Scientific Reports
·
2017
·Vol. 7
·期 1
·1-11
·
IF 4.259
Yang Haibo,Dai Jingjing,Wang Lei,Lin Ying,Wang Fen,Kang Pan
A novel two-step approach consisting of hydrothermal process and subsequently selective etching has been developed to prepare flower-like three-dimensional porous Bi 2 Fe 4 O 9 spheres with good uniformity and highly photocatalytic performance. XRD patterns and SEM images reveal that the Bi 2 Fe 4 O 9 phase does not exhibit any changes after the etching process, and the crystal morphology evolves from micro-platelets to flower-like three-dimensional porous Bi 2 Fe 4 O 9 spheres by controlling the experiment parameters. The change of morphology will lead to the significant increase of specific surface area, which would be beneficial to the enhancement of photocatalytic performance owing to prominent absorption in the ultraviolet and visible light region. As compared to Bi 2 Fe 4 O 9 microplatelets, flower-like three-dimensional porous Bi 2 Fe 4 O 9 spheres exhibit excellent photocatalytic degration rate of methyl orange (MO).
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Stem Cell Research & Therapy
·
2017
·Vol. 8
·期 1
·1-14
·
IF 4.211
Xue Xiao-Lei,Han Xiao-Dan,Li Yuan,Chu Xiao-Fei,Miao Wei-Min,Zhang Jun-Ling,Fan Sai-Jun
Background The hematopoietic system is especially sensitive to total body irradiation (TBI), and myelosuppression is one of the major effects of TBI. Astaxanthin (ATX) is a powerful natural anti-oxidant with low toxicity. In this study, the effect of ATX on hematopoietic system injury after TBI was investigated.Methods Flow cytometry was used to detect the proportion of hematopoietic progenitor cells (HPCs) and hematopoietic stem cells (HSCs), the level of intracellular reactive oxygen species (ROS), expression of cytochrome C, cell apoptosis, and NRF2-related proteins. Immunofluorescence staining was used to detect Nrf2 translocation. Western blot analysis was used to evaluate the expression of apoptotic-related proteins. Enzymatic activities assay kits were used to analyze SOD2, CAT, and GPX1 activities.Results Compared with the TBI group, ATX can improve radiation-induced skewed differentiation of peripheral blood cells and accelerate hematopoietic self-renewal and regeneration. The radio-protective effect of ATX is probably attributable to the scavenging of ROS and the reduction of cell apoptosis. These changes were associated with increased activation of Nrf2 and downstream anti-oxidative proteins, and regulation of apoptotic-related proteins.Conclusion sThis study suggests that ATX could be used as a potent therapeutic agent to protect the hematopoietic system against TBI-induced bone marrow suppression.
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FOOD SCIENCE AND BIOTECHNOLOGY
·
2016
·Vol. 25
·期 4
·1115-1122
·
IF 0.699
Feng Yanli,Chen Wanping,Chen Fusheng
Monacolin K (MK) produced by Monascus spp. is mostly used to regulate cholesterol level, while it can be contaminated by citrinin, a mycotoxin yielded by some Monascus strains. To develop production of citrinin-free MK, an M . sp. MS-1 strain, identified as M. pilosus by morphologies and internal transcribed spacer sequences analysis, was isolated from red fermented rice. After 14 days of fermentation, yields of citrinin-free MK could be up to 0.58 mg/mL and 16.45 mg/g in liquid- and solidstate fermentation products under optimal conditions, respectively. Further determination revealed that no citrinin biosynthesis related genes such as ctnA , pksCT , ctnE , and ctnR were detected. Thus, HPLC combined with citrinin-related gene analyses can be used for rapid screening of non-citrinin production Monascus strains.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2016
·Vol. 18
·期 8
·1-11
·
IF 2.101
Wang Shanshan,Liu Zhonghui,Bartic Carmen,Xu Hong,Ye Jian
Surface-enhanced Raman scattering (SERS) tags show ultrasensitivity and multiplexing abilities due to strong and characteristic Raman signals and therefore can be utilized as optical labeling agents similar to fluorescent dyes and quantum dots for biosensing and bioimaging. However, SERS tags have the difficulty to realize quantitative analysis due to the uniformity and reproducibility issue. In this work, we have reported on a new type of SERS tag called Au rod-in-shell (RIS) gap-enhanced Raman tag (GERT). With the high-resolution transmission electron microscopy (TEM) and optical absorbance measurements, we have demonstrated the subnanometer sized gap junctions inside the RIS GERTs. SERS measurements and FDTD calculations show that the core–shell subnanometer gap geometry in the RIS GERTs not only generates strong SERS hot spots but also isolates SERS hot spots by Au shells to avoid the influence when the particle aggregates form, therefore showing better SERS uniformity and stronger SERS intensity than normal Au nanorods. Those RIS NPs exhibit great potential as the labeling agents for SERS-based bioimaging and biosensing applications.
