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Find video protocols related to scientific articles indexed in Pubmed.
[Evaluation on the status quo of self monitoring of blood glucose and self-efficacy of diabetes patients in community].
Zhonghua Yu Fang Yi Xue Za Zhi
PUBLISHED: 11-13-2014
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To investigate the status quo and influence factors of self monitoring of blood glucose (SMBG) and self-efficacy of diabetes patients' that participated in community diabetes self management group.
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Directed self-organization of quantum dots.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 09-25-2014
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We devise a nonlinear dynamical model of the growth of strained islands on a pattern. We study the morphological instability of a thin film that develops with a characteristic wavelength in the presence of an external forcing due to an underlying patterned substrate with another wavelength. We find in some conditions that the islands can form in well-organized arrays located on either the peaks or valleys of the pattern depending on the film thickness and ratio of the two characteristic wavelengths. These results are rationalized by a kinetic phase diagram and correlated with the morphology when the islands and the wetting layer grow. We find that the islands may be ordered and homogeneous when their coarsening is significantly slowed down, in agreement with experimental observations reported in the literature.
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Prevalence of diabetes and impaired fasting glucose among residents in the Three Gorges Reservoir Region, China.
BMC Public Health
PUBLISHED: 09-15-2014
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The Three Gorges Dam in China is the world's largest hydro-electric scheme in the contemporary world. After the construction of the Dam, great changes took place on the residents' lifestyles characterized by reduced physical activity due to the loss of arable land and a series of psychological problems caused by resettlement, which might be regarded as contributing factors to the development of diabetes in Three Gorges Reservoir Region (TGRR). However, there is no study that has been conducted targeting large population samples with the aim of determining the prevalence of diabetes in TGRR. This study purposed to estimate the prevalence of diabetes and impaired fasting glucose (IFG) in the adult population ?18 years in TGRR and to evaluate the associated risk factors.
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A community-based comprehensive intervention program for 7200 patients with type 2 diabetes mellitus in chongqing (china).
Int J Environ Res Public Health
PUBLISHED: 09-02-2014
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This study assessed the feasibility of community-based comprehensive intervention on Type 2 diabetes mellitus (T2DM) on a large population in China. An intervention study was conducted on 7200 T2DM patients within one year and consisted of six lectures on health issues, and four times face-to-face lifestyle counseling delivered by general health practitioners, at local primary health centers (PHCs). A "knowledge, attitude and practice" (KAP) survey and fasting plasma glucose (FPG) measurement were conducted at baseline and after the intervention, respectively. A total of 6586 T2DM patients completed the intervention. After one year intervention, patients' KAP level improved significantly (p < 0.001) and the average FPG has decreased from 8.53 mmol/L (standard deviation: 2.84) to 7.11 mmol/L (standard deviation: 1.34) (p < 0.001). Patients in rural areas and with lower education level showed higher FPG and poorer KAP level both before and after the intervention. In conclusion, community-based comprehensive intervention for T2DM is feasible on a large population. Improving and repeating the comprehensive strategy is greatly recommended in order to sustain the impact, especially in rural areas and for patients with lower education levels.
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Novel Red Phosphorescent Polymers Bearing Both Ambipolar and Functionalized Ir(III) Phosphorescent Moieties for Highly Efficient Organic Light-Emitting Diodes.
Macromol Rapid Commun
PUBLISHED: 08-30-2014
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A series of novel red phosphorescent polymers is successfully developed through Suzuki cross-coupling among ambipolar units, functionalized Ir(III) phosphorescent blocks, and fluorene-based silane moieties. The photophysical and electrochemical investigations indicate not only highly efficient energy-transfer from the organic segments to the phosphorescent units in the polymer backbone but also the ambipolar character of the copolymers. Benefiting from all these merits, the phosphorescent polymers can furnish organic light-emitting diodes (OLEDs) with exceptional high electroluminescent (EL) efficiencies with a current efficiency (? L ) of 8.31 cd A(-1) , external quantum efficiency (? ext ) of 16.07%, and power efficiency (? P ) of 2.95 lm W(-1) , representing the state-of-the-art electroluminescent performances ever achieved by red phosphorescent polymers. This work here might represent a new pathway to design and synthesize highly efficient phosphorescent polymers.
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Understanding phase-change behaviors of carbon-doped Ge?Sb?Te? for phase-change memory application.
ACS Appl Mater Interfaces
PUBLISHED: 08-14-2014
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Phase-change materials are highly promising for next-generation nonvolatile data storage technology. The pronounced effects of C doping on structural and electrical phase-change behaviors of Ge2Sb2Te5 material are investigated at the atomic level by combining experiments and ab initio molecular dynamics. C dopants are found to fundamentally affect the amorphous structure of Ge2Sb2Te5 by altering the local environments of Ge-Te tetrahedral units with stable C-C chains. The incorporated C increases the amorphous stability due to the enhanced covalent nature of the material with larger tetrahedral Ge sites. The four-membered rings with alternating atoms are reduced greatly with carbon addition, leading to sluggish phase transition and confined crystal grains. The lower RESET power is presented in the PCM cells with carbon-doped material, benefiting from its high resistivity and low thermal conductivity.
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Global and local persistence of influenza A(H5N1) virus.
Emerging Infect. Dis.
PUBLISHED: 07-26-2014
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An understanding of the global migration dynamics of highly pathogenic avian influenza A(H5N1) virus is helpful for surveillance and disease prevention. To characterize the migration network of this virus, we used genetic analysis, which supported a global persistence model in which each of 9 regions acts to some extent as a source. Siberia is the major hub for the dispersal of the virus. Southeast Asia and Africa are major sources of genetically and antigenically novel strains. We found evidence of local persistence of the virus in Southeast Asia and Africa, which is rare for human influenza A viruses. The differences in migration dynamics between avian and human influenza viruses might help with the design of region-specific surveillance efforts and the selection of vaccine candidates.
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Applications of wireless sensor networks in marine environment monitoring: a survey.
Sensors (Basel)
PUBLISHED: 07-09-2014
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With the rapid development of society and the economy, an increasing number of human activities have gradually destroyed the marine environment. Marine environment monitoring is a vital problem and has increasingly attracted a great deal of research and development attention. During the past decade, various marine environment monitoring systems have been developed. The traditional marine environment monitoring system using an oceanographic research vessel is expensive and time-consuming and has a low resolution both in time and space. Wireless Sensor Networks (WSNs) have recently been considered as potentially promising alternatives for monitoring marine environments since they have a number of advantages such as unmanned operation, easy deployment, real-time monitoring, and relatively low cost. This paper provides a comprehensive review of the state-of-the-art technologies in the field of marine environment monitoring using wireless sensor networks. It first describes application areas, a common architecture of WSN-based oceanographic monitoring systems, a general architecture of an oceanographic sensor node, sensing parameters and sensors, and wireless communication technologies. Then, it presents a detailed review of some related projects, systems, techniques, approaches and algorithms. It also discusses challenges and opportunities in the research, development, and deployment of wireless sensor networks for marine environment monitoring.
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Compressive sensing in a photonic link with optical integration.
Opt Lett
PUBLISHED: 07-01-2014
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In this Letter, we present a novel structure to realize photonics-assisted compressive sensing (CS) with optical integration. In the system, a spectrally sparse signal modulates a multiwavelength continuous-wave light and then is mixed with a random sequence in optical domain. The optical signal passes through a length of dispersive fiber, the dispersion amount of which is set to ensure that the group delay between the adjacent wavelength channels is equal to the bit duration of the applied random sequence. As a result, the detected signal is a delay-and-sum version of the randomly mixed signal, which is equivalent to the function of integration required in CS. A proof-of-concept experiment with four wavelengths, corresponding to a compression factor of 4, is demonstrated. More simulation results are also given to show the potential of the technique.
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Integrating carbon nanotubes into silicon by means of vertical carbon nanotube field-effect transistors.
Nanoscale
PUBLISHED: 06-27-2014
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Single-walled carbon nanotubes have been integrated into silicon for use in vertical carbon nanotube field-effect transistors (CNTFETs). A unique feature of these devices is that a silicon substrate and a metal contact are used as the source and drain for the vertical transistors, respectively. These CNTFETs show very different characteristics from those fabricated with two metal contacts. Surprisingly, the transfer characteristics of the vertical CNTFETs can be either ambipolar or unipolar (p-type or n-type) depending on the sign of the drain voltage. Furthermore, the p-type/n-type character of the devices is defined by the doping type of the silicon substrate used in the fabrication process. A semiclassical model is used to simulate the performance of these CNTFETs by taking the conductance change of the Si contact under the gate voltage into consideration. The calculation results are consistent with the experimental observations.
