JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
A facile two-step method for fabrication of plate-like WO3 photoanode under mild conditions.
Faraday Discuss.
PUBLISHED: 11-20-2014
Show Abstract
Hide Abstract
Fabrication of photoelectrodes on a large-scale, with low-cost and high efficiency is a challenge for their practical application in photoelectrochemical (PEC) water splitting. In this work, a typical plate-like WO3 photoanode was fabricated with chemical etching of the as-prepared mixed tungsten-metal oxides (W-M-O, M = Cu, Zn or Al) by a reactive magnetron co-sputtering technique, which results in a greatly enhanced PEC performance for water oxidation in comparison with that obtained from a conventional magnetron sputtering method. The current approach is applicable for the fabrication of some other semiconductor photoelectrodes and is promising for the scaling up of applications for highly efficient solar energy conversion systems.
Related JoVE Video
Self-Organization of Plasmonic and Excitonic Nanoparticles into Resonant Chiral Supraparticle Assemblies.
Nano Lett.
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
Chiral nanostructures exhibit strong coupling to the spin angular momentum of incident photons. The integration of metal nanostructures with semiconductor nanoparticles (NPs) to form hybrid plasmon-exciton nanoscale assemblies can potentially lead to plasmon-induced optical activity and unusual chiroptical properties of plasmon-exciton states. Here we investigate such effects in supraparticles (SPs) spontaneously formed from gold nanorods (NRs) and chiral CdTe NPs. The geometry of this new type of self-limited nanoscale superstructures depends on the molar ratio between NRs and NPs. NR dimers surrounded by CdTe NPs were obtained for the ratio NR/NP = 1:15, whereas increasing the NP content to a ratio of NR/NP = 1:180 leads to single NRs in a shell of NPs. The SPs based on NR dimers exhibit strong optical rotatory activity associated in large part with their twisted scissor-like geometry. The preference for a specific nanoscale enantiomer is attributed to the chiral interactions between CdTe NP in the shell. The SPs based on single NRs also yield surprising chiroptical activity at the frequency of the longitudinal mode of NRs. Numerical simulations reveal that the origin of this chiroptical band is the cross talk between the longitudinal and the transverse plasmon modes, which makes both of them coupled with the NP excitonic state. The chiral SP NR-NP assemblies combine the optical properties of excitons and plasmons that are essential for chiral sensing, chiroptical memory, and chiral catalysis.
Related JoVE Video
Covalent attachment and growth of nanocrystalline films of photocatalytic TiOF2.
Nanoscale
PUBLISHED: 11-04-2014
Show Abstract
Hide Abstract
This manuscript describes a synthesis of nanocrystalline TiOF2 film. The nanocrystalline TiOF2 becomes chemically attached to the surface of the glass slide. These films are robust and can be recycled as photocatalysts for the degradation of organic dyes and solvents. These films also have significant antibacterial properties upon irradiation.
Related JoVE Video
Hierarchically Porous MnO2 Microspheres Doped with Homogeneously Distributed Fe3O4 Nanoparticles for Supercapacitors.
ACS Appl Mater Interfaces
PUBLISHED: 10-06-2014
Show Abstract
Hide Abstract
Hierarchically porous yet densely packed MnO2 microspheres doped with Fe3O4 nanoparticles are synthesized via a one-step and low-cost ultrasound assisted method. The scalable synthesis is based on Fe(2+) and ultrasound assisted nucleation and growth at a constant temperature in a range of 25-70 °C. Single-crystalline Fe3O4 particles of 3-5 nm in diameter are homogeneously distributed throughout the spheres and none are on the surface. A systematic optimization of reaction parameters results in isolated, porous, and uniform Fe3O4-MnO2 composite spheres. The spheres' average diameter is dependent on the temperature, and thus is controllable in a range of 0.7-1.28 ?m. The involved growth mechanism is discussed. The specific capacitance is optimized at an Fe/Mn atomic ratio of r = 0.075 to be 448 F/g at a scan rate of 5 mV/s, which is nearly 1.5 times that of the extremely high reported value for MnO2 nanostructures (309 F/g). Especially, such a structure allows significantly improved stability at high charging rates. The composite has a capacitance of 367.4 F/g at a high scan rate of 100 mV/s, which is 82% of that at 5 mV/s. Also, it has an excellent cycling performance with a capacitance retention of 76% after 5000 charge/discharge cycles at 5 A/g.
Related JoVE Video
Increased drought tolerance through the suppression of ESKMO1 gene and overexpression of CBF-related genes in Arabidopsis.
PLoS ONE
PUBLISHED: 09-03-2014
Show Abstract
Hide Abstract
Improved drought tolerance is always a highly desired trait for agricultural plants. Significantly increased drought tolerance in Arabidopsis thaliana (Columbia-0) has been achieved in our work through the suppression of ESKMO1 (ESK1) gene expression with small-interfering RNA (siRNA) and overexpression of CBF genes with constitutive gene expression. ESK1 has been identified as a gene linked to normal development of the plant vascular system, which is assumed directly related to plant drought response. By using siRNA that specifically targets ESK1, the gene expression has been reduced and drought tolerance of the plant has been enhanced dramatically in the work. However, the plant response to external abscisic acid application has not been changed. ICE1, CBF1, and CBF3 are genes involved in a well-characterized plant stress response pathway, overexpression of them in the plant has demonstrated capable to increase drought tolerance. By overexpression of these genes combining together with suppression of ESK1 gene, the significant increase of plant drought tolerance has been achieved in comparison to single gene manipulation, although the effect is not in an additive way. Accompanying the increase of drought tolerance via suppression of ESK1 gene expression, the negative effect has been observed in seeds yield of transgenic plants in normal watering conditions comparing with wide type plant.
Related JoVE Video
[The clinical analysis for the whole-spine magnetic resonance imaging of axial spondyloarthritis].
Zhonghua Nei Ke Za Zhi
PUBLISHED: 08-23-2014
Show Abstract
Hide Abstract
To investigate spinemagnetic resonance imaging(MRI) findings in patients with axial spondyloarthritis (SpA) and to analyze the correlation between imaging and clinical manifestation.
Related JoVE Video
Origination of asexual plantlets in three species of Crassulaceae.
Protoplasma
PUBLISHED: 08-20-2014
Show Abstract
Hide Abstract
During asexual plant reproduction, cells from different organs can be reprogrammed to produce new individuals, a process that requires the coordination of cell cycle reactivation with the acquisition of other cellular morphological characteristics. However, the factors that influence the variety of asexual reproduction have not yet been determined. Here, we report on plantlet formation in Kalanchoe daigremontiana, Graptopetalum paraguayense, and Crassula portulacea (Crassulaceae) and analyse the effect of initiating cells on asexual reproduction in these three species. Additionally, the roles of WUSCHEL (WUS) and CUP-SHAPED COTYLEDON 1 (CUC1) in the asexual reproduction of these species were analysed through qRT-PCR. Our results indicated that pre-existing stem cell-like cells at the sites of asexual reproduction were responsible for the formation of plantlets. These cells were arrested in different phases of the cell cycle and showed different cell morphological characteristics and cell counts. The accumulation of auxin and cytokinin at the sites of asexual plantlet formation indicated their important functions, particularly for cell cycle reactivation. These differences may influence the pattern and complexity of asexual reproduction in these Crassulaceae species. Additionally, the dynamic expression levels of CUC1 and WUS may indicate that CUC1 functions in the formation of callus and shoot meristems; whereas, WUS was only associated with shoot induction.
Related JoVE Video
DNA binding and condensation properties of the herpes simplex virus type 1 triplex protein VP19C.
PLoS ONE
PUBLISHED: 08-14-2014
Show Abstract
Hide Abstract
Herpesvirus capsids are regular icosahedrons with a diameter of a 125 nm and are made up of 162 capsomeres arranged on a T = 16 lattice. The capsomeres (VP5) interact with the triplex structure, which is a unique structural feature of herpesvirus capsid shells. The triplex is a heterotrimeric complex; one molecule of VP19C and two of VP23 form a three-pronged structure that acts to stabilize the capsid shell through interactions with adjacent capsomeres. VP19C interacts with VP23 and with the major capsid protein VP5 and is required for the nuclear localization of VP23. Mutation of VP19C results in the abrogation of capsid shell synthesis. Analysis of the sequence of VP19C showed the N-terminus of VP19C is very basic and glycine rich. It was hypothesized that this domain could potentially bind to DNA. In this study an electrophoretic mobility shift assay (EMSA) and a DNA condensation assay were performed to demonstrate that VP19C can bind DNA. Purified VP19C was able to bind to both a DNA fragment of HSV-1 origin as well as a bacterial plasmid sequence indicating that this activity is non-specific. Ultra-structural imaging of the nucleo-protein complexes revealed that VP19C condensed the DNA and forms toroidal DNA structures. Both the DNA binding and condensing properties of VP19C were mapped to the N-terminal 72 amino acids of the protein. Mutational studies revealed that the positively charged arginine residues in this N-terminal domain are required for this binding. This DNA binding activity, which resides in a non-conserved region of the protein could be required for stabilization of HSV-1 DNA association in the capsid shell.