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MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 10
·2823-2830
·
IF 4.831
Zhong Yaping,Deng Chun,He Yu,Ge Yili,Song Gongwu
The authors describe a method for increasing the peroxidase-like catalytic properties of copper nanoclusters (Cu-NCs) that are used in non-enzymatic assays. The Cu-NCs were prepared by utilizing 6-thio-β-cyclodextrin as both the template and as effective modulators for increasing the peroxidase-like properties of the Cu-NCs. The β-CD-coated Cu-NCs have an average diameter of 2 nm, are stable in aqueous solutions, display strong fluorescence with excitation/emission peak wavelengths of 360/450 nm, and possess peroxidase-like catalytic activity which makes them a useful enzyme mimic. We have applied the findings to non-enzymatic photometric determination (at 650 nm) of (a) H 2 O 2 in the concentration range of 0.02 to 10 mM using the β-CD/Cu-NC assisted oxidation of tetramethylbenzidine by H 2 O 2 , and (b) glucose in the concentration range of 0.04 to 20 mM after addition of glucose oxidase and formation of H 2 O 2 . The detection limits (at an S/N ratio of 3) are 0.2 μM for H 2 O 2 and 0.4 μM for glucose. The β-CD coating is found to result in a strong increase in the reaction rate, probably because the cavity of β-CD acts as a pocket for the recognition and catalysis of substrate. Hence, the binding specificity becomes similar to that of natural enzymes.
The peroxidase-like catalytic activity of Cu-NCs in non-enzymatic sensors is strongly enhanced by utilizing mono-6-thio-β-cyclodextrin (mono-6-SH-β-CD) as both the template molecule and the effective rate modulator.
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WATER AIR AND SOIL POLLUTION
·
2016
·Vol. 227
·期 9
·1-11
·
IF 1.551
Wu Hailu,Xu Kaiqin,He Xiaojuan,Wang Xinze
Three macrophyte species, Typha augustifolia ( T. augustifolia ), Phragmites australis ( P. australis ), and Acorus calamus L. ( A. calamus L.), have been grown in hydroponic cultivation systems fed with synthetic wastewater. The experiment was designed as 3 × 2 factorial, with three species and two ratios of NH 4
+ /NO 3
− so as to investigate the nitrogen transformation and nitrogen removal capacity of each species. The nitrogen removal mechanism was further disclosed by comparing biomass production, nitrogen mass balance, and root exudates of the three plant species under different NH 4
+ /NO 3
− ratios. The results indicated there exists a linear relationship, with positive significance ( r = 0.946, p < 0.05), between plant biomass and total nitrogen (TN) removal efficiency; in other words, biomass could best reflect plant ability to remove nitrogen. It is also found that NH 4
+ /NO 3
− ratio could influence plant biomass and root exudates significantly. Additionally, the hydrogen donor and source of energy in denitrification happened in this research were mainly organic acids and soluble sugars, accounting for approximately 50 % of the composition in root exudates.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 12
·13280-13287
·
IF 1.798
Liu Jingdong,Ji Hongjun,Wang Shuai,Li Mingyu
