Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
BMC Infect Dis ; 22(1): 903, 2022 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-36460998

RESUMO

BACKGROUND: Kodamaea ohmeri is a rare pathogen with high mortality and is found among blood samples in a considerable proportion; however, gastrointestinal infection of K. ohmeri is extremely rare. Invasive pulmonary aspergillosis is also an uncommon fungal; these two fungal infections reported concomitantly are unprecedented. CASE PRESENTATION: We described a case of a 37-year-old male who got infected with K. ohmeri and invasive pulmonary aspergillosis. We used the mass spectrometry and histopathology to identify these two fungal infections separately. For the treatment of K. ohmeri, we chose caspofungin. As for invasive pulmonary aspergillosis, we used voriconazole, amphotericin B, and then surgery. The patient was treated successfully through the collaboration of multiple disciplines. CONCLUSIONS: We speculate that the destruction of the intestinal mucosa barrier can make the intestine one of the ways for certain fungi to infect the human body.


Assuntos
Fungemia , Aspergilose Pulmonar Invasiva , Saccharomycetales , Adulto , Humanos , Masculino , Caspofungina/uso terapêutico , Fungemia/microbiologia , Aspergilose Pulmonar Invasiva/diagnóstico , Aspergilose Pulmonar Invasiva/tratamento farmacológico
2.
J Integr Neurosci ; 21(3): 81, 2022 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-35633162

RESUMO

BACKGROUND: Anti-GQ1b antibody syndrome referred to a clinical spectrum characterized by acute onset of ataxia, ophthalmoplegia and areflexia, while visual deterioration was rarely reported in terms of ocular disorders. This study aimed to describe the clinical characteristics of anti-GQ1b antibody syndrome with visual impairment. METHODS: The database at the First Affiliated Hospital of Sun Yat-sen University was searched from 2014 to 2020. Patients with anti-GQ1b IgG were identified and divided into two groups according to the existence of optic neuropathy. Clinical and laboratory data of these subjects between the two groups were collected and analyzed. All patients were followed up by telephone to assess the outcome. RESULTS: A total of 12 patients with seropositive anti-GQ1b antibody were included, 75% of which got antecedent infection. Of these cases, 3 showed visual deterioration accompanied by abnormal orbital magnetic resonance imaging or visual evoked potentials, and the other 9 didn't show any evidence of vision impairment. Patients in the optic neuropathy group presented prominent visual impairments as initial symptoms and were more likely to suffer from facial weakness. There were 4 patients in normal visual acuity group complaining of blurred vision due to intraocular muscle paralysis, which was distinguished by subsequent examination. The combination of glucocorticoids and intravenous immunoglobulin was applied to treat patients with optic neuropathy. CONCLUSIONS: This study provides strong evidence that anti-GQ1b antibody syndrome can exhibit visual impairment, which helps further expand the clinical spectrum of anti-GQ1b antibody syndrome. More attention should be paid to the physical and supplementary ophthalmological examination to explore the pathogenesis and treatment of anti-GQ1b antibody syndrome.


Assuntos
Oftalmoplegia , Doenças do Nervo Óptico , Potenciais Evocados Visuais , Gangliosídeos , Humanos , Oftalmoplegia/complicações , Doenças do Nervo Óptico/complicações , Estudos Retrospectivos
3.
World J Microbiol Biotechnol ; 36(3): 49, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157439

RESUMO

Glycerol is a by-product of biodiesel, and it has a great application prospect to be transformed to synthesize high value-added compounds. Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere is a plant growth promoting rhizobacteria that can utilize amount of glycerol to synthesize phenazine-1-carboxylic acid (PCA). PCA has been commercially registered as "Shenqinmycin" in China due to its characteristics of preventing pepper blight and rice sheath blight. The aim of this study was to engineer glycerol utilization pathway in P. chlororaphis GP72. First, the two genes glpF and glpK from the glycerol metabolism pathway were overexpressed in GP72ANO separately. Then, the two genes were co-expressed in GP72ANO, improving PCA production from 729.4 mg/L to 993.4 mg/L at 36 h. Moreover, the shunt pathway was blocked to enhance glycerol utilization, resulting in 1493.3 mg/L PCA production. Additionally, we confirmed the inhibition of glpR on glycerol metabolism pathway in P. chlororaphis GP72. This study provides a good example for improving the utilization of glycerol to synthesize high value-added compounds in Pseudomonas.


