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.
MiCroKiTS 4.0: a database of midbody, centrosome, kinetochore, telomere and spindle.
Nucleic Acids Res.
PUBLISHED: 11-14-2014
Show Abstract
Hide Abstract
We reported an updated database of MiCroKiTS 4.0 (http://microkit.biocuckoo.org) for proteins temporally and spatially localized in distinct subcellular positions including midbody, centrosome, kinetochore, telomere and mitotic spindle during cell division/mitosis. The database was updated from our previously developed database of MiCroKit 3.0, which contained 1489 proteins mostly forming super-complexes at midbody, centrosome and kinetochore from seven eukaryotes. Since the telomere and spindle apparatus are critical for cell division, the proteins localized at the two positions were also integrated. From the scientific literature, we curated 1872 experimentally identified proteins which at least locate in one of the five positions from eight species. Then the ortholog detection was performed to identify potential MiCroKiTS proteins from 144 eukaryotic organisms, which contains 66, 45 and 33 species of animals, fungi and plants, respectively. In total, 87 983 unique proteins with corresponding localization information were integrated into the database. The primary references of experimentally identified localizations were provided and the fluorescence microscope figures for the localizations of human proteins were shown. The orthologous relations between predicted and experimental localizations were also present. Taken together, we anticipate the database can serve as a useful resource for further analyzing the molecular mechanisms during cell division.
Related JoVE Video
CD8 T Cells Are Involved in Skeletal Muscle Regeneration through Facilitating MCP-1 Secretion and Gr1high Macrophage Infiltration.
J. Immunol.
PUBLISHED: 10-22-2014
Show Abstract
Hide Abstract
Inflammatory microenvironments play a key role in skeletal muscle regeneration. The infiltration of CD8 T cells into injured muscle has been reported. However, the role of CD8 T cells during skeletal muscle regeneration remains unclear. In this study, we used cardiotoxin-induced mouse skeletal muscle injury/regeneration model to investigate the role of CD8 T cells. Muscle regeneration was impaired and matrix deposit was increased in CD8?-deficient mice compared with wild-type (WT) mice whose CD8 T cells were infiltrated into damaged muscle after cardiotoxin injection. Adoptive transfer of CD8 T cells to CD8?-deficient mice improved muscle regeneration and inhibited matrix remodeling. Compared with WT mice, CD8? deficiency limited the recruitment of Gr1(high) macrophages (MPs) into muscle, resulting in the reduction of satellite cell number. The expression of MCP-1 (MCP-1/CCL2), which regulates the migration of Gr1(high) MPs, was reduced in CD8?-deficient mice compared with WT mice. Coculture CD8 T cells with MPs promoted MCP-1 secretion. The i.m. injection of MCP-1 markedly promoted the recruitment of Gr1(high) MPs and improved muscle regeneration in CD8?-deficient mice. We conclude that CD8 T cells are involved in skeletal muscle regeneration by regulating the secretion of MCP-1 to recruit Gr1(high) MPs, which facilitate myoblast proliferation.
Related JoVE Video
Retraction: Methanol-induced conformation transition of gland fibroin monitored by FTIR spectroscopy and terahertz spectroscopy.
Analyst
PUBLISHED: 10-08-2014
Show Abstract
Hide Abstract
Retraction of 'Methanol-induced conformation transition of gland fibroin monitored by FTIR spectroscopy and terahertz spectroscopy' by Chao Yan et al., Analyst, 2014, 139, 1967-1972.
Related JoVE Video
An Open-Source System for In Planta Gene Stacking by Bxb1 and Cre Recombinases.
Mol Plant
PUBLISHED: 10-03-2014
Show Abstract
Hide Abstract
The rapid development of crops with multiple transgenic traits arouses the need for an efficient system for creating stacked cultivars. Most major crops rely on classical breeding to introgress the transgene from a laboratory variety to the numerous cultivars adapted to different growing regions. Even with vegetative propagated crops, genetic crosses are conducted during varietal improvement prior to vegetative cloning. The probability to assort the 'x' number of transgenic loci into a single genome may seem trivial, (¼) (x) for a diploid species, but given the 'y' number of other nontransgenic traits that breeders also need to assemble into the same genome, the (¼) (x+y) probability for a 'breeding stack' could quickly make the line conversion process unmanageable. Adding new transgenes onto existing transgenic varieties without creating a new segregating locus would require site-specific integration of new DNA at the existing transgenic locus. Here, we tested a recombinase-mediated gene-stacking scheme in tobacco. Sequential site-specific integration was mediated by the mycobacteriophage Bxb1 integrase-catalyzed recombination between attP and attB sites. Transgenic DNA no longer needed after integration was excised by Cre recombinase-mediated recombination of lox sites. Site-specific integration occurred in ~10% of the integration events, with half of those events usable as substrates for a next round of gene stacking. Among the site-specific integrants, however, a third experienced gene silencing. Overall, precise structure and reproducible expression of the sequentially added triple traits were obtained at an overall rate of ~3% of the transformed clones-a workable frequency for the development of commercial cultivars. Moreover, since neither the Bxb1-att nor the Cre-lox system is under patent, there is freedom to operate.
Related JoVE Video
Catabolism of (2E)-4-Hydroxy-2-nonenal via ?- and ?-1-Oxidation Stimulated by Ketogenic Diet.
J. Biol. Chem.
PUBLISHED: 10-01-2014
Show Abstract
Hide Abstract
Oxidative stress triggers the peroxidation of ?-6-polyunsaturated fatty acids to reactive lipid fragments, including (2E)-4-hydroxy-2-nonenal (HNE). We previously reported two parallel catabolic pathways of HNE. In this study, we report a novel metabolite that accumulates in rat liver perfused with HNE or 4-hydroxynonanoic acid (HNA), identified as 3-(5-oxotetrahydro-2-furanyl)propanoyl-CoA. In experiments using a combination of isotopic analysis and metabolomics studies, three catabolic pathways of HNE were delineated following HNE conversion to HNA. (i) HNA is ?-hydroxylated to 4,9-dihydroxynonanoic acid, which is subsequently oxidized to 4-hydroxynonanedioic acid. This is followed by the degradation of 4-hydroxynonanedioic acid via ?-oxidation originating from C-9 of HNA breaking down to 4-hydroxynonanedioyl-CoA, 4-hydroxyheptanedioyl-CoA, or its lactone, 2-hydroxyglutaryl-CoA, and 2-ketoglutaric acid entering the citric acid cycle. (ii) ?-1-hydroxylation of HNA leads to 4,8-dihydroxynonanoic acid (4,8-DHNA), which is subsequently catabolized via two parallel pathways we previously reported. In catabolic pathway A, 4,8-DHNA is catabolized to 4-phospho-8-hydroxynonanoyl-CoA, 3,8-dihydroxynonanoyl-CoA, 6-hydroxyheptanoyl-CoA, 4-hydroxypentanoyl-CoA, propionyl-CoA, and acetyl-CoA. (iii) The catabolic pathway B of 4,8-DHNA leads to 2,6-dihydroxyheptanoyl-CoA, 5-hydroxyhexanoyl-CoA, 3-hydroxybutyryl-CoA, and acetyl-CoA. Both in vivo and in vitro experiments showed that HNE can be catabolically disposed via ?- and ?-1-oxidation in rat liver and kidney, with little activity in brain and heart. Dietary experiments showed that ?- and ?-1-hydroxylation of HNA in rat liver were dramatically up-regulated by a ketogenic diet, which lowered HNE basal level. HET0016 inhibition and mRNA expression level suggested that the cytochrome P450 4A are main enzymes responsible for the NADPH-dependent ?- and ?-1-hydroxylation of HNA/HNE.
Related JoVE Video
Effect of elevated intraocular pressure on the thickness changes of cat laminar and prelaminar tissue using optical coherence tomography.
Biomed Mater Eng
PUBLISHED: 09-18-2014
Show Abstract
Hide Abstract
The aim of this study was to examine shape the changes of the lamina cribrosa (LC) under different intraocular pressures (IOPs) with different periods. Images of the optic nerve head were obtained using enhanced depth imaging spectral domain optical coherence tomography (EDI SD-OCT). After an initial scan of the IOP at native pressure, subsequent scanning was taken when the IOP values reached 40, 60, 80 and 100 mm Hg. Then scans continued with the IOP maintained at 100 mm Hg for 1 hour, 2 hours, 3 hours and 4 hours. The thicknesses of the LC and prelaminar tissue were measured and the curvature of the LC was calculated. Our study found that as IOP increased, the thicknesses of both LC and prelaminar tissue decreased and the thickness variation of the LC correlated significantly with the increases of IOP when IOP was higher than 60 mm Hg. An exponential function was proposed to express the relationship between IOP and the thickness variations of LC and prelaminar tissue. Creep curves of the LC and prelaminar tissue was also obtained using the Prony model. In conclusion, both the thickness of the prelaminar tissue and LC thinned as the IOP elevated. The thickness of the LC also decreased after 4 hours of constant 100 mm Hg pressure.
Related JoVE Video
Composition-graded nanowire solar cells fabricated in a single process for spectrum-splitting photovoltaic systems.
Nano Lett.
PUBLISHED: 09-10-2014
Show Abstract
Hide Abstract
Nanomaterials such as semiconductor nanowires have unique features that could enable novel optoelectronic applications such as novel solar cells. This paper aims to demonstrate one such recently proposed concept: Monolithically Integrated Laterally Arrayed Multiple Band gap (MILAMB) solar cells for spectrum-splitting photovoltaic systems. Two cells with different band gaps were fabricated simultaneously in the same process on a single substrate using spatially composition-graded CdSSe alloy nanowires grown by the Dual-Gradient Method in a chemical vapor deposition system. CdSSe nanowire ensemble devices tested under 1 sun AM1.5G illumination achieved open-circuit voltages up to 307 and 173 mV and short-circuit current densities as high as 0.091 and 0.974 mA/cm(2) for the CdS- and CdSe-rich cells, respectively. The open-circuit voltages were roughly three times those of similar CdSSe film cells fabricated for comparison due to the superior optical quality of the nanowires. I-V measurements were also performed using optical filters to simulate spectrum-splitting. The open-circuit voltages and fill factors of the CdS-rich subcells were uniformly larger than the corresponding CdSe-rich cells for similar photon flux, as expected. This suggests that if all wires can be contacted, the wide-gap cell is expected to have greater output power than the narrow-gap cell, which is the key to achieving high efficiencies with spectrum-splitting. This paper thus provides the first proof-of-concept demonstration of simultaneous fabrication of MILAMB solar cells. This approach to solar cell fabrication using single-crystal nanowires for spectrum-splitting photovoltaics could provide a future low-cost high-efficiency alternative to the conventional high-cost high-efficiency tandem cells.