In this study, we present a new simple method using formic acid pretreatment to achieve low temperature sintering of Cu nanoparticles, and the Cu nanoparticles have been successfully prepared with a modified polyol method. For formic acid pretreatment, the spherical Cu nanoparticles with an average size of 30 nm were saturated with a mixed solution of formic acid and absolute ethanol directly. The surface composition analysis indicated that the initial oxide on the surface of Cu nanoparticles was completely removed, and formate was generated as a by-product which could decompose at low temperature. According to the thermal analysis results, it was found that the sintering temperature of Cu nanoparticles with formic acid pretreatment was reduced to 160 °C. And the corresponding microstructures further demonstrated that the emerging small exothermic peak of thermal curve over the temperature range between 120 and 160 °C was caused by the formation of sintering necks. The formic acid treated Cu nanoparticle films sintered at 260 and 320 °C exhibited an electrical resistivity of 6.1 and 3.6 μΩ cm respectively.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2016
·Vol. 408
·期 30
·8813-8820
·
IF 3.125
Fu Zhaofu,Li Gongke,Hu Yufei
A novel chemiluminescence (CL) system based on the reaction of fluorescent water-soluble nitrogen-rich quantum dots (N-dots) and diperiodatoargentate(III) (DPA) was developed. The prepared N-dots have a small size (≤10 nm) and high percentage of nitrogen (39.9 %), which exceeds the content of carbon in the same N-dots. The N-dots exhibit characteristic blue fluorescence under UV light and up-conversion luminescence. The relatively intense CL emission is based on the direct oxidation of N-dots by DPA. The CL emission may be attributed to the high nitrogen content and the special structure of the N-dots. The CL mechanism of N-dots and DPA was investigated by using CL, UV–Vis absorption, IR, fluorescence, and radical scavenging experiments. This investigation provides a way to study the optical properties of N-dots. The analytical applicability of the N-dots and DPA CL system in the determination of ferulic acid (FA) was explored. The CL intensity was linearly proportional to the concentration of ferulic acid from 3.0 × 10 −7 to 1.0 × 10 −5 g mL −1 with a detection limit of 8.0 × 10 −8 g mL −1 (3σ); the relative standard deviation was 2.4 % for 4.0 × 10 −7 g mL −1 FA ( n = 9). The proposed method was successfully applied to the determination of ferulic acid in Angelica sinensis . The study provides valuable insight into the role of nitrogen-rich quantum dots in CL.
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International Journal of Environmental Science and Technology
·
2016
·Vol. 13
·期 10
·2449-2458
·
IF 2.344
Shang J. G.,Kong X. R.,He L. L.,Li W. H.,Liao Q. J. H.
Thermally carbonization biochar produced from a traditional Chinese herbal medicine waste ( Astragalus mongholicus residue) was investigated for its performance in ciprofloxacin adsorption. Batch sorption experiments were conducted, and scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller surface area analyses were employed to characterize the biochar. The results demonstrated that thermal activation process improves the adsorbent characteristics. Biochar produced at 800 °C had the best adsorption capacity, a better pore structure and the largest surface areas. The adsorption process fit well to a pseudo-second-order kinetics model. The adsorption isothermal model results revealed that the adsorption process of ciprofloxacin is described better by the Freundlich isotherm and the type of adsorption is a chemical process. The maximum adsorption of ciprofloxacin occurred at pH 7. The present research demonstrated that A. mongholicus biochar might be an attractive and cost-effective adsorbent with good adsorption performance for removing ciprofloxacin from water solution.
