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ABSTRACT: Carbon-modified BiVO(4) microtubes embedded with Ag nanoparticles (BVO@C/Ag MTs) were obtained by a two-step fabrication route. First, the BiVO(4)@carbon core-shell microtubes (BVO@C MTs) were fabricated by using BiVO(4) microtubes (BiVO(4) MTs) as a hard-template through a hydrothermal approach. Next, small Ag nanoparticles (Ag NPs) with well-dispersed distribution were assembled inside the carbon layer of the BVO@C MTs via an in situ reduction method. The results showed that small Ag NPs were well dispersed inside the carbon layer of approximately 8 nm in thickness around the BiVO(4) microtubes. The photocatalytic studies revealed that the BVO@C/Ag MTs exhibited the highest photocatalytic activity for photodegradation of rhodamine B (RB) compared to the pure BVO-MTs, BVO@C MTs under visible light irradiation. The high separation efficiency of photogenerated electron-hole pairs based on the photosynergistic effect among the three components of BiVO(4), carbon, and Ag and the improved visible light utilization from the sensitizing effects of carbon layers both contribute to the enhanced photocatalytic activity. The BVO@C/Ag MTs did not exhibit any significant loss of activity after three cycles of RB photodegradation, which results from the fact that the presence of the carbon layer could inhibit loss and oxidation of Ag NPs during repeated applications. The BVO@C/Ag MTs could be easily recovered by sedimentation due to their one-dimensional nanostructural property.
Nanoscale 10/2012; · 5.91 Impact Factor
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ABSTRACT: Sampling of intracellular metabolites in Mortierella alpina was investigated as part of a metabolomics study. After comparison of four sampling protocols, rapid filtration of the culture using a laboratory-made nylon filter and absorbent gauze under normal pressure followed by quenching in liquid N(2) and grinding (the improved protocol) was the most effective. Rapid filtration under normal pressure decreased intracellular metabolites leakage and subsequent grinding of cells contributed to intracellular metabolites extraction. The above quenching method together with 75 % (v/v) ethanol, buffered with 60 mM HEPES, at 80 °C for 3 min is therefore suitable for sampling intracellular metabolites in M. alpina.
Biotechnology Letters 09/2012; · 1.68 Impact Factor
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ABSTRACT: The TiO(2)/ZnO nanofibers embedded by Au nanoparticles (TiO(2)/ZnO/Au NFs) were fabricated by combining the electrospinning technique (for TiO(2)/ZnO nanofibers) and an in situ reduction approach (for Au nanoparticles). X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electronmicroscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy and photoluminescence spectroscopy, were used to characterize the as-synthesized nanofibers. The results showed that small Au nanoparticles (Au NPs) were well dispersed on the TiO(2)/ZnO nanofibers (TiO(2)/ZnO NFs). And, the TiO(2)/ZnO/Au nanofibers showed high charge separation efficiency under ultraviolet excitation, as evidenced by photoluminescence spectra. The photocatalytic studies revealed that the TiO(2)/ZnO/Au NFs exhibited enhanced photocatalytic efficiency of photodegradation of Methyl orange (MO) and 4-nitrophenol (4-NP) compared with the pure TiO(2) nanofibers, ZnO nanofibers and TiO(2)/ZnO NFs under ultraviolet excitation, which might be attributed to the high separation efficiency of photogenerated electron-hole pairs based on the photosynergistic effect among the three components of TiO(2), ZnO and Au. And, the TiO(2)/ZnO/Au NFs could be easily separated and recycled due to their one-dimensional nanostructural property.
