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Find video protocols related to scientific articles indexed in Pubmed.
Factors affecting recompression of augmented vertebrae after successful percutaneous balloon kyphoplasty: a retrospective analysis.
Acta Radiol
PUBLISHED: 11-20-2014
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The instantaneously recovered stability and strength following vertebral augmentation prevent continuous micro-motion and further collapse of fractured vertebrae. Despite this, during follow-up of our patients, we observed recompression of augmented vertebrae with significant vertebral height loss and aggravation of local kyphotic deformity.
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Transmissive resonator optic gyro based on silica waveguide ring resonator.
Opt Express
PUBLISHED: 11-18-2014
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A transmissive resonator optic gyro (TROG) based on silica waveguide ring resonator with improved long-term bias stability is reported in this paper. The modeling of a transmissive resonator used in optic gyro is carried out. The polarization dependence of resonator and the influences of phase modulator's residual intensity modulation on the gyro output are analyzed. The resonator is simulated, designed, fabricated, tested and used to build up a TROG prototype. A bias stability of 0.22°/s over one hour test with an integration time of 10s is successfully demonstrated. No obvious drift has been found from the Allan variance analysis result of a 10000s test data, which means that the TROG prototype has an improved long-term drift characteristic.
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Laser frequency locking with second-harmonic demodulation.
Appl Opt
PUBLISHED: 10-17-2014
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An external-optical-cavity-based laser frequency-locking method with second-harmonic demodulation was proposed, analyzed, and demonstrated. The second-harmonic component of the cavity output was demodulated to feed back to the frequency-locking loop, resulting in a high sensitivity, great carrier suppression, and large modulation bandwidth. The experimental demodulation curve was consistent with the simulation result. A distributed feedback fiber laser was then locked using this technique. A carrier wave suppression ratio of -67??dB and a laser frequency noise floor of 1??Hz/Hz level above 1 Hz were achieved. This technique has great potential to be used in resonator optic gyroscopes.
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Underwater blast wave pressure sensor based on polymer film fiber Fabry-Perot cavity.
Appl Opt
PUBLISHED: 10-17-2014
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This paper describes the theoretical and experimental aspects of an optical underwater shock wave sensor based on a polymer film optical fiber Fabry-Perot cavity manufactured by vacuum deposition technology. The transduction mechanism of the sensor involves a normally incident acoustic stress wave that changes the thickness of the polymer film, thereby giving rise to a phase shift. This transient interferometric phase is interrogated by a three-phase-step algorithm. Theoretically, the sensor-acoustic-field interaction principle is analyzed, and the phase modulation sensitivity based on the theory of waves in the layered media is calculated. Experimentally, a static calibration test and a dynamic calibration test are conducted using a piston-type pressure calibration machine and a focusing-type electromagnetic shock wave. Results indicate that the repeatability, hysteresis, nonlinearity, and the overall measurement accuracy of the sensor within the full pressure range of 55 MPa are 1.82%, 0.86%, 1.81%, and 4.49%, respectively. The dynamic response time is less than 0.767 ?s. Finally, three aspects that need further study for practical use are pointed out.
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Enhancement of 1.53???m emission in erbium/cerium-doped germanosilicate glass pumped by common 808??nm laser diode.
Appl Opt
PUBLISHED: 10-17-2014
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Erbium-doped germanosilicate glasses with various cerium ions contents have been prepared. Optical absorption and 1.53 ?m emission spectra were measured to characterize the spectroscopic performances of prepared samples. A detailed study of 1.53 ?m spectroscopic properties was carried out when pumped by an 808 nm laser diode. Moreover, an energy level diagram and an energy transfer mechanism between Er3+ and Ce3+ were proposed to elucidate the enhanced 1.53 ?m fluorescence. It is found that the prepared samples have optimal spectroscopic properties when the Ce3+ concentration is fixed to 0.5 mol. %. High spontaneous radiative transition probability (172.66??s-1), large effective emission bandwidth (74 nm), and emission cross section (9.49×10-21??cm2 indicate that 808 nm pumped Er3+/Ce3+ codoped germanosilicate glass might be a suitable material for a broadband optical amplifier.
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Comparison of human and Drosophila atlastin GTPases.
Protein Cell
PUBLISHED: 10-09-2014
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Formation of the endoplasmic reticulum (ER) network requires homotypic membrane fusion, which involves a class of atlastin (ATL) GTPases. Purified Drosophila ATL is capable of mediating vesicle fusion in vitro, but such activity has not been reported for any other ATLs. Here, we determined the preliminary crystal structure of the cytosolic segment of Drosophila ATL in a GDP-bound state. The structure reveals a GTPase domain dimer with the subsequent three-helix bundles associating with their own GTPase domains and pointing in opposite directions. This conformation is similar to that of human ATL1, to which GDP and high concentrations of inorganic phosphate, but not GDP only, were included. Drosophila ATL restored ER morphology defects in mammalian cells lacking ATLs, and measurements of nucleotide-dependent dimerization and GTPase activity were comparable for Drosophila ATL and human ATL1. However, purified and reconstituted human ATL1 exhibited no in vitro fusion activity. When the cytosolic segment of human ATL1 was connected to the transmembrane (TM) region and C-terminal tail (CT) of Drosophila ATL, the chimera still exhibited no fusion activity, though its GTPase activity was normal. These results suggest that GDP-bound ATLs may adopt multiple conformations and the in vitro fusion activity of ATL cannot be achieved by a simple collection of functional domains.
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[Identification of onset and offset of QRS complexes based on the characteristics of angle and amplitude].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 09-16-2014
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In order to quickly and accurately identify the onset and offset of the QRS complex in electrocardiogram (ECG) signal with different forms, a triple local transform method was employed in the present study to detect the suspected onset and offset points of QRS. The accurate onset and offset points of QRS complexes were selected according to the rules drawn by the trial process based on the characteristics of angle and amplitude constituted within these suspected points. The method makes full advantage of the angle and amplitude characteristics of the QRS complex, by which the results can be acquired with some simple arithmetic quickly, accurately and adaptively. The method was investigated with data from the MIT-BIH arrhythmia database and satisfactory results were obtained.
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Shenqifuzheng injection combined with chemotherapy in the treatment of advanced gastric cancer: a systematic review and meta-analysis.
J Cancer Res Ther
PUBLISHED: 09-11-2014
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The aim of this systematic review and meta-analysis was to evaluate the clinical efficacy of Shenqifuzheng (SQFZ) injection combined with chemotherapy in the treatment of advanced gastric cancer.
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Novel Binding Motif and New Flexibility Revealed by Structural Analyses of a Pyruvate Dehydrogenase-Dihydrolipoyl Acetyltransferase Subcomplex from the Escherichia coli Pyruvate Dehydrogenase Multienzyme Complex.
J. Biol. Chem.
PUBLISHED: 09-10-2014
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The Escherichia coli pyruvate dehydrogenase multienzyme complex contains multiple copies of three enzymatic components, E1p, E2p, and E3, that sequentially carry out distinct steps in the overall reaction converting pyruvate to acetyl-CoA. Efficient functioning requires the enzymatic components to assemble into a large complex, the integrity of which is maintained by tethering of the displaced, peripheral E1p and E3 components to the E2p core through non-covalent binding. We here report the crystal structure of a subcomplex between E1p and an E2p didomain containing a hybrid lipoyl domain along with the peripheral subunit-binding domain responsible for tethering to the core. In the structure, a region at the N terminus of each subunit in the E1p homodimer previously unseen due to crystallographic disorder was observed, revealing a new folding motif involved in E1p-E2p didomain interactions, and an additional, unexpected, flexibility was discovered in the E1p-E2p didomain subcomplex, both of which probably have consequences in the overall multienzyme complex assembly. This represents the first structure of an E1p-E2p didomain subcomplex involving a homodimeric E1p, and the results may be applicable to a large range of complexes with homodimeric E1 components. Results of HD exchange mass spectrometric experiments using the intact, wild type 3-lipoyl E2p and E1p are consistent with the crystallographic data obtained from the E1p-E2p didomain subcomplex as well as with other biochemical and NMR data reported from our groups, confirming that our findings are applicable to the entire E1p-E2p assembly.
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Human 2-Oxoglutarate Dehydrogenase Complex E1 Component Forms a Thiamin-derived Radical by Aerobic Oxidation of the Enamine Intermediate.
J. Biol. Chem.
PUBLISHED: 09-10-2014
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Herein are reported unique properties of the human 2-oxoglutarate dehydrogenase multienzyme complex (OGDHc), a rate-limiting enzyme in the Krebs (citric acid) cycle. (a) Functionally competent 2-oxoglutarate dehydrogenase (E1o-h) and dihydrolipoyl succinyltransferase components have been expressed according to kinetic and spectroscopic evidence. (b) A stable free radical, consistent with the C2-(C2?-hydroxy)-?-carboxypropylidene thiamin diphosphate (ThDP) cation radical was detected by electron spin resonance upon reaction of the E1o-h with 2-oxoglutarate (OG) by itself or when assembled from individual components into OGDHc. (c) An unusual stability of the E1o-h-bound C2-(2?-hydroxy)-?-carboxypropylidene thiamin diphosphate (the "ThDP-enamine"/C2?-carbanion, the first postdecarboxylation intermediate) was observed, probably stabilized by the 5-carboxyl group of OG, not reported before. (d) The reaction of OG with the E1o-h gave rise to superoxide anion and hydrogen peroxide (reactive oxygen species (ROS)). (e) The relatively stable enzyme-bound enamine is the likely substrate for oxidation by O2, leading to the superoxide anion radical (in d) and the radical (in b). (f) The specific activity assessed for ROS formation compared with the NADH (overall complex) activity, as well as the fraction of radical intermediate occupying active centers of E1o-h are consistent with each other and indicate that radical/ROS formation is an "off-pathway" side reaction comprising less than 1% of the "on-pathway" reactivity. However, the nearly ubiquitous presence of OGDHc in human tissues, including the brain, makes these findings of considerable importance in human metabolism and perhaps disease.
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Isolation of ?-glucosidase inhibitors including a new flavonol glycoside from Dendrobium devonianum.
Nat. Prod. Res.
PUBLISHED: 09-05-2014
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From the whole plant of Dendrobium devonianum, a new flavonol glycoside, 5-hydroxy-3-methoxy-flavone-7-O-[?-D-apiosyl-(1 ? 6)]-?-D-glucoside, as well as 13 known compounds, was isolated. Their structures were identified based on extensive spectroscopic studies including HR-EI-MS, (1)H, (13)C NMR, DEPT, H-H COSY, HSQC, HMBC and NOESY spectra. The new compound and gigantol were evaluated for their ?-glucosidase inhibitory activity, and both displayed more potent ?-glucosidase inhibitory activity than acarbose, one of the most potent ?-glucosidase inhibitor drugs, with the inhibition rate of 43.4% and 36.7%, respectively, in the concentration of 437.5 ?mol/L.
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The incidence of secondary vertebral fracture of vertebral augmentation techniques versus conservative treatment for painful osteoporotic vertebral fractures: a systematic review and meta-analysis.
Acta Radiol
PUBLISHED: 08-19-2014
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Percutaneous vertebroplasty (PVP) and balloon kyphoplasty (BKP) are minimally invasive and effective vertebral augmentation techniques for managing osteoporotic vertebral compression fractures (OVCFs). Recent meta-analyses have compared the incidence of secondary vertebral fractures between patients treated with vertebral augmentation techniques or conservative treatment; however, the inclusions were not thorough and rigorous enough, and the effects of each technique on the incidence of secondary vertebral fractures remain unclear.
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Dual quinone tagging for MALDI-TOF mass spectrometric quantitation of cysteine-containing peptide.
Anal. Chem.
PUBLISHED: 08-05-2014
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A dual quinone tagging strategy is designed for quantitation of cysteine-containing peptide (CCP) with MALDI-TOF mass spectrometry. The quinone compounds can rapidly and specifically bind to the thiol group of cysteine residues by a Michael addition reaction, which is used to identify both CCP and the number of cysteine residues in CCP through the direct observation of untagged and tagged products. After reduced with DL-dithiothreitol, the intramolecular disulfide bond can also be identified. Using benzoquinone (BQ) and methyl-p-benzoquinone (MBQ) as dual tags and a peptide with an amino acid sequence of SSDQFRPDDCT (C-pep1) as a model target, respectively, the quantitation strategy is performed through the intensity ratio of MBQ-tagged C-pep1 to BQ-tagged C-pep1 as the internal standard. The logarithm value of the intensity ratio is proportional to C-pep1 concentration in a range from 5.0 to 5000 nM. The limit of detection is as low as 2.0 nM. The proposed methodology provides a novel tool for rapid characterization, identification, and quantitation of biomolecules containing thiol reactive sites and has a promising application in the large-scale detection and analysis of cysteine-containing biomolecules.
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Soil organic carbon content estimation with laboratory-based visible-near-infrared reflectance spectroscopy: feature selection.
Appl Spectrosc
PUBLISHED: 07-26-2014
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This study, with Yixing (Jiangsu Province, China) and Honghu (Hubei Province, China) as study areas, aimed to compare the successive projection algorithm (SPA) and the genetic algorithm (GA) in spectral feature selection for estimating soil organic carbon (SOC) contents with visible-near-infrared (Vis-NIR) reflectance spectroscopy and further to assess whether the spectral features selected from one site could be applied to another site. The SOC content and Vis-NIR reflectance spectra of soil samples were measured in the laboratory. Savitzky-Golay smoothing and log10(1/R) (R is reflectance) were used for spectral preprocessing. The reflectance spectra were resampled using different spacing intervals ranging from 2 to 10 nm. Then, SPA and GA were conducted for selecting the spectral features of SOC. Partial least square regression (PLSR) with full-spectrum PLSR and the spectral features selected by SPA (SPA-PLSR) and GA (GA-PLSR) were calibrated and validated using independent datasets, respectively. Moreover, the spectral features selected from one study area were applied to another area. Study results showed that, for the two study areas, the SPA-PLSR and GA-PLSR improved estimation accuracies and reduced spectral variables compared with the full spectrum PLSR in estimating SOC contents; GA-PLSR obtained better estimation results than SPA-PLSR, whereas SPA was simpler than GA, and the spectral features selected from Yixing could be well applied to Honghu, but not the reverse. These results indicated that the SPA and GA could reduce the spectral variables and improve the performance of PLSR model and that GA performed better than SPA in estimating SOC contents. However, SPA is simpler and time-saving compared with GA in selecting the spectral features of SOC. The spectral features selected from one dataset could be applied to a target dataset when the dataset contains sufficient information adequately describing the variability of samples of the target dataset.
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The membrane protein Pannexin1 forms two open-channel conformations depending on the mode of activation.
Sci Signal
PUBLISHED: 07-25-2014
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Pannexin1 (Panx1) participates in several signaling events that involve adenosine triphosphate (ATP) release, including the innate immune response, ciliary beat in airway epithelia, and oxygen supply in the vasculature. The view that Panx1 forms a large ATP release channel has been challenged by the association of a low-conductance, small anion-selective channel with the presence of Panx1. We showed that Panx1 membrane channels can function in two distinct modes with different conductances and permeabilities when heterologously expressed in Xenopus oocytes. When stimulated by potassium ions (K(+)), Panx1 formed a high-conductance channel of ~500 pS that was permeable to ATP. Various physiological stimuli can induce this ATP-permeable conformation of the channel in several cell types. In contrast, the channel had a low conductance (~50 pS) with no detectable ATP permeability when activated by voltage in the absence of K(+). The two channel states were associated with different reactivities of the terminal cysteine of Panx1 to thiol reagents, suggesting different conformations. Single-particle electron microscopic analysis revealed that K(+) stimulated the formation of channels with a larger pore diameter than those formed in the absence of K(+). These data suggest that different stimuli lead to distinct channel structures with distinct biophysical properties.
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Implementation of incident learning in the safety and quality management of radiotherapy: the primary experience in a new established program with advanced technology.
Biomed Res Int
PUBLISHED: 07-22-2014
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To explore the implementation of incident learning for quality management of radiotherapy in a new established radiotherapy program.
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Identification of apolipoprotein C-I as a potential Wilms' tumor marker after excluding inflammatory factors.
Int J Mol Sci
PUBLISHED: 07-15-2014
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Wilms' tumor is one of the most common malignant tumors observed in children, and its early diagnosis is important for late-stage treatment and prognosis. We previously screened and identified protein markers for Wilms' tumor; however, these markers lacked specificity, and some were associated with inflammation. In the current study, serum samples from children with Wilms' tumors were compared with those of healthy controls and patients with systemic inflammatory response syndrome (SIRS). After exclusion of factors associated with inflammation, specific protein markers for Wilms' tumors were identified. After comparing the protein peak values obtained from all three groups, a protein with a m/z of 6438 Da was specified. Purification and identification of the target protein using high-pressure liquid chromatography (HPLC) and two-dimensional liquid chromatography-linearion trap mass spectrometry(2D-LC-LTQ-MS) mass spectrometry, respectively, revealed that it was apolipoprotein C-I (APO C-I). Thus, APO C-I is a specific protein marker for Wilms' tumor.
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Estimating soil organic carbon content with visible-near-infrared (vis-NIR) spectroscopy.
Appl Spectrosc
PUBLISHED: 07-12-2014
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The selection of a calibration method is one of the main factors influencing measurement accuracy with visible-near-infrared (Vis-NIR, 350-2500 nm) spectroscopy. This study, based on both air-dried unground (DU) and air-dried ground (DG) soil samples, used nine spectral preprocessing methods and their combinations, with the aim to compare the commonly used partial least squares regression (PLSR) method with the new machine learning method of support vector machine regression (SVMR) to find a robust method for soil organic carbon (SOC) content estimation, and to further explore an effective Vis-NIR spectral preprocessing strategy. In total, 100 heterogeneous soil samples collected from Southeast China were used as the dataset for the model calibration and independent validation. The determination coefficient (R(2)), root mean square error (RMSE), residual prediction deviation (RPD), and ratio of performance to interquartile range were used for the model evaluation. The results of this study show that both the PLSR and SVMR models were significantly improved by the absorbance transformation (LOG), standard normal variate with wavelet detrending (SW), first derivative (FD), and mean centering (MC) spectral preprocessing methods and their combinations. SVMR obtained optimal models for both the DU and DG soil, with R(2), RMSE, and RPD values of 0.72, 2.48 g/kg, and 1.83 for DU soil and 0.86, 1.84 g/kg, and 2.60 for DG soil, respectively. Among all the PLSR and SVMR models, SVMR showed a more stable performance than PLSR, and it also outperformed PLSR, with a smaller mean RMSE of 0.69 g/kg for DU soil and 0.50 g/kg for DG soil. This study concludes that PLSR is an effective linear algorithm, but it might not be sufficient when dealing with a nonlinear relationship, and SVMR turned out to be a more suitable nonlinear regression method for SOC estimation. Effective SOC estimation was obtained based on the DG soil samples, but the accurate estimation of SOC with DU soil samples needs to be further explored. In addition, LOG, SW, FD, and MC are valuable spectral preprocessing methods for Vis-NIR optimization, and choosing two of them (except for FD + SW and LOG + FD) in a simple combination is a good way to get acceptable results.
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Detailed study of the interaction between human herpesvirus 6B glycoprotein complex and its cellular receptor, human CD134.
J. Virol.
PUBLISHED: 07-09-2014
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Recently, we identified a novel receptor, CD134, which interacts with the human herpesvirus 6B (HHV-6B) glycoprotein (g)H/gL/gQ1/gQ2 complex and plays a key role in the entry of HHV-6B into target cells. However, details of the interaction between the HHV-6B gH/gL/gQ1/gQ2 complex and CD134 were unknown. In this study, we identified a cysteine-rich domain (CRD), CDR2, of CD134 that is critical for binding to the HHV-6B glycoprotein complex and HHV-6B infection. Furthermore, we found that the expression of HHV-6B gQ1 and gQ2 subunits was sufficient for CD134 binding, which is different from the binding of human herpesvirus 6A (HHV-6A) to its receptor, CD46. Finally, we identified a region in gQ1 critical for HHV-6B gQ1 function. These results contribute much to our understanding of the interaction between this ligand and receptor.
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Impact of obstructive sleep apnea on cardiovascular outcomes in patients treated with percutaneous coronary intervention: rationale and design of the sleep and stent study.
Clin Cardiol
PUBLISHED: 06-20-2014
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Elucidating the effects of obstructive sleep apnea (OSA) on cardiovascular outcomes is crucial in risk assessments and therapeutic recommendations for affected individuals. The Sleep and Stent Study is a multicenter observational study investigating the relationships between OSA and cardiovascular outcomes in patients treated with percutaneous coronary intervention (PCI). Eight centers in 5 countries (Singapore, China and Hong Kong, India, Myanmar, and Brazil) are participating in the study, and the recruitment target is 1600 patients. Adult patients age 18 to 80 years who have undergone successful PCI are eligible. Recruited patients will undergo an overnight sleep study using a level-3 portable diagnostic device before hospital discharge. The sleep tracings will be analyzed by a certified sleep technologist and audited by a sleep physician, both of whom will be blinded to other study data. The patients will be divided into 2 groups based on apnea-hypopnea index (AHI): OSA (AHI ?15) and non-OSA (AHI <15) groups. The primary study endpoint of cardiovascular death, myocardial infarction, stroke, and unplanned revascularization will be compared between the OSA and non-OSA groups at a median follow-up of 2 years. Secondary endpoints include all-cause mortality, target-vessel revascularization, stent thrombosis, and hospitalization for heart failure. As of December 31, 2013, a total of 1358 patients have been recruited. Based on the complete preliminary results of the first 785 recruited patients, the prevalence of OSA was 48.3%. We expect the follow-up for primary endpoint to be completed in late 2015; study results will be presented in 2016.
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Hydrothermal fabrication of three-dimensional secondary battery anodes.
Adv. Mater. Weinheim
PUBLISHED: 06-09-2014
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A generalized hydrothermal strategy for fabricating three-dimensional (3D) battery electrodes is presented. The hydrothermal growth deposits electrochemically active nanomaterials uniformly throughout the complex 3D mesostructure of the scaffold. Ni inverse opals coated with SnO2 nanoparticles or Co3 O4 nanoplatelets, and SiO2 inverse opals coated with Fe3 O4 are fabricated, all of which show attractive properties including good capacity retention and C-rate performances.
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In situ observation of random solid solution zone in LiFePO? electrode.
Nano Lett.
PUBLISHED: 06-09-2014
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Nanostructured LiFePO4 (LFP) electrodes have attracted great interest in the Li-ion battery field. Recently there have been debates on the presence and role of metastable phases during lithiation/delithiation, originating from the apparent high rate capability of LFP batteries despite poor electronic/ionic conductivities of bulk LFP and FePO4 (FP) phases. Here we report a potentiostatic in situ transmission electron microscopy (TEM) study of LFP electrode kinetics during delithiation. Using in situ high-resolution TEM, a Li-sublattice disordered solid solution zone (SSZ) is observed to form quickly and reach 10-25 nm × 20-40 nm in size, different from the sharp LFP|FP interface observed under other conditions. This 20 nm scale SSZ is quite stable and persists for hundreds of seconds at room temperature during our experiments. In contrast to the nanoscopically sharp LFP|FP interface, the wider SSZ seen here contains no dislocations, so reduced fatigue and enhanced cycle life can be expected along with enhanced rate capability. Our findings suggest that the disordered SSZ could dominate phase transformation behavior at nonequilibrium condition when high current/voltage is applied; for larger particles, the SSZ could still be important as it provides out-of-equilibrium but atomically wide avenues for Li(+)/e(-) transport.
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The self-limiting dynamics of TGF-? signaling in silico and in vitro, with negative feedback through PPM1A upregulation.
PLoS Comput. Biol.
PUBLISHED: 06-01-2014
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The TGF-?/Smad signaling system decreases its activity through strong negative regulation. Several molecular mechanisms of negative regulation have been published, but the relative impact of each mechanism on the overall system is unknown. In this work, we used computational and experimental methods to assess multiple negative regulatory effects on Smad signaling in HaCaT cells. Previously reported negative regulatory effects were classified by time-scale: degradation of phosphorylated R-Smad and I-Smad-induced receptor degradation were slow-mode effects, and dephosphorylation of R-Smad was a fast-mode effect. We modeled combinations of these effects, but found no combination capable of explaining the observed dynamics of TGF-?/Smad signaling. We then proposed a negative feedback loop with upregulation of the phosphatase PPM1A. The resulting model was able to explain the dynamics of Smad signaling, under both short and long exposures to TGF-?. Consistent with this model, immuno-blots showed PPM1A levels to be significantly increased within 30 min after TGF-? stimulation. Lastly, our model was able to resolve an apparent contradiction in the published literature, concerning the dynamics of phosphorylated R-Smad degradation. We conclude that the dynamics of Smad negative regulation cannot be explained by the negative regulatory effects that had previously been modeled, and we provide evidence for a new negative feedback loop through PPM1A upregulation. This work shows that tight coupling of computational and experiments approaches can yield improved understanding of complex pathways.
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Mid-infrared fluorescence, energy transfer process and rate equation analysis in Er(3+) doped germanate glass.
Sci Rep
PUBLISHED: 05-30-2014
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Er(3+) doped Y2O3 and Nb2O5 modified germanate glasses with different Er(3+) concentrations were prepared. J-O intensity parameters were computed to estimate the structural changes due to the additions of Y2O3 and Nb2O5. The main mid-infrared spectroscopic features were investigated. To shed light on the observed mid-infrared radiative behavior, 975?nm and 1.53??m emission spectra along with their decay lifetimes were also discussed. Moreover, the energy transfer processes of (4)I11/2 and (4)I13/2 level were quantitatively analyzed. In view of the experimental lifetimes, the simplified rate equation was utilized to calculate the energy transfer upconversion processes of upper and lower laser level of 2.7??m emission. The theoretical calculations are in good agreement with the observed 2.7??m fluorescence phenomena. Finally, the stimulated emission and gain cross sections were calculated and the results indicate that Er(3+) doped germanate glasses have great potential for mid-infrared application.
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A two-photon ratiometric fluorescent probe enables spatial coordinates determination of intracellular pH.
Talanta
PUBLISHED: 05-29-2014
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We reported a two-photon ratiometric fluorescent probe for detecting intracellular pH. When excited with 800 nm laser, an optimal output of laser as the routine equipment of two-photon fluorescence microscopy, the two-photon excited fluorescence of this probe showed distinct emission peak shift as large as 109 nm upon the change of pH values in vitro. Very importantly, the experiment results show that this probe has large two-photon absorption cross-section at pH 4.5 at 800 nm of 354 g, which ranks it as one of the best two-photon ratiometric fluorescent pH probes, and its working pH value is between 4.0 and 8.0 which could fit the intracellular pH range. Moreover, utilizing this probe, the two-photon ratiometric fluorescent images in living cells have been obtained, and the spatial coordinates of intracellular pH can be mapped. At the same time, the probe also exhibited selectivity, photostability and membrane permeability. And the photophysical properties of this probe in various solvents indicated that these photophysical properties variations are due to an intramolecular charge transfer process. At last, the imaging depth of the probe in liver biopsy slices was investigated. The experimental results demonstrated the maximum imaging depth can arrive 66 µm in living rat liver tissues.
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Improved delivery of the OVA-CD4 peptide to T helper cells by polymeric surface display on Salmonella.
Microb. Cell Fact.
PUBLISHED: 05-19-2014
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Autotransporter proteins represent a treasure trove for molecular engineers who modify Gram-negative bacteria for the export or secretion of foreign proteins across two membrane barriers. A particularly promising direction is the development of autotransporters as antigen display or secretion systems. Immunologists have been using ovalbumin as a reporter antigen for years and have developed sophisticated tools to detect specific T cells that respond to ovalbumin. Although ovalbumin-expressing bacteria are being used to trace T cell responses to colonizing or invading pathogens, current constructs for ovalbumin presentation have not been optimized.
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Cascaded-Automatic Segmentation for Schistosoma japonicum eggs in images of fecal samples.
Comput. Biol. Med.
PUBLISHED: 05-18-2014
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To recognize parasite eggs automatically, the automatic segmentation of parasite egg images is very important for the extraction of characteristics and genera classification.
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Sexually dimorphic genetic architecture of complex traits in a large-scale F2 cross in pigs.
Genet. Sel. Evol.
PUBLISHED: 05-17-2014
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It is common for humans and model organisms to exhibit sexual dimorphism in a variety of complex traits. However, this phenomenon has rarely been explored in pigs.
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Microcirculatory significance of periprocedural myocardial necrosis after percutaneous coronary intervention assessed by the index of microcirculatory resistance.
Int J Cardiovasc Imaging
PUBLISHED: 05-07-2014
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This study sought to investigate the relationship between the index of microcirculatory resistance (IMR) and periprocedural myocardial necrosis in patients with unstable angina pectoris (UAP). Fifty-seven UAP patients undergoing elective percutaneous coronary intervention (PCI) of a single lesion were recruited. A pressure-temperature sensor wire was used to measure IMR immediately after PCI. Total creatine kinase-MB (CK-MB) and troponin I (TNI) were measured every 8 h after PCI until they began to decline. Of the 57 patients studied, 22 had periprocedural myocardial infarction (MI) according to TNI. Post-PCI IMR >31 U had 86% sensitivity and 91% specificity for predicting periprocedural MI. There are a strong positive correlation between IMR and peak TNI (r = 0.805, p = 0.001), and a moderate positive correlation between IMR and peak CK-MB (r = 0.608, p = 0.003). Periprocedural myocardial injury, even in small area, during reperfusion is associated with impaired microcirculatory integrity as evaluated by IMR. Post-PCI IMR is independent predictive of developing periprocedural MI in patients with UAP, and, therefore, potentially enables a triage of higher risk patients to more intensive therapy.
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[Determination of phenolic compounds in fresh tobacco leaves by high performance liquid chromatography-ultraviolet/mass spectrometry].
Se Pu
PUBLISHED: 05-03-2014
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Twenty-five phenolic compounds in tobacco were analyzed using high performance liquid chromatography-ultraviolet/mass spectrometry (HPLC-UV/MS), including absolute quantification of 11 main phenols by HPLC-UV and relative quantification of other 14 phenols by SHPLC-MS. The validation results of this method were satisfactory. Eleven phenol standards showed good linearity with correlation coefficients (r2) of 0.999 3 - 0.999 9 over the mass concentration range from 0.90 mg/L to 99.00 mg/L (the range of chlorogenic acid and rutin was from 0.95 mg/L to 380.00 mg/L). The recoveries of the 11 phenol standards were 91.0% - 112.4% with the RSDs of 0.33% - 8.11% at the three spiked levels of 22.5 - 24.8, 45.0 - 49.5 and 67.5 - 74.3 mg/L. The reproducibility of the method was good with the RSDs of 1.48% - 13.40%. In addition, the intra-day and inter-day precisions were also satisfactory with the RSDs of 0.35% - 15.54%. Mature fresh tobacco leaves from Yunnan, Henan and Guizhou Provinces, China were analyzed using this method. The results showed that the total amount of main phenols was Guizhou > Yunnan > Henan and there was significant difference between Guizhou and Henan. The amount of rutin was Yunnan > Guizhou > Henan, and there were significant differences among them each other. The method is reproducible with a simple pretreatment covering a wide range of phenols, and can be applied in batch analysis of tobacco leaves.
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The effect of La?O? in Tm³?-doped germanate-tellurite glasses for ~2 ?m emission.
Sci Rep
PUBLISHED: 04-02-2014
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A germanate-tellurite glass (GeO2-TeO?-K?O-Nb?O?-La?O?) with thulium doping has been investigated for application as a laser material around 2.0 ?m regions. Under the 808 nm laser diode pumped, intense 1.8 ?m emission is obtained. Based on the absorption spectra, radiative properties are predicted using Judd-Ofelt theory. The maximum value of emission cross-section of Tm(3+) around 1.8 ?m can reach 1.46 × 10(-20) cm(2), which indicated that the germanate-tellurite glass may provide high gain as a good medium for efficient 1.8 ?m laser system.
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Compositional dependence of room-temperature Stark splitting of Yb³? in several popular glass systems.
Opt Lett
PUBLISHED: 04-02-2014
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The room-temperature Stark splitting properties of Yb3+ are practical and valuable for lasers because the working temperature of the gain media intensively increases with the laser output. In this Letter, the room-temperature Stark splitting properties of Yb3+ in several popular laser glasses are contrastively studied. Yb3+-doped germanate (Ge), borate (B), silicate (Si), bismuthate (Bi), tellurite (Te), and fluorophosphate (FP) glasses exhibit large Stark splitting and tend to operate close to the quasi-four-level scheme, whereas phosphate (P) glass shows the weakest Stark splitting and tends to operate close to the quasi-three-level one. Due to the low thermal conductivity of the glass matrix, Yb3+-doped P glass suffers from serious thermal problems and is difficult to achieve high laser output. The Stark splitting is also used to estimate the crystal-field strength of glass hosts and local Yb3+ ligand asymmetry degree. The results show that P glass shows weaker crystal-field effect and lower Yb3+ ligand asymmetry than Ge, Si, and B glasses.
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Catalyst-free synthesis of skipped dienes from phosphorus ylides, allylic carbonates, and aldehydes via a one-pot SN2' allylation-Wittig strategy.
J. Org. Chem.
PUBLISHED: 04-02-2014
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A catalyst-free allylic alkylation of stabilized phosphorus ylides with allylic carbonates via a regioselective SN2' process is presented. Subsequent one-pot Wittig reaction with both aliphatic and aromatic aldehydes as well as ketenes provides structurally diverse skipped dienes (1,4-dienes) in generally high yields and moderate to excellent stereoselectivity with flexible substituent patterns. This one-pot SN2' allylation-Wittig strategy constitutes a convenient and efficient synthetic method for highly functionalized skipped dienes from readily available starting materials.
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Polymorphism in PHD1 gene and risk of non-small cell lung cancer in a Chinese population.
Tumour Biol.
PUBLISHED: 03-29-2014
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Hypoxia is a common phenomenon in the development of solid tumors, and hypoxia inducible factor 1 (HIF-1) plays a central role in coordinating the cellular response to hypoxia and in oxygen homeostasis. The prolyl hydrolase 1 (PHD1) is a key adjustment factor that mediates the HIF-1 degradation and relates with the process of tumorigenesis. Thus, polymorphism in PHD1 may affect cellular response to hypoxic conditions and associate with cancer susceptibility. We conducted a case-control study with 406 non-small cell lung cancer cases and 812 healthy controls matched on age and sex to examine the effect of rs10680577 polymorphism within the PHD1 promoter on non-small cell lung cancer (NSCLC) risk in a Chinese population. The genotype of rs10680577 polymorphism was detected by non-denaturing polyacrylamide gel electrophoresis. The ins/del genotype of rs10680577 was associated with significantly increased non-small cell lung cancer risk (ins/del vs. ins/ins: OR?=?1.35, 95 % confidence interval (CI) 1.05-1.74, P?=?0.020; ins/del vs. ins/ins?+?del/del: OR?=?1.34, 95 % CI?=?1.04-1.72, P?=?0.022). In addition, the association was more pronounced in the group of >60 years of age. rs10680577 polymorphism is associated with the risk of non-small cell lung cancer in a Chinese population. This is the first time to show that PHD1 rs10680577 is associated NSCLC risk.
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Ho³?Yb³?-codoped germanate-tellurite glasses for 2.0 ?m emission performance.
Appl Opt
PUBLISHED: 03-26-2014
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2.0 ?m emission property of a new germanate-tellurite (GT) glass with Ho³?/Yb³? codoping is synthesized and analyzed. Efficient 2.0 ?m emission of Ho³? ions sensitized by Yb³? ions from the host glass was observed under 980 nm pumping. Based on the measured absorption spectra, the Judd-Ofelt parameters were calculated and discussed. The maximum emission cross section of Ho³? ions transition is 4.36×10(-21) cm2 around 2.0 ?m. The energy transfer efficiency is calculated and fitted the decay signals. The good spectroscopic properties suggest that Ho³?/Yb³?-codoped GT glass may become an attractive host for developing solid state lasers operating in the mid-infrared.
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Predictive factors for lymph node metastasis in early gastric cancer with signet ring cell histology and their impact on the surgical strategy: analysis of single institutional experience.
J. Surg. Res.
PUBLISHED: 03-19-2014
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The prognosis of early gastric cancer (EGC) with signet ring cell histology is more favorable than other undifferentiated gastric adenocarcinomas. An accurate assessment of potential lymph node metastasis is important for the appropriate treatment of EGC with signet ring cell histology. Therefore, this study analyzed the predictive factors associated with lymph node metastasis in patients with this type of EGC.
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Dissecting innate immune signaling in viral evasion of cytokine production.
J Vis Exp
PUBLISHED: 03-19-2014
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In response to a viral infection, the host innate immune response is activated to up-regulate gene expression and production of antiviral cytokines. Conversely, viruses have evolved intricate strategies to evade and exploit host immune signaling for survival and propagation. Viral immune evasion, entailing host defense and viral evasion, provides one of the most fascinating and dynamic interfaces to discern the host-virus interaction. These studies advance our understanding in innate immune regulation and pave our way to develop novel antiviral therapies. Murine ?HV68 is a natural pathogen of murine rodents. ?HV68 infection of mice provides a tractable small animal model to examine the antiviral response to human KSHV and EBV of which perturbation of in vivo virus-host interactions is not applicable. Here we describe a protocol to determine the antiviral cytokine production. This protocol can be adapted to other viruses and signaling pathways. Recently, we have discovered that ?HV68 hijacks MAVS and IKK?, key innate immune signaling components downstream of the cytosolic RIG-I and MDA5, to abrogate NF?B activation and antiviral cytokine production. Specifically, ?HV68 infection activates IKK? and that activated IKK? phosphorylates RelA to accelerate RelA degradation. As such, ?HV68 efficiently uncouples NF?B activation from its upstream activated IKK?, negating antiviral cytokine gene expression. This study elucidates an intricate strategy whereby the upstream innate immune activation is intercepted by a viral pathogen to nullify the immediate downstream transcriptional activation and evade antiviral cytokine production.
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A first generation BAC-based physical map of the half-smooth tongue sole (Cynoglossus semilaevis) genome.
BMC Genomics
PUBLISHED: 03-10-2014
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Half-smooth tongue sole (Cynoglossus semilaevis Günther) has been exploited as a commercially important cultured marine flatfish, and female grows 2-3 times faster than male. Genetic studies, especially on the chromosomal sex-determining system of this species, have been carried out in the last decade. Although the genome of half-smooth tongue sole was relatively small (626.9 Mb), there are still some difficulties in the high-quality assembly of the next generation genome sequencing reads without the assistance of a physical map, especially for the W chromosome of this fish due to abundance of repetitive sequences. The objective of this study is to construct a bacterial artificial chromosome (BAC)-based physical map for half-smooth tongue sole with the method of high information content fingerprinting (HICF).
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Effective control of modified palygorskite to NH4+-N release from sediment.
Environ Technol
PUBLISHED: 03-08-2014
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Sediment capping is an in situ treatment technology that can effectively restrain nutrient and pollutant release from the sediment in lakes and reservoirs. Research on sediment capping has focused on the search for effective, non-polluting and affordable capping materials. The efficiency and mechanism of sediment capping with modified palygorskite in preventing sediment ammonia nitrogen (NH4+-N) release to surface water were investigated through a series of batch and sediment capping experiments. Purified palygorskite and different types of modified palygorskite (i.e. heated, acid-modified and NaCI-modified palygorskite) were used in this investigation. Factors affecting control efficiency, including the temperature, thickness and grain size of the capping layer, were also analysed. The batch tests showed that the adsorption of NH4+-N on modified palygorskite achieved an equilibration in the initial 45 min, and the adsorption isotherm followed the Freundlich equation. Sediment capping experiments showed that compared with non-capped condition, covering the sediment with modified palygorskite and sand both inhibited NH4+-N release to the overlying water. Given its excellent chemical stability and strong adsorption, heated palygorskite, which has a NH4+-N release inhibition ratio of 41.3%, is a more effective sediment capping material compared with sand. The controlling effectiveness of the modified palygorskite increases with thicker capping layer, lower temperature and smaller grain size of the capping material.
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Draft Genome Sequence of an Anaerobic, Thermophilic Bacterium, Thermoanaerobacterium aotearoense SCUT27, Isolated from a Hot Spring in China.
Genome Announc
PUBLISHED: 02-15-2014
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Thermoanaerobacterium aotearoense SCUT27, isolated from a hot spring in China, is a strictly anaerobic, thermophilic bacterium capable of degrading xylan and converting both pentose and hexose to ethanol with high yields. Here, we report the draft genome sequence of SCUT27, which reveals insights into the mechanisms of carbon source coutilization and xylan degradation in this thermophilic microorganism.
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Tunable mid-infrared luminescence from Er(3+) -doped germanate glass.
Luminescence
PUBLISHED: 02-13-2014
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Er(3+) -doped germanate glasses with superior thermal stability were prepared. Judd-Ofelt intensity parameters and important spectroscopic properties were discussed in detail. Upon 800 nm and 980 nm LD pumping, 2.7 µm fluorescence characteristics were investigated and it was found that the effective 2.7 µm emission bandwidth can reach to 101.79 nm in prepared glasses. The tunability of the 2.7 µm emission band can be realized by adjusting the Er(3+) content. Moreover, a high-emission cross-section (11.09 ×10(-21) cm(2) ), large gain bandwidth (772.30 ×10(-28) cm(3) ) and gain coefficient (6.72 cm(-1) ) were obtained in the prepared sample. Hence, Er(3+) -doped germanate glass might be a promising mid-infrared material for tunable amplifiers or lasers. Copyright © 2014 John Wiley & Sons, Ltd.
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Study of metabolite differences of flue-cured tobacco from different regions using a pseudotargeted gas chromatography with mass spectrometry selected-ion monitoring method.
J Sep Sci
PUBLISHED: 02-09-2014
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A pseudotargeted method based on gas chromatography and mass spectrometry with selected-ion monitoring was established to investigate the metabolite differences of flue-cured tobacco from three different growing regions. The mixed solvent of acetonitrile/isopropanol/water (3:3:2, v/v/v) was chosen as the optimal extraction system based on the good repeatability and extraction efficiency. A self-developed software coupled with commercial software was used to establish the pseudotargeted method including 289 peaks and 47 groups. Multivariable statistical analysis indicated that tobacco samples can be obviously separated based on the geographical origins. On the basis of a Mann-Whitney U test, organic acids, phenols, and alkaloids had higher levels in Hunan province. In contrast, a large proportion of amino acids (including L-tyrosine, L-proline, and serine), sucrose, and linoleic acid were the highest in Yunnan province. Meanwhile, multiple metabolic pathways (including carbohydrate metabolism, tricarboxylic acid cycle, and nitrogen metabolism) were influenced by growing regions. Twenty-eight differential metabolites, which had great contributions to the classification of tobacco samples of three growing regions, were further defined. The results demonstrated that the developed pseudotargeted method was a powerful tool to investigate the metabolic profiling of tobacco leaves and discriminate tobacco leaves of different growing regions.
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Facile synthesis of boronic acid-functionalized magnetic carbon nanotubes for highly specific enrichment of glycopeptides.
Nanoscale
PUBLISHED: 02-05-2014
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A stepwise strategy was developed to synthesize boronic acid functionalized magnetic carbon nanotubes (MCNTs) for highly specific enrichment of glycopeptides. The MCNTs were synthesized by a solvothermal reaction of Fe(3+) loaded on the acid-treated CNTs and modified with 1-pyrenebutanoic acid N-hydroxysuccinimidyl ester (PASE) to bind aminophenylboronic acid (APBA) via an amide reaction. The introduction of PASE could bridge the MCNT and APBA, suppress the nonspecific adsorption and reduce the steric hindrance among the bound molecules. Due to the excellent structure of the MCNTs, the functionalization of PASE and then APBA on MCNTs was quite simple, specific and effective. The glycopeptides enrichment and separation with a magnetic field could be achieved by their reversible covalent binding with the boronic group of APBA-MCNTs. The exceptionally large specific surface area and the high density of boronic acid groups of APBA-MCNTs resulted in rapid and highly efficient enrichment of glycopeptides, even in the presence of large amounts of interfering nonglycopeptides. The functional MCNTs possessed high selectivity for enrichment of 21 glycopeptides from the digest of horseradish peroxidase demonstrated by MALDI-TOF mass spectrometric analysis showing more glycopeptides detected than the usual 9 glycopeptides with commercially available APBA-agarose. The proposed system showed better specificity for glycopeptides even in the presence of non-glycopeptides with 50 times higher concentration. The boronic acid functionalized MCNTs provide a promising selective enrichment platform for precise glycoproteomic analysis.
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NS1-based tests with diagnostic utility for confirming dengue infection: a meta-analysis.
Int. J. Infect. Dis.
PUBLISHED: 01-29-2014
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Non-structural protein 1 (NS1)-based tests may offer a larger window of opportunity for dengue diagnosis and could constitute a very useful diagnostic tool. The aim of this study was to establish the overall accuracy of NS1-based tests for diagnosing dengue infection.
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Biphasic catalytic conversion of fructose by continuous hydrogenation of HMF over a hydrophobic ruthenium catalyst.
ChemSusChem
PUBLISHED: 01-28-2014
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The production of chemicals directly from sugars is an important step in biomass conversion. Herein, tetrahydro-2,5-furandimethanol (THFDM), obtained from fructose, is formed by using a combination of acid and hydrophobic Ru/SiO2 in a water/cyclohexane biphasic system. Two key factors enable the high selectivity towards THFDM: modifying the hydrogenation catalyst so that it has hydrophobic properties, and the continuous hydrogenation of generated 5-(hydroxymethyl)furfural in the cyclohexane phase. Moreover, the selectivity towards THFDM is found to depend strongly on the acid catalyst used.
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Proteomic analysis of the follicular fluid of Tianzhu white yak during diestrus.
Int J Mol Sci
PUBLISHED: 01-22-2014
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The aim of this study was to identify differentially expressed proteins in the follicular fluid of Tianzhu white yak during diestrus. Follicles obtained from female yak were divided into four groups according to their diameter: 0-2, 2-4, 4-6 mm, and greater than 6 mm. The follicular fluid was directly aspirated from the follicles and mixed according to follicular size, and two-dimensional gel electrophoresis was carried out on the crude follicular fluid samples. Thirty-four differentially expressed spots were generated from these four sizes of follicles. Fourteen of these spots were analyzed by MALDI-TOF/TOF-MS and identified as: AS3MT, VDP, ANKRD6, C10orf107 protein, MRP4, MAPKAP1, AGO3, profilin-?-actin, SPT2 homolog, AGP, AR, RNF20, obscurin-like-1, and one unnamed protein. These proteins were first reported in follicular fluid, in addition to VDP and AGP. Based on existing knowledge of their function and patterns of expression, we hypothesize that most of these differentially expressed proteins play a role in ovarian follicular growth and development, dominant follicle selection, or follicular atresia and development of oocytes; however, the function of the other differentially expressed proteins in reproduction remains ambiguous.
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Rapamycin attenuates endothelial apoptosis induced by low shear stress via mTOR and sestrin1 related redox regulation.
Mediators Inflamm.
PUBLISHED: 01-22-2014
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Studies indicate the dramatic reduction of shear stress (SS) within the rapamycin eluting stent (RES) segment of coronary arteries. It remains unclear about the role of rapamycin in endothelialization of stented arteries where SS becomes low. Since mTOR (mammalian target of rapamycin) pathway is involved in the antioxidative sestrins expression, we hypothesized that rapamycin attenuated low SS (LSS) induced endothelial dysfunction through mTOR and sestrin1 associated redox regulation.
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Totally laparoscopic resection with natural orifice specimen extraction for carcinoma of sigmoid colon and rectum: a feasible and innovative technique.
J. Clin. Gastroenterol.
PUBLISHED: 01-21-2014
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To testify the feasibility and safety of an innovative technique we performed.
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Metabolomics study of cured tobacco using liquid chromatography with mass spectrometry: method development and its application in investigating the chemical differences of tobacco from three growing regions.
J Sep Sci
PUBLISHED: 01-14-2014
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Cured tobacco is an important plant material. Component studies are a big challenge for its significantly diverse chemical properties and vastly different concentrations. In this work, liquid chromatography with quadrupole time-of-flight mass spectrometry was used to perform a metabolomics study of cured tobacco owing to its efficient separation and detection of semipolar metabolites. A solvent of methanol/water (8:2, v/v) and 30 min of ultrasound time were found to be optimal to perform extraction. 95, 92, and 93% of metabolite features had within 20% of coefficient of variation for repeatability, intraday and interday precision analysis, respectively, indicating a good stability of the method developed. 113 metabolites were identified in cured tobacco based on accurate mass, retention time, and MS/MS fragments. The developed method was applied to a metabolomics study of cured tobacco from three growing regions. Forty three metabolites were found to be contributed to the classification. It is shown that the developed method can be applied to metabolomics analysis of plant materials.
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Highly selective enrichment of phosphopeptides with high-index facets exposed octahedral tin dioxide nanoparticles for mass spectrometric analysis.
Talanta
PUBLISHED: 01-10-2014
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High-index facets exposed octahedral tin dioxide (SnO2) nanoparticles were successfully synthesized and applied to selectively enrich phosphopeptides for mass spectrometric analysis. The high selectivity and capacity of the octahedral SnO2 nanoparticles were demonstrated by effectively enriching phosphopeptides from digests of phosphoprotein (?- or ?-casein), protein mixtures of ?-casein and bovine serum albumin, milk, and human serum samples. The unique octahedral SnO2 with abundant unsaturated coordination Sn atoms exhibited enhanced affinity and selective coordination ability with phosphopeptides due to their high chemical activity. The strong affinity led to highly selective capture and enrichment of phosphopeptides for sensitive detection through the bidentate bonds formed between surface atoms and phosphate. The phosphopeptides could be detected in ?-casein down to 4 × 10(-9)M or in the mixture of ?-casein and BSA with a molar ratio of even 1:100. The performance in selective enrichment of phosphopeptides from drinking milk and human serum showed powerful evidence of high selectivity and efficiency in identifying the low-abundant phosphopeptides from complicated biological samples. This work provided a way to improve the physical and chemical properties of materials by tailoring their exposed facets for selective enrichment of phosphopeptides.
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Expression of N-acetylglucosaminyltransferase V in gastric cancer correlates with metastasis and prognosis.
Int. J. Oncol.
PUBLISHED: 01-08-2014
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N-acetylglucosaminyltransferase V (GnT-V) is an enzyme that catalyzes ?1-6 branching of N-acetylglucosamine on asparagine (N)-linked oligosaccharides (N-glycan) of cell proteins and the dysfunction of which is a common feature of various carcinomas. Nevertheless, the role of GnT-V remains controversial. Therefore, the clinical implication of GnT-V expression may differ in each cancer type. The implication of GnT-V status in patients with gastric cancer has not been studied extensively. In the present study, we examined GnT-V expression in gastric cancer specimen both at protein and mRNA levels. We compared GnT-V expression with clinical and pathologic variables. Kaplan-Meier survival curves were generated to show the cause-specific survival. Furthermore, the small interfering RNA was devised to downregulate the GnT-V mRNA expression in SGC7901 and BGC 823 cells. We characterized the function implication of GnT-V by cell proliferation and invasiveness analysis. Analysis in gastric cancer specimen revealed that GnT-V expression correlated with tumor grade and stage. The overall survival time of positive GnT-V expression in gastric cancer was significantly shorter than that of negative GnT-V expression. Moreover, the downregulation of GnT-V expression by small interfering RNA resulted in a decrease of cell proliferation and invasiveness in SGC7901 and BGC 823 cells accompanied by morphological change. This supports that GnT-V correlates with metastasis and prognosis in gastric cancer. These results contribute to new insight into the underlying molecular mechanisms of GnT-V regulation in gastric cancer with potential translational clinical applications.
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The Protective Effect of Esculentoside A on Experimental Acute Liver Injury in Mice.
PLoS ONE
PUBLISHED: 01-01-2014
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Inflammatory response and oxidative stress are considered to play an important role in the development of acute liver injury induced by carbon tetrachloride (CCl4) and galactosamine (GalN)/lipopolysaccharides (LPS). Esculentoside A (EsA), isolated from the Chinese herb phytolacca esculenta, has the effect of modulating immune response, cell proliferation and apoptosis as well as anti-inflammatory effects. The present study is to evaluate the protective effect of EsA on CCl4 and GalN/LPS-induced acute liver injury. In vitro, CCK-8 assays showed that EsA had no cytotoxicity, while it significantly reduced levels of TNF-? and cell death rate challenged by CCl4. Moreover, EsA treatment up-regulated PPAR-? expression of LO2 cells and reduced levels of reactive oxygen species (ROS) challenged by CCl4. In vivo, EsA prevented mice from CCl4-induced liver histopathological damage. In addition, levels of AST and ALT were significantly decreased by EsA treatment. Furthermore, the mice treated with EsA had a lower level of TNF-?, Interleukin (IL)-1? and IL-6 in mRNA expression. EsA prevented MDA release and increased GSH-Px activity in liver tissues. Immunohistochemical staining showed that over-expression of F4/80 and CD11b were markedly inhibited by EsA. The western bolt results showed that EsA significantly inhibited CCl4-induced phosphonated IkBalpha (P-I?B) and ERK. Furthermore, EsA treatment also alleviated GalN/LPS-induced acute liver injury on liver enzyme and histopathological damage. Unfortunately, our results exhibited that EsA had no effects on CCl4-induced hepatocyte apoptosis which were showed by TUNEL staining and Bax, Caspase-3 and cleaved Caspase-3 expression. Our results proved that EsA treatment attenuated CCl4 and GalN/LPS-induced acute liver injury in mice and its protective effects might be involved in inhibiting inflammatory response and oxidative stress, but not apoptosis with its underlying mechanism associated with PPAR-?, NF-?B and ERK signal pathways.
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The loss of efficiency caused by agents' uncoordinated routing in transport networks.
PLoS ONE
PUBLISHED: 01-01-2014
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Large-scale daily commuting data were combined with detailed geographical information system (GIS) data to analyze the loss of transport efficiency caused by drivers' uncoordinated routing in urban road networks. We used Price of Anarchy (POA) to quantify the loss of transport efficiency and found that both volume and distribution of human mobility demand determine the POA. In order to reduce POA, a small number of highways require considerable decreases in traffic, and their neighboring arterial roads need to attract more traffic. The magnitude of the adjustment in traffic flow can be estimated using the fundamental measure traffic flow only, which is widely available and easy to collect. Surprisingly, the most congested roads or the roads with largest traffic flow were not those requiring the most reduction of traffic. This study can offer guidance for the optimal control of urban traffic and facilitate improvements in the efficiency of transport networks.
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Genotypic diversity analysis of Mycobacterium tuberculosis strains collected from Beijing in 2009, using spoligotyping and VNTR typing.
PLoS ONE
PUBLISHED: 01-01-2014
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Tuberculosis (TB) is a serious problem in China. While there have been some studies on the nationwide genotyping of Mycobacterium tuberculosis (M. tuberculosis), there has been little detailed research in Beijing, the capital of China, which has a huge population. Here, M. tuberculosis clinical strains collected in Beijing during 2009 were genotyped by classical methods.
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Regioselective SN2' Mitsunobu reaction of Morita-Baylis-Hillman alcohols: A facile and stereoselective synthesis of ?-alkylidene-?-hydrazino acid derivatives.
Beilstein J Org Chem
PUBLISHED: 01-01-2014
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A highly regioselective SN2' Mitsunobu reaction between Morita-Baylis-Hillman (MBH) alcohols, azodicarboxylates, and triphenylphosphine is developed, which provides an easy access to ?-alkylidene-?-hydrazino acid derivatives in high yields and good stereoselectivity. This reaction represents the first direct transformation of MBH alcohols into hydrazines.
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Pri-miR-124 rs531564 and pri-miR-34b/c rs4938723 polymorphisms are associated with decreased risk of esophageal squamous cell carcinoma in Chinese populations.
PLoS ONE
PUBLISHED: 01-01-2014
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MicroRNAs are a new class of small non-protein-coding RNAs that sometimes function as tumor suppressors or oncogenes. Aberrant expression and structural alteration of microRNAs have been reported to be involved in tumorigenesis and cancer development. Recently, rs531564/pri-miR-124-1, rs4938723/pri-miR-34b/c, rs7372209/pri-miR-26a-1, rs895819/pre-miR-27a, and rs11134527/pri-miR-218 were reported to be associated with risks of various cancers. In order to evaluate the relationship of these SNPs and esophageal squamous cell carcinoma (ESCC) risk, we conducted a case-control study with 1109 ESCC patients and 1275 control subjects to examine the potential association of these pri/pre-miRNA polymorphisms with ESCC susceptibility. As a result, two SNPs were associated with a significant risk of ESCC. We found that the GG genotype of pri-miR-124-1 rs531564 was associated to a significantly decreased risk of ESCC comparing with the CC/CG genotypes (p = 0.005; OR = 0.61, 95% CI = 0.43-0.86). In addition, the CC genotype of pri-miR-34b/c rs4938723 was associated with a significant decreased risk of ESCC (CC VS.
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In-line polarizer used in all-0°-splice resonator fiber-optic gyro.
Appl Opt
PUBLISHED: 11-13-2013
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A method to suppress the polarization-fluctuation-induced drift in a resonator fiber-optic gyro is proposed in this paper. By inserting one in-line polarizer whose polarization extinction ratio is 30 dB into a polarization-maintaining fiber resonator with 0° polarization-axis splices, the unwanted resonance is introduced to high loss and therefore the ratio of the resonance height of the desired eigen-states of polarization (ESOP) to the unwanted ESOP is 74 dB theoretically; thus the polarization-fluctuation-induced drift is adequately suppressed. The new scheme has excellent operability and high temperature stability simultaneously. Compared to the resonator with twin 90° polarization-axis rotated splices, this scheme does not need precise length difference control. This work is of great importance in the research on resonator integrated optic gyros.
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Reduction of backreflection noise in resonator micro-optic gyro by integer period sampling.
Appl Opt
PUBLISHED: 11-13-2013
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In resonator micro-optic gyros (RMOGs), the interference between the backreflection light beam of one pathway and the signal light beam of the other pathway deteriorates the gyro output waveforms, resulting in severe reduction in the gyros accuracy. In this paper, an integer period sampling (IPS) method is introduced to minimize the sampling error caused by backreflection in RMOG for the first time to our knowledge. The experimental results show that both the bias repeatability and the short-term bias stability become better when the IPS condition is satisfied. A bias stability of 0.41°/s over one hour with an integration time of 10 s has been realized in a RMOG that employs a silica waveguide ring resonator.
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Ocular Penetration and Pharmacokinetics of Topical Clarithromycin Eye Drops to Rabbits.
J Ocul Pharmacol Ther
PUBLISHED: 11-07-2013
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Abstract Purpose: To evaluate the ocular pharmacokinetics of clarithromycin (CLA) eye drops topically applied to the corneas of rabbits. Methods: One 50-?L drop of CLA (0.25%) was administered to each New Zealand white rabbit in a single dose group, and one 50-?L drop of CLA was administered 6 times at 5-min intervals to each rabbit in a loading dose group. The effect of debridement on corneal penetration was also investigated in a de-epithelium group. The drug concentrations in the cornea and aqueous humor (AH) were assayed using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) analysis. Results: Maximum CLA levels were achieved in the corneas and AH at 15 and 60?min, respectively, in the intact epithelium eyes in the single dose group (24.54±10.64??g/g and 0.78±0.22??g/mL, respectively, mean±the standard error of the mean, n=8). In the loading dose group, 30?min after the last application, the CLA level in the corneas reached 92.26±17.62??g/g. In the loading dose group, the drug levels in the corneas and AH were significantly increased compared with the drug levels in the corneas with the intact epithelium and de-epithelium eyes in the single dose group at the corresponding time points (P<0.05). The estimated CLA half-lives in the corneas and AH for the intact eyes were 103.28 and 132.61?min, respectively. Conclusion: Therapeutic CLA levels can be achieved in rabbit corneas after topically applying the drug with eye drops.
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SmartArc-based volumetric modulated arc therapy for endometrial cancer: a dosimetric comparison with helical tomotherapy and intensity-modulated radiation therapy.
BMC Cancer
PUBLISHED: 10-28-2013
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The purpose of the present study was to investigate the feasibility of using volumetric modulated arc therapy with SmartArc (VMAT-S) to achieve radiation delivery efficiency higher than that of intensity-modulated radiotherapy (IMRT) and helical tomotherapy (HT) when treating endometrial cancer, while maintaining plan quality.
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NF-?B Activation Coordinated by IKK? and IKK{varepsilon} Enables Latent Infection of Kaposis Sarcoma-Associated Herpesvirus.