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JOURNAL OF MEMBRANE BIOLOGY
·
2016
·Vol. 249
·期 6
·757-767
·
IF 1.991
Lai Lu,Li Ya-Ping,Mei Ping,Chen Wu,Jiang Feng-Lei,Liu Yi
The mitochondrial toxicity induced by GSH-CdTe Quantum dots (QDs) of different sizes was investigated. The decreases in absorbance and transmission electron microscopy images show that QDs induce the swelling of mitochondria. Results of flow cytometry indicate that QDs cause a reduction of mitochondrial membrane potential (MMP). A remarkable increase in fluidity of protein regions of mitochondrial membrane is observed, whereas the lipid regions are not obviously affected. Cyclosporin A (CsA) effectively prevents the QD-induced mitochondrial swelling. On the basis of these results, it is proposed that QDs induce mitochondrial permeability transition (MPT). Moreover, with increasing QDs size, a pronounced MPT is observed. The difference between the membrane fluidity induced by QDs and Cadmium ion and the ineffective protective effects of EDTA suggests that the mitochondrial toxicity of QDs cannot be only attributed to the release of metal ion. The protective effects of HSA indicate that the interaction of QDs with pore-forming protein gives rise to the increase in membrane fluidity. This hypothesis is demonstrated by the interaction of QDs with model membranes and proteins using differential scanning calorimetry and isothermal titration microcalorimetry. In conclusion, as the size of QDs increases, the binding affinity of QDs with membrane protein increases, and therefore causes a pronounced mitochondrial damage.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 6
·4441-4448
·
IF 2.019
Liu Shuhua,Huang Zongyu,Ren Xiaohui,Chen Xinhang,Qiao Hui,Tang Pinghua,Qi Xiang
A novel P25/Black phosphorus/Graphene hybrid has been successfully prepared by loading two components [P25 and Black phosphorus (BP)] on graphene nanosheets via a simple one-step hydrothermal method. The P25/BP/Graphene hybrids are characterized by scanning electron microscopy (SEM),Raman spectra and X-ray diffraction patterns, which confirm a good crystallized P25 and BP hybridization with graphene. Photoelectrochemical tests verify that the photocurrent density of as-prepared P25/BP/Graphene ternary hybrid (9.32 μA/cm 2 ) is greatly improved at 1 V, which is nearly 34 times higher than that of sole P25 and 4.8 times as much as that of P25/Graphene. The improved photocatalytic activity is proposed to be benefited from the higher carrier mobility and additional accessible sites derive from the special configurations of ternary hybrid, as well as the introduction of the visible and near-infrared-activated BP photocatalyst. More importantly, this work demonstrates that the as-prepared P25/BP/Graphene hybrid would be an attractive candidate as high-performance photocatalyst, and provide positive proof of concept for developing the practical applications of graphene and black phosphorus based composites.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Yang Ming,Weng Lin,Zhu Hanxing,Zhang Fan,Fan Tongxiang,Zhang Di
Although carbon nanotubes ( CNT s) have shown great potential for enhancing the performance of polymer matrices, their reinforcement role still needs to be further improved. Here we implement a structural modification of multi-walled CNTs ( MWCNT s) to fully utilize their fascinating mechanical and electrical properties via longitudinal splitting of MWCNTs into graphitic nanoribbons ( GNR s). This nanofiller design strategy is advantageous for surface functionalization, strong interface adhesion as well as boosting the interfacial contact area without losing the intrinsic graphitic structure. The obtained GNRs have planar geometry, quasi-1D structure and high-quality crystallinity, which outperforms their tubular counterparts, delivering a superior load-bearing efficiency and conductive network for realizing a synchronous improvement of the mechanical and electrical properties of a PVA-based composite. Compared to PVA/CNTs, the tensile strength, Young’s modulus and electrical conductivity of the PVA/GNR composite at a filling concentration of 3.6 vol.% approach 119.1 MPa, 5.3 GPa and 2.4 × 10 −4 S m −1 , with increases of 17%, 32.5% and 5.9 folds, respectively. The correlated mechanics is further rationalized by finite element analysis, the generalized shear-lag theory and the fracture mechanisms.
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