Assuntos
Glicerol/metabolismo , Engenharia Metabólica/métodos , Pseudomonas chlororaphis/genética , Pseudomonas chlororaphis/metabolismo , Aquaporinas/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Capsicum/microbiologia , China , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Regulação Bacteriana da Expressão Gênica , Técnicas de Inativação de Genes , Glicerolfosfato Desidrogenase/genética , Redes e Vias Metabólicas/genética , Fenazinas/metabolismo , Proteínas Repressoras/genética , Rizosfera
4.
J Nanosci Nanotechnol ; 19(8): 5287-5294, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913846

RESUMO

3D hierarchical structure BiOX(X ═ Cl, Br)-(CMC) assembled from 2D nanosheets with {010} facets exposed have been successfully synthesized by the assistance of biomass solvent CMC-Na. All the nitrogen adsorption isotherms and photoelectrochemical results reflected that BiOX(X Cl, Br)-(CMC) exhibit higher specific surface area, superior optical absorption efficiency and separation efficiency of photoinduced electron-hole than BiOX(X═Cl, Br) 2D nanosheets exposed with {001} facets. Besides, 96.5% and 60.3% of tetracycline hydrochloride (TC) were photodegradated in 60 minutes under the visible light irradiation catalyzed by BiOBr-(CMC) and BiOCl-(CMC), which is much better than BiOBr and BiOCl. The formation and enhanced photocatalytic activity of 3D hierarchical structure BiOX-(CMC) may be ascribe to the bi-functional groups of CMC, which can affect the crystallization process and morphology of BiOX. According to the merit of environmental friendly and improved photocatalytic activity of the 3D hierarchitecture, we believe that this work broadens the possibility of designing efficient BiOX photocatalyst with {010} facets exposed.

5.
J Nanosci Nanotechnol ; 19(8): 5150-5157, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913829

RESUMO

Constructing heterojunction is an effective way to enhance the catalytic activities of semiconductor photocatalyst owing to its special synergistic effect. In this study, a novel p-n heterostructured CdWO4/BiOCl nanocomposites were synthesized by a facile hydrothermal and subsequently chemistry bath method. The photocatalytic performance of CdWO4/BiOCl heterojunctions was investigated by degrading phenol and RhB under simulated solar light irradiation. Highly improved photocatalytic activities were achieved on all CdWO4/BiOCl heterojunctions compared with both pure CdWO4 and BiOCl. The CdWO4/BiOCl heterojunction with optimal mole ratio of 25% CdWO4 displayed the highest photoactivity with RhB and phenol being completely degraded in 15 min and 6 h, respectively. Mechanism analysis revealed that the interface of p-n heterojunction of CdWO4/BiOCl composites can produce spontaneously electric field which can effectively separate photogenerated electrons and holes. Moreover, the active species research demonstrated that holes and superoxide radicals proved to be the principal active species during the photocatalytic process. This work demonstrated that the CdWO4/BiOCl photocatalyst may be a promising material for purifying the organic contaminant in practical application.