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Clinical, pathological and prognostic characteristics of gastroenteropancreatic neuroendocrine neoplasms in China: a retrospective study.
BMC Endocr Disord
PUBLISHED: 06-26-2014
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Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare neuroendocrine tumors, and lack of data in Asian populations especially in China. The aim of this retrospective study was to assess the clinical, pathological and prognostic characteristics of GEP-NENs in China.
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Inhibitory effects of a polysaccharide extract from the Chaga medicinal mushroom, Inonotus obliquus (higher Basidiomycetes), on the proliferation of human neurogliocytoma cells.
Int J Med Mushrooms
PUBLISHED: 06-19-2014
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This study aimed to investigate the inhibitory roles of a polysaccharide extract from Inonotus obliquus on U251 human neurogliocytoma cells cultured in vitro. After administering the polysaccharide extract from I. obliquus to U251 cells cultivated in vitro, methyl thiazolyl tetrazoliym assay was performed to measure the inhibitory effects of the extract on tumor cell proliferation. The expression of the apoptosis-related proteins Bcl-2 and caspase-3 were determined by Western blotting. Different concentrations of I. obliquus extract (25, 50, 100, 200, and 500 µg/mL) were added to U251 cells at 24, 48, and 72 hours. Methyl thiazolyl tetrazoliym assay showed that the inhibition ratio increased with increased extract concentration and prolonged treatment duration. The I. obliquus extract sharply decreased the expression of Bcl-2 but dramatically increased the expression of caspase-3. This function was gradually enhanced with increased drug concentration and prolonged treatment duration. The I. obliquus extract can inhibit the proliferation of tumor cells. This inhibition function is closely related to the downregulation of Bcl-2 and the upregulation of caspase-3.
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Enhanced extraordinary optical transmission (EOT) through arrays of bridged nanohole pairs and their sensing applications.
Nanoscale
PUBLISHED: 06-06-2014
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Extraordinary optical transmission (EOT) through arrays of gold nanoholes was studied with light across the visible to the near-infrared spectrum. The EOT effect was found to be improved by bridging pairs of nanoholes due to the concentration of the electromagnetic field in the slit between the holes. The geometrical shape and separation of the holes in these pairs of nanoholes affected the intensity of the transmission and the wavelength of resonance. Changing the geometrical shapes of these nanohole pairs from triangles to circles to squares leads to increased transmission intensity as well as red-shifting resonance wavelengths. The performance of bridged nanohole pairs as a plasmonic sensor was investigated. The bridged nanohole pairs were able to distinguish methanol, olive oil and microscope immersion oil for the different surface plasmon resonance in transmission spectra. Numerical simulation results were in agreement with experimental observations.
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Pancreaticogastrostomy versus pancreaticojejunostomy reconstruction after pancreaticoduodenectomy: a meta-analysis of randomized controlled trials.
Surg. Today
PUBLISHED: 04-30-2014
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We conducted this meta-analysis to establish whether pancreaticogastrostomy (PG) or pancreaticojejunostomy (PJ) is the better method of reconstruction for reducing the risk of postoperative pancreatic fistula (POPF).
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[Application of Best Subsets Regression on the risk classification for Spermophilus Dauricus Focus].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 04-18-2014
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To study the risk classification of animal plague in Spermophilus Dauricus Focus, using the Best Subsets Regression (BSR) model.
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Extraordinary mid-infrared transmission of subwavelength holes in gold films.
J Nanosci Nanotechnol
PUBLISHED: 04-17-2014
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Gold (Au) nanoholes are fabricated with electron-beam lithography and used for the investigation of extraordinary transmission in mid-infrared regime. Transmission properties of the nanoholes are studied as the dependence on hole-size. Transmittance spectra are characterized by Fourier transform infrared spectroscopy (FTIR) and enhanced transmittance through the subwavelength holes is observed. The transmission spectra exhibit well-defined maximum and minimum of which the position are determined by the lattice of the hole array. The hole-size primarily influence the transmission intensity and bandwidth of the resonance peak. With an increase of hole-size, while keep lattice constant fixed, the intensity of the resonance peak and the bandwidth increases, which are due to the localized surface plasmons. Numerical simulation for the transmission through the subwavelength holes is performed and the simulated results agree with the experimental observations.
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Pu-erh tea extract induces the degradation of FET family proteins involved in the pathogenesis of amyotrophic lateral sclerosis.
Biomed Res Int
PUBLISHED: 03-01-2014
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FET family proteins consist of fused in sarcoma/translocated in liposarcoma (FUS/TLS), Ewing's sarcoma (EWS), and TATA-binding protein-associated factor 15 (TAF15). Mutations in the copper/zinc superoxide dismutase (SOD1), TAR DNA-binding protein 43 (TDP-43), and FET family proteins are associated with the development of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease. There is currently no cure for this disease and few effective treatments are available. Epidemiological studies indicate that the consumption of tea is associated with a reduced risk of developing neurodegenerative diseases. The results of this study revealed that components of a pu-erh tea extract (PTE) interacted with FET family proteins but not with TDP-43 or SOD1. PTE induced the degradation of FET family proteins but had no effects on TDP-43 or SOD1. The most frequently occurring ALS-linked FUS/TLS mutant protein, R521C FUS/TLS, was also degraded in the presence of PTE. Furthermore, ammonium chloride, a lysosome inhibitor, but not lactacystin, a proteasome inhibitor, reduced the degradation of FUS/TLS protein by PTE. PTE significantly reduced the incorporation of R521C FUS/TLS into stress granules under stress conditions. These findings suggest that PTE may have beneficial health effects, including preventing the onset of FET family protein-associated neurodegenerative diseases and delaying the progression of ALS by inhibiting the cytoplasmic aggregation of FET family proteins.
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2'-OMe-phosphorodithioate-modified siRNAs show increased loading into the RISC complex and enhanced anti-tumour activity.
Nat Commun
PUBLISHED: 02-17-2014
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Improving small interfering RNA (siRNA) efficacy in target cell populations remains a challenge to its clinical implementation. Here, we report a chemical modification, consisting of phosphorodithioate (PS2) and 2'-O-Methyl (2'-OMe) MePS2 on one nucleotide that significantly enhances potency and resistance to degradation for various siRNAs. We find enhanced potency stems from an unforeseen increase in siRNA loading to the RNA-induced silencing complex, likely due to the unique interaction mediated by 2'-OMe and PS2. We demonstrate the therapeutic utility of MePS2 siRNAs in chemoresistant ovarian cancer mouse models via targeting GRAM domain containing 1B (GRAMD1B), a protein involved in chemoresistance. GRAMD1B silencing is achieved in tumours following MePS2-modified siRNA treatment, leading to a synergistic anti-tumour effect in combination with paclitaxel. Given the previously limited success in enhancing siRNA potency with chemically modified siRNAs, our findings represent an important advance in siRNA design with the potential for application in numerous cancer types.
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Radiofrequency ablation versus antiarrhythmic medication for treatment of ventricular premature beats from the right ventricular outflow tract: prospective randomized study.
Circ Arrhythm Electrophysiol
PUBLISHED: 02-12-2014
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The purpose of this study was to compare the efficacy of radiofrequency catheter ablation (RFCA) versus antiarrhythmic drugs (AADs) for treatment of patients with frequent ventricular premature beats (VPBs) originating from the right ventricular outflow tract (RVOT).
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Dynamic reassortments and genetic heterogeneity of the human-infecting influenza A (H7N9) virus.
Nat Commun
PUBLISHED: 01-25-2014
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Influenza A (H7N9) virus has been causing human infections in China since February 2013, raising serious concerns of potential pandemics. Previous studies demonstrate that human infection is directly linked to live animal markets, and that the internal genes of the virus are derived from H9N2 viruses circulating in the Yangtze River Delta area in Eastern China. Here following analysis of 109 viruses, we show a much higher genetic heterogeneity of the H7N9 viruses than previously reported, with a total of 27 newly designated genotypes. Phylogenetic and genealogical inferences reveal that genotypes G0 and G2.6 dominantly co-circulate within poultry, with most human isolates belonging to the genotype G0. G0 viruses are also responsible for the inter- and intra-province transmissions, leading to the genesis of novel genotypes. These observations suggest the province-specific H9N2 virus gene pools increase the genetic diversity of H7N9 via dynamic reassortments and also imply that G0 has not gained overwhelming fitness and the virus continues to undergo reassortment.
