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2.
Chem Eng J ; 398: 125570, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32508521

RESUMO

The UV-induced advanced oxidation processes (AOPs, including UV/Cl2, UV/NH2Cl, UV/ClO2 and UV/H2O2 ) degradation kinetics and energy requirements of iopamidol as well as DBPs-related toxicity in sequential disinfection were compared in this study. The photodegradation of iopamidol in these processes can be well described by pseudo-first-order model and the removal efficiency ranked in descending order of UV/Cl2  > UV/H2O2  > UV/NH2Cl > UV/ClO2  > UV. The synergistic effects could be attributed to diverse radical species generated in each system. Influencing factors of oxidant dosage, UV intensity, solution pH and water matrixes (Cl- , NH4 + and nature organic matter) were evaluated in detail. Higher oxidant dosages and greater UV intensities led to bigger pseudo-first-order rate constants (Kobs) in these processes, but the pH behaviors exhibited quite differently. The presence of Cl- , NH4 + and nature organic matter posed different effects on the degradation rate. The parameter of electrical energy per order (EE/O) was adopted to evaluate the energy requirements of the tested systems and it followed the trend of UV/ClO2  > UV > UV/NH2Cl > UV/H2O2  > UV/Cl2 . Pretreatment of iopamidol by UV/Cl2 and UV/NH2Cl clearly enhanced the production of classical disinfection by-products (DBPs) and iodo-trihalomethanes (I-THMs) during subsequent oxidation while UV/ClO2 and UV/H2O2 exhibited almost elimination effect. From the perspective of weighted water toxicity, the risk ranking was UV/NH2Cl > UV/Cl2 > UV > UV/H2O2 > UV/ClO2 . Among the discussed UV-driven AOPs, UV/Cl2 was proved to be the most cost-effective one for iopamidol removal while UV/ClO2 displayed overwhelming advantages in regulating the water toxicity associated with DBPs, especially I-THMs. The present results could provide some insights into the application of UV-activated AOPs technologies in tradeoffs between cost-effectiveness assessment and DBPs-related toxicity control of the disinfected waters containing iopamidol.

3.
Chemosphere ; 221: 292-300, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30640012

RESUMO

In this paper, it was demonstrated that UV/H2O2 process can not only obviously promote the degradation rate of IO3-, but also greatly enhance iodo-trihalomethanes (I-THMs) formation in sequential chloramination. UV/H2O2 exhibited much faster IO3- decomposition than either UV or H2O2 treatment alone due to the contribution of highly reactive species including O-, OH and eaq-. The degradation rate of IO3- was affected by H2O2 dosages, pH, UV intensity as well as the presence of natural organic matter (NOM). The calculated pseudo-first order rate constant gradually increased with H2O2 dosages and solution pH, but behaved directly proportional to the UV intensity. Although NOM remarkably reduced the degradation rate of IO3- in UV/H2O2 process, their presence greatly enhanced the formation of I-THMs during subsequent chloramination. The overwhelming majority of iodoform at high UV fluences was also observed, which indicated improved iodination degrees of the detected I-THMs. UV/H2O2 was proved to be more capable on the evolution of IO3- to I- as well as I-THMs than UV and thereby enhanced the toxicity of disinfected waters in the following chloramination process. This study was among the first to provide a comprehensive understanding on the transformation of IO3- as the emerging iodine precursor to form I-THMs via diverse advanced oxidation process technologies like UV/H2O2.


Assuntos
Desinfecção/métodos , Peróxido de Hidrogênio/química , Iodatos/química , Processos Fotoquímicos , Raios Ultravioleta , Cinética , Trialometanos/análise , Poluentes Químicos da Água/química , Purificação da Água/métodos
4.
Biomed Res Int ; 2018: 3195025, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29693005

RESUMO

Pancreatic adenocarcinoma has an exceedingly poor prognosis, accounting for five-year survival of less than 5%. Presently, improving the efficacy of pancreatic adenocarcinoma treatment has been the focus of medical researchers worldwide. Recently, it has been suggested that deregulation of interleukin- (IL-) 6 is caused by a key gene involved in the beginning and development of pancreatic adenocarcinoma. Herein, we investigated whether suppression of IL-6 could augment gemcitabine sensitivity in the PANC-1 cells. We found considerably higher expression of IL-6 in pancreatic adenocarcinoma tissues than that in the adjacent nontumorous tissues. Suppression of IL-6 by shRNA resulted in apoptosis as well as inhibition of cell proliferation and tumorigenicity. In addition, suppression of IL-6 remarkably promoted antitumor effect of gemcitabine, indicating that the combination of shRNA targeting IL-6 with gemcitabine may provide a potential clinical approach for pancreatic cancer therapy.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antimetabólitos Antineoplásicos/farmacologia , Desoxicitidina/análogos & derivados , Interleucina-6/genética , Neoplasias Pancreáticas/tratamento farmacológico , RNA Interferente Pequeno/genética , Adenocarcinoma/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Desoxicitidina/farmacologia , Humanos , Neoplasias Pancreáticas/genética , Gencitabina , Neoplasias Pancreáticas
5.
Biomed Environ Sci ; 27(5): 391-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24827722

RESUMO

The effect of sterilization methods on biological activity of fibronectin on the surface of biomaterials was elaborated in the present study. Sterile protein- modified biomaterials were fabricated by microfilter filtration and UV irradiation, respectively. UV irradiation altered the conformation of surface- adsorbed fibronectin and further affected the attachment, morphology and biological function of endothelial cells. However, microfilter filtration did not to change the normal conformation of fibronectin, or the proliferation and biological function of endothelial cells, indicating that microfilter filtration sterilization is the most suitable method for protein-substrate.


Assuntos
Fibronectinas/efeitos da radiação , Próteses e Implantes/microbiologia , Esterilização/métodos , Adesão Celular/efeitos da radiação , Filtração , Raios Ultravioleta
6.
Oncol Lett ; 7(2): 487-492, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24396475

RESUMO

The objective of the present study was to construct a novel type of non-viral gene delivery vector with high delivery efficiency and specific tumor cell-targeting ability. The CP9 peptide (CYGGRGDTP) containing Arg-Gly-Asp sequence was employed to be conjugated onto polyethylenimine (PEI) to act as the role of the targeting moiety. The chemical linker, N-succinimidyl-3-(2-pyridyldithio) propionate, was applied during the synthesis of the vector (CP9-PEI). The physicochemical characteristics of the vector were evaluated by the methods of 1H-nuclear magnetic resonance, Fourier transform infrared spectroscopy, gel retardation assay, electron microscope observation and particle size detection. HepG2 cells were used to verify the gene delivery efficiency and targeting ability by gene delivery procedure and free CP9 peptide inhibition tests. The results showed that the successful synthesis of CP9-PEI and the synthesized vector may efficiently condense plasmid DNA into round particles with diameters of ~200 nm at a polymer/pDNA ratio of 10. CP9-PEI may deliver the reporter gene into HepG2 cells with higher efficiency and the efficiency may be inhibited by the free CP9 peptide. The present study suggested that the modification of PEI with the CP9 peptide is an effective method to construct a novel tumor cell-targeting non-viral vector, and that the novel vector exhibits great prospect in the field of cancer gene therapy.

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