Related JoVE Video
Hierarchical core-shell structure of ZnO nanorod@NiO/MoO? composite nanosheet arrays for high-performance supercapacitors.
ACS Appl Mater Interfaces
PUBLISHED: 08-14-2014
Show Abstract
Hide Abstract
A hierarchical core-shell structure of ZnO nanorod@NiO/MoO2 composite nanosheet arrays on nickel foam substrate for high-performance supercapacitors was constructed by a two-step solution-based method involving two hydrothermal processes followed by a calcination treatment. Compared to one composed of pure NiO/MoO2 composite nanosheets, the hierarchical core-shell structure electrode displays better pseudocapacitive behaviors in 2 M KOH, including high areal specific capacitance values of 1.18 F cm(-2) at 5 mA cm(-2) and 0.6 F cm(-2) at 30 mA cm(-2) as well as relatively good rate capability at high current densities. Furthermore, it also shows remarkable cycle stability, remaining at 91.7% of the initial value even after 4000 cycles at a current density of 10 mA cm(-2). The enhanced pseudocapacitive behaviors are mainly due to the unique hierarchical core-shell structure and the synergistic effect of combining ZnO nanorod arrays and NiO/MoO2 composite nanosheets. This novel hierarchical core-shell structure shows promise for use in next-generation supercapacitors.
Related JoVE Video
Regulation of the P2X7R by microRNA-216b in human breast cancer.
Biochem. Biophys. Res. Commun.
PUBLISHED: 07-21-2014
Show Abstract
Hide Abstract
Breast cancer is the most common cancer in women around the world. However, the molecular mechanisms underlying breast cancer pathogenesis are only partially understood. Here, in this study, we found that P2X7R was up-regulated and miR-216b was down-regulated in breast cancer cell lines and tissues. Using bioinformatic analysis and 3'UTR luciferase reporter assay, we determined P2X7R can be directly targeted by miR-216b, which can down-regulate endogenous P2X7R mRNA and protein levels. Ectopic expression of miR-216b mimics leads to inhibited cell growth and apoptosis, while blocking expression of the miR-216b results in increased cell proliferation. Furthermore, our findings demonstrate that knockdown of P2X7R promotes apoptosis in breast cancer cells through down-regulating Bcl-2 and increasing the cleavage caspase-3 protein level. Finally, we confirmed that down-regulation of miR-216b in breast cancer is inversely associated with P2X7R expression level. Together, these findings establish miR-216b as a novel regulator of P2X7R and a potential therapeutic target for breast cancer.
Related JoVE Video
Initiator-chain transfer agent combo in the RAFT polymerization of styrene.
Chem. Commun. (Camb.)
PUBLISHED: 07-15-2014
Show Abstract
Hide Abstract
The combo agent with roles of initiator and chain transfer agent was demonstrated in RAFT polymerization of styrene. Polymers with defined structures at both ? and ? ends were obtained, which was verified by the successful synthesis of seven-block segments of PS and PMA by sequential addition of monomers in one pot.
Related JoVE Video
Systematic identification of transcriptional and post-transcriptional regulations in human respiratory epithelial cells during influenza A virus infection.
BMC Bioinformatics
PUBLISHED: 06-26-2014
Show Abstract
Hide Abstract
Respiratory epithelial cells are the primary target of influenza virus infection in human. However, the molecular mechanisms of airway epithelial cell responses to viral infection are not fully understood. Revealing genome-wide transcriptional and post-transcriptional regulatory relationships can further advance our understanding of this problem, which motivates the development of novel and more efficient computational methods to simultaneously infer the transcriptional and post-transcriptional regulatory networks.
Related JoVE Video
Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage: results of a randomized clinical trial in China.
Cancer Prev Res (Phila)
PUBLISHED: 06-09-2014
Show Abstract
Hide Abstract
Broccoli sprouts are a convenient and rich source of the glucosinolate, glucoraphanin, which can generate the chemopreventive agent, sulforaphane, an inducer of glutathione S-transferases (GST) and other cytoprotective enzymes. A broccoli sprout-derived beverage providing daily doses of 600 ?mol glucoraphanin and 40 ?mol sulforaphane was evaluated for magnitude and duration of pharmacodynamic action in a 12-week randomized clinical trial. Two hundred and ninety-one study participants were recruited from the rural He-He Township, Qidong, in the Yangtze River delta region of China, an area characterized by exposures to substantial levels of airborne pollutants. Exposure to air pollution has been associated with lung cancer and cardiopulmonary diseases. Urinary excretion of the mercapturic acids of the pollutants, benzene, acrolein, and crotonaldehyde, were measured before and during the intervention using liquid chromatography tandem mass spectrometry. Rapid and sustained, statistically significant (P ? 0.01) increases in the levels of excretion of the glutathione-derived conjugates of benzene (61%), acrolein (23%), but not crotonaldehyde, were found in those receiving broccoli sprout beverage compared with placebo. Excretion of the benzene-derived mercapturic acid was higher in participants who were GSTT1-positive than in the null genotype, irrespective of study arm assignment. Measures of sulforaphane metabolites in urine indicated that bioavailability did not decline over the 12-week daily dosing period. Thus, intervention with broccoli sprouts enhances the detoxication of some airborne pollutants and may provide a frugal means to attenuate their associated long-term health risks.
Related JoVE Video
Identification and characterization of a Macrobrachium nipponense ferritin subunit regulated by iron ion and pathogen challenge.
Fish Shellfish Immunol.
PUBLISHED: 06-02-2014
Show Abstract
Hide Abstract
Ferritin, a major iron storage protein in most living organisms, plays a crucial role in iron metabolism. In this study, the ferritin subunit MnFer was identified in the oriental river prawn (Macrobrachium nipponense) and functionally characterized. The full-length cDNA of MnFer is 999 bp in size with a 122-bp 5'-untranslated region (UTR), a 364-bp 3'-UTR and a 513-bp open reading frame that encodes a protein possessing 171 amino acids and a deduced molecular weight of 19.40 kDa. Prawn ferritin transcripts are expressed in muscle, heart, hepatopancreas, gill, hemocytes, ovary and testis. Quantitative real-time PCR revealed that the abundance of ferritin transcript was highest in the hepatopancreas followed by muscle. Ferritin transcript expression in muscle increased six-fold 3 h after the injection of iron. In the gill, a four-fold increase in ferritin transcript expression was detected 3 h post-injection; the expression remained elevated for 48 h. Heart ferritin mRNA expression increased up to seven-fold at 24 h post-injection. No significant difference was found in the hepatopancreas. The iron binding capacity of recombinant ferritin protein was also demonstrated in this study. In hemocyte experiments, the transcriptional expression of MnFer showed the strongest response to Aeromonas hydrophila. As a whole, our study suggested that the ferritin from M. nipponense may play critical roles in cellular and organismic iron homeostasis along with in innate immune defense.
Related JoVE Video
Comprehensive Identification of Host Modulators of HIV-1 Replication using Multiple Orthologous RNAi Reagents.
Cell Rep
PUBLISHED: 05-30-2014
Show Abstract
Hide Abstract
RNAi screens have implicated hundreds of host proteins as HIV-1 dependency factors (HDFs). While informative, these early studies overlap poorly due to false positives and false negatives. To ameliorate these issues, we combined information from the existing HDF screens together with new screens performed with multiple orthologous RNAi reagents (MORR). In addition to being traditionally validated, the MORR screens and the historical HDF screens were quantitatively integrated by the adaptation of an established analysis program, RIGER, for the collective interpretation of each gene's phenotypic significance. False positives were addressed by the removal of poorly expressed candidates through gene expression filtering, as well as with GESS, which identifies off-target effects. This workflow produced a quantitatively integrated network of genes that modulate HIV-1 replication. We further investigated the roles of GOLGI49, SEC13, and COG in HIV-1 replication. Collectively, the MORR-RIGER method minimized the caveats of RNAi screening and improved our understanding of HIV-1-host cell interactions.
Related JoVE Video
Increasing incidence of hemorrhagic fever with renal syndrome could be associated with livestock husbandry in Changchun, northeastern China.
BMC Infect. Dis.
PUBLISHED: 05-29-2014
Show Abstract
Hide Abstract
Since the end of the 1990s, the incidence of hemorrhagic fever with renal syndrome (HFRS) has been increasing dramatically in Changchun, northeastern China. However, it is unknown which, and how, underlying risk factors have been involved in the reemergence of the disease.
Related JoVE Video
Female breast cancer survival in Qidong, China, 1972-2011: a population-based study.
BMC Cancer
PUBLISHED: 04-28-2014
Show Abstract
Hide Abstract
Based on data from the population-based Qidong Cancer Registry, we report a survival analysis for female breast cancer patients diagnosed during 1972-2011 in order to assess the long-term trends for the prognosis of this cancer.
Related JoVE Video
Colouration mechanism of underglaze copper-red decoration porcelain (AD 13th-14th century), China.