Related JoVE Video
Creation of Bt rice expressing a fusion protein of Cry1Ac and Cry1I-like using a green tissue-specific promoter.
J. Econ. Entomol.
PUBLISHED: 09-09-2014
Show Abstract
Hide Abstract
The insecticidal genes from Bacillus thuringiensis Berliner (Bt) have long been successfully used for development of insect-resistant rice. However, commercial planting of Bt rice has been delayed by the concern over food safety, although no scientific evidence is ever found to justify the concern. To address this safety concern, we developed a transgenic insect-resistant rice line using a green tissue promoter to minimize the Bt protein expression in the rice seeds. The Bt protein expressed in the rice was a fusion protein of two different Bt toxins, Cry1Ac and Cry1I-like protein. The fusion of the two toxins may be helpful to delay the development of insect resistance to Bt rice. Laboratory and field bioassays demonstrated that the transgenic rice plants created by this study were highly active against the rice leaf folder Cnaphalocrocis medinalis (Guenée) and the striped stem borer Chilo suppressalis (Walker). Western analysis indicated that the fusion protein was specifically expressed in green tissues but not in seeds. Therefore, the transgenic rice created in this study should be useful to mitigate the food safety concern and to delay the development of insect resistance.
Related JoVE Video
Nanodisco balls: control over surface versus core loading of diagnostically active nanocrystals into polymer nanoparticles.
ACS Nano
PUBLISHED: 09-09-2014
Show Abstract
Hide Abstract
Nanoparticles of complex architectures can have unique properties. Self-assembly of spherical nanocrystals is a high yielding route to such systems. In this study, we report the self-assembly of a polymer and nanocrystals into aggregates, where the location of the nanocrystals can be controlled to be either at the surface or in the core. These nanospheres, when surface decorated with nanocrystals, resemble disco balls, thus the term nanodisco balls. We studied the mechanism of this surface loading phenomenon and found it to be Ca(2+) dependent. We also investigated whether excess phospholipids could prevent nanocrystal adherence. We found surface loading to occur with a variety of nanocrystal types including iron oxide nanoparticles, quantum dots, and nanophosphors, as well as sizes (10-30 nm) and shapes. Additionally, surface loading occurred over a range of polymer molecular weights (?30-3000 kDa) and phospholipid carbon tail length. We also show that nanocrystals remain diagnostically active after loading onto the polymer nanospheres, i.e., providing contrast in the case of magnetic resonance imaging for iron oxide nanoparticles and fluorescence for quantum dots. Last, we demonstrated that a fluorescently labeled protein model drug can be delivered by surface loaded nanospheres. We present a platform for contrast media delivery, with the unusual feature that the payload can be controllably localized to the core or the surface.
Related JoVE Video
Serum Helicobacter pylori CagA antibody may not be used as a tumor marker for diagnosing gastric cancer in east Asian countries.
Tumour Biol.
PUBLISHED: 08-29-2014
Show Abstract
Hide Abstract
Gastric cancer (GC) is a highly malignant cancer with increasing incidence and mortality worldwide. Serum Helicobacter pylori CagA antibody has been widely reported to play an important role in diagnosing GC. However, published data on this subject are inconclusive. Therefore, we performed a meta-analysis to evaluate the sensitivity and specificity of serum H. pylori CagA antibody in the diagnosis of GC. We conducted a comprehensive search to identify eligible related studies, in which the pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curves could be determined. A total of 12 studies including 1,524 cases and 3,324 controls who fulfilled all of the inclusion criteria were included for analysis. The summary estimates for serum H. pylori CagA antibody in the diagnosis of GC in these studies were pooled sensitivity 0.71 (95 % CI 0.69-0.73), specificity 0.40 (95 % CI 0.39-0.42), DOR 2.11 (95 % CI 1.55-2.8), and the area under the curve was 0.636. Our meta-analysis showed that serum H. pylori CagA antibody should not be used for detecting GC.
Related JoVE Video
IL-17A produced by both ?? T and Th17 cells promotes renal fibrosis via RANTES-mediated leukocyte infiltration after renal obstruction.
J. Pathol.
PUBLISHED: 08-26-2014
Show Abstract
Hide Abstract
IL-17A-producing T lymphocytes play a crucial role in inflammatory kidney diseases, but their role in renal fibrosis remains to be explored. Here, we demonstrated that up-regulation of IL-17A was associated with the development of obstructive kidney injury. The primary source of IL-17A production in obstructed kidneys was infiltrating ?? T lymphocytes and CD4(+) T cells. IL-17A-deficient mice were protected from myofibroblast activation and extracellular matrix deposition, leading to reduced kidney fibrosis in response to obstructive injury. Mechanistically, IL-17A deficiency suppressed the expression of the chemokine RANTES in infiltrated CD3(+) T cells and peritubular inflammation following renal obstruction. Administration of RANTES-neutralizing antibody significantly reduced the accumulation of T cells and macrophages, and of collagen deposition in obstructed kidneys. Taken together, our results indicate that IL-17A contributes significantly to the pathogenesis of renal fibrosis by regulating RANTES-mediated inflammatory cell infiltration. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Related JoVE Video
High resolution melting curve analysis as a new tool for rapid identification of canine parvovirus type 2 strains.
Mol. Cell. Probes
PUBLISHED: 08-23-2014
Show Abstract
Hide Abstract
A high resolution melting (HRM) curve method was developed to identify canine parvovirus type 2 (CPV-2) strains by nested PCR. Two sets of primers, CPV-426F/426R and CPV-87R/87F, were designed that amplified a 52 bp and 53 bp product from the viral VP2 capsid gene. The region amplified by CPV-426F/426R included the A4062G and T4064A mutations in CPV-2a, CPV-2b and CPV-2c. The region amplified by CPV-87F/87R included the A3045T mutation in the vaccine strains of CPV-2 and CPV-2a, CPV-2b and CPV-2c. Faecal samples were obtained from 30 dogs that were CPV antigen-positive. The DNA was isolated from the faecal samples and PCR-amplified using the two sets of primers, and genotyped by HRM curve analysis. The PCR-HRM assay was able to distinguish single nucleotide polymorphisms between CPV-2a, CPV-2b and CPV-2c using CPV-426F/426R. CPV-2a was distinguished from CPV-2b and CPV-2c by differences in the melting temperature. CPV-2b and CPV-2c could be distinguished based on the shape of the melting curve after generating heteroduplexes using a CPV-2b reference sample. The vaccine strains of CPV-2 were identified using CPV-87F/87R. Conventional methods for genotyping CPV strains are labor intensive, expensive or time consuming; the present PCR-based HRM assay might be an attractive alternative.
Related JoVE Video
miR-204 functions as a tumor suppressor by regulating SIX1 in NSCLC.
FEBS Lett.
PUBLISHED: 08-23-2014
Show Abstract
Hide Abstract
The involvement of miR-204 in lung cancer development is unclear. In our study, we analyzed the expression of miR-204 in tumor- and adjacent-tissue samples from 141 patients with non-small cell lung cancer (NSCLC). MiR-204 expression was decreased in tumor samples compared with non-cancerous tissue-derived controls. Moreover, miR-204 expression negatively correlated with homeobox protein SIX1 expression, tumor size and metastasis. MiR-204 silencing in miR-204-positive NSCLC cell lines promoted cell invasion and proliferation. Concomitantly, MiR-204 overexpression resulted in reduced cell proliferation and invasion, upregulated E-cadherin and downregulated N-cadherin and Vimentin expression. SIX1 was identified as a potential target of miR-204, and SIX1 silencing partially compromised the invasive and proliferative capacity of miR-204-deficient cells. Thus, miR-204 may be involved in the NSCLC development.
Related JoVE Video
Akt2 is involved in loss of epithelial cells and renal fibrosis following unilateral ureteral obstruction.
PLoS ONE
PUBLISHED: 08-22-2014
Show Abstract
Hide Abstract
Obstructive nephropathy is an aggressive form of chronic kidney disease (CKD), which is characterized by an epithelial-to-mesenchymal transition (EMT) and interstitial fibrosis. However, the molecular mechanisms of EMT and fibrosis are complex and not fully understood. In this study, we investigated the contribution of Akt2 to experimental renal EMT and fibrosis using the well-established model of unilateral ureteral obstruction (UUO). We found that Akt2 and phosphor (p)-Akt protein levels were increased in the obstructed kidneys. UUO induced activation of transforming growth factor-?1 (TGF-?1) signaling. Importantly, knockout of Akt2 suppressed UUO-induced EMT, kidney fibrosis, increased GSK3? activity, and decreased expression of Snail and ?-catenin. Inhibition of GSK3? with LiCl (the inhibitor of GSK3?) increased the expression of Snail and ?-catenin in cultured kidney epithelial cells. Our findings suggest that Akt2 partially contributes to interstitial fibrosis following UUO and that inhibition of this signaling pathway may provide a novel approach of prevent progression of renal fibrosis.
Related JoVE Video
Optimization of key factors affecting hydrogen production from sugarcane bagasse by a thermophilic anaerobic pure culture.
Biotechnol Biofuels
PUBLISHED: 08-20-2014
Show Abstract
Hide Abstract
Hydrogen is regarded as an attractive future energy carrier for its high energy content and zero CO2 emission. Currently, the majority of hydrogen is generated from fossil fuels. However, from an environmental perspective, sustainable hydrogen production from low-cost lignocellulosic biomass should be considered. Thermophilic hydrogen production is attractive, since it can potentially convert a variety of biomass-based substrates into hydrogen at high yields.
Related JoVE Video
The Notch ?-secretase inhibitor ameliorates kidney fibrosis via inhibition of TGF-?/Smad2/3 signaling pathway activation.
