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Find video protocols related to scientific articles indexed in Pubmed.
Cucurbit[6]uril-cucurbit[7]uril heterodimer promotes controlled self-assembly of supramolecular networks and supramolecular micelles by self-sorting of amphiphilic guests.
Chem. Commun. (Camb.)
PUBLISHED: 10-16-2014
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We report the synthesis of cucurbit[6]uril-cucurbit[7]uril heterodimer () by click chemistry of monofunctionalized CB[6] and CB[7] derivatives. Combinations of with hydrophobic guest or hydrophilic polymeric guests and deliver hydrophobic or amphiphilic supramolecular block copolymers which form supramolecular networks () and supramolecular micelles (), respectively, in the solid state.
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Effect of gap junctions on the firing patterns and synchrony for different external inputs in the striatal fast-spiking neuron network.
Biomed Mater Eng
PUBLISHED: 09-18-2014
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Gap junctions are the mechanism for striatal fast-spiking interneurons (FSIs) to interconnect with each other and play an important role in determining the physiological functioning of the FSIs. To investigate the effect of gap junctions on the firing activities and synchronization of the network for different external inputs, a simple network with least connections and a Newman-Watts small-world network were constructed. Our research shows that both properties of neural networks are related to the conductance of the gap junctions, as well as the frequency and correlation of the external inputs. The effect of gap junctions on the synchronization of network is different for inputs with different frequencies and correlations. The addition of gap junctions can promote the network synchrony in some conditions but suppress it in others, and they can inhibit the firing activities in most cases. Both the firing rate and synchronization of the network increase along with the increase of the electrical coupling strength for inputs with low frequency and high correlation. Thus, the network of coupled FSIs can act as a detector for synchronous synaptic input from cortex and thalamus.
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RADB: a database of rheumatoid arthritis-related polymorphisms.
Database (Oxford)
PUBLISHED: 09-15-2014
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Rheumatoid arthritis (RA) is an autoimmune disease that has a complex genetic basis. Therefore, it is important to explore the genetic background of RA. The extensive recent application of polymorphic genetic markers, especially single nucleotide polymorphisms, has presented us with a large quantity of genetic data. In this study, we developed the Database of Rheumatoid Arthritis-related Polymorphisms (RADB), to integrate all the RA-related genetic polymorphisms and provide a useful resource for researchers. We manually extracted the RA-related polymorphisms from 686 published reports, including RA susceptibility loci, polymorphisms associated with particular clinical features of RA, polymorphisms associated with drug response in RA and polymorphisms associated with a higher risk of cardiovascular disease in RA. Currently, RADB V1.0 contains 3235 polymorphisms that are associated with 636 genes and refer to 68 countries. The detailed information extracted from the literature includes basic information about the articles (e.g., PubMed ID, title and abstract), population information (e.g., country, geographic area and sample size) and polymorphism information (e.g., polymorphism name, gene, genotype, odds ratio and 95% confidence interval, P-value and risk allele). Meanwhile, useful annotations, such as hyperlinks to dbSNP, GenBank, UCSC, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway, are included. In addition, a tool for meta-analysis was developed to summarize the results of multiple studies. The database is freely available at http://www.bioapp.org/RADB. Database URL: http://www.bioapp.org/RADB.
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Reviewing effectiveness of ankle assessment techniques for use in robot-assisted therapy.
J Rehabil Res Dev
PUBLISHED: 08-22-2014
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This article provides a comprehensive review of studies that investigated ankle assessment techniques to better understand those that can be used in the real-time monitoring of rehabilitation progress for implementation in conjunction with robot-assisted therapy. Seventy-six publications published between January 1980 and August 2013 were selected based on eight databases. They were divided into two main categories (16 qualitative and 60 quantitative studies): 13 goniometer studies, 18 dynamometer studies, and 29 studies about innovative techniques. A total of 465 subjects participated in the 29 quantitative studies of innovative measurement techniques that may potentially be integrated in a real-time monitoring device, of which 19 studies included less than 10 participants. Results show that qualitative ankle assessment methods are not suitable for real-time monitoring in robot-assisted therapy, though they are reliable for certain patients, while the quantitative methods show great potential. The majority of quantitative techniques are reliable in measuring ankle kinematics and kinetics but are usually available only for use in the sagittal plane. Limited studies determine kinematics and kinetics in all three planes (sagittal, transverse, and frontal) where motions of the ankle joint and the subtalar joint actually occur.
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Anti-tumor drug delivery system based on cyclodextrin-containing pH-responsive star polymer: in vitro and in vivo evaluation.
Int J Pharm
PUBLISHED: 08-19-2014
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A cyclodextrin-containing pH-responsive star polymer, with cyclodextrin polymer and pH-sensitive poly(2-(dimethylamino)ethyl methacrylate) as the core and poly(ethylene glycol) as the arm, was evaluated as drug carriers in vitro and in vivo. Doxorubicin (DOX) was successfully loaded into the star polymer to form nanoparticles (DOX-NPs) via host-guest interaction. The physicochemical properties such as drug loading content, size, morphology, stability and physical state of DOX-NPs were characterized in detail by (1)H NMR, DLS, SEM and DSC. Uniform and stable DOX-NPs with high encapsulation efficiency of 77.1% were obtained, and they also exhibited sustainable and controllable release of DOX in vitro. The cellular uptake of DOX-NPs was in concentration-, time- and cell type-dependent manners, and the cytotoxicity of DOX-NPs was significantly high toward HeLa and HepG2 cancer cells. Furthermore, in vivo anti-tumor experiment on BALB/c mice bearing cervical tumor showed that DOX-NPs could effectively suppress the growth of tumor without significant side effect. These findings suggest that the cyclodextrin-containing pH-responsive star polymer has a promising potential in developing novel drug delivery system for cancer therapy.
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[Advances in functional genomics studies underlying acetic acid tolerance of Saccharomyces cerevisiae].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 07-11-2014
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Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals.
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[Dietary habits of school-age children and its associations with blood pressure level in Beijing, China].
Zhonghua Yu Fang Yi Xue Za Zhi
PUBLISHED: 07-03-2014
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To study the dietary habits of school-age children in urban and rural districts and their association with blood pressure levels in Beijing, China.
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Down-regulation of MIF by NF?B under hypoxia accelerated neuronal loss during stroke.
FASEB J.
PUBLISHED: 06-26-2014
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Neuronal apoptosis is one of the major causes of poststroke neurological deficits. Inflammation during the acute phase of stroke results in nuclear translocation of NF?B in affected cells in the infarct area. Macrophage migration inhibitory factor (MIF) promotes cardiomyocyte survival in mice following heart ischemia. However, the role of MIF during stroke remains limited. In this study, we showed that MIF expression is down-regulated by 0.75 ± 0.10-fold of the control in the infarct area in the mouse brains. Two functional cis-acing NF?B response elements were identified in the human MIF promoter. Dual activation of hypoxia and NF?B signaling resulted in significant reduction of MIF promoter activity to 0.86 ± 0.01-fold of the control. Furthermore, MIF reduced caspase-3 activation and protected neurons from oxidative stress- and in vitro ischemia/reperfusion-induced apoptosis. H2O2 significantly induced cell death with 12.81 ± 0.58-fold increase of TUNEL-positive cells, and overexpression of MIF blocked the H2O2-induced cell death. Disruption of the MIF gene in MIF-knockout mice resulted in caspase-3 activation, neuronal loss, and increased infarct development during stroke in vivo. The infarct volume was increased from 6.51 ± 0.74% in the wild-type mice to 9.07 ± 0.66% in the MIF-knockout mice. Our study demonstrates that MIF exerts a neuronal protective effect and that down-regulation of MIF by NF?B-mediated signaling under hypoxia accelerates neuronal loss during stroke. Our results suggest that MIF is an important molecule for preserving a longer time window for stroke treatment, and strategies to maintain MIF expression at physiological level could have beneficial effects for stroke patients.