J Synchrotron Radiat
PUBLISHED: 04-25-2014
Show Abstract
Hide Abstract
Underglaze copper-red decoration, i.e. the copper colourant used to paint diversified patterns on the surface of a body and then covered by transparent glaze and fired at high temperature in a reductive firing environment, is famous all over the world. However, the red colouration mechanism generated by underglaze copper remains unclear. In particular, the fact that the edges of the red patterns are orange has been ignored in previous research. Here, non-destructive analysis has been carried out on a precious fragment of early underglaze red porcelain using synchrotron radiation X-ray fluorescence, X-ray absorption near-edge spectroscopy (XANES) and reflection spectrometry techniques. The results suggest that the copper content in the red region is higher than that in the orange region, and other colour generation elements do not have obvious content difference, indicating that the colour generation effect of the underglaze red product is related to the copper content. XANES analysis shows that the valence states of copper in the red and orange regions are similar and metal copper contributes to their hues. The results of reflection spectrometry demonstrate that tiny orange hues could be attributed to the Mie scatting effect. Therefore, light-scattering effects should be considered when researching the colouration mechanism of underglaze red.
Related JoVE Video
Total parathyroidectomy with trace amounts of parathyroid tissue autotransplantation as the treatment of choice for secondary hyperparathyroidism: a single-center experience.
BMC Surg
PUBLISHED: 04-25-2014
Show Abstract
Hide Abstract
The aim of the study was to evaluate total parathyroidectomy with trace amounts of parathyroid tissue (30 mg) as a surgical option in secondary hyperparathyroidism (sHPT) treatment.
Related JoVE Video
Feasibility and potential benefits of defining the internal gross tumor volume of hepatocellular carcinoma using contrast-enhanced 4D CT images obtained by deformable registration.
Radiat Oncol
PUBLISHED: 04-21-2014
Show Abstract
Hide Abstract
ObjectiveTo study the feasibility and the potential benefits of defining the internal gross tumor volume (IGTV) of hepatocellular carcinoma (HCC) using contrast-enhanced 4D CT images obtained by combining arterial-phase (AP) contrast-enhanced (CE) 3D CT and non-contrast-enhanced (NCE) 4D CT images using deformable registration (DR).MethodsTen HCC patients who had received radiotherapy beforehand were selected for this study. The following CT simulation images were acquired sequentially: NCE 4D CT in free breathing, NCE 3D CT and APCE 3D CT in end-expiration breath holding. All 4D CT images were sorted into ten phases according to breath cycle (CT00¿~¿CT90). Gross tumor volumes (GTVs) were contoured on all CT images and the IGTV-1 was obtained by merging the GTVs in each phase of 4D CT images. The GTV on the APCE 3D CT image was deformably registered to each 4D CT phase image according to liver shape using RayStationTM 3.99.0.7 version treatment planning system. The IGTV-DR was obtained by merging the GTVs after DR on the 4D CT images. Volume differences among the GTVs and between the IGTV-1 and the IGTV-DR were compared.ResultsThe edge of most lesions could be definitively identified using APCE 3D CT images compared to NCE 4D and 3D CT images. The GTV volume on APCE 3D CT images increased by an average of 34.79% (P¿<¿0.05). There was no significant difference among the GTV volumes obtained using NCE 4D and 3D CT images (P¿>¿0.05). The GTV volumes after DR on 4D CT different phase images increased by an average of 36.29% (P¿<¿0.05) as was observed using the APCE 3D CT image (P¿>¿0.05). Lastly, the volume of IGTV-DR increased by an average of 19.91% compared to that of IGTV-1 (P¿<¿0.05).ConclusionNCE 4D CT imaging alone has the potential risk of missing a partial volume of the HCC. The combination of APCE 3D CT and NCE 4D CT images using the DR technique improved the accuracy of the definition of the IGTV in HCC.
Related JoVE Video
Fluorescence resonance energy transfer based immunosensing of human IgG by using quantum dot/GIgG-gold nanoparticles/IgG conjugation.
J Nanosci Nanotechnol
PUBLISHED: 04-18-2014
Show Abstract
Hide Abstract
A novel immunosensor of human immune globulin (IgG) was fabricated based on the fluorescence transfer between luminescent semiconductor quantum dots (QDs) and gold nanoparticles (AuNPs). AuNPs and CdSe/ZnS QDs were respectively labeled with immune reaction pair:IgG and goat anti-human immunoglobulin (GIgG), by optimizing the conditions including pH value and protein amount. In the assembled QD-GIgG-IgG-AuNP fluorescence resonance energy transfer (FRET) immunocomplex system, the presence of AuNP-IgG directly reduced the fluorescence intensity of the GIgG conjugated QDs. As a result, the concentration of AuNP-IgG had a linear relationship with the fluorescence decrease in a range of 0-1.57 microg/mL. Furthermore, the mechanism of the QDs' fluorescence decay has also been discussed and attributed to the light-induced photobleaching. This novel sensing method achieves quantitative detection of trace proteins, suggesting the potential of biomolecule-AuNPs conjugation based analytical methods in further application.
Related JoVE Video
Construction of breast cancer gene regulatory networks and drug target optimization.
Arch. Gynecol. Obstet.
PUBLISHED: 04-17-2014
Show Abstract
Hide Abstract
The purpose of this study was to construct the breast cancer gene regulatory networks through the high-throughput techniques and optimize the drug target genes of breast cancer using bioinformatics analysis, and thus accelerate the process of drug development and improve the cure rate of breast cancer.
Related JoVE Video
Random forests to predict rectal toxicity following prostate cancer radiation therapy.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 04-14-2014
Show Abstract
Hide Abstract
To propose a random forest normal tissue complication probability (RF-NTCP) model to predict late rectal toxicity following prostate cancer radiation therapy, and to compare its performance to that of classic NTCP models.
Related JoVE Video
Shape-morphing nanocomposite origami.
Langmuir
PUBLISHED: 04-01-2014
Show Abstract
Hide Abstract
Nature provides a vast array of solid materials that repeatedly and reversibly transform in shape in response to environmental variations. This property is essential, for example, for new energy-saving technologies, efficient collection of solar radiation, and thermal management. Here we report a similar shape-morphing mechanism using differential swelling of hydrophilic polyelectrolyte multilayer inkjets deposited on an LBL carbon nanotube (CNT) composite. The out-of-plane deflection can be precisely controlled, as predicted by theoretical analysis. We also demonstrate a controlled and stimuli-responsive twisting motion on a spiral-shaped LBL nanocomposite. By mimicking the motions achieved in nature, this method offers new opportunities for the design and fabrication of functional stimuli-responsive shape-morphing nanoscale and microscale structures for a variety of applications.
Related JoVE Video
Biomarker progressions explain higher variability in stage-specific cognitive decline than baseline values in Alzheimer disease.
Alzheimers Dement
PUBLISHED: 03-22-2014
Show Abstract
Hide Abstract
It is unknown which commonly used Alzheimer disease (AD) biomarker values-baseline or progression-best predict longitudinal cognitive decline.
Related JoVE Video
Controlled growth of semiconductor nanofilms within TiO? nanotubes for nanofilm sensitized solar cells.
Chem. Commun. (Camb.)
PUBLISHED: 03-20-2014
Show Abstract
Hide Abstract
Anodized TiO2 nanotubes were decorated by II-VI semiconductor nanofilms via atomic layer deposition (ALD) and further employed as photoanodes of semiconductor nanofilm sensitized solar cells (NFSCs) exhibiting superior photovoltaic performance.
Related JoVE Video
Human coronary plaque wall thickness correlated positively with flow shear stress and negatively with plaque wall stress: an IVUS-based fluid-structure interaction multi-patient study.
Biomed Eng Online
PUBLISHED: 03-07-2014
Show Abstract
Hide Abstract
Atherosclerotic plaque progression and rupture are believed to be associated with mechanical stress conditions. In this paper, patient-specific in vivo intravascular ultrasound (IVUS) coronary plaque image data were used to construct computational models with fluid-structure interaction (FSI) and cyclic bending to investigate correlations between plaque wall thickness and both flow shear stress and plaque wall stress conditions.
Related JoVE Video
Effects of di-(2-ethylhexyl) phthalate on the hypothalamus-pituitary-ovarian axis in adult female rats.
Reprod. Toxicol.
PUBLISHED: 03-06-2014
Show Abstract
Hide Abstract
Di-(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is widely present in the environment and some products with phthalate plasticizer. It has become a serious problem in recent years. The effect of DEHP on female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on hypothalamus-pituitary-ovarian axis in adult female rats. Compared with control rats, the DEHP-treated rats showed: (1) lower body weight; (2) lower organ coefficient of ovary; (3) higher GnRH level in the hypothalamus; (4) higher mRNA and protein levels of GnRHR in the pituitary; and (5) lower serum sex hormone levels. Our data reveal that DEHP exposure may lead to the disruption of estrogen biosynthesis pathways in female rats and imbalance of hypothalamus-pituitary-ovarian axis. DEHP may impose negative influence on the development and function of the reproductive system in female rats.