Int. J. Biochem. Cell Biol.
PUBLISHED: 08-20-2014
Show Abstract
Hide Abstract
Kidney fibrosis is a common feature of chronic kidney disease (CKD). A recent study suggests that abnormal Notch signaling activation contributes to the development of renal fibrosis. However, the molecular mechanism that regulates this process remains unexplored. Unilateral ureteral obstruction (UUO) or sham-operated C57BL6 mice (aged 10 weeks) were randomly assigned to receive dibenzazepine (DBZ, 250?g/100g/d) or vehicle for 7 days. Histologic examinations were performed on the kidneys using Masson's trichrome staining and immunohistochemistry. Real-time PCR and western blot analysis were used for detection of mRNA expression and protein phosphorylation. The expression of Notch 1, 3, and 4, Notch intracellular domain (NICD), and its target genes Hes1 and HeyL were upregulated in UUO mice, while the increase in NICD protein was significantly attenuated by DBZ. After 7 days, the severity of renal fibrosis and expression of fibrotic markers, including collagen 1?1/3?1, fibronectin, and ?-smooth muscle actin, were markedly increased in UUO compared with sham mice. In contrast, administration of DBZ markedly attenuated these effects. Furthermore, DBZ significantly inhibited UUO-induced expression of transforming growth factor (TGF)-?, phosphorylated Smad 2, and Smad 3. Mechanistically, Notch signaling activation in tubular epithelial cells enhanced fibroblast proliferation and activation in a coculture experiment. Our study provides evidence that Notch signaling is implicated in renal fibrogenesis. The Notch inhibitor DBZ can ameliorate this process via inhibition of the TGF-?/Smad2/3 signaling pathway, and might be a novel drug for preventing chronic kidney disease.
Related JoVE Video
[A comparison of 226 Hz and 1 000 Hz tympanometry in diagnosis of infants otitis media effusion].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 08-19-2014
Show Abstract
Hide Abstract
To provide a clinical reference by comparing the conventional 226 Hz tympanometry with 1000 Hz tympanometry in two groups of young children with otitis media effusion evidenced by CT scan.
Related JoVE Video
Epidemiology and genetic characteristics of pigeon circovirus (PiCV) in eastern China.
Arch. Virol.
PUBLISHED: 08-06-2014
Show Abstract
Hide Abstract
Pigeon circovirus (PiCV) is one of four viruses in the family Circoviridae that affect young pigeons around the world. We collected 158 serum or tissue samples from six poultry farms in eastern China to investigate the prevalence and genetic characteristics of PiCV in Chinese pigeons. We tested for PiCV using a PCR assay and found that PiCV was present in 80.7 % (88/109) of diseased pigeons and 63.3 % (31/49) of healthy pigeons; overall, 75.3 % (119/158) of samples were PiCV positive. One PiCV-positive sample from each poultry farm was randomly chosen for amplification of the complete PiCV genome by inverse primer PCR (IP-PCR). The six genomic PiCV strains were designated as AHBZ (KJ704801), HBLF-E2 (KJ704802), JSJN (KJ704803), NJPK-21 (KJ704804), SDDZ (KJ704805) and SHWH-AB4 (KJ704806). We compared these new PiCV genomes to six publicly available PiCV genomes and found that the Rep and Cap genes had sequence identity ranging from 93.8 % to 100 % and 79.1 % to 100 %, respectively. In a phylogenetic analysis, PiCV and eight other members of the genus Circovirus were sister to chicken anemia virus (CAV), the only member of genus Gyrovirus. The results of this study provide evidence that PiCV is present in Chinese pigeons at a high rate and that PiCV is a viral lineage that is distinct from CAV.
Related JoVE Video
Optimization of ionic liquid based simultaneous ultrasonic- and microwave-assisted extraction of rutin and quercetin from leaves of velvetleaf (Abutilon theophrasti) by response surface methodology.
ScientificWorldJournal
PUBLISHED: 07-03-2014
Show Abstract
Hide Abstract
An ionic liquids based simultaneous ultrasonic and microwave assisted extraction (ILs-UMAE) method has been proposed for the extraction of rutin (RU), quercetin (QU), from velvetleaf leaves. The influential parameters of the ILs-UMAE were optimized by the single factor and the central composite design (CCD) experiments. A 2.00 M 1-butyl-3-methylimidazolium bromide ([C4mim]Br) was used as the experimental ionic liquid, extraction temperature 60°C, extraction time 12 min, liquid-solid ratio 32 mL/g, microwave power of 534 W, and a fixed ultrasonic power of 50 W. Compared to conventional heating reflux extraction (HRE), the RU and QU extraction yields obtained by ILs-UMAE were, respectively, 5.49 mg/g and 0.27 mg/g, which increased, respectively, 2.01-fold and 2.34-fold with the recoveries that were in the range of 97.62-102.36% for RU and 97.33-102.21% for QU with RSDs lower than 3.2% under the optimized UMAE conditions. In addition, the shorter extraction time was used in ILs-UMAE, compared with HRE. Therefore, ILs-UMAE was a rapid and an efficient method for the extraction of RU and QU from the leaves of velvetleaf.
Related JoVE Video
Ephedrine QoS: an antidote to slow, congested, bufferless NoCs.
ScientificWorldJournal
PUBLISHED: 06-24-2014
Show Abstract
Hide Abstract
Datacenters consolidate diverse applications to improve utilization. However when multiple applications are colocated on such platforms, contention for shared resources like networks-on-chip (NoCs) can degrade the performance of latency-critical online services (high-priority applications). Recently proposed bufferless NoCs (Nychis et al.) have the advantages of requiring less area and power, but they pose challenges in quality-of-service (QoS) support, which usually relies on buffer-based virtual channels (VCs). We propose QBLESS, a QoS-aware bufferless NoC scheme for datacenters. QBLESS consists of two components: a routing mechanism (QBLESS-R) that can substantially reduce flit deflection for high-priority applications and a congestion-control mechanism (QBLESS-CC) that guarantees performance for high-priority applications and improves overall system throughput. We use trace-driven simulation to model a 64-core system, finding that, when compared to BLESS, a previous state-of-the-art bufferless NoC design, QBLESS, improves performance of high-priority applications by an average of 33.2% and reduces network-hops by an average of 42.8%.
Related JoVE Video
Hierarchical Zn/Ni-MOF-2 Nanosheet-Assembled Hollow Nanocubes for Multicomponent Catalytic Reactions.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 06-23-2014
Show Abstract
Hide Abstract
Metal-organic frameworks (MOFs) are potentially useful molecular materials that can exhibit structure flexibilities induced by some external stimuli. Such structure transformations can furnish MOFs with improved properties. The shape-controlled growth of MOFs combined with crystal-structure transformation is rarely achieved. Herein, we demonstrate the synthesis of hierarchical Zn/Ni-MOF-2 nanosheet-assembled hollow nanocubes (NAHNs) by a facile surfactant-free solvothermal approach. The unique nanostructures undergo crystal-structure transformation from Zn/Ni-MOF-5 nanocubes to Zn/Ni-MOF-2 nanosheets, which is analogous to the dissolution and recrystallization of inorganic nanocrystals. The present synthetic strategy to fabricate isostructural MOFs with hierarchical, hollow, and bimetallic nanostructures is expected to expand the diversity and range of potential applications of MOFs.
Related JoVE Video
Carbamodithioate-Based Dual Functional Fluorescent Probe for Hg(2+) and S (2-)
J Fluoresc
PUBLISHED: 06-11-2014
Show Abstract
Hide Abstract
Carbamodithioate-based compound T1 was designed and synthesized as a dual-functional probe for Hg(2+) ions and S(2-) anions. The underlying signaling mechanism was intramolecular charge transfer (ICT). It could serve as a direct probe towards Hg(2+) ions through "on-off" fluorescence changes and an indirect probe towards S(2-) anions through "on-off-on" fluorescence changes.
Related JoVE Video
Preoperative imatinib facilitates complete resection of locally advanced primary GIST by a less invasive procedure.
Med. Oncol.
PUBLISHED: 06-10-2014
Show Abstract
Hide Abstract
Complete resection is the most effective therapy for gastrointestinal stromal tumors (GISTs). Complete resection of locally advanced primary GIST by less invasive procedure is usually difficult at initial diagnosis. Imatinib has been successful in treating locally advanced and metastatic GIST and this report shares the experiences in preoperative use of imatinib for patients with locally advanced primary GISTs. The procedure of treatment and completeness of resection were retrospectively accessed for locally advanced primary GIST. Disease-free survival (DFS) and overall survival (OS) after resection were analyzed. Thirteen patients were treated with imatinib preoperatively. All patients received surgical resection after a median imatinib treatment of 7 months when most tumors shrunk. All patients achieved R0 resection without tumor rupture. Two patients received an en-bloc multivisceral resection for the invasion of surrounding organs and 3 patients underwent Mile's operation for a low rectal tumor. Eleven patients were disease-free. Median DFS or OS had not been reached, while 1- and 3-year DFS were estimated to be 92.3 and 76.9 %, respectively. 1- and 3-year OS were both estimated to be 100 %. Preoperative use of imatinib is useful in locally advanced primary GIST by downsizing the tumor in most patients and facilitating complete resection through less invasive procedures without tumor rupture.
Related JoVE Video
An inverse method to determine the mechanical properties of the iris in vivo.
Biomed Eng Online
PUBLISHED: 05-23-2014
Show Abstract
Hide Abstract
Understanding the mechanical properties of the iris can help to have an insight into the eye diseases with abnormalities of the iris morphology. Material parameters of the iris were simply calculated relying on the ex vivo experiment. However, the mechanical response of the iris in vivo is different from that ex vivo, therefore, a method was put forward to determine the material parameters of the iris using the optimization method in combination with the finite element method based on the in vivo experiment.
Related JoVE Video
The Clinical Utility of the Cornell Scale for Depression in Dementia as a Routine Assessment in Nursing Homes.
Am J Geriatr Psychiatry
PUBLISHED: 05-14-2014
Show Abstract
Hide Abstract
To examine the clinical utility of the Cornell Scale for Depression in Dementia (CSDD) in nursing homes.