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Associations between serum 25-hydroxyvitamin D and disease activity, inflammatory cytokines and bone loss in patients with rheumatoid arthritis.
Rheumatology (Oxford)
PUBLISHED: 06-06-2014
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The aim of this study was to describe the associations between serum levels of 25-hydroxyvitamin D [25(OH)D] and disease activity, inflammatory cytokines and bone loss/erosions in patients with RA.
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Stimuli-responsive host-guest systems based on the recognition of cryptands by organic guests.
Acc. Chem. Res.
PUBLISHED: 05-08-2014
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CONSPECTUS: As the star compounds in host-guest chemistry, the syntheses of crown ethers proclaimed the birth of supramolecular chemistry. Crown ether-based host-guest systems have attracted great attention in self-assembly processes because of their good selectivity, high efficiency, and convenient responsiveness, enabling their facile application to the "bottom-up" approach for construction of functional molecular aggregates, such as artificial molecular machines, drug delivery materials, and supramolecular polymers. Cryptands, as preorganized derivatives of crown ethers, not only possess the above-mentioned properties but also have three-dimensional spatial structures and higher association constants compared with crown ethers. More importantly, the introduction of the additional arms makes cryptand-based host-guest systems responsive to more stimuli, which is crucial for the construction of adaptive or smart materials. In the past decade, we designed and synthesized crown ether-based cryptands as a new type of host for small organic guests with the purpose of greatly increasing the stabilities of the host-guest complexes and preparing mechanically interlocked structures and large supramolecular systems more efficiently while retaining or increasing their stimuli-responsiveness. Organic molecules such as paraquat derivatives and secondary ammonium salts have been widely used in the fabrication of functional supramolecular aggregates. Many host molecules including crown ethers, cyclodextrins, calixarenes, cucurbiturils, pillararenes, and cryptands have been used in the preparation of self-assembled structures with these guest molecules, but among them cryptands exhibit the best stabilities with paraquat derivatives in organic solvents due to their preorganization and additional and optimized binding sites. They enable the construction of sophisticated molecules or supramolecules in high yields, affording a very efficient way to fabricate stimuli-responsive functional supramolecular systems. This Account mainly focuses on the application of cryptands in the construction of mechanically interlocked molecules such as rotaxanes and catenanes, and stimuli-responsive host-guest systems such as molecular switches and supramolecular polymers due to their good host-guest properties. These cryptands are bicyclic derivatives of crown ethers, including dibenzo-24-crown-8, bis(m-phenylene)-26-crown-8, dibenzo-30-crown-10, and bis(m-phenylene)-32-crown-10. The length of the third arm has a very important influence on the binding strength of these cryptands with organic guests, because it affects not only the size fit between the host and the guest but also the distances and angles that govern the strengths of the noncovalent interactions between the host and the guest. For example, for bis(m-phenylene)-32-crown-10-based cryptands, a third arm of nine atoms is the best. The environmental responsiveness of these cryptand-based host-guest systems arises from either the crown ether units or the third arms. For example, a dibenzo-24-crown-8 unit introduces potassium cation responsiveness and an azobenzene group on the third arm imbues photoresponsiveness. We believe that studies on stimuli-responsive host-guest systems based on cryptands and organic guests will contribute significantly to future research on molecular devices, supramolecular polymers, and other functional supramolecular materials.
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Low-molecular-mass gels responding to ultrasound and mechanical stress: towards self-healing materials.
Chem Soc Rev
PUBLISHED: 04-29-2014
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In this review, we focus on the types of smart supramolecular gels whose self-assembly processes are affected or even triggered by physical forces including sonication and mechanical stress (mechanical force). The types of gels that are responsive to sonication and mechanical stress are examined and summarised. The gels exhibit non-covalent interactions among the gelator molecules and show dynamic and reversible properties controlled by the stimuli. Upon stimulation, the gelators cause instant and in situ gelation of organic solvents or water with different modes and outcomes of self-assembly. On the other hand, sonication and mechanical stress, as external factors, can give rise to dynamic changes in microscopic morphology, optical properties, etc. Certain thixotropic supramolecular gels exhibit perfect self-healing characteristics. The driving forces and the mechanism of the self-assembly process and the responsive outcome of morphological and spectroscopic changes are discussed. Those supramolecular gels responding to sonication and mechanical stress offer a wide range of applications in fields such as smart and adaptive materials, switches, drug control and release, and tissue engineering.
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A multiple-responsive self-healing supramolecular polymer gel network based on multiple orthogonal interactions.
Macromol Rapid Commun
PUBLISHED: 04-12-2014
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Supramolecular polymer networks have attracted considerable attention not only due to their topological importance but also because they can show some fantastic properties such as stimuli-responsiveness and self-healing. Although various supramolecular networks are constructed by supramolecular chemists based on different non-covalent interactions, supramolecular polymer networks based on multiple orthogonal interactions are still rare. Here, a supramolecular polymer network is presented on the basis of the host-guest interactions between dibenzo-24-crown-8 (DB24C8) and dibenzylammonium salts (DBAS), the metal-ligand coordination interactions between terpyridine and Zn(OTf)2 , and between 1,2,3-triazole and PdCl2 (PhCN)2 . The topology of the networks can be easily tuned from monomer to main-chain supramolecular polymer and then to the supramolecular networks. This process is well studied by various characterization methods such as (1) H NMR, UV-vis, DOSY, viscosity, and rheological measurements. More importantly, a supramolecular gel is obtained at high concentrations of the supramolecular networks, which demonstrates both stimuli-responsiveness and self-healing properties.
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Upregulation of SET Expression by BACE1 and its Implications in Down Syndrome.
Mol. Neurobiol.
PUBLISHED: 03-12-2014
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Down syndrome (DS) is one of the most common genetic diseases. Patients with DS display growth delay and intellectual disabilities and develop Alzheimer's disease (AD) neuropathology after middle age, including neuritic plaques and neurofibrillary tangles. Beta-site amyloid ? precursor protein (APP) cleaving enzyme 1 (BACE1), essential for A? production and neuritic plaque formation, is elevated in DS patients. However, its homolog, ?-site APP cleaving enzyme 2 (BACE2), functions as ?-secretase and plays a differential role in plaque formation. In this study, by using Two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (2D SDS-PAGE) and LC-MS/MS proteomic profiling analysis, we found that the SET oncogene protein (SET) expression was associated with BACE1 but not BACE2. SET protein was increased in BACE1 overexpressing cells and was markedly reduced in the BACE1 knockout mice. We found that the overexpression of BACE1 or SET significantly inhibited cell proliferation. Moreover, knockdown of SET in BACE1 overexpression cells significantly rescued BACE1-induced cell growth suppression. Furthermore, both BACE1 and SET protein levels were increased in Down syndrome patients. It suggests that BACE1 overexpression-induced SET upregulation may contribute to growth delay and cognitive impairment in DS patients. Our work provides a new insight that BACE1 overexpression not only promotes neuritic plaque formation but may also potentiate neurodegeneration mediated by SET elevation in Alzheimer-associated dementia in DS.
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Acorns containing deeper plumule survive better: how white oaks counter embryo excision by rodents.
Ecol Evol
PUBLISHED: 01-24-2014
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Several squirrel species excise the embryo of acorns of most white oak species to arrest germination for long-term storage. However, it is not clear how these acorns counter embryo excision and survive in the arms race of coevolution. In this study, we simulated the embryo excision behavior of squirrels by removing 4 mm of cotyledon from the apical end of white oak acorns differing in embryo depths to investigate the effects of embryo excision on acorn germination and seedling performance of white oak species. The embryo depth in the cotyledons was significantly different among white oak acorns, with Quercus mongolica containing the embryo most deeply in the acorns. We found that artificial embryo excision significantly decreased acorn germination rates of Quercus variabilis, Quercus acutissima, Quercus aliena, Quercus aliena var. acutiserrata, Quercus serrata. var. brevipetiolata but not Q. mongolica. Artificial embryo excision exerted significant negative impacts on seedling performance of all oak species except Quercus aliena. Our study demonstrates the role of embryo depth of acorns in countering embryo excision by squirrels and may explain the fact that squirrels do not perform embryo excision in acorns of Q. mongolica with deeper embryos. This apparent adaptation of acorns sheds light on the coevolutionary dynamics between oaks and their seed predators.