Related JoVE Video
Long-term outcome of sensorineural hearing loss in nasopharyngeal carcinoma patients: comparison between treatment with radiotherapy alone and chemoradiotherapy.
Cell Biochem. Biophys.
PUBLISHED: 02-11-2014
Show Abstract
Hide Abstract
The purpose of this study is to assess the long-term effect of sensorineural hearing loss (SNHL) resulted from radiotherapy (RT) alone versus chemoradiotherapy in nasopharyngeal carcinoma patients (NPC). Seventy-two patients initially diagnosed with NPC were enrolled from Shandong Tumor Hospital between March 2003 and May 2007. They were assigned into two groups: RT alone and chemoradiotherapy according to the different treatment regimens. Intensity-modulated radiation therapy was applied for both groups, concurrent and adjuvant cisplatin were administered for chemoradiotherapy group additionally. Hearing threshold test was performed at various time periods after completion of RT. Mean radiation dose to the cochlea in each ear was calculated to determine the correlation between cochlear dose and SNHL. We found that the hearing loss is more severe in the chemoradiotherapy group compared with RT group, from completion of RT up to the 5 years of follow-up period. This is especially obvious in the high frequency range. Hearing level is seriously damaged when cochlea dose exceeds 46 GY. We concluded that concurrent/adjuvant chemotherapy plus RT aggravates SNHL in NPC patients than RT alone and thus inner ear tissue tolerance should be redefined in those patients.
Related JoVE Video
Identification of differentially expressed genes in hepatopancreas of oriental river prawn, Macrobrachium nipponense exposed to environmental hypoxia.
Gene
PUBLISHED: 02-06-2014
Show Abstract
Hide Abstract
Hypoxia represents a major physiological challenge for prawn culture, and the hepatopancreas plays an important role in these processes. Here, we applied high-throughput sequencing technology to detect the gene expression profile of the hepatopancreas in Macrobrachium nipponense in response to hypoxia for 3 h and hypoxia for 24 h. Gene expression profiling identified 1925 genes that were significantly up- or down-regulated by dissolved oxygen availability. Functional categorization of the differentially expressed genes revealed that oxygen transport, electron transport chain, reactive oxygen species generation/scavenging, and immune response were the differentially regulated processes occurring during environmental hypoxia. Finally, quantitative real-time polymerase chain reaction using six genes independently verified the tag-mapped results. Immunohistochemistry analysis revealed, for the first time, hemocyanin protein expression as significant hypoxia-specific signature in prawns,which opens the way for in depth molecular studies of hypoxia exposure. The analysis of changes in hepatic gene expression in oriental river prawn provides a preliminary basis for a better understanding of the molecular response to hypoxia exposures.
Related JoVE Video
Hollow cocoon-like hematite mesoparticles of nanoparticle aggregates: structural evolution and superior performances in lithium ion batteries.
ACS Appl Mater Interfaces
PUBLISHED: 02-06-2014
Show Abstract
Hide Abstract
We report the facile, fast, and template-free preparation of hollow ?-Fe2O3 with unique cocoon-like structure by a one-pot hydrothermal method without any surfactants in a short reaction time of 3 h only. In contrast, typical hydrothermal methods to prepare inorganic hollow structures require 24 h or a few days. Templates and/or surfactants are typically used. The hollow ?-Fe2O3 nanococoon was thoroughly characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Ex situ analysis of a series of samples prepared at different reaction times clearly revealed the structural evolution and possible formation mechanism. Superior electrochemical performance in terms of cyclability, specific capacity, and high rate was achieved, which could be attributed to its unique hollow cocoon-like structure. Structural stability was revealed by analyzing the samples after 120 charge-discharge cycles. The unusual structural stability of the hollow ?-Fe2O3 nanococoons after 120 cycles, which is rarely observed for transition metal oxides of particle aggregates, will guarantee further research investigation. Experimental evidence further demonstrated that hollow nanococoons exceed solid nanococoons in reversible lithium-ion storage.
Related JoVE Video
Molecular cloning, tissue distribution and expression analysis of a manganese superoxide dismutase in blunt snout bream Megalobrama amblycephala.
Fish Shellfish Immunol.
PUBLISHED: 01-25-2014
Show Abstract
Hide Abstract
The full-length mitochondrial manganese superoxide dismutase cDNA of blunt snout bream Megalobrama amblycephala (denoted as MamMnSOD) was identified in liver using homology cloning and rapid amplification of cDNA ends. The full-length cDNA of MamMnSOD consisted of 986 bp, with an open reading frame encoding 224 amino acids, a 58-bp 5' untranslated region and a 256-bp 3' untranslated region. The deduced amino acid sequences of MamMnSOD showed high sequence homology to mitochondrial MnSODs from crustaceans. Several motifs, including three mitochondrial MnSOD signatures, amino acid residues responsible for coordinating the manganese, and the putative active center, were almost completely conserved in the deduced amino acid sequences of MamMnSOD. The mRNA expression of MamMnSOD in the tissues of heart, liver, spleen, kidney, muscle, intestine, and gill was examined by quantitative real-time PCR; the highest expression was in the liver. Transcription of MamMnSOD was kinetically modulated in response to nitrite stress in liver and gill tissues. The purified recombinant MamMnSOD showed potent antioxidant activity. Polyclonal antibodies generated from the recombinant product of MamMnSOD were used to specifically identify the native protein in liver of M. amblycephala. Collectively, the findings of this study strongly suggested that MamMnSOD combats oxidative stress and cellular damage induced by nitrite, by detoxifying harmful reactive oxygen species in M. amblycephala.
Related JoVE Video
Image-based modeling for better understanding and assessment of atherosclerotic plaque progression and vulnerability: data, modeling, validation, uncertainty and predictions.
J Biomech
PUBLISHED: 01-13-2014
Show Abstract
Hide Abstract
Medical imaging and image-based modeling have made considerable progress in recent years in identifying atherosclerotic plaque morphological and mechanical risk factors which may be used in developing improved patient screening strategies. However, a clear understanding is needed about what we have achieved and what is really needed to translate research to actual clinical practices and bring benefits to public health. Lack of in vivo data and clinical events to serve as gold standard to validate model predictions is a severe limitation. While this perspective paper provides a review of the key steps and findings of our group in image-based models for human carotid and coronary plaques and a limited review of related work by other groups, we also focus on grand challenges and uncertainties facing the researchers in the field to develop more accurate and predictive patient screening tools.
Related JoVE Video
Gene expression profiling reveals large regulatory switches between succeeding stipe stages in Volvariella volvacea.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
The edible mushroom Volvariella volvacea is an important crop in Southeast Asia and is predominantly harvested in the egg stage. One of the main factors that negatively affect its yield and value is the rapid transition from the egg to the elongation stage, which has a decreased commodity value and shelf life. To improve our understanding of the changes during stipe development and the transition from egg to elongation stage in particular, we analyzed gene transcription in stipe tissue of V. volvacea using 3'-tag based digital expression profiling. Stipe development turned out to be fairly complex with high numbers of expressed genes, and regulation of stage differences is mediated mainly by changes in expression levels of genes, rather than on/off modulation. Most explicit is the strong up-regulation of cell division from button to egg, and the very strong down-regulation hereof from egg to elongation, that continues in the maturation stage. Button and egg share cell division as means of growth, followed by a major developmental shift towards rapid stipe elongation based on cell extension as demonstrated by inactivation of cell division throughout elongation and maturation. Examination of regulatory genes up-regulated from egg to elongation identified three potential high upstream regulators for this switch. The new insights in stipe dynamics, together with a series of new target genes, will provide a sound base for further studies on the developmental mechanisms of mushroom stipes and the switch from egg to elongation in V. volvacea in particular.
Related JoVE Video
Discovery of protein interactions using parallel analysis of translated ORFs (PLATO).
Nat Protoc
PUBLISHED: 12-12-2013
Show Abstract
Hide Abstract
Parallel analysis of translated open reading frames (ORFs) (PLATO) can be used for the unbiased discovery of interactions between full-length proteins encoded by a library of prey ORFs and surface-immobilized bait antibodies, polypeptides or small-molecular-weight compounds. PLATO uses ribosome display (RD) to link ORF-derived mRNA molecules to the proteins they encode, and recovered mRNA from affinity enrichment is subjected to analysis using massively parallel DNA sequencing. Compared with alternative in vitro methods, PLATO provides several advantages including library size and cost. A unique advantage of PLATO is that an alternative reverse transcription-quantitative PCR (RT-qPCR) protocol can be used to test binding of specific, individual proteins. To illustrate a typical experimental workflow, we demonstrate PLATO for the identification of the immune target of serum antibodies from patients with inclusion body myositis (IBM). Beginning with an ORFeome library in an RD vector, the protocol can produce samples for deep sequencing or RT-qPCR within 4 d.
Related JoVE Video
[The expression and significance of unfolded protein response-related gene in synovial fluid macrophages in patients with spondyloarthritis and other arthritis].