6.
J Nanosci Nanotechnol ; 18(7): 4858-4864, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442666

RESUMO

An electrochemical palladium/ferric oxide (Pd/Fe2O3) nanocomposite modified glassy carbon electrode (GCE) was fabricated by hydrothermal method of Fe2O3 and electrochemical deposition of palladium nanoparticles, respectively. As-prepared Pd/Fe2O3 composite modified electrode exhibits enhanced electrocatalytic activity towards the catalytic oxidation of nitrite compared to Fe2O3, PdNPs modified electrodes and bare electrode. The parameters such as the influence of amount of Pd nanoparticles deposition onto the Pd/Fe2O3 modified electrode (ME) and effect of solution pH were investigated and discussed in detail. Under the optimal conditions, the Pd/Fe2O3 modified GCE can be used to detect nitrite concentration in a wide linear range of 10 and 1000 µM with the detection limit of 0.1 µM. The presence of Cu2+, Na+, Cl-, PO3-4 SO2-4, Mg2+ K+, NO-3, and NH+4 showed a trivial effect on the response of nitrite determination, revealing that developed modified electrode has an excellent anti-interference ability to common ions. It also shows good stability and reproducibility.

7.
J Nanosci Nanotechnol ; 18(5): 3585-3591, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442870

RESUMO

An electrochemical sensor ground on nickel oxide (NiO) nanoparticles and multi-walled carbon nanotubes (MWCNTs) was exploited for the detection of nitrite. Scanning electron microscopy (SEM) ensure the morphology of the nanocomposite consisted of NiO nanoparticle and MWCNTs. High Resolution Transmission electron microscopy (HR-TEM) reveals that the structure of NiO nanoparticles and MWCNTs. Scanning transmission electron microscopy (STEM) persuasively verified presence of the C, Ni and O element. The electrochemical character of the nanocomposite were researched by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the behavior of electrochemical oxidation to nitrite on NiO/MWCNTs/CP was explored by chronoamperometry. In tests, the NiO/MWCNTs/CP shown a sensitive current response toward nitrite, the oxidation peak current are linearly related to nitrite concentration in the range from 10-6 M to 10-4 M (R = 0.997) with a sensitivity of 3.53 µA µM-1 and a detection limit of 0.25 µM (S/N = 3). The validity of utilizing the proposed electrode to determine nitrite in tap water was also demonstrated.

8.
J Nanosci Nanotechnol ; 18(8): 5575-5581, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29458612

RESUMO

Bi2MoO6-BiOCl nanoplate composites were successfully synthesized by a simple solvothermal process. The morphology, microstructure and optical properties of the as-prepared Bi2MoO6-BiOCl nanocomposites were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Vis diffuse reflection spectroscopy (DRS). A noteworthy enhancement in the visible-light-responsive photocatalytic degradation of RhB was observed over the Bi2MoO6-BiOCl nanocomposites compared to its individual components. The enhanced photocatalytic performance of Bi2MoO6-BiOCl nanocomposites could be attributed to the heterojunction interface in the composite, which can both efficiently separate photogenerated electron-hole pairs and also restrain the recombination of photoinduced charges.

9.
J Nanosci Nanotechnol ; 18(6): 4065-4071, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442744

RESUMO

Herein, a novel visible-light-driven heterojunction AgI/WO3 nanocomposite was successfully prepared using a facile two-step hydrothermal-precipitation process and applied for photodegradation of organic pollutants. The information of phase structures, morphology, optical properties of the asprepared samples was analysed in detail by XRD, TEM, EDS, STEM, DRS measurement and so on. Formation of the heterostructure and intimate interactions between AgI and WO3 can promote highly effective photogenerated electron-hole pairs separation, which enable the heterojuctions to perform excellent photocatalytic activity as greatly enhanced photocatalysts compared to that of pristine AgI and WO3 for decomposing Rhodamine B (RhB) dye under visible light irradiation. In addition, the AgI/WO3 (1:1) nanocomposites exhibit optimal photocatalytic activity. Moreover, the as-prepared samples exhibit good stability, which is favorable for its potential application. Additionally, we have an analysis on a possible photocatalytic mechanism based on trapping experiments together with other experimental results.