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Trifunctional Ir(III) ppy-type asymmetric phosphorescent emitters with ambipolar features for highly efficient electroluminescent devices.
Chem. Commun. (Camb.)
PUBLISHED: 01-25-2014
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Simple trifunctional Ir(III) ppy-type asymmetric phosphorescent emitters with ambipolar character are reported, which afford highly efficient OLEDs.
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One order of magnitude faster phase change at reduced power in Ti-Sb-Te.
Nat Commun
PUBLISHED: 01-12-2014
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To date, slow Set operation speed and high Reset operation power remain to be important limitations for substituting dynamic random access memory by phase change memory. Here, we demonstrate phase change memory cell based on Ti0.4Sb2Te3 alloy, showing one order of magnitude faster Set operation speed and as low as one-fifth Reset operation power, compared with Ge2Sb2Te5-based phase change memory cell at the same size. The enhancements may be rooted in the common presence of titanium-centred octahedral motifs in both amorphous and crystalline Ti0.4Sb2Te3 phases. The essentially unchanged local structures around the titanium atoms may be responsible for the significantly improved performance, as these structures could act as nucleation centres to facilitate a swift, low-energy order-disorder transition for the rest of the Sb-centred octahedrons. Our study may provide an alternative to the development of high-speed, low-power dynamic random access memory-like phase change memory technology.
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Arabidopsis plastidial folylpolyglutamate synthetase is required for seed reserve accumulation and seedling establishment in darkness.
PLoS ONE
PUBLISHED: 01-01-2014
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Interactions among metabolic pathways are important in plant biology. At present, not much is known about how folate metabolism affects other metabolic pathways in plants. Here we report a T-DNA insertion mutant (atdfb-3) of the plastidial folylpolyglutamate synthetase gene (AtDFB) was defective in seed reserves and skotomorphogenesis. Lower carbon (C) and higher nitrogen (N) content in the mutant seeds than that of the wild type were indicative of an altered C and N partitioning capacity. Higher levels of organic acids and sugars were detected in the mutant seeds compared with the wild type. Further analysis revealed that atdfb-3 seeds contained less total amino acids and individual Asn and Glu as well as NO3-. These results indicate significant changes in seed storage in the mutant. Defects in hypocotyl elongation were observed in atdfb-3 in darkness under sufficient NO3- conditions, and further enhanced under NO3- limited conditions. The strong expression of AtDFB in cotyledons and hypocotyl during early developmental stage was consistent with the mutant sensitivity to limited NO3- during a narrow developmental window. Exogenous 5-formyl-tetrahydrofolate completely restored the hypocotyl length in atdfb-3 seedlings with NO3- as the sole N source. Further study demonstrated that folate profiling and N metabolism were perturbed in atdfb-3 etiolated seedlings. The activity of enzymes involved in N reduction and assimilation was altered in atdfb-3. Taken together, these results indicate that AtDFB is required for seed reserves, hypocotyl elongation and N metabolism in darkness, providing novel insights into potential associations of folate metabolism with seed reserve accumulation, N metabolism and hypocotyl development in Arabidopsis.
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Reconstruction of gene regulatory network related to photosynthesis in Arabidopsis thaliana.
Front Plant Sci
PUBLISHED: 01-01-2014
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Photosynthesis is one of the most important biological processes on the earth. So far, though the molecular mechanisms underlying photosynthesis is well understood, however, the regulatory networks of photosynthesis are poorly studied. Given the current interest in improving photosynthetic efficiency for greater crop yield, elucidating the detailed regulatory networks controlling the construction and maintenance of photosynthetic machinery is not only scientifically significant but also holding great potential in agricultural application. In this study, we first identified transcription factors (TFs) related to photosynthesis through the TRAP approach using position weight matrix information. Then, for TFs related to photosynthesis, interactions between them and their targets were also determined by the ARACNE approach. Finally, a gene regulatory network was established by combining TF-targets information generated by these two approaches. Topological analysis of the regulatory network suggested that (a) the regulatory network of photosynthesis has a property of "small world"; (b) there is substantial coordination mediated by transcription factors between different components in photosynthesis.
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Crystalline liquid and rubber-like behavior in Cu nanowires.
Nano Lett.
PUBLISHED: 08-05-2013
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Via in situ TEM tensile tests on single crystalline copper nanowires with an advanced tensile device, we report here a crystalline-liquid-rubber-like (CRYS-LIQUE-R) behavior in fracturing crystalline metallic nanowires. A retractable strain of the fractured crystalline Cu nanowires can approach over 35%. This astonishing CRYS-LIQUE-R behavior of the fracturing highly strained single crystalline Cu nanowires originates from an instant release of the stored ultralarge elastic energy in the crystalline nanowires. The release of the ultralarge elastic energy was estimated to generate a huge reverse stress as high as ~10 GPa. The effective diffusion coefficient (D(eff)) increased sharply due to the consequent pressure gradient. In addition, due to the release of ultrahigh elastic energy, the estimated concomitant temperature increase was estimated as high as 0.6 Tm (Tm is the melting point of nanocrystalline Cu) on the fractured tip of the nanowires. These factors greatly enhanced the atomic diffusion process. Molecular dynamic simulations revealed that the very high reverse stress triggered dislocation nucleation and exhaustion.
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[Clinical value of B ultrasonography in the diagnosis of transient synovitis of hip in dogs].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 08-03-2013
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To investigate the value of B ultrasonography in the early diagnosis of transient synovitis of hip (TSH) in dogs, and provide the valid base and data for the clinic early diagnosis of TSH.
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Research on a logarithmically bent Laue crystal analyzer for X-ray monochromatic backlight imaging.
Rev Sci Instrum
PUBLISHED: 08-02-2013
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A new logarithmically bent Laue imaging crystal analyzer (LBLICA) was proposed to obtain the monochromatic image of plasmas and exhibited a great potential for application in the Inertial Confinement Fusion experiment over a large field of view (FOV) and with a high spatial resolution. The imaging geometry of the LBLICA has been discussed. According to the Bragg condition and the equation of the logarithmic spiral, the key image parameters of the crystal analyzer, including the system magnification, the spatial resolution, and the FOV, have been analyzed theoretically. An experiment has been performed with a Cu target X-ray tube as a backlighter to backlight a mesh grid consisting of 50-?m Cu wires, and the monochromatic image of the grid has been obtained with a spatial resolution of approximately 30 ?m.
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Shenghua Decoction reduces uterine bleeding and regulates T-cell paradigm in human deciduas of RU486 medical abortion.
J Ethnopharmacol
PUBLISHED: 06-21-2013
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Excessive uterine bleeding is the most common and problematic side effect of RU486 medical abortion. Shenghua Decoction (SHD) is a well-known traditional Chinese herbal prescription for reducing uterine bleeding induced by RU486 medical abortion. However, its therapeutic mechanism still remains unclear. The Th1/Th2/Th17/Treg paradigm plays an important role in achieving maternal-fetal immunotolerance and its bias participates in RU486-induced abortion. Our previous research on mice demonstrated that the uterine bleeding volume is negatively related to the proportions of Th1 and Th17 cells whereas positively related to the proportions of Th2 and Treg cells. Additionally, Th1-type cytokine inducing effect was identified in our previous study. Therefore, it was hypothesized that SHD reduced the uterine bleeding in RU486 medical abortion by inducing Th1/Th2/Th17/Treg paradigm bias. The purpose of this study was to determine the regulatory effect and the mechanism of SHD on human decidual Th1/Th2/Th17/Treg paradigm for alleviating uterine bleeding in RU486 medical abortion.
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Hepatitis B virus X protein in the proliferation of hepatocellular carcinoma cells.