Zhonghua Nei Ke Za Zhi
PUBLISHED: 11-26-2013
Show Abstract
Hide Abstract
OBJECTIVE To investigate whether unfolded protein response (UPR) plays a role in the pathogenesis of spondyloarthritis (SpA), and to assess UPR-related gene expression in SpA and other arthritis patients.
Related JoVE Video
Cohort Effects in Age-Associated Cognitive Trajectories.
J. Gerontol. A Biol. Sci. Med. Sci.
PUBLISHED: 11-23-2013
Show Abstract
Hide Abstract
The age-specific prevalence and incidence of dementia and cognitive impairment in the United States have either remained stable or even slightly declined during the 1980s-1990s. A suggested but untested reason for this improvement in cognitive function over time is higher educational attainment among more recent cohorts.
Related JoVE Video
The histamine H4 receptor mediates inflammation and Th17 responses in preclinical models of arthritis.
Ann. Rheum. Dis.
PUBLISHED: 10-14-2013
Show Abstract
Hide Abstract
The histamine H4 receptor (H4R) has been shown to drive inflammatory responses in models of asthma, colitis and dermatitis, and in these models it appears to affect both innate and adaptive immune responses. In this study, we used both H4R-deficient mice and a specific H4R antagonist, JNJ 28307474, to investigate the involvement of the H4R in mouse arthritis models.
Related JoVE Video
Enhanced expression of EsWAX1 improves drought tolerance with increased accumulation of cuticular wax and ascorbic acid in transgenic Arabidopsis.
Plant Physiol. Biochem.
PUBLISHED: 09-16-2013
Show Abstract
Hide Abstract
Drought can activate several stress responses in plants, such as stomatal closure, accumulation of cuticular wax and ascorbic acid (AsA), which have been correlated with improvement of drought tolerance. In this study, a novel MYB gene, designed as EsWAX1, was isolated and characterized from Eutrema salsugineum. EsWAX1 contained a full-length open reading frame (ORF) of 1068 bp, which encoding 355 amino acids. Transcript levels of EsWAX1 were quickly inducible by drought stress and ABA treatment, indicating that EsWAX1 may act as a positive regulator in response to drought stress. Ectopic expression of EsWAX1 increased accumulation of cuticular wax via modulating the expression of several wax-related genes, such as CER1, KCS2 and KCR1. Scanning electron microscopy further revealed higher densities of wax crystalline structures on the adaxial surfaces of leaves in transgenic Arabidopsis plants. In addition, the expression of several AsA biosynthetic genes (VTC1, GLDH and MIOX4) was significantly up-regulated in EsWAX1-overexpressing lines and these transgenic plants have approximately 23-27% more total AsA content than WT plants. However, the high-level expression of EsWAX1 severely disrupted plant normal growth and development. To reduce negative effects of EsWAX1 over-expression on plant growth, we generated transgenic Arabidopsis plants expressing EsWAX1 driven by the stress-inducible RD29A promoter. Our data indicated the RD29A::EsWAX1 transgenic plants had greater tolerance to drought stress than wild-type plants. Taken together, the EsWAX1 gene is a potential regulator that may be utilized to improve plant drought tolerance by genetic manipulation.
Related JoVE Video
[Inhibitory effects of human umbilical cord-derived mesenchymal stem cells on proliferation of peripheral blood mononuclear cells from spondyloarthritis patients].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 09-14-2013
Show Abstract
Hide Abstract
To explore the inhibitory effects of human umbilical cord-derived mesenchymal stem cells (hUCMSC) on the proliferation of peripheral blood mononuclear cells (PBMC) from spondyloarthritis (SpA) patients.
Related JoVE Video
Investigation on XRCC1 genetic polymorphism and its relationship with breast cancer risk factors in Chinese women.
Med. Oncol.
PUBLISHED: 08-19-2013
Show Abstract
Hide Abstract
Breast cancer (BC) remains one of the most common cancers among women. The human X-ray repair cross-complementing 1 (XRCC1) gene plays key roles in base excision repair, and genetic polymorphisms of XRCC1 may be associated with the susceptibility to BC. This study aimed to evaluate the relationship between the XRCC1 genetic polymorphisms and BC susceptibility. A total of 354 BC patients and 366 cancer-free controls were enrolled in this study. Data about the risk factors of BC were collected using questionnaires. The XRCC1 genetic polymorphism was determined using created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. No significant differences in the allelic and genotypic frequencies of c.1804C>A genetic polymorphism were detected between cases and controls. The distributions of BC patients risk factors were not significantly different between CC, CA, and AA genotypes. These findings indicate that the c.1804C>A genetic polymorphism of XRCC1 gene is not significantly associated with BC susceptibility in the Chinese women.
Related JoVE Video
Identification and mRNA expression of antioxidant enzyme genes associated with the oxidative stress response in the Wuchang bream (Megalobrama amblycephala Yih) in response to acute nitrite exposure.
Comp. Biochem. Physiol. C Toxicol. Pharmacol.
PUBLISHED: 08-03-2013
Show Abstract
Hide Abstract
Aquatic organisms possess cellular detoxification systems to deal with pollutants. To explore the influence of reactive oxygen species (ROS) generated in response to nitrite on oxidative stress defenses and the antioxidant system in Megalobrama amblycephala, the full length cDNA sequences were determined for three antioxidant-related genes, namely catalase (MaCAT), selenium-dependent glutathione peroxidase (MaGPx1) and Cu/Zn superoxide dismutase (MaCu/Zn-SOD). Encoded polypeptides that exhibited high identity and similarity with corresponding proteins in other fish species. Expression levels of these antioxidant genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) technique. MaCAT, MaGPx1 and MaCu/Zn-SOD expression was greatest in the liver and qRT-PCR was used to assess expression of these genes in juvenile fish during 72h of exposure to 15mg/L nitrite. Prolonged nitrite exposure resulted in the formation of excess ROS that caused oxidative damage to lipids and proteins and reduced the activities of antioxidant enzymes. Fish exposed to nitrite also showed liver damage. This study provides transcriptional data for MaCAT, MaGPx1 and MaCu/Zn-SOD that suggest expression is related positively with oxidative stress induced by nitrite exposure, indicating that imbalance between ROS and antioxidant defenses is one mechanism underlying nitrite toxicity in M. amblycephala.
Related JoVE Video
X-ray crystal structure of phosphodiesterase 2 in complex with a highly selective, nanomolar inhibitor reveals a binding-induced pocket important for selectivity.
J. Am. Chem. Soc.
PUBLISHED: 08-02-2013
Show Abstract
Hide Abstract
To better understand the structural origins of inhibitor selectivity of human phosphodieasterase families (PDEs 1-11), here we report the X-ray crystal structure of PDE2 in complex with a highly selective, nanomolar inhibitor (BAY60-7550) at 1.9 Å resolution, and the structure of apo PDE2 at 2.0 Å resolution. The crystal structures reveal that the inhibitor binds to the PDE2 active site by using not only the conserved glutamine-switch mechanism for substrate binding, but also a binding-induced, hydrophobic pocket that was not reported previously. In silico affinity profiling by molecular docking indicates that the inhibitor binding to this pocket contributes significantly to the binding affinity and thereby improves the inhibitor selectivity for PDE2. Our results highlight a structure-based design strategy that exploits the potential binding-induced pockets to achieve higher selectivity in the PDE inhibitor development.
Related JoVE Video
[Relationship between sleep quality and nocturnal pain in ankylosing spondylitis].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 07-27-2013
Show Abstract
Hide Abstract
To evaluate the relationship between sleep quality and nocturnal pain in ankylosing spondylitis (AS) patients.
Related JoVE Video
[Impact of duloxetine on depression and anxiety in patients with ankylosing spondylitis: a case-control study].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 07-27-2013
Show Abstract
Hide Abstract
To evaluate the effects of duloxetine on depression, anxiety, pain, disease activity and function in patients with ankylosing spondylitis (AS).
Related JoVE Video
Nitrite-induced hepatotoxicity in Bluntsnout bream (Megalobrama amblycephala): The mechanistic insight from transcriptome to physiology analysis.
Environ. Toxicol. Pharmacol.
PUBLISHED: 07-26-2013
Show Abstract
Hide Abstract
Previous studies have investigated the physiological responses to acute nitrite exposure in fish; however, little information is available for the underlying molecular mechanisms of nitrite toxicity in aquatic ecosystems. In an effort to understand the underlying mechanisms of nitrite tolerance and to illuminate global gene expression patterns modulated by nitrite toxicity, we sampled livers from juvenile Megalobrama amblycephala exposed in 0.1, 15 and 30mgL(-1) nitrite and performed short read (100bp) next generation RNA sequencing (RNA-seq). The RNA-seq reads from all the exposures (?24million reads) were assembled into unigenes datasets according to an available reference transcriptome. Using reads from each nitrite concentration, we performed RNA-seq based gene expression analysis that identified a total of 357 differentially expressed genes. The differentially expressed genes were related to oxidative stress, apoptotic pathway, oxygen transport, immune responses and the metabolism of proteins and fats. Quantitative real-time polymerase chain reaction using six genes independently verified the RNA-seq results, the present study suggests several new candidate genes commonly regulated in liver of M. amblycephala. In addition to liver histology examinations, this study provides important mechanistic insights into nitrite-induced liver toxicity in a whole-animal physiology context, which will help in understanding the syndromes caused by nitrite poisoning.