10.
J Nanosci Nanotechnol ; 17(2): 1407-412, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-29687974

RESUMO

A new magnetic Fe3O4@C@Ag3PO4 nanocomposites photocatalyst with visible light response has been prepared by solvothermal, hydrothermal and precipitation process. The photocatalyst exhibited high photocatalytic activity and stability for the degradation of rhodamine B (RhB). Almost 100% of RhB was photodegraded with the assistance of magnetic Fe3O4@C@Ag3PO4 nanocomposites after 40 min, and the photocatalyst showed no obvious loss of photocatalytic activity after four times of cyclic utilization. Furthermore, the magnetic Fe3O4@C@Ag3PO4 nanocomposites can be separated by external magnetic field. Further study proved that the photogenerated holes were the main active species in the degradation process.

11.
Int J Toxicol ; 35(6): 634-643, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27306319

RESUMO

Multiwalled carbon nanotubes (MWCNTs) have been explored in pharmaceutical applications such as tumor targeting and delivery of drugs, in which MWCNTs are given through intravenous injection. However, the biosafety of MWCNTs is of concern for such application. Therefore, in the current study, we used a fatty liver model to investigate the possible toxicity of MWCNTs to the liver, as MWCNTs were retained mainly in the liver of mice after intravenous injection. Male Sprague Dawley rats were used to generate the fatty liver model, and the effects of intravenous administration of MWCNTs on fatty liver were studied. Hematoxylin and eosin staining for hepatocellular anatomy and Masson trichrome staining for hepatic fibrosis were conducted. Histologically, MWCNTs aggravated steatohepatitis with higher nonalcoholic fatty liver disease scores. Analysis of liver injury markers indicated that MWCNTs administration resulted in chronic hepatitis, along with increased liver fat and altered liver oxidation, including the increase of P6 protein and the depletion of glutathione. In conclusion, our results suggest that MWCNTs can aggravate nonalcoholic steatohepatitis in Sprague Dawley rats, and oxidative injury may be involved in this process.


Assuntos
Fígado/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Hepatopatia Gordurosa não Alcoólica , Animais , Aspartato Aminotransferases/sangue , Dieta Hiperlipídica , Ácidos Graxos não Esterificados/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/sangue , Injeções Intravenosas , Fígado/metabolismo , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo , Triglicerídeos/metabolismo , gama-Glutamiltransferase/sangue
12.
Phys Chem Chem Phys ; 17(43): 29354-62, 2015 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-26473944

RESUMO

In this study, C3N4/Zn(1-x)Cd(x)S (0 ≤ x ≤ 1) heterostructures with adjustment of the band gap were successfully prepared by calcination and a hydrothermal synthesis method. The photocatalytic properties of C3N4/Zn(1-x)Cd(x)S composite photocatalysts were evaluated by the photocatalytic degradation of RhB under visible light irradiation. The results showed that the combination of the two semiconductor photocatalysts (C3N4 and Zn(1-x)Cd(x)S) greatly enhanced the photocatalytic degradation efficiency of RhB compared to the pure C3N4 and Zn(1-x)Cd(x)S under visible light irradiation. Among them, the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst exhibited the highest photocatalytic activities with the degradation efficiency of RhB arriving to 97.9% within 90 min. The remarkable photocatalytic activity of the 0.1C3N4/Zn0.8Cd0.2S composite photocatalyst was mainly attributed to the appropriate band structure and the effective separation of photogenerated electron-hole pairs. Additionally, a possible basic mechanism of the composite semiconductor photocatalytic process was also discussed. Moreover, it was also investigated that O2(˙⁻) and h(+) were the main reactive oxidative species in this photocatalytic process of the degradation of RhB on the 0.1C3N4/Zn0.8Cd0.2S heterostructure photocatalyst.