Front Biosci (Landmark Ed)
PUBLISHED: 06-11-2013
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Hepatocellular carcinoma (HCC) is one of the most common and deadly malignant neoplasms worldwide. Chronic hepatitis B virus (HBV) infection is closely associated with the occurrence of HCC. The HBV genome encodes a ubiquitous transactivator, termed the HBV X protein (HBx), that is essential for HBV replication in vivo. HBx is involved in multiple steps of carcinoma development. Even in the preneoplastic stage, HBx acts as a tumor promoter. HBx participates in several mechanisms that have been linked to cell proliferation, including gene transcription, cell cycle regulation, and several signaling pathways. Moreover, HBx mutants, especially those with mutations in the COOH-terminal end, have been implicated in hepatocarcinogenesis. Therefore, therapeutic strategies targeting HBx could be effective at multiple stages of HCC development, even as early as the preneoplastic stage.
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Bending-induced electromechanical coupling and large piezoelectric response in a micromachined diaphragm.
Sci Rep
PUBLISHED: 05-31-2013
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We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr?.??Ti?.??)O? (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initially exhibit electromechanical coupling or the piezoelectric response. However, upon the application of static air pressure to the diaphragm, both electromechanical coupling and the piezoelectric response can be induced in the originally depolarized diaphragm. The piezoelectric response increases as the curvature increases and a giant piezoelectric response can be obtained from a bent diaphragm. The obtained results clearly demonstrate that a high strain gradient in a diaphragm can polarize a PZT film through a flexoelectric effect, and that the induced piezoelectric response of the diaphragm can be controlled by adjusting its curvature.
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Metformin suppresses hepatocellular carcinoma cell growth through induction of cell cycle G1/G0 phase arrest and p21CIP and p27KIP expression and downregulation of cyclin D1 in vitro and in vivo.
Oncol. Rep.
PUBLISHED: 05-31-2013
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Metformin is used as a first-line therapy for type 2 diabetes, with reports of its usefulness for the prevention and control of several types of cancers. This study investigated the effects of metformin on hepatocellular carcinoma (HCC). The human HCC cell lines HepG2 and PLC/PRF/5 were cultured and treated with metformin or 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), an activator of adenosine monophosphate (AMP)-activated protein kinase. Changes in cell viability and cell cycle distribution were evaluated by MTT and flow cytometry, respectively. Apoptosis was assessed by fluorescent-dye staining. An HCC model was established in 6- to 8-week-old BALB/c-nu mice by subcutaneous injection of PLC/PRF/5 cells. After 1 week, mice were treated intragastrically with metformin or vehicle. Tumor xenograft tissues were examined using immunohistochemistry for evaluation of the the expression of cyclin D1, p21CIP and p27KIP. HCC cells and tissues from the in vitro and in vivo experiments, respectively, were subjected to protein extraction and western blotting. We found that metformin treatment reduced HCC cell viability in a dose-dependent manner similar to AICAR treatment. In addition, metformin treatment induced HCC cell cycle arrest at G1/G0 phase and apoptosis. Intragastric treatment of the mouse PLC/PRF/5 cell xenograft model with metformin showed that metformin not only blocked tumor progression, but also reduced tumor morbidity. Treatment with metformin upregulated the expression of p21CIP and p27KIP, but downregulated cyclin D1 levels, both in vitro and in vivo. Metformin treatment also upregulated the expression of phosphorylated AMPK protein in xenograft tissues. These findings indicate that metformin warrants further evaluation as a novel therapeutic and preventive strategy against HCC.
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Origin and diversity of novel avian influenza A H7N9 viruses causing human infection: phylogenetic, structural, and coalescent analyses.
Lancet
PUBLISHED: 05-01-2013
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On March 30, 2013, a novel avian influenza A H7N9 virus that infects human beings was identified. This virus had been detected in six provinces and municipal cities in China as of April 18, 2013. We correlated genomic sequences from avian influenza viruses with ecological information and did phylogenetic and coalescent analyses to extrapolate the potential origins of the virus and possible routes of reassortment events.
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Submucosal tunneling endoscopic resection for small upper gastrointestinal subepithelial tumors originating from the muscularis propria layer.
Surg Endosc
PUBLISHED: 04-18-2013
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This prospective study was designed to evaluate the safety and efficacy of submucosal tunneling endoscopic resection (STER) for small (?3 cm) upper gastrointestinal (GI) subepithelial tumors (SETs) originating from the muscularis propria (MP) layer.
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Enhanced degradation of haloacid by heterologous expression in related Burkholderia species.
Biotechnol. Bioeng.
PUBLISHED: 03-08-2013
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Haloacids are environmental pollutant and can be transformed to non-toxic alkanoic acids by microbial dehalogenase. Bacterium Burkholderia species MBA4 was enriched from soil for its ability to bioremediate haloacids such as mono-chloroacetate (MCA), mono-bromoacetate (MBA), 2-mono-chloropropionate, and 2-mono-bromopropionate. MBA4 produces an inducible dehalogenase Deh4a that catalyzes the dehalogenation process. The growth of MBA4 on haloacid also relies on the presence of a haloacid-uptake system. Similar dehalogenase genes can be found in the genome of many related species. However, wildtype Burkholderia caribensis MWAP64, Burkholderia phymatum STM815, and Burkholderia xenovorans LB400 were not able to grow on MCA. When a plasmid containing the regulatory and structural gene of Deh4a was transformed to these species, they were able to grow on haloacid. The specific enzyme activities in these recombinants ranges from 2- to 30-fold that of MBA4 in similar condition. Reverse transcription-quantitative real-time PCR showed that the relative transcript levels in these recombinant strains ranges from 9 to over 1,600 times that of MBA4 in similar condition. A recombinant has produced nearly five times of dehalogenase that MBA4 could ever achieve. While the expressions of Deh4a were more relaxed in these phylogenetically related species, an MCA-uptake activity was found to be inducible. These metabolically engineered strains are better degraders than the haloacid-enriched MBA4.
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Harnessing a nanostructured fluorescence energy transfer sensor for quick detection of extremely small amounts of glucose.
J Diabetes Sci Technol
PUBLISHED: 02-27-2013
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Fluorescence technique is one of the major solutions for achieving the continuous and noninvasive glucose sensor for diabetes. In this article, a highly sensitive nanostructured sensor is developed to detect extremely small amounts of aqueous glucose by applying fluorescence energy transfer (FRET). A one-pot method is applied to produce the dextran-fluorescein isothiocyanate (FITC)-conjugating mesoporous silica nanoparticles (MSNs), which afterward interact with the tetramethylrhodamine isothiocyanate (TRITC)-labeled concanavalin A (Con A) to form the FRET nanoparticles (FITC-dextran-Con A-TRITC@MSNs). The nanostructured glucose sensor is then formed via the self-assembly of the FRET nanoparticles on a transparent, flexible, and biocompatible substrate, e.g., poly(dimethylsiloxane). Our results indicate the diameter of the MSNs is 60 ± 5 nm. The difference in the images before and after adding 20 ?l of glucose (0.10 mmol/liter) on the FRET sensor can be detected in less than 2 min by the laser confocal laser scanning microscope. The correlation between the ratio of fluorescence intensity, I(donor)/I(acceptor), of the FRET sensor and the concentration of aqueous glucose in the range of 0.04-4 mmol/liter has been investigated; a linear relationship is found. Furthermore, the durability of the nanostructured FRET sensor is evaluated for 5 days. In addition, the recorded images can be converted to digital images by obtaining the pixels from the resulting matrix using Matlab image processing functions. We have also studied the in vitro cytotoxicity of the device. The nanostructured FRET sensor may provide an alternative method to help patients manage the disease continuously.
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Effect of nifedipine versus telmisartan on prevention of atrial fibrillation recurrence in hypertensive patients.