Related JoVE Video
Detection and distribution of torque teno sus virus 1 in porcine reproductive and respiratory syndrome virus positive/negative pigs.
Vet. Microbiol.
PUBLISHED: 05-03-2014
Show Abstract
Hide Abstract
To investigate the detection rate and distribution of torque teno sus virus 1 (TTSuV1) in porcine reproductive and respiratory syndrome virus (PRRSV) positive/negative pigs, 2384 pathological tissues samples collected from 6 provinces of Eastern China from 2010 to 2013 were amplified using previously published PRRSV and TTSuV1 primers. The presence and viral load of TTSuV1 were investigated in a wide range of samples from 5 PRRSV positive/negative 4-week-old pigs by real-time TaqMan PCR. TTSuV1 was detected in 65.3% of 1115 PRRSV-positive samples, and 47.2% of 1269 negative samples. Viral DNA was most commonly detected in the immune organs, including spleen, lung, pancreas, and mesenteric and inguinal lymph nodes, followed by serum, liver, kidney, trachea, anal swabs, nasal swabs and sex glands of PRRSV-positive or negative pigs. TTSuV1 DNA loads in PRRSV-positive pigs increased from 2 to 5 times in almost all the corresponding parts compared with PRRSV-negative pigs. Statistical analysis showed that PRRSV may have a synergistic effect with TTSuV1, and promote the replication and proliferation of TTSuV1.
Related JoVE Video
A novel method of naturally contouring the reconstructed ear: modified antihelix complex affixed to grooved base frame.
Plast. Reconstr. Surg.
PUBLISHED: 04-30-2014
Show Abstract
Hide Abstract
Prior reports of ear reconstruction have cited favorable results. Although greater attention has been devoted to fabricating a more refined cartilaginous framework, many patients still complain that the contours are unnatural. The authors' aim was to offer a new technique that resolves some lingering issues.
Related JoVE Video
Multiple systemic transplantations of human amniotic mesenchymal stem cells exert therapeutic effects in an ALS mouse model.
Cell Tissue Res.
PUBLISHED: 04-28-2014
Show Abstract
Hide Abstract
Amyotrophic lateral sclerosis (ALS) is an adult-onset progressive neurodegenerative disease involving degeneration of motor neurons in the central nervous system. Stem cell treatment is a potential therapy for this fatal disorder. The human amniotic membrane (HAM), an extremely rich and easily accessible tissue, has been proposed as an attractive material in cellular therapy and regenerative medicine because of its advantageous characteristics. In the present study, we evaluate the long-term effects of a cellular treatment by intravenous administration of human amniotic mesenchymal stem cells (hAMSCs) derived from HAM into a hSOD1(G93A) mouse model. The mice received systemic administration of hAMSCs or phosphate-buffered saline (PBS) at the onset, progression and symptomatic stages of the disease. hAMSCs were detected in the spinal cord at the final stage of the disease, in the form of isolates or clusters and were negative for ?-tubulin III and GFAP. Compared with the treatment with PBS, multiple hAMSC transplantations significantly retarded disease progression, extended survival, improved motor function, prevented motor neuron loss and decreased neuroinflammation in mice. These findings demonstrate that hAMSC transplantation is a promising cellular treatment for ALS.
Related JoVE Video
[Involvement of chemokine CXCL16 in myocardial infarction and its influence on phagocyticactivity of macrophage in vitro].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 04-16-2014
Show Abstract
Hide Abstract
To explore whether chemokine CXCL16 is up-regulated after myocardial infarction and promotes the phagocytic activity of macrophage in vitro.
Related JoVE Video
Target triggered self-assembly of Au nanoparticles for amplified detection of Bacillus thuringiensis transgenic sequence using SERS.
Biosens Bioelectron
PUBLISHED: 04-09-2014
Show Abstract
Hide Abstract
The research methods for DNA detection have been widely extended since the application of nanotechnology, but it remains a challenge to detect specific DNA sequences or low abundance genes in the biological samples with accuracy and sensitivity. Here we developed a SERS biosensing platform by target DNA (tDNA) triggered self-assembly of Au nanoparticles (Au NPs) probes on DNA nanowires for signal amplification in DNA analysis. Based on the hybridization chain reactions (HCR) and surface enhanced Raman scattering (SERS) technology, the SERS intensity reveals a good linearity with tDNA ranging from 50 pM to 500 pM under optimal conditions. The specific detection of tDNA sequence was realized with a detection limit of 50 pM (S/N=3). To demonstrate the specificity and universality of the strategy, the single-base mismatches in DNA and the Bacillus thuringiensis (Bt) transgenic sequence were successively applied in the SERS assay. The results showed that the sensitivity and accuracy of the SERS-based assay were comparable with real-time PCR. Besides, the method would provide precise and ultra-sensitive detection of tDNA but also informative supplement to the SERS biosensing platform.
Related JoVE Video
Cassava genome from a wild ancestor to cultivated varieties.
Nat Commun
PUBLISHED: 03-20-2014
Show Abstract
Hide Abstract
Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology.
Related JoVE Video
Paratesticular fibrous pseudotumor: a report of five cases and literature review.
Front Med
PUBLISHED: 03-14-2014
Show Abstract
Hide Abstract
Paratesticular fibrous pseudotumor is a rare benign tumor that originates from intrascrotal tissue, such as tunica vaginalis, epididymis, or spermatic cord. Five cases of fibrous pseudotumor in our hospital were reviewed retrospectively, and the clinical manifestations were analyzed. Three cases of unilateral nodules, comprising one case located in the tunica vaginalis and two cases located in the epididymis, underwent local excision of the unilateral nodule. Two cases of diffuse incrassation in the tunica vaginalis underwent right radical orchiectomy. Postoperative pathological examination showed that all were fibrous pseudotumors. An average follow-up of 26 months showed uneventful results without recurrence for all patients. Fibrous pseudotumor is not a neoplasm but a reactive fibrous inflammatory hyperplasia. Definitive diagnosis requires pathological examination. Radical orchiectomy should be avoided when possible, and local excision should be performed because of the lack of obvious evidence of potential malignancy.
Related JoVE Video
Methanol-induced conformation transition of gland fibroin monitored by FTIR spectroscopy and terahertz spectroscopy.
Analyst
PUBLISHED: 03-04-2014
Show Abstract
Hide Abstract
Silk fibroin extracted from the gland of Bombyx mori silkworm is employed as an ideal system to investigate its conformation transition in methanol/D2O solution. The transition process was monitored by Fourier transform infrared (FTIR) spectroscopy coupled with terahertz time domain spectroscopy (THz-TDS). Analysis of FTIR spectra suggests that, with increasing time of treatment, an increasing band at 1634 cm(-1) is observed indicating the formation of ?-pleated sheets coincident with the loss of intensity of a band at 1673 cm(-1) indicating decrease of the random coil structure. In addition, there is a burst phase of 33% occurring during the first 2 minutes when the gland fibroin membranes are immersed into methanol/D2O solution. THz spectra present distinct features for conformations of silk fibroin, in combination with the results obtained from FTIR; the peaks observed at 1.54 THz (51 cm(-1)), 1.67 THz (55 cm(-1)), and 1.84 THz (61 cm(-1)) can be attributed to a ?-pleated sheet, ?-helix, and random coil, respectively. Intensity change of bands centered at 1.54 THz and 1.84 THz confirms the formation of the ?-pleated sheet and the disappearance of the random coil. Kinetic curves obtained from THz spectra indicate that the methanol-induced conformation transition from the random coil to the ?-pleated sheet is fitted with an exponential function. The results suggest that THz-TDS presents great potential as a complementary approach in studying the secondary structure of a protein, providing significant insight into the silk-spinning process in vivo.
Related JoVE Video
Hydrogen-bonding recognition-induced aggregation of gold nanoparticles for the determination of the migration of melamine monomers using dynamic light scattering.
Anal. Chim. Acta
PUBLISHED: 03-03-2014
Show Abstract
Hide Abstract
The migration of melamine monomers from food contact materials has aroused particular attention since the 2008 melamine-tainted milk scandal in China. However, the determination of melamine monomer's migratory quantity (MMMQ) has remained an open question because of the complex sample pretreatment and the low sensitivity. Based on the hydrogen bonding interaction between DNA thymine and melamine, this paper described a simple and rapid method focusing on the measurement of MMMQ from melamine tableware by gold nanoparticles (GNPs) and dynamic light scattering (DLS). With the presence of probe DNA (p-DNA), the GNPs were stable in NaCl solution (0.06 M), whereas they became aggregated when the p-DNA hybridized with melamine. The change in the hydrodynamic diameter of GNPs could be detected by DLS technology. Under the optimal conditions, the average diameter increased linearly with the concentration of melamine over the range from 5.0 to 320.0 ?g L(-1), and showed a detection limit of 2.0 ?g L(-1) (3?/slope). The MMMQ was investigated within a range from 6.00×10(-4) to 2.58×10(-1) mg dm(-2) (n?3) in four different food simulants at different temperatures and time points. The results suggest that the DLS method has great potential in the analysis of the migration of melamine monomers.
Related JoVE Video
Anisotropic two-dimensional electron gas at SrTiO3(110).
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 03-03-2014
Show Abstract
Hide Abstract
Two-dimensional electron gases (2DEGs) at oxide heterostructures are attracting considerable attention, as these might one day substitute conventional semiconductors at least for some functionalities. Here we present a minimal setup for such a 2DEG--the SrTiO3(110)-(4 × 1) surface, natively terminated with one monolayer of tetrahedrally coordinated titania. Oxygen vacancies induced by synchrotron radiation migrate underneath this overlayer; this leads to a confining potential and electron doping such that a 2DEG develops. Our angle-resolved photoemission spectroscopy and theoretical results show that confinement along (110) is strikingly different from the (001) crystal orientation. In particular, the quantized subbands show a surprising "semiheavy" band, in contrast with the analog in the bulk, and a high electronic anisotropy. This anisotropy and even the effective mass of the (110) 2DEG is tunable by doping, offering a high flexibility to engineer the properties of this system.
Related JoVE Video
Neuroprotection against A?25-35-induced apoptosis by Salvia miltiorrhiza extract in SH-SY5Y cells.
Neurochem. Int.