Journal of hazardous materials 08/2012; 237-238:331-8. · 4.14 Impact Factor
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ABSTRACT: Zn(2)TiO(4)@carbon core/shell nanofibers (Zn(2)TiO(4)@C NFs) with different thickness of carbon layers (from 2 to 8 nm) were fabricated by combining the electrospinning technique and hydrothermal method. The results showed that a uniform carbon layer was formed around the electrospun Zn(2)TiO(4) nanofiber (Zn(2)TiO(4) NFs). By adjusting the hydrothermal fabrication parameters, the thickness of carbon layer varied linearly with the concentration of glucose. Furthermore, the core/shell structure formed between Zn(2)TiO(4) and carbon enhanced the charge separation of pure Zn(2)TiO(4) under ultraviolet excitation, as evidenced by photoluminescence spectra. The photocatalytic studies revealed that the Zn(2)TiO(4)@C NFs exhibited enhanced photocatalytic efficiency of photodegradation of Rhodamine B (RB) compared with the pure Zn(2)TiO(4) NFs under ultraviolet excitation, which might be attributed to the high separation efficiency of photogenerated electrons and holes based on the synergistic effect between carbon and Zn(2)TiO(4). Notably, the Zn(2)TiO(4)@C NFs could be recycled easily by sedimentation without a decrease of the photocatalytic activity.
Journal of hazardous materials 06/2012; 229-230:265-72. · 4.14 Impact Factor
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ABSTRACT: In this paper, Bi(2)MoO(6) microtubes (BMO-MTs) were obtained by a two-step fabrication route. By using the electrospun polyacrylonitrile (PAN) microfibers as structure-directing hard template and through ethylene glycol solvothermal method, polyacrylonitrile/Bi(2)MoO(6) (PAN/BMO) hybrid microfibers with core-shell structures were prepared. Through heat treatment of the as-prepared PAN/BMO to remove the PAN core, Bi(2)MoO(6) with tubes-structured were obtained. The thickness of BMO-MTs was controlled by changing the Bi(2)MoO(6) loading percentage of PAN/BMO which could be obtained through ethylene glycol solvothermal process with precursor different concentration for the preparation of Bi(2)MoO(6). And, the crystal structure and morphology of BMO-MTs strongly depended on the calcination temperature when heat-treating the as-prepared PAN/BMO. Photocatalytic tests show that the BMO-MTs possess a much higher degradation rate of Rhodamine B (RB) than that of Bi(2)MoO(6) prepared by solid-state reaction and conventional P25. The improved photocatalytic performance could be ascribed to the hollow multi channelled structure and large surface area. The BMO-MTs could be reclaimed easily by sedimentation from the photocatalytic reaction solution due to the large length to diameter ratio of one-dimensional tubes structures. Moreover, such simple and versatile strategy can provide a general way to fabricate other tubes structures of Bi(III)-containing oxides, such as Bi(2)WO(6) and BiVO(4) microtubes.
Journal of hazardous materials 05/2012; 225-226:155-63. · 4.14 Impact Factor
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ABSTRACT: The hydrophobic core in Bcl-x(L) composed of Trp137, Ile140, Trp181, Ile182, Trp188 and Phe191 is highly conserved and essential for protein folding, protein stability and binding affinity with BH3-peptide. 9 mutants of Ile140 residue were constructed and characterized in order to get better understanding of the effect of the hydrophobic core. Binding assay demonstrated that binding affinities between 4 charged mutants and BH3-peptide were significantly weakened or lost, suggesting that the integrity of the hydrophobic core has close relationship with binding. The CD spectroscopy results indicated that disruption of the hydrophobic core may affect local conformation within the protein and result in intrinsic inactivity. Further chemical-induced protein folding results on these 4 mutants revealed that the conserved hydrophobic core is also important for the protein stability.
Protein and Peptide Letters 04/2012; 19(9):991-6. · 1.94 Impact Factor
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ABSTRACT: Ambient aerosol samples were collected at an urban site and an upwind rural site of Beijing during the CAREBEIJING-2008 (Campaigns of Air quality REsearch in BEIJING and surrounding region) summer field campaign. Contributions of primary particles and secondary organic aerosols (SOA) were estimated by chemical mass balance (CMB) modeling and tracer-yield method. The apportioned primary and secondary sources explain 73.8% ± 9.7% and 79.6% ± 10.1% of the measured OC at the urban and rural sites, respectively. Secondary organic carbon (SOC) contributes to 32.5 ± 15.9% of the organic carbon (OC) at the urban site, with 17.4 ± 7.6% from toluene, 9.7 ± 5.4% from isoprene, 5.1 ± 2.0% from α-pinene, and 2.3 ± 1.7% from β-caryophyllene. At the rural site, the secondary sources are responsible for 38.4 ± 14.4% of the OC, with the contributions of 17.3 ± 6.9%, 13.9 ± 9.1%, 5.6 ± 1.9%, and 1.7 ± 1.0% from toluene, isoprene, α-pinene, and β-caryophyllene, respectively. Compared with other regions in the world, SOA in Beijing is less aged, but the concentrations are much higher; between the sites, SOA is more aged and affected by regional transport at the urban site. The high SOA loading in Beijing is probably attributed to the high regional SOC background (∼2 μg m(-3)). The toluene SOC concentration is high and comparable at the two sites, implying that some anthropogenic components, at least toluene SOA, are widespread in Beijing and represents a major factor in affecting the regional air quality. The aerosol gaseous precursor concentrations and temperature correlate well with SOA, both affecting SOA formation. The significant SOA enhancement with increasing water uptake and acidification indicates that the aqueous-phase reactions are largely responsible SOA formation in Beijing.