Hypertension
PUBLISHED: 02-25-2013
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It is controversial whether angiotensin II receptor blockers provide better protection than calcium antagonists against atrial fibrillation (AF) recurrence in hypertensive patients. This study was designed to compare the effect of nifedipine- and telmisartan-based antihypertensive treatments for preventing AF recurrence in hypertensive patients with paroxysmal AF. A total of 149 hypertensive patients with paroxysmal AF were randomized to nifedipine- or telmisartan-based antihypertensive treatment groups. The target blood pressure (BP) was <130/80 mm Hg. Clinic BP, ECG, Holter monitoring, and echocardiography were followed up for 2 years. The primary end point was the incidence of overall and persistent AF recurrence. During follow-up, there was no statistical difference in the rate of patients lowering to target BP between both groups, whereas nifedipine group had slightly better BP control but similar heart rate control at 24 months. The incidence of AF recurrence was similar in both groups (nifedipine versus telmisartan: 58.7% versus 55.4%; P=0.742), and Kaplan-Meier analysis showed no significant difference in the freedom from AF recurrence (log-rank test; P=0.48). However, the rate of developing persistent AF in telmisartan group was lower than that in nifedipine group (5.4% versus 16.0%; P=0.035). Patients in telmisartan group had lower values of left atrial diameter, left atrial volume index, and left ventricular mass index at the end of follow-up. The effects of telmisartan in preventing AF recurrences in hypertensive patients with paroxysmal AF after intensive lowering BP is similar to that of nifedipine, but telmisartan has more potent effects on preventing progression to persistent AF.
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Predictors of HIV testing among men who have sex with men in a large Chinese city.
Sex Transm Dis
PUBLISHED: 02-14-2013
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HIV testing is the gateway for prevention and care. We explored factors associated with HIV testing among Chinese men who have sex with men (MSM).
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Comparative proteomic analysis of rd29A:RdreB1BI transgenic and non-transgenic strawberries exposed to low temperature.
J. Plant Physiol.
PUBLISHED: 02-06-2013
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Low-temperature stress is one of the major abiotic stresses in plants worldwide, and the dehydration responsive element binding protein (DREB) transcription factor induces expression of genes involved in environmental stress tolerance in plants. A proteomic approach based on two-dimensional gel electrophoresis (2-DE) and subsequent mass spectrometric identification was used to study the changes in the leaf proteome profiles of rd29A:RdreB1BI transgenic and non-transgenic strawberries exposed to low-temperature conditions. By comparing the proteomic profiles, we located 21 protein spots that were reproducibly up- or down-regulated by more than twofold between transgenic and non-transgenic strawberries. Eight identified proteins function in energy and metabolism, four in biosynthetic processes, four were stress and defense related, three spots were identified as cold-stress related expressed sequence tags (ESTs), and two were unknown proteins. The change patterns of low-temperature tolerance proteins, including photosynthetic proteins (RuBisCO large subunit and RuBisCO activase), cytoplasmic Cu/Zn-superoxide dismutase (Cu/Zn-SOD), late embryogenesis abundant protein 14-A (Lea14-A), eukaryotic translation initiation factor 5A (eIF5A), and cold-stress related ESTs, were differentially regulated between non-transgenic and rd29A:RdreB1BI transgenic strawberries. They are likely important gene products in the regulatory network of the RdreB1BI gene. Consequently, this study provides the first characterization of the transgenic strawberry proteome and the predicted target proteins of the RdreB1BI gene by using proteomic approaches.
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Effects of childhood trauma on personality in a sample of Chinese adolescents.
Child Abuse Negl
PUBLISHED: 01-18-2013
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Childhood trauma is a major public health problem which has an impact on personality development, yet no studies have examined the association between exposure to trauma and personality in a sample of Chinese adolescents. Four hundred eighty-five students completed the Childhood Trauma Questionnaire-Short Form (CTQ-SF) and the Eysenck Personality Questionnaire (EPQ). The CTQ-SF cut-off scores for exposure were used to calculate the prevalence of trauma. The possible associations between specific types of trauma and the EPQ subscale scores were examined. The rates of emotional abuse (EA), physical abuse (PA), sexual abuse (SA), emotional neglect (EN), and physical neglect (PN) were 18.76%, 11.13%, 27.01%, 49.48%, and 68.66%, respectively. Individuals subjected to EA, PA, and SA had significantly higher neuroticism (EPQ-N) and psychoticism (EPQ-P) scores on the EPQ compared with those who had not experienced EA, PA, or SA (all p values<0.05). Significant positive correlations existed between CTQ-SF subscale scores for EA, SA, CTQ-SF total scores, and EPQ-N, EPQ-P scores (all p values<0.05). Significant number of subjects in this adolescent sample reported experience of childhood abuse and neglect. Exposure to childhood trauma is associated with personality development in Chinese adolescents.
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Adjunctive aripiprazole versus placebo for antipsychotic-induced hyperprolactinemia: meta-analysis of randomized controlled trials.
PLoS ONE
PUBLISHED: 01-01-2013
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To compare the safety and efficacy of adjunctive aripiprazole versus placebo for antipsychotic-induced hyperprolactinemia.
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MrBayes tgMC³: a tight GPU implementation of MrBayes.
PLoS ONE
PUBLISHED: 01-01-2013
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MrBayes is model-based phylogenetic inference tool using Bayesian statistics. However, model-based assessment of phylogenetic trees adds to the computational burden of tree-searching, and so poses significant computational challenges. Graphics Processing Units (GPUs) have been proposed as high performance, low cost acceleration platforms and several parallelized versions of the Metropolis Coupled Markov Chain Mote Carlo (MC(3)) algorithm in MrBayes have been presented that can run on GPUs. However, some bottlenecks decrease the efficiency of these implementations. To address these bottlenecks, we propose a tight GPU MC(3) (tgMC(3)) algorithm. tgMC(3) implements a different architecture from the one-to-one acceleration architecture employed in previously proposed methods. It merges multiply discrete GPU kernels according to the data dependency and hence decreases the number of kernels launched and the complexity of data transfer. We implemented tgMC(3) and made performance comparisons with an earlier proposed algorithm, nMC(3), and also with MrBayes MC(3) under serial and multiply concurrent CPU processes. All of the methods were benchmarked on the same computing node from DEGIMA. Experiments indicate that the tgMC(3) method outstrips nMC(3) (v1.0) with speedup factors from 2.1 to 2.7×. In addition, tgMC(3) outperforms the serial MrBayes MC(3) by a factor of 6 to 30× when using a single GTX480 card, whereas a speedup factor of around 51× can be achieved by using two GTX 480 cards on relatively long sequences. Moreover, tgMC(3) was compared with MrBayes accelerated by BEAGLE, and achieved speedup factors from 3.7 to 5.7×. The reported performance improvement of tgMC(3) is significant and appears to scale well with increasing dataset sizes. In addition, the strategy proposed in tgMC(3) could benefit the acceleration of other Bayesian-based phylogenetic analysis methods using GPUs.
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Detection of sudden pedestrian crossings for driving assistance systems.
IEEE Trans Syst Man Cybern B Cybern
PUBLISHED: 11-30-2011
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In this paper, we study the problem of detecting sudden pedestrian crossings to assist drivers in avoiding accidents. This application has two major requirements: to detect crossing pedestrians as early as possible just as they enter the view of the car-mounted camera and to maintain a false alarm rate as low as possible for practical purposes. Although many current sliding-window-based approaches using various features and classification algorithms have been proposed for image-/video-based pedestrian detection, their performance in terms of accuracy and processing speed falls far short of practical application requirements. To address this problem, we propose a three-level coarse-to-fine video-based framework that detects partially visible pedestrians just as they enter the camera view, with low false alarm rate and high speed. The framework is tested on a new collection of high-resolution videos captured from a moving vehicle and yields a performance better than that of state-of-the-art pedestrian detection while running at a frame rate of 55 fps.
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Fabrication and photoluminescence properties of graphite fiber/ZnO nanorod core-shell structures.
J Nanosci Nanotechnol
PUBLISHED: 11-23-2011
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Graphite fiber/ZnO nanorod core-shell structures were synthesized by thermal evaporation process. The core-shell hybrid architectures were comprised of ZnO nanorods grown on the surface of graphite fiber. In addition, Hollow ZnO hierarchical structure can be obtained by oxidizing the graphite fiber. Room temperature photoluminescence (PL) of the as-made graphite fiber/ZnO nanorod structures shows two UV peaks at around 3.274 eV and 3.181 eV. The temperature-dependent photoluminescence spectra demonstrate the two UV emissions are attributed to the intrinsic optical transitions and extrinsic defect-related emissions in ZnO. These hybrid structures may be used as the building block for fabrication of nanodevices.
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K-shell emission x-ray imaging of Z-pinch plasmas with a pinhole and a logarithmic spiral crystal.