Related JoVE Video
C60/Bi2TiO4F2 heterojunction photocatalysts with enhanced visible-light activity for environmental remediation.
ACS Appl Mater Interfaces
PUBLISHED: 07-17-2013
Show Abstract
Hide Abstract
Fullerene (C60)-enhanced Bi2TiO4F2 hierarchical microspheres were prepared by a facile solvothermal method. Compared to the pure Bi2TiO4F2 photocatalyst, the C60/Bi2TiO4F2 samples exhibit much stronger photocatalytic performance for degrading Rhodamine B (RhB) and Eosin Y (EY) under visible light irradiation. Such greatly enhanced photocatalytic activity may be ascribed to strong combination and heterojunctions between C60 and Bi2TiO4F2, favorable for charge separation and light adsorption. Loading C60 on Bi2TiO4F2 results in a new photocatalytic mechanism (based on photo-generated hvb(+) and ·O2(-) radicals) different from that of pure Bi2TiO4F2.
Related JoVE Video
Thymosin ?4 Attenuates Early Diabetic Nephropathy in a Mouse Model of Type 2 Diabetes Mellitus.
Am J Ther
PUBLISHED: 07-13-2013
Show Abstract
Hide Abstract
The chronic inflammatory processes and endothelial dysfunction play important roles in the development of diabetic nephropathy (DN); the study aims to evaluate the effect of thymosin ?4 (T?4), which has apparent anti-inflammatory properties and is capable of improving endothelial dysfunction, in early DN in a mouse model of type 2 diabetes mellitus. KK Cg-Ay/J (KK) mice, aged 12-14 weeks, were divided into the following groups: KK control group that was treated with saline; KK T?4 group that was treated with T?4 100 ng/10 g of intraperitoneal injection once a day. Nondiabetic age-matched C57BL mice were used as additional normal control and also treated with T?4. The urinary albumin/creatinine ratio (ACR), plasma urea nitrogen and creatinine, body weight, fasting blood glucose and 2-hour blood glucose during oral glucose tolerance testing, blood hemoglobin A1c, cholesterol, and triglyceride were determined at baseline time and 12 weeks after T?4 treatment for phenotypic characterizations. The KK T?4 group had reduced the mean fasting blood glucose, 2-hour blood glucose during oral glucose tolerance testing, hemoglobin A1c, and triglyceride levels compared with that in the KK control group (P < 0.05). T?4 treatment markedly reduced ACR (KK T?4 = 328.54 ± 46.14 mg/g vs. KK control = 540.34 ± 50.31 mg/g, P < 0.05). T?4 also significantly ameliorated renal pathological changes of KK T?4 mice as compared with that in KK control mice. T?4 treatment did not affect glucose homeostasis and urinary ACR and glomeruli of C57BL mice. These data in a novel mouse model of DN suggest that T?4 may ameliorate renal damage. This peptide may be a novel potential alternative agent for treatment of DN.
Related JoVE Video
B7-H4 expression is associated with cancer progression and predicts patient survival in human thyroid cancer.
Asian Pac. J. Cancer Prev.
PUBLISHED: 06-28-2013
Show Abstract
Hide Abstract
This study aimed to investigate the expression of B7-H4 in human thyroid cancer and determine any association with patient clinicopathological parameters and survival.
Related JoVE Video
Functional promoter -31G/C variant of Survivin gene predict prostate cancer susceptibility among Chinese: a case control study.
BMC Cancer
PUBLISHED: 06-24-2013
Show Abstract
Hide Abstract
Abnormal expression of Baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5, also called as survivin), a novel member of the inhibitor of apoptosis protein (IAP) family, has implications in many types of cancer and is considered as a new therapeutic target. We suppose that genetic variant rs9904341 in the 5 UTR region of survivin gene may be associated with the development and progression of prostate cancer (PCa) in Chinese population.
Related JoVE Video
Stretchable nanoparticle conductors with self-organized conductive pathways.
Nature
PUBLISHED: 06-13-2013
Show Abstract
Hide Abstract
Research in stretchable conductors is fuelled by diverse technological needs. Flexible electronics, neuroprosthetic and cardiostimulating implants, soft robotics and other curvilinear systems require materials with high conductivity over a tensile strain of 100 per cent (refs 1-3). Furthermore, implantable devices or stretchable displays need materials with conductivities a thousand times higher while retaining a strain of 100 per cent. However, the molecular mechanisms that operate during material deformation and stiffening make stretchability and conductivity fundamentally difficult properties to combine. The macroscale stretching of solids elongates chemical bonds, leading to the reduced overlap and delocalization of electronic orbitals. This conductivity-stretchability dilemma can be exemplified by liquid metals, in which conduction pathways are retained on large deformation but weak interatomic bonds lead to compromised strength. The best-known stretchable conductors use polymer matrices containing percolated networks of high-aspect-ratio nanometre-scale tubes or nanowires to address this dilemma to some extent. Further improvements have been achieved by using fillers (the conductive component) with increased aspect ratio, of all-metallic composition, or with specific alignment (the way the fillers are arranged in the matrix). However, the synthesis and separation of high-aspect-ratio fillers is challenging, stiffness increases with the volume content of metallic filler, and anisotropy increases with alignment. Pre-strained substrates, buckled microwires and three-dimensional microfluidic polymer networks have also been explored. Here we demonstrate stretchable conductors of polyurethane containing spherical nanoparticles deposited by either layer-by-layer assembly or vacuum-assisted flocculation. High conductivity and stretchability were observed in both composites despite the minimal aspect ratio of the nanoparticles. These materials also demonstrate the electronic tunability of mechanical properties, which arise from the dynamic self-organization of the nanoparticles under stress. A modified percolation theory incorporating the self-assembly behaviour of nanoparticles gave an excellent match with the experimental data.
Related JoVE Video
Characterization of Streptococcus suis serotype 2 isolates from China.
Vet. Microbiol.
PUBLISHED: 06-04-2013
Show Abstract
Hide Abstract
Streptococcus suis (S. suis) is a major pathogen in the pig industry and an important zoonotic agent that causes severe invasive diseases in humans. Previous studies based on multilocus sequence typing (MLST) and the associations between sequence types and genotypes or virulence suggested that North American S. suis serotype 2 isolates are composed of multiple populations. This study investigated the population structure of S. suis serotype 2 isolates in China. We constructed a phylogenetic tree for S. suis serotype 2 isolates based on 16S rRNA gene typing and MLST, studied associations between clades and sources, analyzed the genotype distributions of virulence markers [muramidase-released protein (MRP), extracellular protein factor (EF), and suilysin (SLY)] in different clades, computed the selection pressures for these virulence marker genes, and verified the associations between clades and virulence. There were two primary clades (populations) in the phylogenetic tree of S. suis serotype 2. The two populations were associated with different tissue tropisms. The genotypic distributions and selection pressures of MRP, EF, and SLY were different between the two populations, which suggested that they had different evolutionary paths. The two populations also displayed differences in virulence in experimentally infected mice. The results provide insights into the population structure of S. suis serotype 2 isolates in China and suggest that S. suis serotype 2 clade 1 is an overlooked population that deserves further evaluation.
Related JoVE Video
Skeletal myoblast transplantation on gene expression profiles of insulin signaling pathway and mitochondrial biogenesis and function in skeletal muscle.
Diabetes Res. Clin. Pract.
PUBLISHED: 05-28-2013
Show Abstract
Hide Abstract
The study aims to investigate the gene expression profiling of insulin signaling pathway and mitochondrial biogenesis and function in the skeletal muscle of KK mice.
Related JoVE Video
Carbon and graphene double protection strategy to improve the SnO(x) electrode performance anodes for lithium-ion batteries.
Nanoscale
PUBLISHED: 05-15-2013
Show Abstract
Hide Abstract
SnOx is a promising high-capacity anode material for lithium-ion batteries (LIBs), but it usually exhibits poor cycling stability because of its huge volume variation during the lithium uptake and release process. In this paper, SnOx carbon nanofibers (SnOx@CNFs) are firstly obtained in the form of a nonwoven mat by electrospinning followed by calcination in a 0.02 Mpa environment at 500 °C. Then we use a simple mixing method for the synthesis of SnOx@CNF@graphene (SnOx@C@G) nanocomposite. By this technique, the SnOx@CNFs can be homogeneously deposited in graphene nanosheets (GNSs). The highly scattered SnOx@C@G composite exhibits enhanced electrochemical performance as anode material for LIBs. The double protection strategy to improve the electrode performance through producing SnOx@C@G composites is versatile. In addition, the double protection strategy can be extended to the fabrication of various types of composites between metal oxides and graphene nanomaterials, possessing promising applications in catalysis, sensing, supercapacitors and fuel cells.