Environmental Science & Technology 04/2012; 46(18):9846-53. · 4.80 Impact Factor
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ABSTRACT: A novel ultraviolet (UV)-assisted imprinting procedure that employs photosensitive tin(II) 2-ethylhexanoate is presented for the facile size-tunable fabrication of functional tin dioxide (SnO(2)) nanostructures by varying annealing temperatures. These imprinted SnO(2) nanostructures were also used as new masters for size reduction lithography. SnO(2) lines down to 40 nm wide were obtained from a silicon master with 200 nm wide lines by simply performing size reduction lithography twice. This leads to 80 and 87.5% reduction in the width and height of imprinted lines, respectively. An imprinted pattern annealed at 400 °C demonstrated transmittance greater than 90% over the range of 350-700 nm, which is high enough to make the pattern useful as a transparent SnO(2) mold. This demonstrated approach allows the accessibility to size-tunable molds, eliminating the need for conventional expensive imprinting masters with very fine structures, as well as functional SnO(2) nanostructures, potentially useful in applications where ordered surface nanostructures are required, such as photonic crystals, biological sensors, and model catalysts.
ACS Applied Materials & Interfaces 04/2012; 4(5):2507-14. · 4.53 Impact Factor
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Zengcai Guo,
Bin Chen,
Jingbo Mu,
Mingyi Zhang,
Peng Zhang,
Zhenyi Zhang,
Jingfeng Wang, Xin Zhang,
Yangyang Sun,
Changlu Shao,
Yichun Liu
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ABSTRACT: One-dimensional 2,9,16,23-tetra-nitrophthalocyanine iron(II) (TNFePc)/TiO(2) nanofiber heterostructures have been successfully obtained by a simple combination of electrospinning technique and solvothermal process. The as-obtained products were characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and IR spectrum. The results revealed that the TNFePc nanosheets were successfully grown on the primary TiO(2) nanofibers. And, the coverage density of the secondary TNFePc nanostructures could be controlled by adjusting the experimental parameters. Photocatalytic tests displayed that the H(2)O(2) assisted TNFePc/TiO(2) nanofiber heterostructures (TNFePc/TiO(2)-H(2)O(2)) possessed a much higher degradation rate of methyl orange than the pure TiO(2) and TNFePc/TiO(2) nanofiber without H(2)O(2) under visible light. Moreover, the TNFePc/TiO(2) nanofiber heterostructures could be easily recycled without the decrease of the photocatalytic activity due to their one-dimensional nanostructural property of TiO(2) nanofibers.