Rev Sci Instrum
PUBLISHED: 10-07-2011
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An in-chamber, mini x-ray imaging instrument employs a pinhole and a logarithmic spiral crystal has been developed for obtaining K-shell line images of the imploding aluminum wire array on the "Yang" accelerator. The logarithmic spiral crystal acts as a monochromator and a non-dispersive mirror that reflects the pinhole image to a x-ray film detector with a very narrow photon energy bandwidth (<1 eV, mainly determined by the width of rocking curve of the crystal). Two imaging configurations with the use of Quartz (10 ?10) crystal and Mica (002) crystal are designed, respectively, to image the Al Ly(?2) line (1727.7 eV) emission and Al He(?) intercombination line (1588.3 eV) emission. The primary experimental data corresponding to these two configurations are presented and discussed.
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Optimization of high-definition video coding and hybrid fiber-wireless transmission in the 60 GHz band.
Opt Express
PUBLISHED: 09-02-2011
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The paper addresses the problem of distribution of high-definition video over fiber-wireless networks. The physical layer architecture with the low complexity envelope detection solution is investigated. We present both experimental studies and simulation of high quality high-definition compressed video transmission over 60 GHz fiber-wireless link. Using advanced video coding we satisfy low complexity and low delay constraints, meanwhile preserving the superb video quality after significantly extended wireless distance.
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High accuracy microwave frequency measurement based on single-drive dual-parallel Mach-Zehnder modulator.
Opt Express
PUBLISHED: 09-02-2011
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A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing a two-stage frequency measurement cooperating with digital signal processing. In the experiment, 10 GHz measurement range is guaranteed and the average uncertainty of estimated microwave frequency is 5.4 MHz, which verifies the measurement accuracy is significantly improved by achieving an unprecedented 10(-3) relative error. This high accuracy frequency measurement technique is a promising candidate for high-speed electronic warfare and defense applications.
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MIMO-OFDM WDM PON with DM-VCSEL for femtocells application.
Opt Express
PUBLISHED: 09-02-2011
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We report on experimental demonstration of 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20 km WDM-PON with directly modulated (DM) VCSELs for femtocells application. MIMO-OFDM algorithms effectively compensate for impairments in the wireless link. Error-free signal demodulation of 64 subcarrier 4-QAM signals modulated at 198.5 Mb/s net data rate is achieved after fiber and 2 m indoor wireless transmission. We report BER of 7x10(-3) at the receiver for 16-QAM signals modulated at 397 Mb/s after 1 m of wireless transmission. Performance dependence on different wireless transmission path lengths, antenna separation, and number of subcarriers have been investigated.
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Digital predistortion of 75-110 GHz W-band frequency multiplier for fiber wireless short range access systems.
Opt Express
PUBLISHED: 09-02-2011
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We present a W-band fiber-wireless transmission system based on a nonlinear frequency multiplier for high-speed wireless short range access applications. By implementing a baseband digital signal predistortion scheme, intensive nonlinear distortions induced in a sextuple frequency multiplier can be effectively pre-compensated. Without using costly W-band components, a transmission system with 26 km fiber and 4 m wireless transmission operating at 99.6 GHz is experimentally validated. Adjacent-channel power ratio (ACPR) improvements for IQ-modulated vector signals are guaranteed and transmission performances for fiber and wireless channels are studied. This W-band predistortion technique is a promising candidate for applications in high capacity wireless-fiber access systems.
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100 Gbit/s hybrid optical fiber-wireless link in the W-band (75-110 GHz).
Opt Express
PUBLISHED: 09-02-2011
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We experimentally demonstrate an 100 Gbit/s hybrid optical fiber-wireless link by employing photonic heterodyning up-conversion of optical 12.5 Gbaud polarization multiplexed 16-QAM baseband signal with two free running lasers. Bit-error-rate performance below the FEC limit is successfully achieved for air transmission distances up to 120 cm.
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Preparation, characterization and application of a new stir bar sorptive extraction based on poly(vinylphthalimide-co-N,N-methylenebisacrylamide) monolith.
J Sep Sci
PUBLISHED: 08-01-2011
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In this study, a new stir bar sorptive extraction (SBSE) coating based on poly(vinylphthalimide-co-N,N-methylenebisacrylamide) monolith (SBSE-VPMB) was prepared. The influences of the contents of monomer in polymerization mixture and the percentage of porogen solvent on the extraction performance were investigated thoroughly. Several characteristic techniques, such as elemental analysis, scanning electron microscopy, mercury intrusion porosimetry and infrared spectroscopy, were used to characterize the monolithic material. The analysis of oxfendazole (OFZ) and mebendazole (MBZ) in milk and honey samples by the combination of SBSE with HPLC with diode array detection was selected as paradigms for the practical evaluation of the new coating. Under the optimized extraction conditions, the limits of detection (S/N=3) for OFZ and MBZ were 0.23-0.60 ?g/L in milk and 0.24-1.08 ?g/L in honey, respectively. The method also showed good linearity, repeatability, high feasibility and acceptable recoveries for real samples. At the same time, the extraction performance and the distribution coefficients (K(VPMB/W)) of OFZ and MBZ on SBSE-VPMB were compared with other SBSEs based on porous monoliths and commercial SBSE.
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NT-proBNP, but not ANP and C-reactive protein, is predictive of paroxysmal atrial fibrillation in patients undergoing pulmonary vein isolation.
J Interv Card Electrophysiol
PUBLISHED: 07-11-2011
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The purpose of this study is to evaluate the relationship between plasma high-sensitivity C-reactive protein (hs-CRP), atrial natriuretic peptides (ANP), N-terminal-pro-brain natriuretic peptide (NT-proBNP) levels, and the risk and recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (PAF).
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Methylation of a phosphatase specifies dephosphorylation and degradation of activated brassinosteroid receptors.
Sci Signal
PUBLISHED: 05-12-2011
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Internalization of cell surface receptors, followed by either recycling back to the plasma membrane or degradation, is crucial for receptor homeostasis and signaling. The plant brassinosteroid (BR) receptor, BRASSINOSTEROID INSENSITIVE 1 (BRI1), undergoes constitutive cycling between the plasma membrane and the internal membranes. We show that protein phosphatase 2A (PP2A) dephosphorylated BRI1 and that Arabidopsis thaliana rcn1, a mutant for a PP2A subunit, caused an increase in BRI1 abundance and BR signaling. We report the identification, in A. thaliana, of a suppressor of bri1, sbi1, which caused selective accumulation of BR-activated BRI1, but not the BR co-receptor BAK1 (BRI1-ASSOCIATED KINASE 1), in the membranous compartment. SBI1 mRNA was induced by BRs, and SBI1 encodes a leucine carboxylmethyltransferase (LCMT) that methylated PP2A and controlled its membrane-associated subcellular localization. We propose that BRs increase production of SBI1, which methylates PP2A, thus facilitating its association with activated BRI1. This leads to receptor dephosphorylation and degradation, and thus to the termination of BR signaling.
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Distribution of photonically generated 5 Gbits/s impulse radio ultrawideband signals over fiber.
Opt Lett
PUBLISHED: 03-16-2011
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We propose an approach to generate ultrawideband (UWB) pulses with tunable high-speed modulation based on pulse compression. Flexible generation of up to a record 5?Gbits/s on-off keying impulse radio UWB signals are successfully demonstrated as well. We also investigate 5?Gbits/s on-off keying bit-error-rate (BER) performance after 40?km single mode fiber transmission by employing a digital signal processing receiver, and the BER below forward error correction limit is achieved.
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Comparison of proportions for composite endpoints with missing components.
J Biopharm Stat
PUBLISHED: 03-11-2011
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Composite endpoints are commonly used in clinical trials. When there are missing values in their individual components, inappropriate handling of the missingness may create inefficient or even biased estimates of the proportions of successes in composite endpoints. Assuming missingness is completely at random or dependent on baseline covariates, we derived a maximum likelihood estimator of the proportion of successes in a three-component composite endpoint and closed-form variance for the proportion, and compared two groups in the difference in proportions and in the logarithm of a relative risk. Sample size and statistical power were studied. Simulation studies were used to evaluate the performance of the developed methods. With a moderate sample size the developed methods works satisfactorily.
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Strategies for the discovery of therapeutic aptamers.
Expert Opin Drug Discov
PUBLISHED: 03-02-2011
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Therapeutic aptamers are synthetic, structured oligonucleotides that bind to a very broad range of targets with high affinity and specificity. They are an emerging class of targeting ligand that show great promise for treating a number of diseases. A series of aptamers currently in various stages of clinical development highlights the potential of aptamers for therapeutic applications.
