decreased remarkably given a longer residence time.

We are interested in developing novel natural product-derived P-gp inhibitors to reverse cancer drug resistance. Here, we have synthesized 55 novel derivatives of methylated epigallocatechin (EGC), gallocatechin (GC), and dihydromyricetin (DHM). Three EGC derivatives (23, 35, and 36) and three GC derivatives (50, 51, and 53) are significantly better than epigallocatechin gallate (EGCG) with a relative fold (RF) ranging from 31.4 to 53.6. The effective concentration (EC50) of 23 and 51 ranges from 102 to 195 nM. Compounds 23 and 51 are noncytotoxic to fibroblasts with IC50 > 100 μM. Compound 23 is specific for P-gp without modulating activity toward MRP1 or BCRP. Compounds 23 and 51 are non-P-gp substrates. Important pharmacophores for P-gp modulation were identified. In summary, methylated EGC and GC derivatives represent a new class of potent, specific, noncytotoxic, and nonsubstrate P-gp modulators.

Three chiral 4,4′-substituted 1,1′-spirobiindane-7,7′-diols and related monodentate spiro phosphoramidite ligands have been readily synthesized from enantiomerically pure 1,1′-spirobiindane-7,7′-diol. Excellent enantioselectivities were obtained with these new ligands in the rhodium-catalyzed asymmetric hydrogenation of dehydroamino acid derivatives and enamides. Comparing SIPHOS, ligands 4,4′-dibromo-SIPHOS and 4,4′-diphenyl-SIPHOS gave similarly high enantioselectivities although the rates in hydrogenations of enamides are somewhat slower. Methoxy substituents at the 4,4′-position of ligands slightly reduced enantioselectivities of hydrogenation reactions.

Fill factor >0.90 is acquired for c-Si solar cell with Ag front-electrode. Ag/Si hetero-junction determines the high fill factor according to model analysis. Combined with field-effect passivation, a 20.15% efficiency c-Si solar cell is achieved.

Ginsenoside-Rg1 (G-Rg1), a saponin that is a primary component of ginseng, is very useful and important in traditional Chinese medicine for stroke. The objective of this study was to explore the mechanisms underlying the neuroprotective effect of G-Rg1 on focal cerebral ischemia/reperfusion.Focal cerebral ischemia was induced by middle cerebral artery occlusion. Neurological examinations were performed by using Longa's 5-point scale. The brain infarct volume was determined by the 2,3,5-triphenyltetrazolium chloride staining. The permeability of the blood-brain barrier (BBB) was evaluated by Evans blue dye. Western blot and quantitative RT-PCR were used to assess protease-activated receptor-1 (PAR-1) expression.After G-Rg1 treatment, there was a significant decrease in the neurobehavioral function score compared with normal saline (NS) treatment after ischemia/reperfusion (P0.05). G-Rg1 significantly reduced the infarct volume compared with NS treatment after ischemia/reperfusion (P0.001). The permeability of the BBB was significantly decreased in the G-Rg1 group compared with the NS group (P0.05 or P0.01). Western blot and quantitative real time RT-PCR indicated that G-Rg1 administration down-regulated the expression of PAR-1 in the ischemic hemisphere compared with NS administration (P0.01 and P0.05, respectively). The level of PAR-1 expression strongly correlated with BBB permeability in both the G-Rg1- and NS-treated rats (r=0.856 and r=0.908, respectively, P0.01).G-Rg1 may ameliorate the neurological injury, the brain infarct volume and the BBB permeability induced by focal cerebral ischemia in rats and its neuroprotective mechanism is related to the down-regulation of PAR-1 expression.

Five starlike complexes with terminal butterfly Fe/S cluster cores, [Fe 2 (μ-Ph 2 P)(CO) 6 ] 3 [(μ-SCH 2 CH 2 ) 3 N] (2), [Fe 2 (μ-PhS)(CO) 6 ] 3 [(μ-SCH 2 CH 2 ] 3 N] (3), [Fe 2 (μ-PhC=NPh)(CO) 6 )] 3 [1,3,5-(μ-SCH 2 ) 3 C 6 H 3 ] (5), and [Fe 2 (μ-RSC=S)(CO) 6 ] 3 [1,3,5-(μ-SCH 2 ) 3 C 6 H 3 ] (7, R = Me; 8, R = PhCH 2 ), were prepared by a "one pot" reaction of the trithiol N(CH 2 CH 2 SH) 3 or 1,3,5-(HSCH 2 ) 3 -C 6 H 3 with Fe 3 (CO) 1 2 and Et 3 N, followed by treatment of the intermediate three-μ-CO-containing trianions {[Fe 2 (μ-CO)(CO) 6 ] 3 [(μ-SCH 2 CH 2 ) 3 N]} 3 - (1) and {[Fe 2 (μ-CO)-(CO) 6 ] 3 [1,3,5-(μ-SCH 2 ) 3 C 6 H 3 ]} 3 - (4) with Ph 2 PCl, PhSBr, PhC(Cl)=NPh, CS 2 /MeI, and CS 2 /PhCH 2 Br, respectively. These products have been fully characterized by elemental analysis, spectroscopy, and X-ray crystallography.

The aim of the present study was to analyze the differences between the genes of the mitochondrial DNA (mtDNA) displacement loop (D-loop) region and the Cambridge Reference sequence, in order to screen the mutation sites and investigate the correlation between mutations, clinical parameters and complications associated with obstructive sleep apnea-hypopnea syndrome (OSAHS). mtDNA was obtained from male patients with OSAHS in the Zhejiang Province. In total, 60 male patients with OSAHS and 102 healthy adults were assessed to determine the levels of fasting blood glucose, total cholesterol, triglyceride (TG) and high-density and low-density lipoproteins (LDL). Furthermore, peripheral mtDNA was extracted and bidirectional sequencing was conducted to enable mutation screening. In the mtDNA D-loop region, 178 mutation sites were identified, of which 115 sites were present in the two groups. The number of non-common sites in the OSAHS group was significantly higher compared with the control group (P0.05). A total of 21 cases in the severe OSAHS group exhibited mutation rates of >10%. In the control group, there were 24 cases where the np73A-G and np263A-G mutations were predominant. The np303–np315 region was identified to be the highly variable region and various mutation forms were observed. Statistically significant differences were observed in the neck perimeter, TG and LDL levels among the OSAHS-no-mutation subgroups (P