Journal of hazardous materials 04/2012; 219-220:156-63. · 4.14 Impact Factor
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ABSTRACT: This study aimed to explore the inhibitory effect of Celastrus orbiculatus Thunb. (COT) on tumor growth, metastasis and antiogenesis of hepatocelluar carcinoma (HCC) in an orthotopic nude mouse model using fluorescence imaging technology. Human HCC Hep-G2 cells expressing red fluorescent protein (RFP) were orthotopically implanted onto the liver of nude mice. One group of mice was treated with ethyl acetate extract of COT p.o. at a dose of 20 mg/kg starting on day 3 post-tumor implantation (early treatment). All other mice were randomized into four groups from day 20 post-tumor implantation and received either no treatment, oxaliplatin (25 mg/kg), or low-dose (20 mg/kg) or high-dose (40 mg/kg) COT. Real-time whole-body fluorescence imaging was performed to measure tumor growth and monitor metastasis development during the study. Vascular endothelial growth factor(VEGF) expression in the tumors collected at autopsy was analyzed by immunohistochemical staining and reverse transcription-polymerase chain reaction(RT-PCR). High-dose treatments, early treatment with COT, demonstrated significant efficacy on controlling tumor volume and tumor weight in the human HCC Hep-G2 orthotopic tumor model. No significant differences were found for metastasis incidence among the different study groups. VEGF expression in the tumors was significantly reduced by oxaliplatin and COT treatment. This study demonstrates the inhibitory efficacy of COT on the growth of HCC tumor. VEGF inhibition may contribute in part to the inhibition of HCC tumor growth. The results of the present report suggest COT has potential to treat HCC.
Anticancer research 04/2012; 32(4):1213-20. · 1.73 Impact Factor
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ABSTRACT: Calmodulin-binding proteins (CBPs) have been known to be involved in both biotic and abiotic stress responses. Recently, two closely related CBPs, Arabidopsis SAR Deficient 1 and CBP60g, were found to belong to a new family of transcription factors that regulate salicylic acid (SA) biosynthesis triggered by microbe-associated molecular patterns. In this study, we found that overexpression of CBP60g in Arabidopsis caused elevated SA accumulation, increased expression of the defense genes, and enhanced resistance to Pseudomonas syringae. In addition to the enhanced defense response, the CBP60g overexpression lines showed hypersensitivity to abscisic acid (ABA) and enhanced tolerance to drought stress. We also found that treatment with ABA and drought stress leads to a higher expression level of the ICS1 gene, which encodes isochorismate synthase, in the CBP60g overexpression lines than in the wild-type control plants. Our results suggest that CBP60g serves as a molecular link that positively regulates ABA- and SA-mediated pathways in plants. KEY MESSAGE: Overexpression of CBP60g in Arabidopsis enhanced the defense response, hypersensitivity to abscisic acid and tolerance to drought stress.
Plant Cell Reports 03/2012; 31(7):1269-81. · 2.27 Impact Factor
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ABSTRACT: The 3D open Bi(2)MoO(6)/ZnTiO(3) hierarchical heterostructures with Bi(2)MoO(6) ultrathin nanosheets (<10nm) grown on hexagonal-phase ZnTiO(3) nanofibers were fabricated by combining the electrospinning technique and solvothermal method. And, the Bi(2)MoO(6)/ZnTiO(3) hierarchical heterostructures had remarkable light absorption in the visible region. The photocatalytic studies revealed that the hierarchical heterostructures system exhibited exceptional photocatalytic activity in visible-light degradation of Rhodamine B, which might be attributed to the synergistic system with excellent charge separation characteristics and the unique morphology of Bi(2)MoO(6) nanosheets with the extended absorption in the visible light region. What is more, the 3D open structure supported on nanofibrous candidates possessed large surface areas and excellent recyclability.
Journal of hazardous materials 03/2012; 217-218:422-8. · 4.14 Impact Factor
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ABSTRACT: Recovery of aneurysm-induced oculomotor nerve paresis (ONP) after endosaccular coiling has not yet been adequately assessed. The aim of this study was to investigate the factors that affect the outcome of ONP after endovascular treatment of posterior communicating artery (PcomA) aneurysms.
We retrospectively evaluated the clinical characteristics and the outcome of oculomotor nerve function in a series of 36 patients with ONP due to PcomA aneurysms treated by endovascular coiling. Univariate analysis was applied to test the association between ONP recovery and clinical variables.
Thirty-six consecutive patients (20 women, 16 men; mean age, 54.3±9 years) presenting with ONP underwent endosaccular coiling were enrolled in this study. Subarachnoid hemorrhage was present in 21 patients. The mean size of the aneurysms was 9.3±3.9mm. ONP was complete in 14 patients (38.9%) and partial in 22 patients (61.1%) at admission. Seventeen patients (47.2%) had complete recovery of oculomotor nerve function, 15 had incomplete recovery (41.7%), and 4 (11.1%) remained unchanged after treatment. Factors showing significant association with recovery of oculomotor nerve function were the length and degree of ONP before treatment (P=0.035 and P=0.019, respectively).