PUBLISHED: 02-28-2014
Show Abstract
Hide Abstract
The neurotoxicity of ?-amyloid protein (A?) contributes significantly to the pathogenesis of Alzheimer's disease (AD), and hence the attractive therapeutic strategies focusing on the modulation of A?-induced neurotoxicity are warranted. The present study aims to investigate the neuroprotection and underlying mechanisms by which Salvia miltiorrhiza Bunge (Lamiaceae) extract (SME) protects against A?25-35-induced apoptosis in SH-SY5Y cells. 2h Pre-treatment of SH-SY5Y cells with SME (0.01, 0.1 or 0.2mg raw herb/ml) concentration-dependently attenuated A?25-35-induced cell death, as evidenced by the increase in cell viability and decrease in neuronal apoptosis. In addition, SME suppressed the increased intracellular reactive oxygen species levels, decreased the protein expression of cleaved caspase-3, cytosolic cytochrome c, and Bax/Bcl-2 ratio. These findings taken together suggest that SME provides substantial neuroprotection against A?25-35-induced neurotoxicity in SH-SY5Y cells, at least in part, via inhibiting oxidative stress and attenuating the mitochondria-dependent apoptotic pathway. The approach used in this study may also be useful for the screening of therapeutic agents for AD and other related neurodegenerative disease.
Related JoVE Video
Delayed laparoscopic cholecystectomy is safe and effective for acute severe calculous cholecystitis in patients with advanced cirrhosis: a single center experience.
Gastroenterol Res Pract
PUBLISHED: 02-11-2014
Show Abstract
Hide Abstract
Acute calculous cholecystitis is a common disease in cirrhotic patients. Laparoscopic cholecystectomy can resolve this problem but is performed based on the premise that the local inflammation must been controlled. An Initial ultrasound guided percutaneous transhepatic cholecystostomy may reduce the local inflammation and provide advantages in subsequent surgery. In this paper, we detailed our experience of treating acute severe calculous cholecystitis in patients with advanced cirrhosis by delayed laparoscopic cholecystectomy plus initiated ultrasound guided percutaneous transhepatic cholecystostomy and provided the analysis of the treatment effect. We hope this paper can provided a kind of standard procedure for this special disease; however, further prospective comparative randomized trials are needed to assess this treatment in cirrhotic patients with acute cholecystitis.
Related JoVE Video
Expression of cytoskeleton regulatory protein Mena in human hepatocellular carcinoma and its prognostic significance.
Med. Oncol.
PUBLISHED: 02-10-2014
Show Abstract
Hide Abstract
The molecular mechanisms of the development and progression of hepatocellular carcinoma (HCC) are poorly understood. The main objective of this study was to analyze the expression of Enabled [mammalian Ena (Mena)] protein and its clinical significance in human HCC. The Mena expression was examined at mRNA and protein levels by real-time quantitative polymerase chain reaction and Western blotting analysis in ten paired HCC tissues and the adjacent normal tissues. The expression of Mena protein in 81 specimens of HCC tissues was determined by immunohistochemistry. Associations of Mena expression with the clinicopathological features were analyzed, and prognosis of HCC patients was evaluated. The result shows the expression of Mena mRNA and protein was higher in HCC than in the adjacent normal tissues in ten paired samples. Mena was mainly accumulated in the cytoplasm of tumor cells and over-expressed in 40.74% (33/81) patients by immunohistochemical staining. Over-expression of Mena was significantly associated with poor cellular differentiation (P = 0.025), advanced tumor stage (P = 0.003) and worse disease-free survival (DFS, P < 0.001). In addition, Mena is an independent prognostic factor for DFS in multivariate analysis (HR 2.309, 95% CI 1.104-4.828; P = 0.026). Mena is up-regulated in HCC and associated with tumor differentiation and clinical stage. Mena may be an independent prognostic marker for DFS of HCC patients.
Related JoVE Video
Glutathionylated 4-hydroxy-2-(E)-alkenal enantiomers in rat organs and their contributions toward the disposal of 4-hydroxy-2-(E)-nonenal in rat liver.
Free Radic. Biol. Med.
PUBLISHED: 02-05-2014
Show Abstract
Hide Abstract
The major route for elimination of 4-hydroxy-2-(E)-nonenal (4-HNE) has long been considered to be through glutathionylation and eventual excretion as a mercapturic acid conjugate. To better quantitate the glutathionylation process, we developed a sensitive LC-MS/MS method for the detection of glutathione (GSH) conjugates of 4-hydroxy-2-(E)-alkenal enantiomers having a carbon skeleton of C5 to C12. The newly developed method enabled us to quantify 4-hydroxy-2-(E)-alkenal-glutathione diastereomers in various organs, i.e., liver, heart, and brain. We identified the addition of iodoacetic acid as a critical step during sample preparation to avoid an overestimation of glutathione-alkenal conjugation. Specifically, we found that in the absence of a quenching step reduced GSH and 4-hydroxy-2-(E)-alkenals react very rapidly during the extraction and concentration steps of sample preparation. Rat liver perfused with d11-4-hydroxy-2-(E)-nonenal (d11-4-HNE) revealed enantioselective conjugation with GSH and transportation out of the liver. In the d11-4-HNE-perfused rat livers, the amount of d11-(S)-4-HNE-GSH released from the rat liver was higher than that of d11-(R)-4-HNE-GSH, and more d11-(R)-4-HNE-GSH than d11-(S)-4-HNE-GSH remained in the perfused liver tissues. Overall, the glutathionylation pathway was found to account for only 8.7% of the disposition of 4-HNE, whereas catabolism to acetyl-CoA, propionyl-CoA, and formate represented the major detoxification pathway.
Related JoVE Video
Crystallization, preliminary X-ray crystallographic and cryo-electron microscopy analysis of a bifunctional enzyme fucokinase/L-fucose-1-P-guanylyltransferase from Bacteroides fragilis.
Acta Crystallogr F Struct Biol Commun
PUBLISHED: 02-04-2014
Show Abstract
Hide Abstract
Fucokinase/L-fucose-1-P-guanylyltransferase (FKP) is a bifunctional enzyme which converts L-fucose to Fuc-1-P and thence to GDP-L-fucose through a salvage pathway. The molecular weights of full-length FKP (F-FKP) and C-terminally truncated FKP (C-FKP, residues 300-949) are 105.7 and 71.7?kDa, respectively. In this study, both recombinant F-FKP and C-FKP were expressed and purified. Size-exclusion chromatography experiments and analytical ultracentrifugation results showed that both F-FKP and C-FKP are trimers. Native F-FKP protein was crystallized by the vapour-diffusion method and the crystals belonged to space group P212121 and diffracted synchrotron X-rays to 3.7?Å resolution. The crystal unit-cell parameters are a = 91.36, b = 172.03, c = 358.86?Å, ? = ? = ? = 90.00°. The three-dimensional features of the F-FKP molecule were observed by cryo-EM (cryo-electron microscopy). The preliminary cryo-EM experiments showed the F-FKP molecules as two parallel disc-shaped objects stacking together. Combining all results together, it is assumed that there are six FKP molecules in one asymmetric unit, which corresponds to a calculated Matthews coefficient of 2.19?Å(3)?Da(-1) with 43.83% solvent content. These preliminary crystallographic and cryo-EM microscopy analyses provide basic structural information on FKP.
Related JoVE Video
Phase evolution of magnetron sputtered nanostructured ATO on grid during lithiation-delithiation processes as model electrodes for Li-ion battery.
Phys Chem Chem Phys
PUBLISHED: 02-04-2014
Show Abstract
Hide Abstract
Sb-doped SnO2 (ATO) nanostructured thin films were deposited on holey carbon grids by magnetron sputtering at room temperature. Li/electrolyte/ATO cells were assembled by using the deposited ATO grids as test electrodes. The phase component of the ATO electrodes deposited on grids before and after induction at different charge-discharge stages was characterized by using a transmission electron microscope. The results of the investigation show that the nanostructured ATO thin films undergo a reversible lithiation-delithiation process: the decomposition of SnO2 and the occurrence of metallic Sn followed by the formation of an Li-Sn alloy during the discharge process, and then the reversible de-alloying reaction of the Li-Sn alloy and Sn reaction with Li2O, and even partial formation of SnO2 during charge process. The work also shows that the method deposited the active materials directly on the holey carbon grids is a simple and effective way for the investigation of the phase evolution of the electrodes in electrochemical cells.
Related JoVE Video
Transgenic rice as bioreactor for production of the Candida antarctica lipase B.
Plant Biotechnol. J.
PUBLISHED: 01-28-2014
Show Abstract
Hide Abstract
Candida antarctica lipase B (CALB) is a versatile biocatalyst used for a wide range of biotransformation. Methods for low cost production of this enzyme are highly desirable. Here, we report a mass production method of CALB using transgenic rice seeds as the bioreactor. The transgenic rice transformed with the CALB gene under the control of the promoter of the rice seed storage protein GT1 was found to have accumulated a large quantity of CALB in seeds. The transgenic line with the highest lipolytic activity reached to 85 units per gram of dry seeds. One unit is defined as the amount of lipase necessary to liberate 1 ?mol p-nitrophenol from p-nitrophenyl butyrate in 1 min. The rice recombinant lipase (rOsCALB) from this line represents 40% of the total soluble proteins in the crude seed extracts. The enzyme purified from the rice seeds had an optimal temperature of 40 °C, and optimal pH of 8.5, similar to that of the fermentation products. Test of its conversion ability as a biocatalyst for biodiesel production suggested that rOsCALB is functionally identical to the fermentation products in its industrial application.
Related JoVE Video
Production and purification of a novel xanthan lyase from a xanthan-degrading Microbacterium sp. strain XT11.
ScientificWorldJournal
PUBLISHED: 01-27-2014
Show Abstract
Hide Abstract
A xanthan lyase was produced and purified from the culture supernatant of an excellent xanthan-modifying strain Microbacterium sp. XT11. Xanthan lyase was induced by xanthan but was inhibited by its structural monomer glucose. Its production by strain XT11 is much higher than that by all other reported strains. The purified xanthan lyase has a molecular mass of 110 kDa and a specific activity of 28.2?U/mg that was much higher than that of both Paenibacillus and Bacillus lyases. It was specific on the pyruvated mannosyl residue in the intact xanthan molecule, but about 50% lyase activity remained when xanthan was partially depyruvated. Xanthan lyase was optimally active at pH 6.0-6.5 and 40°C and alkali-tolerant at a high pH value of 11.0. The metal ions including K(+), Ca(2+), Na(+), Mg(2+), Mn(2+), and Li(+) strongly stimulated xanthan lyase activity but ions Zn(2+) and Cu(2+) were its inhibitor. Xanthan lyase should be a novel enzyme different from the other xanthan lyases ever reported.