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Noninvasive diagnostic devices for diabetes through measuring tear glucose.
J Diabetes Sci Technol
PUBLISHED: 02-10-2011
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This article reviews the development of a noninvasive diagnostic for diabetes by detecting ocular glucose. Early diagnosis and daily management are very important to diabetes patients to ensure a healthy life. Commercial blood glucose sensors have been used since the 1970s. Millions of diabetes patients have to prick their finger for a drop of blood 4-5 times a day to check blood glucose levels--almost 1800 times annually. There is a strong need to have a noninvasive device to help patients to manage the disease easily and painlessly. Instead of detecting the glucose in blood, monitoring the glucose level in other body fluids may provide a feasible approach for noninvasive diagnosis and diabetes control. Tear glucose has been studied for several decades. This article reviews studies on ocular glucose and its monitoring methods. Attempts to continuously monitor the concentration of tear glucose by using contact lens-based sensors are discussed as well as our current development of a nanostructured lens-based sensor for diabetes. This disposable biosensor for the detection of tear glucose may provide an alternative method to help patients manage the disease conveniently.
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Predictors of late recurrence of atrial fibrillation after catheter ablation.
Int. J. Cardiol.
PUBLISHED: 01-11-2011
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To predict the recurrence of atrial fibrillation is important for selecting patients who will be undergoing catheter ablation, several studies respectively evaluated the risk factor of the recurrence of atrial fibrillation post-ablation.
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Comparative pharmacokinetics and metabolism studies in lean and diet- induced obese mice: an animal efficacy model for 11?-hydroxysteroid dehydrogenase type 1 (11?-HSD1) inhibitors.
Drug Metab Lett
PUBLISHED: 01-05-2011
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Diet-induced obese (DIO) mice have been commonly used as an animal model in the efficacy assessment for new drug candidates. Although high-fat feeding has been reported to cause profound physiological changes, including the expression of drug-metabolizing enzymes, limited studies have been reported regarding the effect of obesity/diabetes on pharmacokinetics (PK) in animals. In this study, we investigated PK profiles of three 11 -HSD-1 inhibitors in the DIO mice and compared them to the normal lean mice. After oral administration, the in vivo exposure (AUC) of all three compounds was higher in DIO mice, which was consistent with the observed lower systemic clearance (CL) in DIO mice compared to lean mice. As illustrated by Compound E, a compound metabolized predominantly by CYP3A and 2C, the metabolic profiles for Compound E were qualitatively similar between DIO and lean mice, but quantitatively lower in the DIO mice. Indeed, P-450 activities for CYP3A and 2C as well as 2D were found to be lower in liver microsomes prepared from DIO mice. The calculated hepatic clearance (CLH) from in vitro studies with liver microsomes correlated well with the observed in vivo clearance for both DIO and lean mice. The calculated oral bioavailability (F%) based on intrinsic hepatic clearance (C(LH, int)) predicted ~3 fold increase in F% for the DIO mice, which was comparable to the observed value. Collectively, these data suggest that the higher F% is most likely due to the lower first-pass effect in DIO mice. This study highlights the needs to take caution when extrapolating PK and exposure data from healthy animals to diseased animals in designing pharmacological studies.
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MicroRNA-21 is a new marker of circulating tumor cells in gastric cancer patients.
Cancer Biomark
PUBLISHED: 01-01-2011
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The detection of circulating tumor cells (CTCs) has received great attention. MicroRNA-21 (miR-21) plays crucial roles in carcinogenesis and is considered as one of the most studied oncomiRNAs. We determined if miR-21 could be used a marker for the detection of CTCs in gastric cancer patients. Peripheral blood samples were collected from 53 preoperative patients with gastric cancer and 20 healthy volunteers. Real-time reverse transcription-polymerase chain reaction was used to detect the level of miR-21. Receiver operator characteristic curves (ROC) were constructed. Patients with gastric cancer display a significantly higher level of miR-21 in peripheral blood than those from controls. The miR-21 level was associated with the tumor node metastasis (TNM) stage, tumor size and tissue categories. The area under ROC curve was up to 0.853 ± 0.086. This study highlights the potential of the detection of miR-21 in peripheral blood as a novel tool for monitoring CTCs in gastric cancer patients.
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A three-layer PMMA electrophoresis microchip with Pt microelectrodes insulated by a thin film for contactless conductivity detection.
Lab Chip
PUBLISHED: 12-07-2010
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A three-layer poly (methyl methacrylate) (PMMA) electrophoresis microchip integrated with Pt microelectrodes for contactless conductivity detection is presented. A 50 ?m-thick PMMA film is used as the insulating layer and placed between the channel plate (containing the microchannel) and the electrode plate (containing the microelectrode). The three-layer structure facilitates the achievement of a thin insulating layer, obviates the difficulty of integrating microelectrodes on a thin film, and does not compromise the integration of microchips. To overcome the thermal and chemical incompatibilities of polymers and photolithographic techniques, a modified lift-off process was developed to integrate Pt microelectrodes onto the PMMA substrate. A novel two-step bonding method was created to assemble the complete PMMA microchip. A low limit of detection of 1.25 ?g ml(-1) for Na(+) and high separation efficiency of 77,000 and 48,000 plates/m for Na(+) and K(+) were obtained when operating the detector at a low excitation frequency of 60 kHz.
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Aptamers as affinity reagents in an integrated electrophoretic lab-on-a-chip platform.
Anal. Chem.
PUBLISHED: 10-14-2010
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Nucleic acid based affinity reagents (e.g., aptamers) offer several possible advantages over antibodies as specific recognition elements in biochemical assays. Besides offering improved cost and stability, aptamers are ideal for rapid electrophoretic analysis due to their low molecular weight and high negative charge. While aptamers have proven well-suited for affinity-shift electrophoretic analysis, demonstrating a fully integrated aptamer-based assay platform represents an important achievement toward low-cost point-of-care analysis, particularly for remote or resource poor settings where cost and ambient stability of reagents is a key consideration. Here we perform and evaluate the suitability of aptamer-based affinity assays for two clinically relevant target analytes (IgE using a known aptamer and NF-?B using a thio-modified aptamer) in an integrated electrophoretic gel-shift platform. Key steps of (i) mixing sample with aptamer, (ii) buffer exchange, and (iii) preconcentration of sample were successfully integrated on-chip upstream of a fluorescence-based gel-shift analysis step. This approach, utilizing a size-exclusion membrane optimized here for aptamer retention and preconcentration with sample, enables automated sample-to-answer for trace analytes in 10 min or less. We addressed notable nonspecific interference from serum proteins by adding similar nucleic acid competitors to suppress such interactions with the aptamer. Nanomolar sensitivities were demonstrated and integrated preconcentration of sample provides an important means of further improving detection sensitivities. Aptamers proved superior in many respects to antibody reagents, particularly with regard to speed and resolution of gel-shifts associated with specific binding to target.
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Up-regulation of Fas/FasL activation contribute to the apoptosis enhancement of RU486 by Gong-Qing Decoction, a traditional Chinese prescription.
J Ethnopharmacol
PUBLISHED: 08-14-2010
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To elucidate the mechanisms of Gong Qing Decoction(GQD) on human trephocytes and decidual cells in vivo based upon the effective practice of alleviating uterine bleeding in RU486 medical abortion.
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Treatment of unstable proximal femoral fractures: comparison of the proximal femoral nail antirotation and gamma nail 3.