Endosaccular coiling of PcomA aneurysms in patients with ONP resulted in cure or improvement of oculomotor nerve dysfunction in the majority of patients. The length and degree of preoperative ONP were the statistically significant predictors of complete ONP recovery.
Clinical neurology and neurosurgery 03/2012; 114(9):1238-42. · 1.30 Impact Factor
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Wen-Hao Tang,
Hui Jiang,
Lu-Lin Ma,
Kai Hong,
Qun Zhong,
Chi-Sun Yang,
Lian-Ming Zhao,
De-Feng Liu,
Jia-Ming Mao,
Yi Yang,
Qian Chen,
Ren-Pei Yuan, Xin Zhang,
Bin Li,
Nan Wei
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ABSTRACT: To investigate the relationship of sperm morphology with reproductive hormones in infertile men and the pathogenesis of teratozoospermia.
This study included 90 infertile men aged 25 - 40 years. We measured their testis volumes using the Prader orchidometer, conducted routine semen analyses according to the WHO laboratory standard, and determined the concentrations of reproductive hormones and sex hormone-binding globulin (SHBG) by chemiluminescence and the levels of free testosterone (FT) and bioavailable testosterone (BioT).
All the subjects showed normal sperm concentration. Based on the results of semen morphology analysis, the 90 infertile men were equally divided into groups 1 (morphologically normal sperm <4%), 2 (morphologically normal sperm > or = 4% and <10%), and 3 (morphologically normal sperm > or = 10%), with no significant differences in age among the three groups (P>0.05). The volumes of the left testis were (14.27 +/- 3.65) ml, (16.90 +/- 3.57) ml and (14.57 +/- 3.57) ml, respectively (P = 0.006 group 1 vs group 2, P = 0.741 group 1 vs group 3, P = 0.014 group 2 vs group 3), and those of the right testis were (14.60 +/- 3.70) ml, (16.60 +/- 3.35) ml and (14.67 +/- 3.54) ml, respectively (P = 0.050). There were no significant differences among the three groups in prolactin, follicle-stimulating hormone, luteinising hormone, estradiol, total testosterone and SHBG, (P>0.05). The levels of serum FT were (0.25 +/- 0.07) nmol/L, (0.29 +/- 0.07) nmol/L and (0.31 +/- 0.13) nmol/L (P = 0.086 group 1 vs group 2, P= 0.010 group 1 vs group 3, P= 0.364 group 2 vs group 3), and those of BioT were (5.81 +/- 1.58) nmol/L, (6.78 +/- 1.55) nmol/L and (7.29 +/- 3.02) nmol/L, respectively (P = 0.086 group 1 vs group 2, P = 0.010 group 1 vs group 3, P = 0.364 group 2 vs group 3). The percentage of morphologically normal sperm was positively correlated with the levels of serum FT and BioT (P<0.05).
The higher the levels of serum FT and BioT, the higher the percentage of morphologically normal sperm, which suggests that serum FT and BioT might be involved in the pathogenesis of teratozoospermia.
Zhonghua nan ke xue = National journal of andrology 03/2012; 18(3):243-7.
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Medecine sciences: M/S 03/2012; 28(3):250-4. · 0.64 Impact Factor
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Jie Hu,
Yong-hua Su,
Xia Yin,
Qun-ying Hong,
Chun Li,
Mao-song Ye,
Jing Li,
Qin Hu,
Yuan Shi,
Chun-xue Bai, Xin Zhang
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ABSTRACT: To explore the diagnostic values of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the patients with hilar and mediastinal masses.
A total of 91 patients with mediastinal/hilar masses undergoing EBUS-TBNA in Zhongshan Hospital between September 2009 and March 2011 were retrospectively enrolled. Their unknown etiologies were difficult to be assessed by a traditional biopsy. The association of pathologic examinations and clinical data were analyzed.