Related JoVE Video
The importance of costal cartilage framework stabilization in microtia reconstruction: Anthropometric comparison based on 216 cases.
J Plast Reconstr Aesthet Surg
PUBLISHED: 01-24-2014
Show Abstract
Hide Abstract
This study explored anthropometric changes in the reconstructed auricle and the contralateral normal ear in a series of 216 microtia patients using different stabilization methods. Our main personal modifications concerning the preparation of the framework were the following: 1. The individualized framework grafting was based on patients with different ages and different degrees of the strength and thickness of the rib cartilage. 2. The framework was stabilized as a "C" shape by using a piece of cartilage or suture to reinforce the two end points of the "C". In group A (the thickness of cartilage was more than 5 mm), a block of residual cartilage fixed by wire was added between the tragus and the base frame of the inferior crus by the modified method but was not applied in the original method. In group B (the thickness of cartilage was less than 5 mm), a 4-0 braided suture was used to reinforce the two structures but was not used in the original method. No significant differences were found in the height or width measurements of the cartilage framework and the contralateral normal side in either group at the time of implantation. At the follow-up, the height and width measurements were obviously increased in both groups operated on by the original method compared with the initial implanted or contralateral normal measurements. There were no significant differences in the height or width measurements by the modified method in either group. The authors' techniques produced acceptable results and generated some useful parameters for the growth study of the reconstructed auricle and the contralateral normal ear. The modifications in framework stabilization allow a harmonious outline of the reconstructed auricle to be attained, which is almost symmetrical to the contralateral normal auricle.
Related JoVE Video
Down-regulated Six2 by knockdown of neurofibromin results in apoptosis of metanephric mesenchyme cells in vitro.
Mol. Cell. Biochem.
PUBLISHED: 01-21-2014
Show Abstract
Hide Abstract
Embryonic Six2-positive nephron progenitor cells adjacent to ureteric bud tips ultimately give rise to nephron structures, including proximal and distal tubules, podocytes, Bowman's capsules, and the glomeruli. This process requires an internal balance between self-renew and differentiation of the nephron progenitor cells, which is mediated by numerous molecules. Recent studies have shown that the neurofibromin (Nf1) null mutant mouse embryos have an 18- to 24-h developmental delay in metanephros manifesting retardation in its cephalad repositioning and reduction number of glomeruli. However, the underlying inter-/intracellular signaling mechanisms responsible for reducing number of glomeruli during nephrogenesis remain to be fully elucidated. Here, we originally detected the Nf1 expression in developing kidney and metanephric mesenchyme cells. Surprisingly, Nf1 knockdown by small interfering RNAs in the metanephric mesenchyme cells (mK3) resulted in a decreased expression of Six2, the key marker of renal progenitor cells, while the ratio of apoptotic cells was significantly increased. Furthermore, overexpression of Six2 in mk3 cells partially rescued apoptosis phenotype. Collectively, these results implied that knockdown of Nf1 resulted in apoptosis of mK3 cells in vitro probably through down-regulation of Six2 expression. Collectively, we demonstrated that down-regulated Six2 by knockdown of Nf1 resulted in apoptosis of mK3 cells in vitro. These results implied that inhibition of Nf1 may delay metanephros development via down-regulation of Six2.
Related JoVE Video
Differentiation of adipose-derived stem cells toward nucleus pulposus-like cells induced by hypoxia and a three-dimensional chitosan-alginate gel scaffold in vitro.
Chin. Med. J.
PUBLISHED: 01-21-2014
Show Abstract
Hide Abstract
Injectable three-dimensional (3D) scaffolds have the advantages of fluidity and moldability to fill irregular-shaped defects, simple incorporation of bioactive factors, and limited surgical invasiveness. Adipose-derived stem cells (ADSCs) are multipotent and can be differentiated toward nucleus pulposus (NP)-like cells. A hypoxic environment may be important for differentiation to NP-like cells because the intervertebral disc is an avascular tissue. Hence, we investigated the induction effects of hypoxia and an injectable 3D chitosan-alginate (C/A) gel scaffold on ADSCs.
Related JoVE Video
A gene knock-in method used to purify plasmid pSPI12 from Salmonella enterica serovar Pullorum and characterization of IpaJ.
J. Microbiol. Methods
PUBLISHED: 01-16-2014
Show Abstract
Hide Abstract
A small plasmid with 4080 bp long, designated pSPI12, was purified from Salmonella enterica serovar Pullorum using a gene knock-in method by inserting a kanamycin resistance cassette in the plasmid. The G+C content of the plasmid was 51.8%, which is in the range of Salmonella genomic DNA. A sequence analysis revealed that pSPI12 had 99.1% homology to pSFD10, which was first reported in the vaccine strain S. enterica serovar Chloreaesuis C500, but not prevalent among other strains of S. Chloreaesuis. The plasmid has seven open reading frames (ORFs), with one ORF containing a putative virulence-related protein, which had 49% homology with invasion plasmid antigen J protein (IpaJ) secreted by type III secretion system of Shigella flexneri. The putative IpaJ protein was expressed and purified as a His-tagged fusion protein reacted with convalescent sera against S. Pullorum, confirming its identification as an immunogen of the pathogen. In addition, the gene was upregulated for 1h post-infection of HD-11 cells with the pathogen by a quantitative real-time reverse transcription PCR assay. The results suggest that IpaJ may be a virulent protein involved in the early stage of infection by S. Pullorum.
Related JoVE Video
Glycyrrhizin inhibits lipopolysaccharide-induced inflammatory response by reducing TLR4 recruitment into lipid rafts in RAW264.7 cells.
Biochim. Biophys. Acta
PUBLISHED: 01-14-2014
Show Abstract
Hide Abstract
The aim of this study was to investigate the effect of glycyrrhizin on LPS-induced endotoxemia in mice and clarify the possible mechanism.
Related JoVE Video
Species-dependent neuropathology in transgenic SOD1 pigs.
Cell Res.
PUBLISHED: 01-13-2014
Show Abstract
Hide Abstract
Mutations in the human copper/zinc superoxide dismutase 1 (hSOD1) gene cause familial amyotrophic lateral sclerosis (ALS). It remains unknown whether large animal models of ALS mimic more pathological events seen in ALS patients via novel mechanisms. Here, we report the generation of transgenic pigs expressing mutant G93A hSOD1 and showing hind limb motor defects, which are germline transmissible, and motor neuron degeneration in dose- and age-dependent manners. Importantly, in the early disease stage, mutant hSOD1 did not form cytoplasmic inclusions, but showed nuclear accumulation and ubiquitinated nuclear aggregates, as seen in some ALS patient brains, but not in transgenic ALS mouse models. Our findings revealed that SOD1 binds PCBP1, a nuclear poly(rC) binding protein, in pig brain, but not in mouse brain, suggesting that the SOD1-PCBP1 interaction accounts for nuclear SOD1 accumulation and that species-specific targets are key to ALS pathology in large mammals and in humans.
Related JoVE Video
Expression of Cry1Ab and Cry2Ab by a Polycistronic Transgene with a Self-Cleavage Peptide in Rice.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Insect resistance to Bacillus thuringiensis (Bt) crystal protein is a major threat to the long-term use of transgenic Bt crops. Gene stacking is a readily deployable strategy to delay the development of insect resistance while it may also broaden insecticidal spectrum. Here, we report the creation of transgenic rice expressing discrete Cry1Ab and Cry2Ab simultaneously from a single expression cassette using 2A self-cleaving peptides, which are autonomous elements from virus guiding the polycistronic viral gene expression in eukaryotes. The synthetic coding sequences of Cry1Ab and Cry2Ab, linked by the coding sequence of a 2A peptide from either foot and mouth disease virus or porcine teschovirus-1, regardless of order, were all expressed as discrete Cry1Ab and Cry2Ab at high levels in the transgenic rice. Insect bioassays demonstrated that the transgenic plants were highly resistant to lepidopteran pests. This study suggested that 2A peptide can be utilized to express multiple Bt genes at high levels in transgenic crops.
Related JoVE Video
Complete genome sequence of a novel pigeon torque teno virus in china.
Genome Announc
PUBLISHED: 12-21-2013
Show Abstract
Hide Abstract
Torque teno virus is a nonenveloped single-stranded DNA virus infecting humans and nonprimate species. We report the complete genome sequence of a pigeon torque teno virus isolated from pigeons in Jiangsu Province, China, in 2012. This genome sequence will be useful for viral diagnostics and disease control.
Related JoVE Video
Ultrathin pt-cu nanosheets and nanocones.
J. Am. Chem. Soc.
PUBLISHED: 12-02-2013
Show Abstract
Hide Abstract
In this work, we have successfully synthesized free-standing ultrathin Pt-Cu alloy nanosheets of 4-6 atom thickness with tunable lateral size from 10 to 50 nm. The nanosheets with diameters >20 nm can be converted into nanocones in a controllable way. These nanosheets and nanocones exhibit excellent electrocatalytic activities for the oxidation of ethanol in comparison to commercial Pt black and Pt/C catalysts.
Related JoVE Video
Construction of targeting-clickable and tumor-cleavable polyurethane nanomicelles for multifunctional intracellular drug delivery.