13.
Environ Toxicol ; 28(8): 442-50, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21656646

RESUMO

Growing evidence has indicated the potential adverse effects on cardiovascular system of some nanomaterials, including fullerenes. In this study, we have evaluated the biological effects of multiwall carbon nano-onions (MWCNOs) (average size of 31.2 nm, ζ potential of 1.6 mV) on human umbilical vein endothelial cells (HUVECs). It was found that MWCNOs exhibited a dose-dependent inhibitory effect on cell growth; EC50 was 44.12 µg/mL. Thus, three concentrations were chosen (0.2, 1, and 5 µg/mL) for further experiments. Flow cytometry analysis revealed that 1 and 5 µg/mL MWCNOs could induce apoptosis in HUVECs, the apoptotic rates were 12% and 24% at 24 h after exposure. On the other hand, MWCNOs did not affect the cell cycle distribution during 24 h period. Using γH2AX foci formation as an indicator for DNA damage, it was shown that 5 µg/mL MWCNOs can induce γH2AX foci formation in HUVECs at 6, 12, and 24 h after treatment, whereas 0.2 µg/mL MWCNOs induced γH2AX foci formation only at 6 h after treatment. In addition, all three concentrations of MWCNOs induced the generation of reactive oxygen species (ROS), and inhibition of ROS generation can partially decrease the γH2AX foci formation induced by MWCNOs. Taken together, these data first suggested that MWCNOs can induce DNA damage and apoptosis in HUVECs, and that ROS might be involved in this process.


Assuntos
Apoptose/efeitos dos fármacos , Dano ao DNA , Fulerenos/toxicidade , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citometria de Fluxo , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Espécies Reativas de Oxigênio/metabolismo
14.
Artigo em Zh | MEDLINE | ID: mdl-24053910

RESUMO

OBJECTIVE: To investigate the pulmonary toxicity of different concentrations of nano-silica (nano-SiO2) under continuous dynamic inhalation conditions in the rat. METHODS: 48 male Sprague-Dawley rats were randomly divided into four groups, including the dispersant control group (saline) and nano-SiO2 low-dose group (0.3%, w/v), the middle-dose group (1%) and the high-dose group (3%). Animals were sacrificed at 28 d after exposure under continuous dynamic inhalation conditions, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected. And following items were observed: body coefficient, BALF related items (leukocytes and classification, total protein content, LDH activity), lung tissue pathological changes (HE staining), and pulmonary fibrosis forming (collagen fiber VG staining). RESULTS: Compared to the dispersant control group, there was no significant change on lung organ coefficient in Nano-SiO2 group (P < 0.05). The BALF total WBC count in 1% and 3% in nano-SiO2 groups showed higher value than the dispersant control group (P < 0.05). No obvious changes were found on total protein content and LDH activity in nano-SiO2 groups compared to the dispersant control group (P > 0.05). For differential WBC counts, lymphocyte count in BALF in nano-SiO2 groups was significantly decreased (P < 0.05), monocyte and macrophage counts were significantly increased (P < 0.05), but there was no difference on the proportion of neutrophils (P > 0.05). HE staining results showed that the obvious thickening of alveolar wall in nano-SiO2 groups, inflammatory cell infiltration also increased around the bronchial and vascular wall. Lung fibrosis VG staining showed no significant change of collagen fiber distribution. CONCLUSION: Under our experimental conditions, the continuous dynamic inhalation of nano-SiO2 only caused the significant inflammation in rat lungs, pulmonary fibrosis phenomenon could not be observed significantly.


Assuntos
Exposição por Inalação , Fibrose Pulmonar/induzido quimicamente , Dióxido de Silício/toxicidade , Animais , Líquido da Lavagem Broncoalveolar/química , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Ratos , Ratos Sprague-Dawley , Dióxido de Silício/administração & dosagem
15.
Orthop Surg ; 15(2): 471-479, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36458444