Among them, 61 patients had malignant lesions while 30 patients were diagnosed with benign diseases. In the cases with malignant lesions, the diagnostic sensitivity, specificity and accordance rate were 91.67%, 100% and 91.80% respectively. The diagnostic accordance rate of benign lesions was 60%. And 36.9% (24/65) of the samples were small-sized so as to improve the diagnostic accuracy. The combination of cytology and histology significantly increased the diagnostic accordance versus cytology alone in all cases (P < 0.01). But there was no statistically significant difference in the malignant lesion subgroup with a better tendency (P > 0.05). No severe complication occurred.
With a high diagnostic accuracy and a low complication rate for the patients with hilar and mediastinal masses of unknown etiologies, EBUS-TBNA has different values for diagnosing malignant and benign lesions.
Zhonghua yi xue za zhi 02/2012; 92(8):528-31.
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ABSTRACT: Among the three embryonic germ layers, the mesoderm is a major source of the mesenchymal precursors giving rise to skeletal and connective tissues, but these precursors have not previously been identified and characterized. Using human embryonic stem cells directed toward mesendodermal differentiation, we show that mesenchymal stem/stromal cells (MSCs) originate from a population of mesodermal cells identified by expression of apelin receptor. In semisolid medium, these precursors form FGF2-dependent compact spheroid colonies containing mesenchymal cells with a transcriptional profile representative of mesoderm-derived embryonic mesenchyme. When transferred to adherent cultures, individual colonies give rise to MSC lines with chondro-, osteo-, and adipogenic differentiation potentials. Although the MSC lines lacked endothelial potential, endothelial cells could be derived from the mesenchymal colonies, suggesting that, similar to hematopoietic cells, MSCs arise from precursors with angiogenic potential. Together, these studies identified a common precursor of mesenchymal and endothelial cells, mesenchymoangioblast, as the source of mesoderm-derived MSCs.
Cell stem cell 12/2010; 7(6):718-29. · 23.56 Impact Factor
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Edward H. Sandy,
Jun Yao,
Shixue Zheng,
Alhaji B. Gogra,
Huilun Chen,
Hui Zheng,
Thomas B.R. Yormah, Xin Zhang,
Gyula Zaray,
Brunello Ceccanti,
Martin M.F. Choi
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ABSTRACT: This work investigated the toxicity of two isomeric alkylphthalates, i.e., di-n-octyl phthalate (DOP) and di-2-ethylhexyl phthalate (DEHP) to two model bacteria, Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), which have been previously used to study the toxicity of environmental pollutants. Microcalorimetry was used as the key analytical tool alongside scanning electron microscopy (SEM) and traditional microbiology techniques. The thermokinetic parameters from microcalorimetry showed that the phthalates had a biphasic effect on the metabolic activities of the bacteria; serving as energy sources for the bacteria thereby stimulating their growth at low dosages (≤150 μg/mL), but displaying inhibitory effects at higher dosages (≥300 μg/mL), indicated by a sharp decrease in growth rate constants at 450 μg/mL. The SEM revealed that the bacterial cells were morphological deformed, with shrunk cells and elongated strands at 600 μg/mL of both phthalates. The elongated strands inferred that the phthalates inhibited the reproductive processes of the bacteria by possibly impeding some stages of cell division. The half inhibitory concentrations of the phthalates showed that DEHP was more toxic than DOP. Additionally, E. coli, a facultative anaerobe, was more susceptible to the toxic effects of phthalates than B. subtilis, an obligate aerobe capable of forming endospores crucial for tolerating extreme environmental conditions.
Journal of Hazardous Materials. 10/2010;
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ABSTRACT: For the high-performance sensor-less vector control of an induction motor, the accuracy of the motor parameters has an important impact on the performance of the whole system. In this paper, we propose a novel method for the offline identification of motor parameters. In our method, first we use DC or single phase AC as an excitation signals. Then we measure the voltage of DC bus and current of stator on condition that the motor is at standstill. We analyze the obtained data by means of voltage reconstruction and FFT. Finally we simplify the T-form equivalent circuit and estimate the motor parameters based on the stable mathematical model. Moreover, we give an identification error analysis from three aspects, dead time, diode voltage drop and phase lagging. The effectiveness of our method is demonstrated by both simulation and experimental results.
Intelligent Control and Automation, 2008. WCICA 2008. 7th World Congress on; 07/2008
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Journal of Materials Science 01/2004; 39(18):5845-5848. · 2.02 Impact Factor