Related JoVE Video
Thermodynamic and structural insights into nanocomposites engineering by comparing two materials assembly techniques for graphene.
ACS Nano
PUBLISHED: 05-15-2013
Show Abstract
Hide Abstract
Materials assembled by layer-by-layer (LBL) assembly and vacuum-assisted flocculation (VAF) have similarities, but a systematic study of their comparative advantages and disadvantages is missing. Such a study is needed from both practical and fundamental perspectives aiming at a better understanding of structure-property relationships of nanocomposites and purposeful engineering of materials with unique properties. Layered composites from polyvinyl alcohol (PVA) and reduced graphene (RG) are made by both techniques. We comparatively evaluate their structure, mechanical, and electrical properties. LBL and VAF composites demonstrate clear differences at atomic and nanoscale structural levels but reveal similarities in micrometer and submicrometer organization. Epitaxial crystallization and suppression of phase transition temperatures are more pronounced for PVA in LBL than for VAF composites. Mechanical properties are virtually identical for both assemblies at high RG contents. We conclude that mechanical properties in layered RG assemblies are largely determined by the thermodynamic state of PVA at the polymer/nanosheet interface rather than the nanometer scale differences in RG packing. High and nearly identical values of toughness for LBL and VAF composites reaching 6.1 MJ/m(3) observed for thermodynamically optimal composition confirm this conclusion. Their toughness is the highest among all other layered assemblies from RG, cellulose, clay, etc. Electrical conductivity, however, is more than 10× higher for LBL than for VAF composites for the same RG contents. Electrical properties are largely determined by the tunneling barrier between RG sheets and therefore strongly dependent on atomic/nanoscale organization. These findings open the door for application-oriented methods of materials engineering using both types of layered assemblies.
Related JoVE Video
[Inhibitory effect of human umbilical cord-derived mesenchymal stem cells on interleukin-17 production in peripheral blood T cells from spondyloarthritis patients].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 05-01-2013
Show Abstract
Hide Abstract
In this study, the inhibitory effect of human umbilical cord-derived mesenchymal stem cells (hUCMSC) on interleukin-17 (IL-17) production in peripheral blood T cells from patients with spondyloarthritis (SpA) were investigated, in order to explore the therapeutic potential of hUCMSC in the SpA. Peripheral blood mononuclear cells (PBMNC) were isolated from patients with SpA (n = 12) and healthy subjects (n = 6). PBMNC were cultured in vitro with hUCMSC or alone. The expression of IL-17 in CD4(+) T cells or ?/? T cells were determined in each subject group by flow cytometry. IL-17 concentrations in PBMNC culture supernatants were measured by ELISA. The results indicated that the proportion of IL-17-producing CD4(+) T cells and IL-17-producing ?/? T cells of SpA patients were 4.5 folds and 5 folds of healthy controls [CD3(+)CD4(+)IL-17(+) cells (3.42 ± 0.82)% vs (0.75 ± 0.25)%, P < 0.01; CD3(+)??TCR(+)IL-17(+) cells (0.30 ± 0.10)% vs (0.06 ± 0.02)%, P < 0.01]. After co-culture of PBMNC in patients with hUCMSC, the increased proportions of CD3(+)CD4(+)IL-17(+) cells and CD3(+)??TCR(+)IL-17(+) cells in SpA patients were inhibited significantly by hUCMSC [CD3(+)CD4(+)IL-17(+) cells (3.42 ± 0.82)% vs (1.81 ± 0.59)% (P < 0.01); CD3(+)??TCR(+)IL-17(+) cells (0.30 ± 0.10)% vs (0.16 ± 0.06)% (P < 0.01]. In response to phytohemagglutinin (PHA, 1 µg/ml), PBMNC from SpA patients secreted more IL-17 than that from healthy control [(573.95 ± 171.68) pg/ml vs (115.53 ± 40.41) pg/ml (P < 0.01)]. In the presence of hUCMSC, PBMNC of SpA patients produced less amount of IL-17 [(573.95 ± 171.68) pg/ml vs (443.20 ± 147.94) pg/ml, (P < 0.01)]. It is concluded that the IL-17 production in peripheral blood T cells from SpA patients can be inhibited by hUCMSC, which have therapeutic potential for SpA.
Related JoVE Video
Time domain mapping of spin torque oscillator effective energy.
Phys. Rev. Lett.
PUBLISHED: 04-24-2013
Show Abstract
Hide Abstract
Stochastic dynamics of spin torque oscillators can be described in terms of magnetization drift and diffusion over a current-dependent effective energy surface given by the Fokker-Planck equation. Here we present a method that directly probes this effective energy surface via time-resolved measurements of the microwave voltage generated by a spin torque oscillator. We show that the effective energy approach provides a simple recipe for predicting spectral linewidths and line shapes near the generation threshold. Our time domain technique also accurately measures the fieldlike component of spin torque in a wide range of the voltage bias values.
Related JoVE Video
[Evaluating the effect of preventive medicine for residents living around mosquito breeding water during rest period of malaria].
Zhonghua Yu Fang Yi Xue Za Zhi
PUBLISHED: 04-23-2013
Show Abstract
Hide Abstract
To evaluate the effect of preventive medicine for residents living around mosquito breeding water during rest period of malaria by delimiting a certain range.
Related JoVE Video
Nomograms to predict late urinary toxicity after prostate cancer radiotherapy.
World J Urol
PUBLISHED: 04-14-2013
Show Abstract
Hide Abstract
To analyze late urinary toxicity after prostate cancer radiotherapy (RT): symptom description and identification of patient characteristics or treatment parameters allowing for the generation of nomograms.
Related JoVE Video
Tissue kallikrein is related to the severity of coronary artery disease.
Clin. Chim. Acta
PUBLISHED: 04-13-2013
Show Abstract
Hide Abstract
The impairment of the tissue kallikrein (KLK1)-kinin system (KKS) may result in atheroma development. However, it remains unclear if the KKS correlates with coronary artery disease (CAD).
Related JoVE Video
Application of the revised Tumour Node Metastasis (TNM) staging system of clear cell renal cell carcinoma in eastern China: advantages and limitations.
Asian J. Androl.
PUBLISHED: 04-08-2013
Show Abstract
Hide Abstract
This study was designed to evaluate whether the revised 2010 Tumour Node Metastasis (TNM) staging system could lead to a more accurate prediction of the prognosis of renal cell carcinoma (RCC) patients. A total of 1216 patients who had undergone radical nephrectomy or partial nephrectomy for RCC from 2003 to 2011 were enrolled. All of the patients had pathologically confirmed clear cell RCC (ccRCC). All cases were staged by both the 2002 and 2010 TNM staging systems after pathological review, and survival data were collected. Univariate and multivariate Cox regression models were used to evaluate cancer-specific survival (CSS) and progression-free survival (PFS) after surgery. Continuous variables, such as age and tumour diameter, were calculated as mean values and standard deviations (s.d.) or as median values. Survival was calculated by the Kaplan-Meier method, and the log-rank test assessed differences between groups. Statistically significant differences in CSS and PFS were noted among patients in T3 subgroups using the new 2010 staging system. Therefore, the revised 2010 TNM staging system can lead to a more accurate prediction of the prognosis of ccRCC patients. However, when using the revised 2010 staging system, we found that more than 92% of patients (288/313) with T3 tumours were staged in the T3a subgroup, and their survival data were not significantly different from those of patients with T2b tumours. In addition, T2 subclassification failed to independently predict survival in RCC patients.
Related JoVE Video
Solitary infantile myofibromatosis in the bones of the upper extremities: Two rare cases and a review of the literature.
Oncol Lett
PUBLISHED: 03-24-2013
Show Abstract
Hide Abstract
Infantile myofibromatosis (IM) is the most common fibrous tumor of infancy. IM may arise in a solitary or multicentric form, with similar histopathological findings, however, the clinical features and prognoses may vary. The solitary form tends to occur predominantly in males and is typically observed in the dermis, subcutis or deep soft tissues. The reported incidence of solitary osseous myofibromatosis is rare. Furthermore, the majority of solitary IM cases of the bone occur in the craniofacial bones, while the occurrence of solitary osseous myofibromatosis on the extremities has been sporadically reported. The present study describes two cases of solitary IM involving the bones of the upper extremities in females who were over two years old. The cases show unusual symptom presentation and the tumor origin is in a rarely observed location. The study discusses the clinical, radiological and pathological features, in addition to the previously described etiology, prognosis and treatment options for this condition.
Related JoVE Video
Expression of synuclein gamma indicates poor prognosis of triple-negative breast cancer.
Med. Oncol.