RESUMO

OBJECTIVE: The percutaneous IS screws and the minimally invasive percutaneous plate are the most popular internal methods for Zone II unstable sacral fractures. However, the choice of fixation remains controversial for orthopaedic surgeons. The purpose of study was to evaluate and compare the clinical results of percutaneous iliosacral (IS) screw fixation under three-dimensional (3D) navigation and minimally invasive percutaneous plate fixation in the treatment of Zone II unstable sacral fractures. METHODS: A retrospective study was performed, including 64 patients with Zone II unstable sacral fractures who underwent percutaneous IS screw fixation under 3D navigation (navigation group) and minimally invasive percutaneous plate fixation (plate group) from January 2011 and March 2021 in our department. The age, gender, fracture type, mechanism of injury, injury severity score (ISS), time from admission to operation, operative time, intraoperative blood loss, hospital stay, incision length, follow-up time, time to clinical healing, and complications were recorded and analyzed. Matta standard was used to assess fracture reduction outcomes. The Majeed function system assessed functional outcomes at the last follow-up. RESULTS: The average follow-up time was (14.42 ± 1.57) months in the navigation group and (14.79 ± 1.37) months in the plate group. No statistical difference between the two groups in age, gender, fracture type, mechanism of injury, ISS, time from admission to operation, and time to clinical healing. However, significant differences were detected in operative time, intraoperative blood loss, hospital stay, and incision length (p < 0.001). According to Matta standard at 2 days postoperatively, the excellent and good rate was 91.42% in the navigation group, and it was 93.10% in the plate group. There was no significant difference between the two groups (p = 0.961). According to Majeed function system at the follow-up, the excellent and good rate was 97.14% in the navigation group, and 93.10% in the plate group. The difference between the two groups was not statistically significant (p = 0.748). There were no neurovascular injuries associated with this procedure. The incidence of complications was 44.82% (13/29) in the plate group, while 14.28% (5/35) in the navigation group (p = 0.007). CONCLUSION: This study found that compared with minimally invasive percutaneous plate fixation, percutaneous IS screw fixation under 3D navigation is a suitable option for the treatment of Zone II unstable sacral fractures. This approach is characterized by its shorter operation time, less surgical trauma, less bleeding, less hospital time, and fewer complications.


Assuntos
Fraturas Ósseas , Ossos Pélvicos , Fraturas da Coluna Vertebral , Humanos , Fraturas Ósseas/cirurgia , Fixação Interna de Fraturas/métodos , Perda Sanguínea Cirúrgica , Estudos Retrospectivos , Ossos Pélvicos/cirurgia , Ossos Pélvicos/lesões , Resultado do Tratamento , Fraturas da Coluna Vertebral/cirurgia , Parafusos Ósseos
16.
Biology (Basel) ; 12(10)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37887002

RESUMO

Phenazine compounds are widely used in agricultural control and the medicine industry due to their high inhibitory activity against pathogens and antitumor activity. The green and sustainable method of synthesizing phenazine compounds through microbial fermentation often requires a complex culture medium containing tryptone and yeast extract, and its cost is relatively high, which greatly limits the large-scale industrial production of phenazine compounds by fermentation. The aim of this study was to develop a cost-effective minimal medium for the efficient synthesis of phenazine compounds by Pseudomonas chlororaphis. Through testing the minimum medium commonly used by Pseudomonas, an ME medium for P. chlororaphis with a high production of phenazine compounds was obtained. Then, the components of the ME medium and the other medium were compared and replaced to verify the beneficial promoting effect of Fe2+ and NH4+ on phenazine compounds. A cost-effective general defined medium (GDM) using glycerol as the sole carbon source was obtained by optimizing the composition of the ME medium. Using the GDM, the production of phenazine compounds by P. chlororaphis reached 1073.5 mg/L, which was 1.3 times that achieved using a complex medium, while the cost of the GDM was only 10% that of a complex medium (e.g., the KB medium). Finally, by engineering the glycerol metabolic pathway, the titer of phenazine-1-carboxylic acid reached the highest level achieved using a minimum medium so far. This work demonstrates how we systematically analyzed and optimized the composition of the medium and integrated a metabolic engineering method to obtain the most cost-effective fermentation strategy.