Biomacromolecules
PUBLISHED: 11-22-2013
Show Abstract
Hide Abstract
New strategies for the construction of versatile nanovehicles to overcome the multiple challenges of targeted delivery are urgently needed for cancer therapy. To address these needs, we developed a novel targeting-clickable and tumor-cleavable polyurethane nanomicelle for multifunctional delivery of antitumor drugs. The polyurethane was synthesized from biodegradable poly(?-caprolactone) (PCL) and l-lysine ethyl ester diisocyanate (LDI), further extended by a new designed l-cystine-derivatized chain extender bearing a redox-responsive disulfide bond and clickable alkynyl groups (Cys-PA), and finally terminated by a detachable methoxyl-poly(ethylene glycol) with a highly pH-sensitive benzoic-imine linkage (BPEG). The obtained polymers show attractive self-assembly characteristics and stimuli-responsiveness, good cytocompatibility, and high loading capacity for doxorubicin (DOX). Furthermore, folic acid (FA) as a model targeting ligand was conjugated to the polyurethane micelles via an efficient click reaction. The decoration of FA results in an enhanced cellular uptake and improved drug efficacy toward FA-receptor positive HeLa cancer cells in vitro. As a proof-of-concept, this work provides a facile approach to the design of extracellularly activatable nanocarriers for tumor-targeted and programmed intracellular drug delivery.
Related JoVE Video
CPLM: a database of protein lysine modifications.
Nucleic Acids Res.
PUBLISHED: 11-08-2013
Show Abstract
Hide Abstract
We reported an integrated database of Compendium of Protein Lysine Modifications (CPLM; http://cplm.biocuckoo.org) for protein lysine modifications (PLMs), which occur at active ?-amino groups of specific lysine residues in proteins and are critical for orchestrating various biological processes. The CPLM database was updated from our previously developed database of Compendium of Protein Lysine Acetylation (CPLA), which contained 7151 lysine acetylation sites in 3311 proteins. Here, we manually collected experimentally identified substrates and sites for 12 types of PLMs, including acetylation, ubiquitination, sumoylation, methylation, butyrylation, crotonylation, glycation, malonylation, phosphoglycerylation, propionylation, succinylation and pupylation. In total, the CPLM database contained 203 972 modification events on 189 919 modified lysines in 45 748 proteins for 122 species. With the dataset, we totally identified 76 types of co-occurrences of various PLMs on the same lysine residues, and the most abundant PLM crosstalk is between acetylation and ubiquitination. Up to 53.5% of acetylation and 33.1% of ubiquitination events co-occur at 10 746 lysine sites. Thus, the various PLM crosstalks suggested that a considerable proportion of lysines were competitively and dynamically regulated in a complicated manner. Taken together, the CPLM database can serve as a useful resource for further research of PLMs.
Related JoVE Video
EKPD: a hierarchical database of eukaryotic protein kinases and protein phosphatases.
Nucleic Acids Res.
PUBLISHED: 11-08-2013
Show Abstract
Hide Abstract
We present here EKPD (http://ekpd.biocuckoo.org), a hierarchical database of eukaryotic protein kinases (PKs) and protein phosphatases (PPs), the key molecules responsible for the reversible phosphorylation of proteins that are involved in almost all aspects of biological processes. As extensive experimental and computational efforts have been carried out to identify PKs and PPs, an integrative resource with detailed classification and annotation information would be of great value for both experimentalists and computational biologists. In this work, we first collected 1855 PKs and 347 PPs from the scientific literature and various public databases. Based on previously established rationales, we classified all of the known PKs and PPs into a hierarchical structure with three levels, i.e. group, family and individual PK/PP. There are 10 groups with 149 families for the PKs and 10 groups with 33 families for the PPs. We constructed 139 and 27 Hidden Markov Model profiles for PK and PP families, respectively. Then we systematically characterized ?50 000 PKs and >10 000 PPs in eukaryotes. In addition, >500 PKs and >400 PPs were computationally identified by ortholog search. Finally, the online service of the EKPD database was implemented in PHP + MySQL + JavaScript.
Related JoVE Video
Well-Defined Metal-Organic Framework Hollow Nanocages.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 10-02-2013
Show Abstract
Hide Abstract
Metal-organic frameworks (MOFs) have demonstrated great potentials in a variety of important applications. To enhance the inherent properties and endow materials with multifunctionality, the rational design and synthesis of MOFs with nanoscale porosity and hollow feature is highly desired and remains a great challenge. In this work, the formation of a series of well-defined MOF (MOF-5, Fe(II) -MOF-5, Fe(III) -MOF-5) hollow nanocages by a facile solvothermal method, without any additional supporting template is reported. A surface-energy-driven mechanism may be responsible for the formation of hollow nanocages. The addition of pre-synthesized poly(vinylpyrrolidone)- (PVP) capped noble-metal nanoparticles into the synthetic system of MOF hollow nanocages yields the yolk-shell noble metal@MOF nanostructures. The present strategy to fabricate hollow and yolk-shell nanostructures is expected to open up exciting opportunities for developing a novel class of inorganic-organic hybrid functional nanomaterials.
Related JoVE Video
Recycling rare earth elements from industrial wastewater with flowerlike nano-Mg(OH)(2).
ACS Appl Mater Interfaces
PUBLISHED: 09-27-2013
Show Abstract
Hide Abstract
Treatment of wastewater containing low-concentration yet highly-expensive rare earth elements (REEs) is one of the vital issues in the REEs separation and refining industry. In this work, the interaction and related mechanism between self-supported flowerlike nano-Mg(OH)2 and low-concentration REEs wastewater were investigated. More than 99% REEs were successfully taken up by nano-Mg(OH)2. Further analysis revealed that the REEs could be collected on the surface of Mg(OH)2 as metal hydroxide nanoparticles (<5 nm). An ion-exchange model was proposed as a critical factor for both guaranteeing the reaction speed and maintaining the self-supported structure of the materials. In addition, a method was developed to further separate the immobilized REEs and the residual magnesium hydroxide by varying the solution pH. In a pilot-scale experiment, the REEs from practical wastewater were immobilized effectively at a high flow rate. We anticipate this work can provide a good example for the recycling of valuable REEs in practical industrial applications.
Related JoVE Video
Chemical bonding-induced low dielectric loss and low conductivity in high-K poly(vinylidenefluoride-trifluorethylene)/graphene nanosheets nanocomposites.
ACS Appl Mater Interfaces
PUBLISHED: 09-25-2013
Show Abstract
Hide Abstract
Blending high-permittivity (?r) ceramic powders or conductive fillers into polymers to form 0-3-type composites has been regarded as one of the most promising processes to achieve high-dielectric-permittivity materials with excellent processing performance. The high dielectric loss and conductivity induced by the interface between the matrix and fillers as well as the leakage current have long been a great challenge of dielectric composites, and the resolution of these challenges is still an open question. In this work, poly(vinylidenefluoride-trifluorethylene with double bonds)/graphene nanosheets (P(VDF-TrFE-DB)/GNS) terpolymer nanocomposites were fabricated via a solution-cast process. GNSs were functionalized with KH550 to improve the dispersion in the terpolymer matrix solution and crosslinked with P(VDF-TrFE-DB) by a free-radical addition reaction in the nanocomposites. Compared with neat terpolymer, significantly increased dielectric permittivity and a low loss were observed for the composites. For instance, at 1 kHz the P(VDF-TrFE-DB)/GNS composites with 4 vol % GNS possessed a dielectric permittivity of 74, which is over seven times larger than that of neat terpolymer. However, a rather low dielectric loss (0.08 at 1 kHz) and conductivity (3.47 × 10(-7) S/m at 1 kHz) are observed in the P(VDF-TrFE-DB)/GNS composites containing up to 12 vol % GNS. The covalent bonding constructed between P(VDF-TrFE-DB) and GNS is responsible for the reduced aspect ratio of the GNS and the crystalline properties of P(VDF-TrFE-DB) as well as the improved compatibility between them. As a result, the high-dielectric-loss conductivity of polymer composites, mainly induced by conduction loss and the interface polarization between the matrix and filler, were effectively restricted. Meanwhile, the 3D network established between P(VDF-TrFE-DB) and GNS endows the P(VDF-TrFE-DB)/GNS composites at high temperature with excellent mechanical and dielectric properties. Besides preparing high-performance dielectric composites, this facile route may also be utilized to fabricate high-performance nanocomposites by inhibiting the poor compatibility between fillers and polymeric matrix.
Related JoVE Video
Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation.
Biochem. Biophys. Res. Commun.
PUBLISHED: 09-12-2013
Show Abstract
Hide Abstract
Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase C? (PLC?) signaling pathway with either a specific PLC? inhibitor or knockdown PLC? reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression.
Related JoVE Video
Dynamical color-controllable lasing with extremely wide tuning range from red to green in a single alloy nanowire using nanoscale manipulation.
Nano Lett.
PUBLISHED: 09-11-2013
Show Abstract
Hide Abstract
Multicolor lasing and dynamic color-tuning in a wide spectrum range are challenging to realize but critically important in many areas of technology and daily life, such as general lighting, display, multicolor detection, and multiband communication. By exploring nanoscale growth and manipulation, we have demonstrated the first active dynamical color control of multicolor lasing, continuously tunable between red and green colors separated by 107 nm in wavelength. This is achieved in a purposely engineered single CdSSe alloy nanowire with composition varied along the wire axis. By looping the wide-gap end of the alloy nanowire through nanoscale manipulation, two largely independent (only weakly coupled) laser cavities are formed respectively for the green and red color modes. Our approach simultaneously overcomes the two fundamental challenges for multicolor lasing in material growth and cavity design. Such multicolor lasing and continuous color tuning in a wide spectral range represents a new paradigm shift and would eventually enable color-by-design and white-color lasers for lighting, illumination, and many other applications.
Related JoVE Video
Cotransplantation of olfactory ensheathing cells and schwann cells combined with treadmill training promotes functional recovery in rats with contused spinal cords.