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Propagation of epileptiform activity can be independent of synaptic transmission, gap junctions, or diffusion and is consistent with electrical field transmission.
J. Neurosci.
PUBLISHED: 01-24-2014
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The propagation of activity in neural tissue is generally associated with synaptic transmission, but epileptiform activity in the hippocampus can propagate with or without synaptic transmission at a speed of ?0.1 m/s. This suggests an underlying common nonsynaptic mechanism for propagation. To study this mechanism, we developed a novel unfolded hippocampus preparation, from CD1 mice of either sex, which preserves the transverse and longitudinal connections and recorded activity with a penetrating microelectrode array. Experiments using synaptic transmission and gap junction blockers indicated that longitudinal propagation is independent of chemical or electrical synaptic transmission. Propagation speeds of 0.1 m/s are not compatible with ionic diffusion or pure axonal conduction. The only other means of communication between neurons is through electric fields. Computer simulations revealed that activity can indeed propagate from cell to cell solely through field effects. These results point to an unexpected propagation mechanism for neural activity in the hippocampus involving endogenous field effect transmission.
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Association between polymorphisms in the promoter region of interleukin-10 and susceptibility to inflammatory bowel disease.
Mol. Biol. Rep.
PUBLISHED: 01-10-2014
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The aim of this study was to assess the association of polymorphisms in the promoter region of the IL-10 gene with the risk of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Fifteen studies (3,693 cases and 4,574 controls) were included in a meta-analysis of association between IL-10 -1082G/A, -819C/T and -592C/A polymorphisms, and IBD, CD and UC using allele contrast and the recessive, dominant, and additive models. Hardy-Weinberg equilibrium was confirmed for each study. Heterogeneity and study quality were investigated using stratification analyses and sensitivity analyses. Polymorphism -1082G/A showed significant association with CD, with odds ratios (ORs) for the GG + GA genotype and GG versus AA genotype of 1.278 (1.004-1.627) and 1.238 (1.027-1.492) in all subjects. Significant associations were found in the Caucasian subgroup using the allele contrast, dominant, and additive models. C-allele carriers of the -819C/T polymorphism were at increased risk of IBD (OR 1.093, 95% CI 1.004-1.190). Association with the -819C/T polymorphism was also found in Caucasians with CD (C vs. T: OR 1.104, 95% CI 1.010-1.206; CC + CT vs. TT: OR 1.328, 95% CI 1.006-1.754; CC vs. TT: OR 1.339, 95% CI 1.008-1.778), and with UC (CC vs. CT + TT: OR 1.188, 95% CI 1.019-1.385). No significant association was found between the -592C/A polymorphism and IBD, CD or UC. In conclusion, the meta-analysis demonstrated clear association between the IL-10 polymorphisms -1082G/A and -819C/T and the risk of IBD.
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Lin28a Protects against Hypoxia/Reoxygenation Induced Cardiomyocytes Apoptosis by Alleviating Mitochondrial Dysfunction under High Glucose/High Fat Conditions.
PLoS ONE
PUBLISHED: 01-01-2014
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The aim of the present study was to investigate the role of Lin28a in protecting against hypoxia/reoxygenation (H/R)-induced cardiomyocytes apoptosis under high glucose/high fat (HG/HF) conditions.
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Faecalibacterium prausnitzii inhibits interleukin-17 to ameliorate colorectal colitis in rats.
PLoS ONE
PUBLISHED: 01-01-2014
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It has been shown that Faecalibacterium prausnitzii (F. prausnitzii), one of the dominant intestinal bacterial flora, may protect colonic mucosa against the development of inflammation and subsequent inflammatory bowel disease (IBD), with the underlying mechanisms being unclear.
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Incorporating cache management behavior into seed dispersal: the effect of pericarp removal on acorn germination.
PLoS ONE
PUBLISHED: 01-01-2014
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Selecting seeds for long-term storage is a key factor for food hoarding animals. Siberian chipmunks (Tamias sibiricus) remove the pericarp and scatter hoard sound acorns of Quercus mongolica over those that are insect-infested to maximize returns from caches. We have no knowledge of whether these chipmunks remove the pericarp from acorns of other species of oaks and if this behavior benefits seedling establishment. In this study, we tested whether Siberian chipmunks engage in this behavior with acorns of three other Chinese oak species, Q. variabilis, Q. aliena and Q. serrata var. brevipetiolata, and how the dispersal and germination of these acorns are affected. Our results show that when chipmunks were provided with sound and infested acorns of Quercus variabilis, Q. aliena and Q. serrata var. brevipetiolata, the two types were equally harvested and dispersed. This preference suggests that Siberian chipmunks are incapable of distinguishing between sound and insect-infested acorns. However, Siberian chipmunks removed the pericarp from acorns of these three oak species prior to dispersing and caching them. Consequently, significantly more sound acorns were scatter hoarded and more infested acorns were immediately consumed. Additionally, indoor germination experiments showed that pericarp removal by chipmunks promoted acorn germination while artificial removal showed no significant effect. Our results show that pericarp removal allows Siberian chipmunks to effectively discriminate against insect-infested acorns and may represent an adaptive behavior for cache management. Because of the germination patterns of pericarp-removed acorns, we argue that the foraging behavior of Siberian chipmunks could have potential impacts on the dispersal and germination of acorns from various oak species.
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MCPerm: a Monte Carlo permutation method for accurately correcting the multiple testing in a meta-analysis of genetic association studies.
PLoS ONE
PUBLISHED: 01-01-2014
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Traditional permutation (TradPerm) tests are usually considered the gold standard for multiple testing corrections. However, they can be difficult to complete for the meta-analyses of genetic association studies based on multiple single nucleotide polymorphism loci as they depend on individual-level genotype and phenotype data to perform random shuffles, which are not easy to obtain. Most meta-analyses have therefore been performed using summary statistics from previously published studies. To carry out a permutation using only genotype counts without changing the size of the TradPerm P-value, we developed a Monte Carlo permutation (MCPerm) method. First, for each study included in the meta-analysis, we used a two-step hypergeometric distribution to generate a random number of genotypes in cases and controls. We then carried out a meta-analysis using these random genotype data. Finally, we obtained the corrected permutation P-value of the meta-analysis by repeating the entire process N times. We used five real datasets and five simulation datasets to evaluate the MCPerm method and our results showed the following: (1) MCPerm requires only the summary statistics of the genotype, without the need for individual-level data; (2) Genotype counts generated by our two-step hypergeometric distributions had the same distributions as genotype counts generated by shuffling; (3) MCPerm had almost exactly the same permutation P-values as TradPerm (r = 0.999; P<2.2e-16); (4) The calculation speed of MCPerm is much faster than that of TradPerm. In summary, MCPerm appears to be a viable alternative to TradPerm, and we have developed it as a freely available R package at CRAN: http://cran.r-project.org/web/packages/MCPerm/index.html.
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A stimuli-responsive orthogonal supramolecular polymer network formed by metal-ligand and host-guest interactions.
Chem. Commun. (Camb.)
PUBLISHED: 11-28-2013
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A stimuli-responsive supramolecular polymer network was constructed by the orthogonal assembly of metal-ligand interactions and host-guest interactions.
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[Breeding of robust industrial ethanol-tolerant Saccharomyces cerevisiae strain by artificial zinc finger protein library].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 09-10-2013
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Breeding of robust industrial Saccharomyces cerevisiae strains with high ethanol tolerance is of great significance for efficient fuel ethanol production. Zinc finger proteins play important roles in gene transcription and translation, and exerting control on the regulation of multiple genes. The sequence and localization of the zinc finger motif can be designed and engineered, and the artificial zinc finger protein can be used to regulate celluar metabolism. Stress tolerance of microbial strains is related to multiple genes. Therefore, it is possible to use artificially-designed zinc finger proteins to breed stress tolerant strains. In this study, a library containing artificial zinc finger protein encoding genes was transformed into the model yeast strain S288c. A recombinant strain named M01 with improved ethanol tolerance was obtained. The plasmid in M01 was isolated, and then transformed into the industrial yeast strain Sc4126. Ethanol tolerance of the recombinant strain of Sc4126 were significantly improved. When high gravity ethanol fermentation using 250 g/L glucose was performed, comparing with the wild-type strain, fermentation time of the recombinant strain was decreased by 24 h and the final ethanol concentration was enhanced by 6.3%. The results of this study demonstrate that artificial zinc finger proteins are able to exert control on stress tolerance of yeast strains, and these results provide basis to construct robust industrial yeast strains for efficient ethanol fermentation.
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Reconsidering the effects of tannin on seed dispersal by rodents: Evidence from enclosure and field experiments with artificial seeds.
Behav. Processes
PUBLISHED: 08-02-2013
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The question of how tannin affects feeding and hoarding preferences of rodents still remains poorly understood, in part, because it is difficult to control for other seed traits when considering the sole effect of tannin. Here, we constructed a series of artificial seeds with different tannin levels, made from wheat flour, peanut powder and hydrolysable tannins, to determine the direct effects of tannin on both feeding and hoarding preferences. We first presented seeds to individual rodents of two species (Tamias sibiricus and Apodemus peninsulae) confined in semi-natural enclosures and then monitored patterns of seed dispersal and consumption by free-ranging animals in a temperate forest in the Xiaoxingan Mountains, Heilongjiang Province of China. Our results showed that small rodents displayed a significant preference for low-tannin seeds for both consumption and caching in both captive and field experiments. Moreover, our two-year study consistently showed that tannin concentration was significantly and negatively correlated with the number of cached seeds at both the individual and population levels. Seed size, compared with tannin concentrations, appeared to have little effect on dispersal distances and the number of seeds cached. Low-tannin seeds tended to be dispersed greater distances by rodents in the field than those with higher levels of tannin. These results failed to support those of previous reports indicating that acorns containing higher tannins are more likely to be cached by food hoarding animals.
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Benzo-21-crown-7/secondary ammonium salt [2]rotaxanes with fluoro/chlorocarbon blocking groups.
Org. Lett.
PUBLISHED: 07-09-2013
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Three threaded structures capped by fluoro/chlorocarbon blocking groups with different sizes were constructed by template synthesis based on the benzo-21-crown-7/secondary ammonium salt recognition motif, as confirmed by (1)H NMR, electrospray mass spectrometry and single crystal X-ray analysis. The transformation from a rotaxane-like entity into a rotaxane was achieved by replacing the end group from the trifluoroacetic ester group to its trichloroacetic ester analogue.
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Biological function of Presenilin and its role in AD pathogenesis.
Transl Neurodegener
PUBLISHED: 05-19-2013
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Presenilins (PSs) are the catalytic core of ?-secretase complex. However, the mechanism of FAD-associated PS mutations in AD pathogenesis still remains elusive. Here we review the general biology and mechanism of ?-secretase and focus on the catalytic components - presenilins and their biological functions and contributions to the AD pathogenesis. The functions of presenilins are divided into ?-secretase dependent and ?-secretase independent ones. The ?-secretase dependent functions of presenilins are exemplified by the sequential cleavages in the processing of APP and Notch; the ?-secretase independent functions of presenilins include stabilizing ?-catenin in Wnt signaling pathway, regulating calcium homeostasis and their interaction with synaptic transmission.
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The chemical chaperon 4-phenylbutyric acid ameliorates hepatic steatosis through inhibition of de novo lipogenesis in high-fructose-fed rats.
Int. J. Mol. Med.
PUBLISHED: 05-16-2013
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Non-alcoholic fatty liver disease caused by dietary factors such as a high fructose intake is a growing global concern. The aim of this study was to investigate the intervention effects of an endoplasmic reticulum stress (ERS) inhibitor 4-phenylbutyric acid (PBA) on liver steatosis induced by high-fructose feeding in rats and the possible underlying mechanisms. Wistar rats were divided into the control, high-fructose group (HFru) and PBA intervention (HFru-PBA) groups. PBA intervention was initiated following 4 weeks of high-fructose feeding. After 8 weeks of feeding, the ERS markers p-PERK, p-eIF2?, p-IRE-1, spliced XBP-1, ATF-6 were measured by western blotting. Liver triglyceride contents and morphological changes were examined. The protein expression of lipogenic key enzymes (ACC, FAS and SCD-1) and upstream transcriptional factors (SREBP-1c and ChREBP) were measured. The ERS-related cell events, oxidative stress and apoptosis, were evaluated by standard methods. Results demonstrated that PBA intervention significantly resolved hepatic ERS and improved liver steatosis induced by high-fructose feeding in rats. The protein expression of ACC, FAS, SCD-1 and SREBP-1c was upregulated in high-fructose-fed rats, whereas it decreased following PBA intervention. Oxidative stress and apoptosis were observed in livers of high-fructose-fed rats, but were alleviated by PBA intervention. ERS is involved in the development of fatty liver induced by a high fructose intake. ERS inhibition by PBA can therefore ameliorate liver steatosis through inhibition of hepatic lipogenesis.
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Preparation and characterization of lignin based macromonomer and its copolymers with butyl methacrylate.
Int. J. Biol. Macromol.
PUBLISHED: 05-14-2013
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Copolymerization of butyl methacrylate (BMA) with biobutanol lignin (BBL) was achieved by free-radical polymerization (FRP) using a lignin-based macromonomer. The lignin-based macromonomer containing acrylic groups was prepared by reacting acryloyl chloride with biobutanol lignin using triethylamine (TEA) as absorb acid agentin. From the results of elemental analysis and GPC, the average degree of polymerization (DP) of BBL was estimated to be five. A detailed molecular characterization has been performed, including techniques such as (1)H NMR, (13)C NMR and UV-vis spectroscopies, which provided quantitative information about the composition of the copolymers. The changes in the solubility of lignin-g-poly(BMA) copolymers in ethyl ether were dependent on the length of poly(BMA) side chain. TGA analysis indicated that the lignin-containing poly(BMA) graft copolymers exhibited high thermal stability. The bulky aromatic group of lignin increased the glass-transition temperature of poly(BMA). In order to confirm the main structure of copolymer, (AC-g-BBL)-co-BMA copolymer was also synthesized by atom transfer radical polymerization (ATRP), and the results revealed that the copolymer prepared by ATRP had the same solution behavior as that prepared by FRP, and the lignin-based macromonomer showed no homopolymerizability due to the steric hindrance. In addition, the lignin-co-BMA copolymer had a surprisingly higher molecular weight than poly(BMA) under the same reaction condition, suggesting that a branched lignin based polymer could be formed.
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Threaded structures based on the benzo-21-crown-7/secondary ammonium salt recognition motif using esters as end groups.
Org. Biomol. Chem.
PUBLISHED: 05-10-2013
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It was demonstrated that various threaded structures could be constructed by employing different esters as end groups based on the benzo-21-crown-7/secondary ammonium salt recognition motif. The chemical structures of all synthesized compounds were confirmed by (1)H and (13)C NMR spectroscopy as well as mass spectrometry. Single crystal X-ray analysis revealed that all compounds are threaded structures in the solid state. NMR experiments distinguished the rotaxane-like entities from [2]rotaxanes. The threaded structures capped by linear n-alkyl end groups are rotaxane-like entities. The gradual elongation of the ester alkyl chain tails results in the increased stability of the corresponding threaded structures. When the tail is an isopropyl group, a mechanically interlocked rotaxane can be constructed.
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MicroRNA/mRNA profiling and regulatory network of intracranial aneurysm.
BMC Med Genomics
PUBLISHED: 04-20-2013
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Intracranial aneurysm (IA) is one of the most lethal forms of cerebrovascular diseases characterized by endothelial dysfunction, vascular smooth muscle cell phenotypic modulation, inflammation and consequently loss of vessel cells and extracellular matrix degradation. Besides environmental factors, genetics seem to be a very important factor in the genesis of this disease. Previous mRNA expression studies revealed a large number of differentially expressed genes between IA and control tissue. However, microRNAs (miRNA), small non-coding RNAs which are post-transcriptional regulators of gene expression, have been barely studied. Studying miRNAs could provide a hypothetical mechanism underlying rupture of IA.
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Guest induced morphological transformation from nanospheres to nanowires by hydrogen bond self-assembly.
Dalton Trans
PUBLISHED: 03-02-2013
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Phosphorescent nanospheres of a carboxyl-functionalized iridium complex ([Ir(ppy)2(Hdcbpy)], ppy: 2-phenylpyridine; Hdcbpy: 4-carboxy-2,2-bipyridyl-4-carboxylate) were prepared by a conventional precipitation method. Driven by hydrogen bond interaction between carboxylic groups of the complex and the guest molecule tris(imidazoline), these nanospheres can be transformed into 1-dimensional nanowires in the presence of tris(imidazoline) at the concentration of the iridium complex higher than 4.8 mM, while nanowires change back to nanospheres with the diameter obviously smaller than that of the sole complex of [Ir(ppy)2(Hdcbpy)]. The interaction between carboxylic groups and tris(imidazoline) molecules was confirmed by FT-IR spectra. The structures of the nanowires and nanospheres were further studied by XRD diffraction analysis. With the morphological transformation from nanospheres to nanowires, the phosphorescence of nanostructures was blue shifted from 590 to 564 nm.
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Effectiveness of robot-assisted therapy on ankle rehabilitation--a systematic review.
J Neuroeng Rehabil
PUBLISHED: 02-22-2013
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The aim of this study was to provide a systematic review of studies that investigated the effectiveness of robot-assisted therapy on ankle motor and function recovery from musculoskeletal or neurologic ankle injuries.
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Hospital survey on patient safety culture in China.
BMC Health Serv Res
PUBLISHED: 01-11-2013
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Patient safety culture is an important measure in assessing the quality of health care. There is a growing recognition of the need to establish a culture of hospital focused on patient safety. This study explores the attitudes and perceptions of patient safety culture for health care workers in China by using a Hospital Survey on Patient Safety Culture (HSPSC) questionnaire and comparing it with the psychometric properties of an adapted translation of the HSPSC in Chinese hospitals with that of the US.
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Facial corticobulbar motor-evoked potential monitoring during the clipping of large and giant aneurysms of the anterior circulation.
J Clin Neurosci
PUBLISHED: 01-11-2013
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Surgical outcomes for large and giant intracranial aneurysms are suboptimal. Two important reasons for higher complication rates are either occlusion of perforators or parent arteries during aneurysm clipping, or prolonged temporary occlusion of the main arteries. Somatosensory-evoked potential (SSEP) monitoring and transcranial motor-evoked potential (TcMEP) monitoring are standard techniques for monitoring ischemia either during temporary arterial occlusion or after permanent clipping. In our study, facial corticobulbar motor-evoked potential (FCoMEP) monitoring was included to determine whether this modality improved intraoperative monitoring. FCoMEP were recorded intraoperatively in 21 patients undergoing surgical clipping of large and giant aneurysms of the anterior circulation. Valid TcMEP parameters were obtained for all patients. A correlation tending to significance between a prolonged temporary clipping time and TcMEP decrement was observed. In addition to this, the inclusion of FCoMEP improved the sensitivity of extremity muscle motor-evoked potential (ExMEP, which included TcMEP) monitoring (from 80% to 100%). In the long-term assessment, a favorable outcome was achieved in 16 of the 21 patients (76%). In conclusion, FCoMEP provides complementary corticobulbar tract information for detecting perforating vessel compromise that may lead to motor impairment and that is not identified by ExMEP.
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Identification and characterization of small molecule inhibitors of signal transducer and activator of transcription 3 (STAT3) signaling pathway by virtual screening.
Bioorg. Med. Chem. Lett.
PUBLISHED: 01-07-2013
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Inhibition of the signal transducer and activator of transcription 3 (STAT3) signaling pathway has been considered a novel therapeutic strategy to treat human cancers that harbor aberrantly-active STAT3. In this study, a series of small molecules were identified as novel inhibitors of STAT3 signaling pathway through virtual screening. A tricyclic scaffold containing compound, 6, was identified as an inhibitor of IL-6/STAT3 signaling with an IC50 of 26.68 ?M. In addition, this compound inhibited Tyr705 phosphorylation of STAT3 and had no obvious effect on upstream tyrosine kinases. Thus, compound 6 is a potential lead structure and valuable for further drug development.
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Literature review regarding patient safety culture.
J Evid Based Med
PUBLISHED: 01-05-2013
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Quite a number of articles on patient safety culture have been published in recent 10 years to assess the safety culture in hospitals using the Hospital Survey on Patient Safety Culture in many countries. However, until now there have been no relevant studies to investigate the quality of these, and their contribution to present-day thinking.
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Discovery of novel inhibitors of signal transducer and activator of transcription 3 (STAT3) signaling pathway by virtual screening.
Eur J Med Chem
PUBLISHED: 01-04-2013
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Inhibition of the signal transducer and activator of transcription 3 (STAT3) signaling pathway has been considered a novel therapeutic strategy to treat human cancers that harbor aberrantly-active STAT3. In this study, nearly 204,000 compounds in Specs database were screened by virtual screening, and samples of top 100 compounds identified as candidate small-molecule inhibitors of STAT3 were evaluated by STAT3-dependent luciferase reporter assay as well as other cell-based assays. A benzothiazole core scaffold containing compound, 9, was identified as an inhibitor of IL-6/STAT3 signaling with an IC50 of 3.567 ?M. It is the first time to discover benzothiazole scaffold as a potent STAT3 signaling inhibitor. We further investigated the (structure-activity relationship) SAR of the benzothiazole analogues, and discovered compound 16w as a better small-molecule inhibitor. Both compounds inhibited the phosphorylation of STAT3 and had no obvious effect on upstream JAK2 kinase.
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Synthesis of a water-soluble bis(m-phenylene)-32-crown-10-based cryptand and its pH-responsive binding to a paraquat derivative.
Chem. Commun. (Camb.)
PUBLISHED: 01-04-2013
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By introducing a third arm with two anionic carboxylate groups, a water-soluble bis(m-phenylene)-32-crown-10-based cryptand was synthesized. Its pH-controlled host-guest complexation with a paraquat derivative in water was studied.
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Serine Protease MP2 Activates Prophenoloxidase in the Melanization Immune Response of Drosophila melanogaster.
PLoS ONE
PUBLISHED: 01-01-2013
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In arthropods, melanization plays a major role in the innate immune response to encapsulate and kill the invasive organisms. It is mediated by a serine protease cascade and is regulated by serpins. The identification of the molecular components of melanization and the regulation of those components are still unclear in Drosophila melanogaster, although some genetic research on the activation of melanization has been reported. Here we report that Drosophila serine protease MP2 directly cleaves both recombinant and native prophenoloxidase-1. Overexpression or repression of MP2 in flies resulted in increased and decreased rates of cleavage, respectively, of prophenoloxidase-1. Moreover, serine protease inhibitor Spn27A formed SDS-stable complexes with MP2, both in vitro and in vivo. The amidase activity of MP2 was inhibited efficiently by Spn27A. Spn27A also prevented MP2 from cleaving prophenoloxidase-1. Taken together, these results indicate that under our experimental conditions MP2 functions as a prophenoloxidase-activating protease, and that this function is inhibited by Spn27A. MP2 and Spn27A thus constitute a regulatory unit in the prophenoloxidase activation cascade in Drosophila. The combination of genetic, molecular genetic and biochemical approaches should allow further advances in our understanding of the prophenoloxidase-activating cascade in insects and indirectly shed further light on protease-cascades in humans and other vertebrates.
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Identification and expression profile analysis of antimicrobial peptide/protein in Asian corn borer, Ostrinia furnacalis (Guenée).
Int. J. Biol. Sci.
PUBLISHED: 01-01-2013
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Antimicrobial peptides/proteins (AMPs) are a group of immune proteins that exhibit strong antibiotic properties against numerous infectious bacterial strains. They are evolutionarily conserved and present in every kingdom and phylum, ranging from prokaryotes to humans. We analyzed the transciptome from the larvae of Asian corn borer, Ostrinia furnacalis (Guenée), and identified several putative AMP transcripts, OfgLys5, OfgLys6, OfgLys10, OfgAtt, and OfgIID. OfgLys5, OfgLys6, and OfgLys10 are all highly homologous with c-type lysozymes, and OfgAtt shows significant identities with Lepidoptera attacin. The amino acid sequence of OfgLys5 and OfgLys6 possessed all conserved features critical for fundamental structure and function of c-type lysozyme, including the two catalytic sites, Glu(32) and Asp(50). OfgAtt is a typical glycine-rich protein. The antimicrobial activity of O. furnacalis hemolymph increased significantly after injection with Escherichia coli, Micrococcus luteus, or Beauveria bassiana. OfgAtt, IDD, and Lys6 are expressed at low level prior to the challenge, but strongly induced against Gram-positive and negative bacteria, and fungi. Under the same inducement conditions, the transcripts of these three genes elevated most when fifth instar larvae were injected. Therefore, O. furnacalis larvae are induced to produce antimicrobial materials in the hemolymph after the infection, and increase of lysozyme and attacin may contribute to the antimicrobial activity.
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Regulation of sleep by neuropeptide Y-like system in Drosophila melanogaster.
PLoS ONE
PUBLISHED: 01-01-2013
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Sleep is important for maintenance of normal physiology in animals. In mammals, neuropeptide Y (NPY), a homolog of Drosophila neuropeptide F (NPF), is involved in sleep regulation, with different effects in human and rat. However, the function of NPF on sleep in Drosophila melanogaster has not yet been described. In this study, we investigated the effects of NPF and its receptor-neuropeptide F receptor (NPFR1) on Drosophila sleep. Male flies over-expressing NPF or NPFR1 exhibited increased sleep during the nighttime. Further analysis demonstrated that sleep episode duration during nighttime was greatly increased and sleep latency was significantly reduced, indicating that NPF and NPFR1 promote sleep quality, and their action on sleep is not because of an impact of the NPF signal system on development. Moreover, the homeostatic regulation of flies after sleep deprivation was disrupted by altered NPF signaling, since sleep deprivation decreased transcription of NPF in control flies, and there were less sleep loss during sleep deprivation and less sleep gain after sleep deprivation in flies overexpressing NPF and NPFR1 than in control flies, suggesting that NPF system auto-regulation plays an important role in sleep homeostasis. However, these effects did not occur in females, suggesting a sex-dependent regulatory function in sleep for NPF and NPFR1. NPF in D1 brain neurons showed male-specific expression, providing the cellular locus for male-specific regulation of sleep by NPF and NPFR1. This study brings a new understanding into sleep studies of a sexually dimorphic regulatory mode in female and male flies.
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A benzo-21-crown-7/secondary ammonium salt [c2]daisy chain.
Org. Lett.
PUBLISHED: 12-13-2011
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A [c2]daisy chain has been constructed from a heteroditopic monomer based on the benzo-21-crown-7/secondary ammonium salt recognition motif as shown by single crystal X-ray analysis. It has been further demonstrated that the complexation behavior of this heteroditopic monomer in solution can be controlled by changing the solution pH or adding/removing K(+).
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[2]Pseudorotaxanes based on the recognition of cryptands to vinylogous viologens.
Org. Lett.
PUBLISHED: 11-11-2011
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Host-guest complexation between two crown ether-based cryptands and two vinylogous viologens has been studied. Formation of [2]pseudorotaxanes from a dibenzo-24-crown-8-based cryptand and these vinylogous viologens can be reversibly controlled by adding and removing potassium cation in acetone. Furthermore, the complexation between a bis(m-phenylene)-32-crown-10-based cryptand and a vinylogous viologen exhibits a high association constant, 1.18 × 10(6) M(-1) in acetone, and leads to the formation of a supramolecular poly[2]pseudorotaxane in the solid state.
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Synthesis of a four-armed cage molecule and its pH-controlled complexation with paraquat.
Chem. Commun. (Camb.)
PUBLISHED: 08-11-2011
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A four-armed cage molecule was synthesized and its pH-controlled host-guest complexation with paraquat was studied. The influences of the location and composition of the arms were also investigated, guiding us to search for more complicate hosts with higher binding affinities.
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pH-responsive assembly and disassembly of a supramolecular cryptand-based pseudorotaxane driven by ?-? stacking interaction.
Chem. Commun. (Camb.)
PUBLISHED: 08-02-2011
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Driven by ?-? stacking interaction, a supramolecular cryptand-based [2]pseudorotaxane was formed and its formation was demonstrated to be pH-responsive.
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Signature microRNA expression profile of essential hypertension and its novel link to human cytomegalovirus infection.
Circulation
PUBLISHED: 06-20-2011
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Essential hypertension has been recognized as a disease resulting from a combination of environmental and genetic factors. Recent studies demonstrated that microRNAs (miRNAs) are involved in cardiac hypertrophy and heart failure. However, little is known about the roles of miRNAs in essential hypertension.
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Patient safety education for undergraduate medical students: a systematic review.
BMC Med Educ
PUBLISHED: 06-14-2011
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To reduce harm caused by health care is a global priority. Medical students should be able to recognize unsafe conditions, systematically report errors and near misses, investigate and improve such systems with a thorough understanding of human fallibility, and disclose errors to patients. Incorporating the knowledge of how to do this into the medical student curriculum is an urgent necessity. This paper aims to systematically review the literature about patient safety education for undergraduate medical students in terms of its content, teaching strategies, faculty availability and resources provided so as to identify evidence on how to promote patient safety in the curriculum for medical schools. This paper includes a perspective from the faculty of a medical school, a major hospital and an Evidence Based Medicine Centre in Sichuan Province, China.
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Supramolecular polymer nanofibers via electrospinning of a heteroditopic monomer.
Chem. Commun. (Camb.)
PUBLISHED: 05-23-2011
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Driven by the benzo-21-crown-7/secondary ammonium salt recognition motif, a linear supramolecular polymer was formed from self-organization of a low-molecular-weight self-complementary monomer in chloroform. From this supramolecular polymer, nanofibers were obtained successfully via electrospinning.
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Patient safety research in China: a literature review.
J Evid Based Med
PUBLISHED: 05-01-2011
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A number of articles on patient safety have been published in Chinese-language journals in last decade. However, until now there have been no studies of their overall quality or contribution to current thinking. This study explored the themes and designs of studies on patient safety published in Chinese-language journals.
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Fluorescence and morphology modulation in a photochromic diarylethene self-assembly system.
Langmuir
PUBLISHED: 03-25-2011
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Switchable supramolecular self-assemblies on the basis of interaction between melamine group containing photochromic diarylethene unit (DTE) and naphthalimide derivate (1) were designed and fabricated. 1 can gelate several aprotic solvents with different morphologies. The gel turned into partial gel in ethyl acetate with the addition of DTE as a guest molecule. Both the absorption and fluorescence spectra of the assembly can be reversibly switched by alternating UV/visible light irradiation. Meanwhile, the morphology of the coassembly of 1(2)·DTE changed to film from original pieces of gel 1 in ethyl acetate. When 1(2)·DTE was irradiated by UV light, the film morphology was converted into aggregated flakes. Moreover, the surface wettability of the complex can also be switched by light irradiation. The photochromic diarylethene unit is able to modulate the fluorescence and morphology of the assembled system only by virtue of light irradiation. Therefore, these results provide further insights into fluorescence and morphology controlling, especially application in upscale smart responsive materials.
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Radical scavenging activity of flavonoids from Trollius chinensis Bunge.
Nutrition
PUBLISHED: 03-12-2011
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Flos trollii is considered as functional tea, as well as a traditional medicinal herb, in China. In this study, total phenolic and flavonoid contents of Flos trollii were determined by a colorimetric method. The antioxidative potential of the hydroalcoholic extract of Flos trollii (FTE, extracted by alcohol:water, 80:20) was also evaluated by various antioxidant assays.
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NF-?B signaling inhibits ubiquitin carboxyl-terminal hydrolase L1 gene expression.
J. Neurochem.
PUBLISHED: 01-28-2011
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Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is a deubiquitinating enzyme that plays a regulatory role in targeting proteins for proteasomal degradation. UCH-L1 is highly expressed in neurons and has been demonstrated to promote cell viability and maintain neuronal integrity. Reduced UCH-L1 levels have been observed in various neurodegenerative diseases, and expression of UCH-L1 can rescue synaptic dysfunction and memory deficits in Alzheimers Disease model mice. However, the mechanisms regulating UCH-L1 expression have not been determined. In this study, we cloned a 1782 bp of the 5 flanking region of the human UCH-L1 gene and identified a 43 bp fragment containing the transcription start site as the minimal region necessary for promoter activity. Sequence analysis revealed several putative regulatory elements including NF-?B, NFAT, CREB, NRSF, YY1, AP1, and STAT in the UCH-L1 promoter. A functional NF-?B response element was identified in the UCH-L1 promoter region. Expression of NF-?B suppressed UCH-L1 gene transcription. In the RelA knockout system where NF-?B activity is ablated, UCH-L1 expression was significantly increased. Furthermore, activation of NF-?B signaling by the inflammatory stimulator lipopolysaccharide and TNF? resulted in a decrease of UCH-L1 gene expression by inhibiting its transcription. As NF-?B is an important signaling module in inflammatory response, our study suggests a possibility that inflammation might compromise neuronal functions via the interaction of NF-?B and UCH-L1. A better understanding of the NF-?B-regulated UCH-L1 transcription will provide insights to the role of inflammatory responses in Alzheimers disease and Parkinsons disease.
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Human cytomegalovirus infection is a novel etiology for essential hypertension.
Med. Hypotheses
PUBLISHED: 01-18-2011
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Essential hypertension is a major risk factor for cardiovascular, cerebrovascular, and renal diseases. However, the underlying cause and pathologic mechanisms of essential hypertension are poorly understood. Vascular inflammation and endothelial dysfunction are implicated in the pathogenesis of hypertension based on associations with elevated expression of adhesion molecules and chemokines and dysfunctional nitric oxide synthase. Human cytomegalovirus (HCMV) has been implicated in several cardiovascular disorders, including atherosclerosis, coronary heart disease, and cardiac transplant arteriopathy. Recent studies have suggested that HCMV is associated with cardiovascular disorders through impaired endothelial nitric oxide synthase function and subsequent endothelial dysfunction, which manifest as impaired vasculature dilation in vivo. However, direct links between human cytomegalovirus infection and essential hypertension remain undefined. Based on current studies, we present a hypothesis that human cytomegalovirus is an opportunistic pathogen that causes essential hypertension by disrupting nitric oxide synthesis and immune defense and by activating inflammation and the renin-angiotensin system.
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[The expression of DNMT1 in laryngeal squamous cell carcinoma and its clinical significance].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 12-01-2010
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To investigate the expression of DNMT1 in laryngeal squamous cell carcinoma (LSCC) and its relationship with clinicopathological factors.
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Improved complexation of paraquat derivatives by the formation of crown ether-based cryptands.
Chem. Commun. (Camb.)
PUBLISHED: 09-10-2010
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Self-assembly allows the construction of advanced molecular or supramolecular systems from small building blocks. Host-guest recognition, for its self-selectivity, environmental responsiveness and convenient application to complex molecular devices, plays a significant role in self-assembled systems. During this process, the association constant between the host and guest is an important standard to identify the properties of the systems. In order to prepare mechanically interlocked structures and large supramolecular systems efficiently from small molecules based on a host-guest recognition motif, it is necessary to increase host-guest association constants. Crown ether-based cryptands have been designed and prepared to improve the binding of paraquat derivatives. This feature article aims to describe the design and syntheses of crown ether-based cryptand hosts for paraquat derivatives and the application of the cryptand/paraquat recognition motif in the fabrication of threaded structures, molecular switches and supramolecular polymers.
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[Protective effects of luteolin on neurons against oxygen-glucose deprivation/reperfusion injury via improving Na+/K+ -ATPase activity].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 07-13-2010
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Luteolin, a flavone, has considerable neuroprotective effects by its anti-oxidative mechanism. However, it is still unclear whether luteolin can protect neurons against oxygen-glucose deprivation/reperfusion (OGD/R) induced injury.
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Association between the IL7R T244I polymorphism and multiple sclerosis: a meta-analysis.
Mol. Biol. Rep.
PUBLISHED: 06-30-2010
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Previously published analyses of the association between the interleukin 7 receptor (IL7R) T244I polymorphism (rs6897932) and multiple sclerosis (MS) have yielded conflicting results. We performed a meta-analysis to assess whether the combined data showed this association, and to investigate its effect size. We analyzed 10 studies identified from PubMed (12,185 MS patients and 15,855 controls) and calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for the C-allele, the C/C genotype (recessive effect) and the C/C + C/T (dominant effect) genotype. Heterogeneity within and between studies was observed: allele C: Q = 30.86, P = 0.002; genotype C/C: Q = 30.28, P = 0.003. Using a random-effects model, the C-allele and the C/C genotype were associated with MS (OR = 1.11, 95% CI = 1.04-1.19, P = 0.001 for the C-allele; OR = 1.15, 95% CI = 1.06-1.24, P = 0.0009 for the C/C genotype). The C/C + C/T genotype was also associated with MS using a fixed-effects model (OR = 1.15, 95% CI = 1.05-1.26, P = 0.003). There was no significant publication bias among the selected studies according to the funnel plot. We also performed the analysis on a European subgroup. This revealed an association between IL7R T244I and MS (P < 0.00001 for the C-allele and the C/C genotype; P = 0.0004 for the C/C + C/T genotype), no heterogeneity was observed (allele C: P = 0.07; genotype C/C: P = 0.10). In conclusion, the meta-analysis demonstrated that the IL7R T244I polymorphism was associated with susceptibility to MS.
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Sonication-triggered instantaneous gel-to-gel transformation.
Chemistry
PUBLISHED: 06-24-2010
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Two new peptide-based isomers containing cholesterol and naphthalic groups have been designed and synthesized. We found that the position of L-alanine in the linker could tune the gelation properties and morphologies. The molecule with the L-alanine residue positioned in the middle of the linker (1b) shows better gelation behavior than that with L-alanine directly linked to the naphthalimido moiety (1a). As a result, a highly thermostable organogel of 1b with a unique core-shell structure was obtained at high temperature and pressure in acetonitrile. Moreover, the gels of 1a and 1b could undergo an instantaneous gel-to-gel transition triggered by sonication. Ultrasound could break the core-shell microsphere of 1b and the micelle structure of 1a into entangled fibers. By studying the mechanism of the sonication-triggered gel-to-gel transition process of these compounds, it can be concluded that ultrasound has a variety of effects on the morphology, such as cutting, knitting, unfolding, homogenizing, and even cross-linking. Typically, ultrasound can cleave and homogenize pi-stacking and hydrophobic interactions among the gel molecules and then reshape the morphologies to form a new gel. This mechanism of morphology transformation triggered by sonication might be attractive in the field of material storage and controlled release.
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Photoresponsive host-guest systems based on a new azobenzene-containing cryptand.
Org. Lett.
PUBLISHED: 05-15-2010
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A new azobenzene-bridged cryptand was synthesized; it can be well controlled between cis and trans isomers by irradiation with different wavelengths or by being heated. It was found that this cryptand exhibits an ON-OFF binding ability with 2,7-diazapyrenium (DAP) derivatives. It binds DAP derivatives as the cis isomer only, as demonstrated by various methods. The fluorescence property of DAP derivatives endows these host-guest systems with detectable fluorescent output signals, which makes monitoring these photoresponsive systems convenient.
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Anion-assisted complexation of paraquat by cryptands based on bis(m-phenylene)-[32]crown-10.
Chemistry
PUBLISHED: 04-15-2010
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The complexation of tightly ion-paired divalent salts such as paraquat dichloride by cryptands based on crown ethers can be improved by the introduction of ion-pair recognition as a means of also binding the counteranions. A series of diamide-based cryptands derived from bis(m-phenylene)-[32]crown-10 and designed to complex the bipyridinium dication with anion assistance was synthesized. The ion-pair recognition process was fully characterized by (1)H NMR spectroscopy, UV/Vis spectroscopy, electrospray ionization mass spectrometry and single crystal X-ray analysis. (1)H NMR spectroscopy demonstrated that these new heteroditopic cryptand hosts can complex both the positive and negative components of the paraquat dichloride salt. UV/Vis spectroscopy showed that the addition of chloride anion into equimolar solutions of cryptands 3c or 3g with paraquat bis(hexafluorophosphate) salt (2a) improves the binding of the cryptands to the paraquat guest. Electrospray ionization mass spectrometry and single-crystal X-ray analysis confirmed the 1:1 stoichiometries and ion-pair recognition of these cryptand/paraquat complexes. It was found that the cryptand 3g, with 13 atoms and an isophthalamide moiety in the third chain, exhibited the best binding affinity for tightly ion-paired paraquat dichloride (2b), due to the combination of its spatial compatibility and additional anion-binding site.
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Formation of a large-scale ordered honeycomb pattern by an organogelator via a self-assembly process.
Chem. Commun. (Camb.)
PUBLISHED: 03-30-2010
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We have developed a facile strategy to fabricate a large-scale, orderly-patterned honeycomb structure by using supramolecular self-assembly of a low mass organic molecule.
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Quality of reporting of trial abstracts needs to be improved: using the CONSORT for abstracts to assess the four leading Chinese medical journals of traditional Chinese medicine.
Trials
PUBLISHED: 03-25-2010
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Due to language limitations, the abstract of journal article may be the only way for people of non-Chinese speaking countries to know about trials in traditional Chinese medicine (TCM). However, little is known about the reporting quality of these trial abstracts. Our study is to assess the reporting quality of abstracts of randomized controlled trials (RCT) published in four leading Chinese medical journals of TCM, and to identify any differences in reporting between the Chinese and English version of the same abstract publication.
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Assessment of the quality of reporting in abstracts of randomized controlled trials published in five leading Chinese medical journals.
PLoS ONE
PUBLISHED: 01-22-2010
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Clear, transparent and sufficiently detailed abstracts of randomized trials (RCTs), published in journal articles are important because readers will often base their initial assessment of a trial on such information. However, little is known about the quality of reporting in abstracts of RCTs published in medical journals in China.
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Electroencephalograph (EEG) signal processing method of motor imaginary potential for attention level classification.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 12-08-2009
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Research of visual attention is one of the important domains of psychology and neurophysiology. In this study, an attention related electroencephalograph (EEG) signal processing method was proposed to distinguish the different levels of peoples attention during the imaginary limbs motor. There were two EEG feedback experiments (playing tennis and walking) to measure the different levels of visual attention. Three imaginary motor tasks (attention, inattention, and rest task) were performed with the flash stimulus displayed on the screen in the experiments. A nonlinear dynamics parameter of multi-scale entropy (MSE) was extracted from those EEG data recorded. According to the statistics analysis of 14 subjects, there was an obvious declining tendency of MSE with the level of attention declining, which validated the effectiveness of the proposed method to classify the visual attention level.
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Quality of trials reported as conference abstracts in China: how well are they reported?
Int J Technol Assess Health Care
PUBLISHED: 10-23-2009
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Clear, transparent, and sufficiently detailed abstracts of journal articles and conference abstracts are important because readers often base their assessment of a trial on such information. There are concerns over the reliability and quality of trials published only in the proceedings of scientific meetings. This study aims to assess the reporting quality of abstracts of randomized trials published in Chinese medical conference abstracts.
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Oral potassium iodide for the treatment of sporotrichosis.
Cochrane Database Syst Rev
PUBLISHED: 10-13-2009
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Sporotrichosis is a subacute or chronic disease, usually affecting the skin caused by a dimorphic (existing in two forms), aerobic (oxygen requiring) fungus called Sporothrix schenckii. Oral potassium iodide is widely used for cutaneous sporotrichosis in clinical medicine with more and more reports published. However, the benefits and adverse reactions of these treatments have not yet been systematically reviewed.
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[Repair effect of BMSCs on digestive tract injury].
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
PUBLISHED: 07-15-2009
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To investigate the effect of BMSCs on the repair of digestive tract injury and its mechanisms.
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Hypolipidemic effect of the polysaccharide from Pholiota nameko.
Nutrition
PUBLISHED: 05-26-2009
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This study was conducted to investigate the hypolipidemic effect of the polysaccharide isolated from Pholiota nameko (PNPS-1).
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Synthesis of bis(m-phenylene)-32-crown-10-based discrete rhomboids driven by metal-coordination and complexation with paraquat.
J. Org. Chem.
PUBLISHED: 04-23-2009
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Two bis(m-phenylene)-32-crown-10 derivatives containing two pyridyl or carboxyl groups were made. They were used to prepare three bis(m-phenylene)-32-crown-10-based discrete rhomboids by coordination-driven self-assembly with high yields. The formation of these crown ether-based rhomboids was confirmed by NMR, UV-vis, CSI-TOF-MS, and elemental analysis. The complexation of these crown ether-based assemblies with paraquat (N,N-dimethyl-4,4-bipyridinium) was studied. The complexation of neutral bis(crown ether) rhomboid 1 with paraquat was found to be statistical with a 1:2 stoichiometry. The average apparent association constant K(av) of the complexation of rhomboid 1 with paraquat was found to be about 8.8(+/-0.8) x 10(3) M(-1) in acetone, about 17 times higher than the reported association constant value for the complexation of the corresponding simple bis(m-phenylene)-32-crown-10 with paraquat. This is possibly because the carboxylate groups provide additional noncovalent interactions between the host and guest. No obvious complexation was observed between the cationic rhomboids and paraquat when studied by NMR, UV-vis, and CSI-TOF-MS analysis. This could be attributed to the combination of the charge repulsion between cationic pyridinium rings and cationic platinum atoms and the weak pi-pi stacking and charge transfer interactions between the phenyl rings and the pyridinium rings caused by the electron-withdrawing effect of the cationic platinum atoms.
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Inclusion of tetracycline hydrochloride within supramolecular gels and its controlled release to bovine serum albumin.
Langmuir
PUBLISHED: 03-31-2009
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Three amphiphilic 3,4,5-trihydroxybenzoic derivatives with alkyl chains of different lengths were designed and synthesized. A small amount of these compounds can trap a large quantity of the water-soluble drug tetracycline hydrochloride (TH) within a stable gel in aqueous ethanol. Release experiments were carried out with solutions of bovine serum albumin (BSA) and various concentrations of L-isoleucine, L-phenylalanine, and L-tryptophan. The results indicate that the release rate of TH for a BSA solution (10 mg/mL) was faster than that with the other solutions because of the strong interaction between TH and BSA. Furthermore, to gain an insight into the release dynamics, we studied the release ratios as a function of the square root of time (t1/2). During the initial 1.75 h, diffusion is the dominant release process in water, whereas intermolecular interaction controls TH release in the BSA solution.
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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.

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

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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.