17.
Artigo em Zh | MEDLINE | ID: mdl-23256996

RESUMO

OBJECTIVE: To observe the effects of multi-walled carbon nano-onions (MWCNOs) on platelet adhesion and experimental thrombosis in rats. METHODS: Experimental rats were randomly divided into sham operation group, solvent group, and MWCNO group, each including 6 ∼ 9 rats. An inverted fluorescence microscope and a flow chamber were used to observe the effects of 20 g/ml MWCNOs on platelet adhesion at shear rates of 500 s(-1) and 1000 s(-1); the experiment was repeated at least three times in each group. A rat model of carotid artery thrombosis was induced by 25% FeCl3, and the effects of 2 mg/kg MWCNOs on the blood flow and wet weight of thrombus per millimeter in the model were observed. RESULTS: When the shear rate was 500 s(-1), the MWCNO group showed a significantly smaller number of adhering platelets than the solvent group (58.3 ± 16.1 platelets/0.01 mm(2) vs 190.1 ± 36.0 platelets/0.01 mm(2)), but the inhibitory effect of MWCNOs on platelet adhesion disappeared as the shear rate increased to 1000 s(-1). The wet weights of thrombus per millimeter at 0 h after injection of a solvent or MWCNOs via the caudal vein were 0.83 ± 0.12 mg/mm in the solvent group and 0.97 ± 0.11 mg/mm in the MWCNO group, and the wet weights of thrombus per millimeter at 12 h after injection were 0.89 ± 0.12 mg/mm in the solvent group and 1.01 ± 0.15 mg/mm in the MWCNO group, exhibiting no significant differences between the two groups (P > 0.05). There were also no significant differences between the two groups in terms of blood flow at 0 h and 12 h after injection (P > 0.05). CONCLUSION: MWCNOs have inhibitory effect on platelet adhesion in vitro, but the injection of MWCNOs via the caudal vein has no effects on the blood flow and wet weight of thrombus per millimeter in experimental thrombosis in rats.


Assuntos
Plaquetas/efeitos dos fármacos , Nanotubos de Carbono/efeitos adversos , Adesividade Plaquetária/efeitos dos fármacos , Trombose/patologia , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Trombose/induzido quimicamente
18.
Artigo em Zh | MEDLINE | ID: mdl-22931766

RESUMO

OBJECTIVE: To observe the pulmonary toxicity of multi-walled carbon nanotubes (MWCNTs) in high-fat diet SD rats. METHODS: One hundred forty male SD rats were randomly divided into 6 groups. The normal control group, high-fat diet model group, vehicle group, and group treated with low dose of MWCNTs consisted of 30 rats, respectively, which were divided in 3 subgroups (10 rats each subgroup), respectively. The groups treated with medium and high loses of MWCNTs consisted of 10 rats, respectively. All the animals were exposed to high-fat-diet except for the control group which was given with normal diet. Before intravenous exposure, the high-fat diet model group, vehicle group, and three MWCNTs treated groups were gavaged with 700 thousand U/kg Vit D3 for three days, then given with high-fat-diet. The vehicle group was exposed to normal saline containing 1% Tween 80 and the low exposure group was exposed to MWCNTs at the dose of 50 µg/kg by tail vein injection twice a week for 8, 12 or 16 weeks. Other tow exposure groups were exposed to MWCNTs at the doses of 100, and 200 µg/kg by tail vein injection twice a week, respectively for 16 weeks. The lungs were from the executed rats, the lung indexes were calculated, the pathological changes of lungs were examined under light microscope after HE staining. qRT-PCR assay was utilized to detect the expression levels of pro-inflammation cytokines IL-1ß (IL-1ß) and TNF-α mRNA in the lungs. RESULTS: As compared with the vehicle group, the lung indexes in groups exposed to 100 and 200 µg/kg MWCNTs increased significantly (P < 0.05). It was found under light microscope that the MWCNTs were accumulated in lungs of three exposure groups in 16 weeks after exposure, including pneumorrhagia, alveolar walls thicken, fibrosis, and granulomas. As compared with the vehicle group, the levels of IL-1ß mRNA in group exposed to 50 µg/kg MWCNTs for 12 weeks and the groups exposed to 50, 100 and 200 µg/kg MWCNTs for 16 weeks decreased significantly (P < 0.05). As compared with the vehicle group, the levels of TNF-α mRNA in the groups exposed to 50 µg/kg MWCNTs for 8 and 16 weeks increased significantly (P < 0.05), the level of TNF-α mRNA in the groups exposed to 50 µg/kg MWCNTs for 12 weeks decreased significantly (P < 0.05). As compared with the vehicle group, the level of TNF-α mRNA in the groups exposed to 200 µg/kg MWCNTs for 16 weeks reduced significantly (P < 0.05). CONCLUSION: The MWCNTs accumulation and chronic inflammatory changes were found in the lungs of rats exposed to MWCNTs by tail vein injection.