Cell Transplant
PUBLISHED: 08-29-2013
Show Abstract
Hide Abstract
The present study investigated the ability of cotransplantation of Schwann cells (SCs) and olfactory ensheathing cells (OECs) combined with treadmill training in facilitating neuronal plasticity and promoting hindlimb function recovery of subacute moderate thoracic (T10) spinal cord contusion in rats. Two weeks postinjury, SCs were injected directly into the lesion, while OECs were injected into the adjacent tissues. The treadmill training with the rats began postinjury on day 7, with each session lasting 20 ± 10 min per day, 5 days per week, for 10 weeks. At the 11th week postinjury, OECs were found migrating longitudinally and laterally from the injection site to the injury site through the gray and white matter, while some traveled along the central canal or pia. The SCs remained densely packed and concentrated at the transplant site. The transplanted SCs supported ingrowth of numerous, densely populated neurofilament-positive (NF(+)), MBP(+) axons. The OECs promoted elongation of moderate NF(+), GAP-43(+) axons and a few MBP(+) axons in parallel with OEC processes. The GFAP immunoreactivity in the spared tissue surrounding the graft of SCs and OECs at the lesion site was less intense than that in the DMEM group. Treadmill training had no effect on GFAP immunoreactivity. Treadmill training increased the number of TH-immunoreactive neurons in the gray matter of L2 spinal cord. Moreover, cotransplantation of OECs and SCs significantly increased the BBB score during 5-8 weeks postinjury alongside treadmill training between 5 and 11 weeks. Cotransplantation of OECs and SCs combined with treadmill training resulted in the highest BBB score at 4 and 11 weeks. The study details the differential mechanisms of neuronal plasticity: (1) axon growth and remyelination induced by cotransplantation of OECs and SCs and (2) neuron plasticity below the lesion enhanced by treadmill training. The synergistic effects of the combined strategy enhance functional recovery. This manuscript is published as part of the International Association of Neurorestoratology (IANR) supplement issue of Cell Transplantation.
Related JoVE Video
Biomimetic Multifunctional Nanochannels Based on the Asymmetric Wettability of Heterogeneous Nanowire Membranes.
Adv. Mater. Weinheim
PUBLISHED: 08-25-2013
Show Abstract
Hide Abstract
A charged heterogeneous nanowire membrane with asymmetric wettability serves as a biomimetic passive channel when the bilayer is hydrophilic; It also functions as pH valve based on the hydrophobic CaWO4 layer (contact angle of 145.3?±0.3?) and hydrophilic MnO2 layer. Moreover, a reversible ionic rectification is realized in the above-mentioned semi-hydrophobic and hydrophilic state with strong acid environment or in the complete hydrophobic stage with a moderate discrepancy (CA of CaWO4 and MnO2 layer are 141.3?±0.3? and 157.6?±2.0?, respectively) in near neuter condition.
Related JoVE Video
Biofilm Formation, Host-Cell Adherence, and Virulence Genes Regulation of Streptococcus suis in Response to Autoinducer-2 Signaling.
Curr. Microbiol.
PUBLISHED: 08-20-2013
Show Abstract
Hide Abstract
Autoinducer-2 (AI-2) is a universal signal molecule mediating intra- and interspecies communication among bacteria. AI-2 is a byproduct of the LuxS enzyme during the catabolism of S-adenosylhomocysteine and plays critical roles in regulating various behaviors of bacteria. In our previous study, the function of LuxS in AI-2 production was verified in Streptococcus suis (SS). Decreased levels of SS biofilm formation and host-cell adherence as well as the inability to produce AI-2 were observed in SS having a luxS mutant gene. In this study, exogenous addition of a low concentration of AI-2 synthesized in vitro was found to promote biofilm formation and host-cell adherence. However, higher concentrations of AI-2 inhibited SS biofilm formation and host-cell adherence. Real-time PCR results showed that the mRNA level of virulence factors of SS biofilm, gdh, cps2, sly, and mrp increased and ef, fbps, and gapdh decreased with increasing AI-2 concentrations. These findings demonstrated that AI-2 supplemented exogenously acted as a concentration-dependent signaling molecule to regulate SS biofilm formation, host-cell adherence, and transcription levels of many virulence genes.
Related JoVE Video
Transcriptomics: advances and approaches.
Sci China Life Sci
PUBLISHED: 08-14-2013
Show Abstract
Hide Abstract
Transcriptomics is one of the most developed fields in the post-genomic era. Transcriptome is the complete set of RNA transcripts in a specific cell type or tissue at a certain developmental stage and/or under a specific physiological condition, including messenger RNA, transfer RNA, ribosomal RNA, and other non-coding RNAs. Transcriptomics focuses on the gene expression at the RNA level and offers the genome-wide information of gene structure and gene function in order to reveal the molecular mechanisms involved in specific biological processes. With the development of next-generation high-throughput sequencing technology, transcriptome analysis has been progressively improving our understanding of RNA-based gene regulatory network. Here, we discuss the concept, history, and especially the recent advances in this inspiring field of study.
Related JoVE Video
[Study on gender difference of tinnitus in medical staff].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 08-14-2013
Show Abstract
Hide Abstract
To investigate whether there is gender difference in the incidence and severity of tinnitus in medical staff (including doctors, nurses, and technicians).
Related JoVE Video
Staphylococcus aureus and Escherichia coli elicit different innate immune responses from bovine mammary epithelial cells.
Vet. Immunol. Immunopathol.
PUBLISHED: 08-07-2013
Show Abstract
Hide Abstract
Escherichia coli and Staphylococcus aureus are the most important pathogenic bacteria causing bovine clinical mastitis and subclinical mastitis, respectively. However, little is known about the molecular mechanisms underlying the different host response patterns caused by these bacteria. The aim of this study was to characterize the different innate immune responses of bovine mammary epithelium cells (MECs) to heat-inactivated E. coli and S. aureus. Gene expression of Toll-like receptor 2 (TLR2) and TLR4 was compared. The activation of nuclear factor kappa B (NF-?B) and the kinetics and levels of cytokine production were analyzed. The results show that the mRNA for TLR2 and TLR4 was up-regulated when the bovine MECs were stimulated with heat-inactivated E. coli, while only TLR2 mRNA was up-regulated when the bovine MECs were stimulated with heat-inactivated S. aureus. The expression of tumor necrosis factor-? (TNF-?), interleukin (IL)-1?, IL-6 and IL-8 increased more rapidly and higher when the bovine MECs were stimulated with heat-inactivated E. coli than when they were stimulated with heat-inactivated S. aureus. E. coli strongly activated NF-?B in the bovine MECs, while S. aureus failed to activate NF-?B. Heat-inactivated S. aureus could induce NF-?B activation when bovine MECs cultured in medium without fetal calf serum. These results were confirmed using TLR2- and TLR4/MD2-transfected HEK293 cells and suggested that differential TLR recognition and the lack of NF-?B activation account for the impaired immune response elicited by heat-inactivated S. aureus.
Related JoVE Video
Block copolymer templated assembly of active Pd nanocube arrays.
Macromol Rapid Commun
PUBLISHED: 08-05-2013
Show Abstract
Hide Abstract
Two-dimensional (2D) palladium nanocube array is achieved on plasma-etched block copolymer templates, while the well-aligned nanocubes remain active. Anisotropic nanocubes are site-selectively assembled on various nanopatterns by capillary force. The nanocube array is proved to be easily tunable, and the dimensional commensurability plays a key role in the configurations of the nanocube assemblies. Not only catalytic nanocube array under confinement but also template for the growth of nanoscale zinc oxide (ZnO) nanorods is exemplified as the potential application of the nanoarray.
Related JoVE Video
Baicalin inhibits Staphylococcus aureus-induced apoptosis by regulating TLR2 and TLR2-related apoptotic factors in the mouse mammary glands.
Eur. J. Pharmacol.
PUBLISHED: 08-04-2013
Show Abstract
Hide Abstract
Baicalin, the major active constituent of the isolated root of Scutellaria baicalensis, is widely used in China and Southeast Asian countries. Evidence has indicated that baicalin has multiple biological activities, including anti-apoptotic properties. Mastitis is a severe problem in humans and other animals and is characterized by mammary gland cell apoptosis. Staphylococcus aureus (S. aureus) is the major pathogen that causes mastitis. This study was designed to evaluate the protective effects of baicalin on the mammary glands during S. aureus-induced mastitis. In the present study, a mouse model was infected with S. aureus to induce mammary gland injury. Baicalin treatment was administered between 6 and 24h after infection. Toll-like receptor 2, p53, BAX, BCL-2 and caspase-3 expression were analyzed using qPCR and Western blotting. The results indicated that baicalin significantly attenuated pathological damage and cell death in the mammary glands. Further studies revealed that baicalin down-regulated the expression of Toll-like receptor 2 (TLR2) and the phosphorylation of p53 in the mammary glands after S. aureus-induced mastitis. Baicalin also promoted the expression of BCL-2 at the mRNA and protein levels but inhibited BAX and caspase-3 (CASP-3) cleavage. Baicalin inhibited apoptosis and had protective effects on mammary gland tissues during S. aureus-induced mastitis. These effects were displayed by reductions in TLR2 expression and p53 phosphorylation and the regulation of apoptosis-related factors (BCL-2, BAX and CASP-3) in mammary gland tissues.
Related JoVE Video
Impaired phosphate and tension homologue deleted on chromosome 10 expression and its prognostic role in radical surgery for hepatocellular carcinoma with family aggregation resulting from hepatitis B and liver cirrhosis.
Exp. Biol. Med. (Maywood)
PUBLISHED: 07-04-2013
Show Abstract
Hide Abstract
This study aimed to retrospectively investigate the expression of the phosphate and tension homologue deleted on chromosome 10 (PTEN) protein and its prognostic role in hepatocellular carcinoma (HCC) with family aggregation resulting from hepatitis B and liver cirrhosis, which have not been established. Immunohistochemical analysis was performed to evaluate the PTEN protein expression in HCC and paired para-cancerous tissues from 79 patients with HCC caused by hepatitis B and liver cirrhosis. Of these cases, 34 represented HCC with family aggregation (HCCF group), and 45 represented HCC with no family aggregation (HCCN group). Follow-up data were collected for 3 months to 10 years and analysed for HCC recurrence, survival time and prognostic risk factors. The expression of the PTEN protein in the HCC tissue was dramatically lower in the HCCF group than in the HCCN group. The six-month, one-year and two-year overall recurrence (OR) rates of the HCCF group were significantly higher than those of the HCCN group. The one-year, two-year and five-year overall survival (OS) rates of the HCCF group were lower than those of the HCCN group. Impaired PTEN protein expression was an independent prognostic risk factor that was significantly correlated with OR and OS in HCC patients. Dramatically impaired PTEN protein expression in HCC patients with family aggregation resulting from hepatitis B and liver cirrhosis was correlated with OR and OS, and impaired PTEN expression was an independent risk factor for prognosis after radical surgery.
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.