PUBLISHED: 03-18-2013
Show Abstract
Hide Abstract
Synuclein gamma (SNCG), previously identified as breast cancer-specific gene 1, is highly expressed in malignant cells but not in normal epithelium. Studies have demonstrated that the expression of SNCG is an independent predictive marker for recurrence and metastasis in breast cancer. Triple-negative breast cancer (TNBC) is characterized by a lack of expression of both the estrogen receptor and progesterone receptor proteins as well as HER-2 and is often associated with particularly poor outcomes, early development of chemotherapy resistance, and ineffectiveness of targeted therapy. This study aimed to reveal whether SNCG-positive TNBC is more likely than SNCG-negative TNBC to have a more aggressive phenotype. One hundred and two TNBC patients were divided into two groups according to the SNCG protein expression. Clinical and biological features of SNCG-positive tumors were compared with SNCG-negative tumors. Association between survival and SNCG expression was analyzed by the Kaplan-Meier method. Hazard ratios and 95 % confidence intervals (CIs) were calculated using Cox regression. And 34.3 % TNBCs showed moderate to strong positive SNCG expression. Patients whose tumors expressed SNCG had significantly shorter disease-free survival (P = 0.013) and a higher probability of death (P = 0.002) when compared with those whose tumors did not express SNCG. The hazard ratio of metastasis or recurrence based on SNCG expression status was 2.800 (95 % CI 1.193-6.574; P = 0. 018). There was no significant correlation between SNCG expression and age, lymph node involvement, and tumor stage histological type, except tumor size which was significantly associated with SNCG expression (P = 0.032, R = 0.212). This study suggests that SNCG expression indicates [Symbol: see text]correlates with?[Symbol: see text] a much poorer prognosis of TNBC. SNCG is expected to be a useful marker for TNBC progression and a potential target for TNBC treatment.
Related JoVE Video
Mass spectrometry based phospholipidomics of mammalian thymus and leukemia patients: implication for function of iNKT cells.
Anal Bioanal Chem
PUBLISHED: 03-15-2013
Show Abstract
Hide Abstract
In previous studies phospholipids have been proved to be involved in biochemical, physiological, and pathological processes. As a special class of phospholipids, peroxisome-derived lipids (PDLs) have been proved to be potential ligands of invariant natural killer T (iNKT) cells in recent studies. Here, on the basis of phospholipidomics, we focused on the relative quantity of PDLs extracted from mammalian thymus or bone marrow using electrospray ionization mass spectrometry (MS). In phospholipid analysis, we identified 12 classes of phospholipids and accounted for their relative quantities by comparing their relative abundances in the MS(1) map. Our results show that PDLs are present in mammalian thymus as well as mouse spleen and liver. Interestingly, the relative quantity of PDLs extracted from human acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) bone marrows is higher than that extracted from bone marrow of healthy donors. Our results may help to explain the close correlation between PDLs and iNKT cell function in thymus, spleen, liver, and especially in leukemia patients. We think that our phospholipidomics work may reveal a function of iNKT cells.
Related JoVE Video
Mesoporous TiN microspheres with hierarchical chambers and enhanced visible light-driven hydrogen evolution.
ChemSusChem
PUBLISHED: 03-11-2013
Show Abstract
Hide Abstract
Mesoporous titanium nitride (TiN) microspheres with tunable chamber structures were synthesized through NH3 nitridation of organotitania obtained via solvothermal alcoholysis. Owing to high content of organic species in organotitania, which stabilized the original structure and also promoted the nitridation at low temperature, TiN duplicated the solid, yolk-shell, and hollow chambers of organotitania in NH3 nitridation and also formed the mesoporous structure after removing organic species. During visible light-induced photocatalytic water splitting, the yolk-shell TiN demonstrated a higher H2 evolution efficiency than the solid, hollow, and crushed TiN; the yolk-shell TiN obtained through N2 nitridation; and other semiconductor photocatalysts reported so far without the aid of noble metals. This could be attributed mainly to the narrow energy band gap for absorbing visible light, high surface area, and excellent electrical conductivity, which facilitated light harvesting, reactant adsorption, and photoelectron-hole separation to suppress their recombination. Moreover, it could be easily recycled and thus used repetitively.
Related JoVE Video
Suppression of Grb2 expression improved hepatic steatosis, oxidative stress, and apoptosis induced by palmitic acid in vitro partly through insulin signaling alteration.
In Vitro Cell. Dev. Biol. Anim.
PUBLISHED: 03-11-2013
Show Abstract
Hide Abstract
In this study, we aimed to study the role of growth factor receptor-bound protein 2 (Grb2) in palmitic acid-induced steatosis and other "fatty liver" symptoms in vitro. HepG2 cells, with or without stably suppressed Grb2 expression, were incubated with palmitic acid for 24 h to induce typical clinical "fatty liver" features, including steatosis, impaired glucose metabolism, oxidative stress, and apoptosis. MTT and Oil Red O assays were applied to test cell viability and fat deposition, respectively. Glucose uptake assay was used to evaluate the glucose utilization of cells. Quantitative polymerase chain reaction and Western blot were used to measure expressional changes of key markers of insulin signaling, lipid/glucose metabolism, oxidative stress, and apoptosis. After 24-h palmitic acid induction, increased fat accumulation, reduced glucose uptake, impaired insulin signaling, enhanced oxidative stress, and increased apoptosis were observed in HepG2 cells. Suppression of Grb2 in HepG2 significantly reduced fat accumulation, improved glucose metabolism, ameliorated oxidative stress, and restored the activity of insulin receptor substrate-1/Akt and MEK/ERK pathways. In addition, Grb2 deficiency attenuated hepatic apoptosis shown by reduced activation of caspase-3 and fluorescent staining. Modulation of Bcl-2 and Bak1 also contributed to reduced apoptosis. In conclusion, suppression of Grb2 expression in HepG2 cells improved hepatic steatosis, glucose metabolism, oxidative stress, and apoptosis induced by palmitic acid incubation partly though modulating the insulin signaling pathway.
Related JoVE Video
A high-efficiency strategy for synthesizing cyclic polymers of methacryates in one pot.
Macromol Rapid Commun
PUBLISHED: 02-22-2013
Show Abstract
Hide Abstract
An unprecedented strategy for the high-efficiency preparation of the cyclic polymers is developed. In this strategy, the atom transfer radical polymerization, the substitution of chain-end halide by azide group and Cu-catalyzed alkyne-azide cyclization, i.e., the frequently used three separated steps for the preparation of cyclic polymers, are integrated into a one-pot reaction by the introduction of a "regulator". The kernel of this novel strategy is the utilization of the different rates between the competitive ATRP propagation and SN 2 substitution of a tertiary-carbon halogen and secondary-carbon halogen. 0.55 g (yield = 59%) cyclic poly(methyl methacrylate) is obtained from 3.0 mL reaction solution. This work proposed a high-efficiency and bright promising strategy for the preparation of cyclic polymer, which would evoke more research interests on cyclic polymer.
Related JoVE Video
Protoplasts: a useful research system for plant cell biology, especially dedifferentiation.
Protoplasma
PUBLISHED: 01-21-2013
Show Abstract
Hide Abstract
As protoplasts have the characteristics of no cell walls, rapid population growth, and synchronicity, they are useful tools for research in many fields, especially cellular biology (Table 1). This article is an overview that focuses on the application of protoplasts to investigate the mechanisms of dedifferentiation, including changes in hormone signals, epigenetic changes, and organelle distribution during the dedifferentiation process. The article also emphasizes the wide range of uses for protoplasts in studying protein positions and signaling during different stresses. The examples provided help to show that protoplast systems, for example the mesophyll protoplast system of Arabidopsis, represent promising tools for studying developmental biology. Meanwhile, specific analysis of protoplast, which comes from different tissue, has specific advantages and limitations (Table 2), and it can provide recommendations to use this system.
Related JoVE Video
The short chain cell-permeable ceramide (C6) restores cell apoptosis and perifosine sensitivity in cultured glioblastoma cells.
Mol. Biol. Rep.
PUBLISHED: 01-17-2013
Show Abstract
Hide Abstract
Primary glioblastoma multiforme is the most malignant form of astrocytic tumor with an average survival of approximately 12-14 months. The combination of novel Akt inhibitors with anti-cancer therapeutics has achieved improved anti-tumor efficiency. In the current study, we examined the synergistic anti-cancer ability of Akt inhibitor perifosine in combination with short-chain ceramide (C6) against glioblastoma cells (U87MG and U251MG), and studied the underlying mechanisms. We found that perifosine, which blocked Akt/mammalian target of rapamycin activation, only induced moderate cell death and few cell apoptosis in cultured glioblastoma cells. On the other hand, perifosine administration induced significant protective autophagy, which inhibited cell apoptosis induction. Inhibition of autophagy by 3-methyaldenine or by autophagy-related gene-5 RNA interference significantly enhanced perifosine-induced apoptosis and cytotoxicity. We found that the short chain cell-permeable ceramide (C6) significantly enhanced cytotoxic effects of perifosine in cultured glioblastoma cells. For mechanism study, we observed that ceramide (C6) inhibited autophagy induction to restore cell apoptosis and perifosine sensitivity. In conclusion, our study suggests that autophagy inhibition by ceramide (C6) restores perifosine-induced apoptosis and cytotoxicity in glioblastoma cells.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.