Assuntos
Dieta Hiperlipídica , Pulmão/patologia , Nanotubos de Carbono/toxicidade , Animais , Citocinas/análise , Injeções Intravenosas , Pulmão/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley
19.
Mutat Res ; 721(2): 184-91, 2011 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-21296185

RESUMO

Carbon nanomaterials have multiple applications in various areas. However, it has been suggested that exposure to nanoparticles may be a risk for the development of vascular diseases due to injury and dysfunction of the vascular endothelium. Therefore, in the present study, the cytotoxic and genotoxic effects of multi-wall carbon nanotubes (MWCNTs) on human umbilical vein endothelial cells (HUVECs) were evaluated. Optical and transmission electronic microscopy (TEM) study showed that MWCNTs were able to enter cells rapidly, distribute in the cytoplasm and intracellular vesicles and induce morphological changes. Exposure to MWCNTs reduced the viability of HUVECs, and induced apoptosis in HUVECs. Furthermore, MWCNTs could cause DNA damage as indicated by the formation of γH2AX foci. MWCNTs also affected cellular redox status, e.g., increasing intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels, as well as altering superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) levels. On the other hand, the free radical scavenger N-acetyl-l-cysteine (NAC) preincubation can inhibit the cytotoxic and genotoxic effects of MWCNTs. Taken together, these results demonstrated that MWCNTs could induce cytotoxic and genotoxic effects in HUVECs, probably through oxidative damage pathways.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Endotélio Vascular/efeitos dos fármacos , Mutagênicos/toxicidade , Nanotubos de Carbono/toxicidade , Células Cultivadas , Relação Dose-Resposta a Droga , Histonas/metabolismo , Humanos , Malondialdeído , Espécies Reativas de Oxigênio/metabolismo , Veias Umbilicais/citologia
20.
J Nanosci Nanotechnol ; 11(3): 2501-5, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21449413

RESUMO

In this paper, a green chemical synthetic route was developed to synthesize WO3 nanoparticles with an average size of 70 nm. The products were characterized in detail by multiform techniques: X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The photoluminescence of the obtained WO3 nanoparticles was also investigated. The effects of the hydrothermal temperature on the crystalline phase and morphology of the products have been studied systematically. The photocatalytic activity of the samples was evaluated by photocatalytic decolorization of methylene blue (MB) aqueous solution. The electrocatalytic activity was characterized using voltammetric techniques. The results showed that the obtained WO3 nanoparticles have an excellent photocatalytic and electrocatalytic performance for the MB.


Assuntos
Cristalização/métodos , Química Verde/métodos , Azul de Metileno/química , Azul de Metileno/efeitos da radiação , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Tungstênio/química , Catálise , Luz , Teste de Materiais , Conformação Molecular , Nanoestruturas/efeitos da radiação , Nanotecnologia/métodos , Tamanho da Partícula , Soluções , Propriedades de Superfície , Tungstênio/efeitos da radiação , Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA