Abstract
The delivery of alkyl radicals through photocatalytic deoxygenation of primary alcohols under mild conditions is a so far unmet challenge. In this report, we present a one-pot strategy for ...deoxygenative Giese reaction of alcohols with electron-deficient alkenes, by using xanthate salts as alcohol-activating groups for radical generation under visible-light photoredox conditions in the presence of triphenylphosphine. The convenient generation of xanthate salts and high reactivity of sequential C–S/C–O bond homolytic cleavage enable efficient deoxygenation of primary, secondary and tertiary alcohols with diverse functionality and structure to generate the corresponding alkyl radicals, including methyl radical. Moreover, chemoselective radical monodeoxygenation of diols is achieved via selective formation of xanthate salts.
This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 ...mg Cl2 min/L). The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L). By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L). However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are the emerging contaminants leading to a serious worldwide health problem. Although disinfection like ultraviolet (UV) ...irradiation could remove part of ARB and ARGs, there still are residual ARB and ARGs in the effluent of wastewater treatment plants.
Conjugative transfer is main concern of the risk of ARGs and little is known about the effects of UV disinfection on the transfer ability of the non-inactivated ARB in the effluent which will enter the environment. Hence the influences of UV irradiation and reactivation on ARB conjugative transfer ability were studied under laboratory condition, focusing on the survival bacteria from UV irradiation and the reactivated bacteria, as well as their descendants. The experimental results imply that even 1 mJ/cm2 UV disinfection can significantly decrease the conjugative transfer frequency of the survival bacteria. However, viable but not culturable state cells induced by UV can reactivate through both photoreactivation and dark repair and retain the same level of transfer ability as the untreated strains. This finding is essential for re-considering about the post safety of UV irradiated effluent and microbial safety control strategies were required.
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•Survival bacteria from UV disinfection got lowered transfer ability.•UV induced antibiotic resistant bacteria into VBNC state, which will reactivate.•The reactivated bacteria regained their gene transfer ability.
Prostate cancer (PC) is a very important kind of male malignancies. When PC evolves into a stage of hormone resistance or metastasis, the fatality rate is very high. Currently, discoveries and ...advances in miRNAs as biomarkers have opened the potential for the diagnosis of PC, especially early diagnosis. miRNAs not only can noninvasively or minimally invasively identify PC, but also can provide the data for optimization and personalization of therapy. Moreover, miRNAs have been shown to play an important role to predict prognosis of PC. The purpose of this meta‐analysis is to integrate the currently published expression profile data of miRNAs in PC, and evaluate the value of miRNAs as biomarkers for PC. All of relevant records were selected via electronic databases: Pubmed, Embase, Cochrane, and CNKI based on the assessment of title, , and full text. we extracted mean ± SD or fold change of miRNAs expression levels in PC versus BPH or normal controls. Pooled hazard ratios (HRs) with 95% confidence intervals (CI) for overall survival (OS) and recurrence‐free survival (RFS), were also calculated to detect the relationship between high miRNAs expression and PC prognosis. Selected 104 articles were published in 2007‐2017. According to the inclusion criteria, 104 records were included for this meta‐analysis. The pooled or stratified analyze showed 10 up‐regulated miRNAs (miR‐18a, miR‐34a, miR‐106b, miR‐141, miR‐182, miR‐183, miR‐200a/b, miR‐301a, and miR‐375) and 14 down‐regulated miRNAs (miR‐1, miR‐23b/27b, miR‐30c, miR‐99b, miR‐139‐5p, miR‐152, miR‐187, miR‐204, miR‐205, miR‐224, miR‐452, miR‐505, and let‐7c) had relatively good diagnostic and predictive potential to discriminate PC from BPH/normal controls. Furthermore, high expression of miR‐32 and low expression of let‐7c could be used to differentiate metastatic PC from local/primary PC. Additional interesting findings were that the expression profiles of five miRNAs (miR‐21, miR‐30c, miR‐129, miR‐145, and let‐7c) could predict poor RFS of PC, while the evaluation of miR‐375 was associated with worse OS. miRNAs are important regulators in PC progression. Our results indicate that miRNAs are suitable for predicting the different stages of PC. The detection of miRNAs is an effective way to control patient's prognosis and evaluate therapeutic efficacy. However, large‐scale detections based on common clinical guidelines are still necessary to further validate our conclusions, due to the bias induced by molecular heterogeneity and differences in study design and detection methods.
miRNAs have been shown to play an important role to predict prognosis of PC. The purpose of this meta‐analysis is to integrate the currently published expression profile data of miRNAs in PC, and evaluate the value of miRNAs as biomarkers for PC.
Growing attention has been paid to the dissemination of antibiotic resistance genes (ARGs) in wastewater microbial communities; however, the disinfection processes, as microbial control technologies, ...have not been evaluated for their impacts on ARGs transfer. In this study, the effects of ultraviolet (UV) disinfection and chlorination on the frequency of ARGs transfer have been explored based on the conjugative transfer model between Gram-negative strains of E. coli. The results indicated that UV disinfection and chlorination exhibit distinct influences on the conjugative transfer. Low UV doses (up to 8 mJ/cm2) had little influence on the frequency of conjugative transfer, and UV exposure only decreased the bacterial number but did not change the cell permeability. By comparison, low chlorine doses (up to 40 mg Cl min/L) significantly promoted the frequency of conjugative transfer by 2–5-fold. The generated chloramine stimulated the bacteria and improved the cell permeability. More pilus were induced on the surface of conjugative cells, which acted as pathways for ARGs transfer. The frequency of ARG transfers was greatly suppressed by high doses of UV (>10 mJ/cm2) or chlorine (>80 mg Cl min/L).
The ever‐increasing demand for clean and renewable power sources has sparked intensive research on water splitting to produce hydrogen, in which the exploration of electrocatalysts is the central ...issue. Herein, a new strategy, metal–organic framework template‐directed fabrication of hierarchically structured Co3O4@X (X = Co3O4, CoS, C, and CoP) electrocatalysts for efficient oxygen evolution reaction (OER) is developed, where Co3O4@X are derived from cobalt carbonatehydroxide@zeolitic‐imidazolate‐framework‐67 (CCH@ZIF‐67). Unique hierarchical structure and synergistic effect of resulting catalysts endow abundant exposed active sites, facile ion diffusion path, and improved conductivity, being favorable for improving catalytic activity of them. Consequently, these derivatives Co3O4@X reveal highly efficient electrocatalytic performance with long‐term durability for the OER, much superior to previously reported cobalt‐based catalysts as well as the Ir/C catalyst. Particularly, Co3O4@CoP exhibits the highest electrocatalytic capability with the lower overpotential of 238 mV at the current density of 10 mA cm−2. Furthermore, Co3O4@X can also efficiently catalyze other small molecules through electro‐oxidation reaction (e.g., glycerol, methanol, or ethanol). It is expected that the strategy presented here can be extended to the fabrication of other composite electrode materials with hierarchical structures for more efficient water splitting.
A new strategy for the fabrication of hierarchically structured composites as highly effective and stable electrocatalysts is proposed. The oxidation, sulfurization, carbonization, and phosphorization of premade cobalt carbonate hydroxide@zeolitic‐imidazolate‐framework‐67 (CCH@ZIF‐67) produced Co3O4@X (X = Co3O4, CoS, C, and CoP) derivatives, respectively, which as electrocatalysts exhibit excellent performance in the oxygen evolution reaction with low overpotential and high stability.
Differential evolution has been shown to be an effective methodology for solving optimization problems over continuous space. In this paper, we propose an eigenvector-based crossover operator. The ...proposed operator utilizes eigenvectors of covariance matrix of individual solutions, which makes the crossover rotationally invariant. More specifically, the donor vectors during crossover are modified, by projecting each donor vector onto the eigenvector basis that provides an alternative coordinate system. The proposed operator can be applied to any crossover strategy with minimal changes. The experimental results show that the proposed operator significantly improves DE performance on a set of 54 test functions in CEC 2011, BBOB 2012, and CEC 2013 benchmark sets.
•Recent breakthroughs which changed our views on SMMs are highlighted.•The latest advances of this challenging field in China were emphasized.•Synthetic strategies to design high-performance SMMs are ...demonstrated.•Directions to which further efforts should be focused in the field are discussed.
The discovery of the first example of lanthanide-based single molecule magnets (Ln-SMMs), a revolutionary progress, marked the beginning of a new age for SMMs, has greatly inspired researchers to invest their efforts in the design of high-performance SMMs by introducing lanthanide ions, especially dysprosium ions. Lanthanide ions have always been considered as excellent candidates to construct single-molecule magnets for high-density data storage and quantum calculation. Impressive progress has been made in field of Ln-SMMs where synthetic chemists have played a major role through producing suitable systems for detailed study by physicists and materials scientists. In this review, some recent breakthroughs changing the perspective of the field will be highlighted with special emphasis on the synthetic efforts made in this fascinating and challenging field. Their findings on the elucidation of relaxation dynamics and the synthetic strategies towards high-performance Ln-SMMs provide valuable insights required to optimize the contribution of an Ising type spin to a molecular magnet and indicate the directions to which further synthetic efforts should be focused.
Neuro-oncological ventral antigen 1 (Nova1) is a neuron-specific RNA-binding protein in human paraneoplastic opsoclonus-myoclonus ataxia accompanying with malignant tumors, but its role in ...hepatocellular carcinoma (HCC) remains elusive. In this study, we found that overexpressed intratumoral Nova1 was associated with poor survival rate and increased recurrence rate of HCC, especially early recurrence, and was an independent prognostic factor for overall survival rate and tumor recurrence. HCC cell lines over-expressing Nova1 exhibited greater potentials in cell proliferation, invasion and migration, while knockdown of Nova1 had the opposite effects. All these findings indicate that Nova1 may act as a prognostic marker for poor outcome and high recurrence in HCC.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
AIM To evaluate the hepatoprotective effect of lycopene(Ly) on non-alcoholic fatty liver disease(NAFLD) in rat. METHODS A rat model of NAFLD was first established by feeding a high-fat diet for 14 ...wk. Sixty-five rats were randomly divided into normal group, model group and Ly treatment groups. Alanine aminotransferase(ALT), aspartate aminotransferase(AST), triglycerides(TG), total cholesterol(TC) in serum and low density lipoproteincholesterol(LDL-C), high density lipoprotein-cholesterol(HDL-C), free fatty acid(FFA), malondialdehyde(MDA), superoxide dismutase(SOD), glutathione(GSH) in liver tissue were evaluated, respectively. While the hepatoprotective effect was also confirmed by histopathological analysis, the expression levels of TNF-α and cytochrome P450(CYP) 2E1 in rat liver were determined by immunohistochemistry analysis.RESULTS A significant decrease was observed in the levels of serum AST(2.07-fold), ALT(2.95-fold), and the blood lipid TG(2.34-fold) and TC(1.66-fold) in the dose of 20 mg/kg Ly-treated rats(P < 0.01), compared to the model group. Pretreatment with 5, 10 and 20 mg/kg of Ly significantly raised the levels of antioxidant enzyme SOD in a dose-dependent manner,to 90.95 ± 9.56, 109.52 ± 11.34 and 121.25 ± 10.68(P < 0.05, P < 0.01), as compared with the model group. Similarly, the levels of GSH were significantly increased(P < 0.05, P < 0.01) after the Ly treatment. Meanwhile, pretreatment with 5, 10 and 20 mg/kg of Ly significantly reduced MDA amount by 30.87, 45.51 and 54.49% in the liver homogenates, respectively(P < 0.01). The Ly treatment group showed significantly decreased levels of lipid products LDL-C(P < 0.05, P < 0.01), improved HDL-C level and significantly decreased content of FFA, compared to the model group(P < 0.05, P < 0.01). Furthermore, the Ly-treated group also exhibited a down-regulated TNF-α and CYP2E1 expression, decreased infiltration of liver fats and reversed histopathological changes, all in a dosedependent manner(P < 0.05, P < 0.01). CONCLUSION This study suggests that Ly has a protective effect on NAFLD, down-regulates expression of TNF-α, and that CYP2E1 may be one of the action mechanisms for Ly.
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