Orthopedics
PUBLISHED: 07-09-2010
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The goal of this study was to compare the results of proximal femoral nail antirotation (PFNA; Synthes, Oberdorf, Switzerland) fixation with those of Gamma nail 3 (GN-3; Stryker, Mahwah, New Jersey) fixation for unstable proximal femoral fractures. A total of 136 unstable trochanteric fractures were divided into 2 treatment groups: 66 patients were treated with the PFNA and 70 were treated with the GN-3. The 2 groups were comparable with regard to demographic variables. Patients treated with the PFNA experienced less intraoperative blood loss (P=.007). Three femoral shaft fractures (2 PFNA, 1 GN-3) were observed intraoperatively; all were minor splits in the cortex at the tip of the nail and were treated successfully with delayed full weight bearing. Follow-up occurred at 1, 3, 6, and 12 months postoperatively and yearly thereafter. Reduction of the fracture was considered good in 74 patients (35 PFNA, 39 GN-3) and the position of the implant was considered ideal in 103 (48 PFNA, 55 GN-3) on postoperative radiographs. The 2 groups were similar with regard to postoperative complications, and no case of cutout or nonunion was noted during the follow-up period. At last follow-up, there was no difference in the functional outcome. Shortening of the femoral shaft was 5.30+/-0.36 mm in PFNA group and 5.49+/-0.39 mm in GN-3 group (P=.73). There was no difference in clinical outcome between the PFNA and GN-3 groups, although the PFNA shows some advantages over the GN-3. We consider these 2 methods to be useful in the treatment of unstable proximal femoral fractures.
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Two-stage steam gasification of waste biomass in fluidized bed at low temperature: parametric investigations and performance optimization.
Bioresour. Technol.
PUBLISHED: 06-22-2010
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Steam gasification of waste biomass has been studied in a two-stage fluidized bed reactor, which has the primary pyrolysis fluidized bed using silica sand as bed material and the secondary reforming fixed bed with catalyst. The main objectives are parametric investigation and performance improvement especially at low temperature of around 600 °C using the wood chip and the pig manure compost as feedstock. Main operating variables studied are pyrolysis temperature, catalytic temperature, steam/biomass-C ratio, space velocity and different catalyst. Reaction temperatures and steam/C ratio have important role on the gasification process. About 60 vol.% H2 (dry and N2 free) and about 2.0 Nm3/kg biomass (dry and ash free basis) can be obtained under good conditions. Compared to Ni/Al2O3, Ni/BCC (Ni-loaded brown coal char) has a better ability and a hopeful prospect for the stability with coking resistance.
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An efficient tree classifier ensemble-based approach for pedestrian detection.
IEEE Trans Syst Man Cybern B Cybern
PUBLISHED: 05-06-2010
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Classification-based pedestrian detection systems (PDSs) are currently a hot research topic in the field of intelligent transportation. A PDS detects pedestrians in real time on moving vehicles. A practical PDS demands not only high detection accuracy but also high detection speed. However, most of the existing classification-based approaches mainly seek for high detection accuracy, while the detection speed is not purposely optimized for practical application. At the same time, the performance, particularly the speed, is primarily tuned based on experiments without theoretical foundations, leading to a long training procedure. This paper starts with measuring and optimizing detection speed, and then a practical classification-based pedestrian detection solution with high detection speed and training speed is described. First, an extended classification/detection speed metric, named feature-per-object (fpo), is proposed to measure the detection speed independently from execution. Then, an fpo minimization model with accuracy constraints is formulated based on a tree classifier ensemble, where the minimum fpo can guarantee the highest detection speed. Finally, the minimization problem is solved efficiently by using nonlinear fitting based on radial basis function neural networks. In addition, the optimal solution is directly used to instruct classifier training; thus, the training speed could be accelerated greatly. Therefore, a rapid and accurate classification-based detection technique is proposed for the PDS. Experimental results on urban traffic videos show that the proposed method has a high detection speed with an acceptable detection rate and a false-alarm rate for onboard detection; moreover, the training procedure is also very fast.
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Enantioselectively controlled release of chiral drug (metoprolol) using chiral mesoporous silica materials.
Nanotechnology
PUBLISHED: 03-30-2010
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Chiral porous materials have attracted burgeoning attention on account of their potential applications in many areas, such as enantioseparation, chiral catalysis, chemical sensors and drug delivery. In this report, chiral mesoporous silica (CMS) materials with various pore sizes and structures were prepared using conventional achiral templates (other than chiral surfactant) and a chiral cobalt complex as co-template. The synthesized CMS materials were characterized by x-ray diffraction, nitrogen physisorption, scanning electron microscope and transmission electron microscope. These CMS materials, as carriers, were demonstrated to be able to control the enantioselective release of a representative chiral drug (metoprolol). The release kinetics, as modeled by the power law equation, suggested that the release profiles of metoprolol were remarkably dependent on the pore diameter and pore structure of CMS materials. More importantly, R- and S-enantiomers of metoprolol exhibited different release kinetics on CMS compared to the corresponding achiral mesoporous silica (ACMS), attributable to the existence of local chirality on the pore wall surface of CMS materials. The chirality of CMS materials on a molecular level was further substantiated by vibrational circular dichroism measurements.
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Development of a Mab-based heterologous immunoassay for the broad-selective determination of organophosphorus pesticides.
J. Agric. Food Chem.
PUBLISHED: 03-20-2010
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A broad-selective monoclonal antibody (Mab) for organophosphorus (OP) pesticides was raised using heterologous indirect enzyme-linked immunosorbent assay (ELISA) to screen hybridomas. On the basis of this Mab, five coating antigens were used to develop homologous and heterologous indirect competitive ELISAs. With the most suitable competitor, a sensitive and broad-selective ELISA was developed. The IC(50) values were estimated to be 20.32 ng/mL for parathion, 21.44 ng/mL for methyl-parathion, 42.15 ng/mL for fenitrothion, and 58.85 ng/mL for isocarbophos. Spike recoveries were between 70.52 and 103.27% for the detection of single pesticide residues of the four OP pesticides in purple-clayed paddy soil. Moreover, the chosen ELISA was then applied to the detection of mixtures of parathion and methyl-parathion in soil samples. The average recovery and coefficient of variation were 80.91 and 4.82%, respectively. Results proved that this broad-selective ELISA would be useful for the multiresidue determination of OP pesticides.
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Lethal effect and in vivo genotoxicity of profenofos to Chinese native amphibian (Rana spinosa) tadpoles.
Arch. Environ. Contam. Toxicol.
PUBLISHED: 03-01-2010
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Amphibian populations are decreasing in size due to environmental stressors in most areas of southern China. Pesticides are known to be a group of potential stressors to amphibians, especially in agricultural ecosystems. Profenofos, an organophosphate insecticide and acaricide, is widely used for controlling insect pests in China. The aim of this study is to evaluate the acute lethality and genotoxicity of profenofos to amphibian under controlled conditions. Results showed that profenofos was highly lethal to tadpoles of Rana spinosa, with 50% lethal concentration (LC(50)) values of 1.59, 1.14, 0.77, and 0.58 mg l(-1) at 24, 48, 72, and 96 h, respectively. DNA damage of erythrocytes was observed by alkaline single-cell gel electrophoresis assay at all tested sublethal concentrations. The study also showed, by micronucleus test, that profenofos at moderate to high sublethal concentration might have genotoxicity to the tadpole after 96 h exposure. Furthermore, based on our results, it is suggested that the alkaline single-cell gel electrophoresis assay could be used as a screening tool for biomonitoring of pesticide contamination in aquatic systems or agricultural ecosystems.
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Engineering of new prodigiosin-based biosensors of Serratia for facile detection of short-chain N-acyl homoserine lactone quorum-sensing molecules.
Environ Microbiol Rep
PUBLISHED: 02-23-2010
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Many Gram-negative bacteria use quorum sensing (QS) to regulate expression of multiple genes, by utilizing small diffusible signalling molecules called N-acyl homoserine lactones (acyl-HSLs). Serratia sp. ATCC 39006 produces the red pigment prodigiosin under QS control, in response to the short-chain signal C4-HSL. In this study, we have demonstrated that an acyl-HSL-deficient mutant can be used as a visual biosensor to detect short-chain acyl-HSLs. We have quantified the acyl-HSL sensitivity spectrum of the Serratia 39006 prodigiosin QS system, and have demonstrated a strong specificity for the natural ligand C4-HSL. Mutations in the pigX and pigZ genes in Serratia 39006 resulted in an overproduction of prodigiosin, caused by increased transcription of the prodigiosin biosynthetic operon. A new biosensor (SP19) with enhanced prodigiosin production was created by addition of pigX and pigZ mutations to the existing biosensor. We have demonstrated that SP19 is superior to biosensor strains CV026 and Agrobacterium NTL4 (pZLR4) for the detection of short-chain acyl-HSLs present in spent culture supernatants. Researchers working with QS bacteria that produce short-chain acyl-HSLs can use strain SP19 as a simple visual acyl-HSL biosensor with no requirement for expensive detection equipment.
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