J. Virol.
PUBLISHED: 10-23-2013
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All herpesviruses share a remarkable propensity to establish latent infection. Human Kaposis sarcoma-associated herpesvirus (KSHV) effectively enters latency after de novo infection, suggesting that KSHV has evolved with strategies to facilitate latent infection. NF-?B activation is imperative for latent infection of gammaherpesviruses. However, how NF-?B is activated during de novo herpesvirus infection is not fully understood. Here, we report that KSHV infection activates the inhibitor of ?B kinase ? (IKK?) and the IKK-related kinase epsilon (IKK?) to enable host NF-?B activation and KSHV latent infection. Specifically, KSHV infection activated IKK? and IKK? that were crucial for latent infection. Knockdown of IKK? and IKK? caused aberrant lytic gene expression and impaired KSHV latent infection. Biochemical and genetic experiments identified RelA as a key player downstream of IKK? and IKK?. Remarkably, IKK? and IKK? were essential for phosphorylation of S(536) and S(468) of RelA, respectively. Phosphorylation of RelA S(536) was required for phosphorylation of S(468), which activated NF-?B and promoted KSHV latent infection. Expression of the phosphorylation-resistant RelA S(536)A increased KSHV lytic gene expression and impaired latent infection. Our findings uncover a scheme wherein NF-?B activation is coordinated by IKK? and IKK?, which sequentially phosphorylate RelA in a site-specific manner to enable latent infection after KSHV de novo infection.
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Investigation of the relationship between the metabolic profile of tobacco leaves in different planting regions and climate factors using a pseudotargeted method based on gas chromatography/mass spectrometry.
J. Proteome Res.
PUBLISHED: 10-14-2013
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An improved pseudotargeted method using gas chromatography/mass spectrometry (GC/MS) was developed to investigate the metabolic profile of tobacco leaves from three planting regions (Yunnan, Guizhou, and Henan provinces). The analytical characteristics of the method with regard to reproducibility, precision, linearity, and stability were satisfactory for metabolic profiling study. Partial least-squares-discriminant analysis and hierarchical cluster analysis demonstrated that the metabolic profiles of tobacco from the Yunnan and Guizhou regions were different from that from the Henan province. The amino acid (e.g., phenylalanine, leucine, and tyrosine) and carbohydrate (e.g., fructose, trehalose, and sucrose) contents were the highest in Henan tobacco. The highest contents of organic acids (e.g., isocitrate, citrate, and fumarate) of the TCA cycle and antioxidants (e.g., quinate, chlorogenic acid, and ascorbate) were found in Guizhou tobacco. The correlation coefficients between metabolite content and climate factors (rainfall, sunshine, and temperature) demonstrated that drought facilitated the accumulation of sugars and amino acids. The content of TCA cycle intermediates could be influenced by multiple climate factors. This study demonstrates that the pseudotargeted method with GC/MS is suitable for the investigation of the metabolic profiling of tobacco leaves and the assessment of differential metabolite levels related to the growing regions.
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Atomistic insight into the minimum wear depth of Cu(111) surface.
Nanoscale Res Lett
PUBLISHED: 10-13-2013
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In the present work, we investigate the minimum wear depth of single crystalline Cu(111) under single asperity friction by means of molecular dynamics simulations. The atomistic mechanisms governing the incipient plasticity are elucidated by characterizing specific defect structures and are correlated to the observed mechanical and frictional responses of the material. Furthermore, the effect of probe radius on the friction process is studied. Our simulations indicate that the formation of wear impression is closely associated with defect nucleation and the minimum wear depth is equivalent to the critical penetration depth at which plasticity initiates. It is found that the probe radius has a strong influence on the formation of defect structures and the observed mechanical responses.
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Two-photon imaging of the cornea visualized in the living mouse using vital dyes.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 09-14-2013
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To acquire morphological and component information on the overall cornea in the living C57BL/6 mouse using fluorescent viability dyes and two-photon (2PH) laser microscopy.
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Efficient 2.05?m emission of Ho(3+)/Yb(3+)/Er(3+) triply doped fluorotellurite glasses.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 09-11-2013
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The 2.05?m emission has been obtained using a 980nm laser excitation in Ho(3+)/Yb(3+)/Er(3+) triply doped fluorotellurite glass. Strong emission near 2.05?m is demonstrated and the corresponding energy transfer mechanisms are discussed and analyzed according to the photoluminescence performance and absorption measurements. Yb(3+) and Er(3+) ions can absorb the pumping energy and transfer it to Ho(3+) ions efficiently. These results indicate that this Ho(3+)/Yb(3+)/Er(3+) triply doped fluorotellurite glass has potential applications in 2.0?m laser.
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Effect of cryogenic treatment on wear resistance of Ti-6Al-4V alloy for biomedical applications.
J Mech Behav Biomed Mater
PUBLISHED: 08-21-2013
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The effect of cryogenic treatment on wear resistance of Ti-6Al-4V alloy for biomedical applications was experimentally investigated in this paper. Cryogenic treatments with the same soaking time of 24h at different temperatures of -80°C, -140°C and -196°C were conducted and the treatments at the same temperature of -196°C were then further given different soaking time of 3h, 48h and 72h to be investigated. After cryogenic treatment, the Vickers hardness of specimens was measured. Wear resistance of Ti-6Al-4V alloy was measured by pin-on-disk wear test under dry sliding condition. The results demonstrated that the Vickers hardness increased slightly with the reduction of temperature while it increased obviously with the elongation of soaking time at -196°C. The friction coefficients of specimens cryo-treated at -196°C were lower than those of untreated and of cryo-treated at -80°C and -140°C. And the longer the soaking time is during the cryogenic treatment, the higher the friction coefficient reduction can be achieved. The obvious reduction of mass loss can be obtained at -196°C with 72h soaking. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to detect the microstructure and worn surface of specimens. By cryogenic treatment, the plowing in the worn surface was smoothed and shallowed, and the degree of plastic deformation in the subsurface was decreased. There was no obvious phase transformation which can be detected in the microstructure after cryogenic treatment. However, the tendency of refinement in grain size can be detected by XRD which improved the wear resistance of Ti-6Al-4V alloy.
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Structural insight into Golgi membrane stacking by GRASP65 and GRASP55 proteins.
J. Biol. Chem.
PUBLISHED: 08-12-2013
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The stacking of Golgi cisternae involves GRASP65 and GRASP55. The oligomerization of the N-terminal GRASP domain of these proteins, which consists of two tandem PDZ domains, is required to tether the Golgi membranes. However, the molecular basis for GRASP assembly is unclear. Here, we determined the crystal structures of the GRASP domain of GRASP65 and GRASP55. The structures reveal similar homotypic interactions: the GRASP domain forms a dimer in which the peptide-binding pockets of the two neighboring PDZ2 domains face each other, and the dimers are further connected by the C-terminal tail of one GRASP domain inserting into the binding pocket of the PDZ1 domain in another dimer. Biochemical analysis suggests that both types of contacts are relatively weak but are needed in combination for GRASP-mediated Golgi stacking. Our results unveil a novel mode of membrane tethering by GRASP proteins and provide insight into the mechanism of Golgi stacking.
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ROOT HAIR DEFECTIVE3 family of dynamin-like GTPases mediates homotypic endoplasmic reticulum fusion and is essential for Arabidopsis development.
Plant Physiol.
PUBLISHED: 08-06-2013
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In all eukaryotic cells, the endoplasmic reticulum (ER) forms a tubular network whose generation requires the fusion of ER membranes. In Arabidopsis (Arabidopsis thaliana), the membrane-bound GTPase ROOT HAIR DEFECTIVE3 (RHD3) is a potential candidate to mediate ER fusion. In addition, Arabidopsis has two tissue-specific isoforms of RHD3, namely RHD3-like (RL) proteins, and their function is not clear. Here, we show that a null allele of RHD3, rhd3-8, causes growth defects and shortened root hairs. A point mutant, rhd3-1, exhibits a more severe growth phenotype than the null mutant, likely because it exerts a dominant-negative effect on the RL proteins. Genetic analysis reveals that the double deletion of RHD3 and RL1 is lethal and that the rhd3 rl2 plants produce no viable pollen, suggesting that the RL proteins are redundant to RHD3. RHD3 family proteins can replace Sey1p, the homolog of RHD3 in yeast (Saccharomyces cerevisiae), in the maintenance of ER morphology, and they are able to fuse membranes both in vivo and in vitro. Our results suggest that RHD3 proteins mediate ER fusion and are essential for plant development and that the formation of the tubular ER network is of general physiological significance.
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Identification and characterization of microRNAs in the developing maize endosperm.
Genomics
PUBLISHED: 08-04-2013
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MicroRNAs (miRNAs) are non-coding RNAs that are approximately 20-22 nucleotides long. miRNAs have been shown to be important regulators that control a large variety of biological functions in eukaryotic cells. To investigate the roles of miRNAs in maize endosperm development, two small RNA libraries of maize endosperm at two developmental stages were sequenced. A total of 17,773,394 and 18,586,523 small RNA raw reads were obtained, respectively. Further analysis identified and characterized 95 known miRNAs belonging to 20 miRNA families. In addition, 18 novel miRNAs were identified and grouped into 11 families. Potential targets for 5 of the novel miRNA families were successfully predicted. We had also identified 12 corresponding miRNAs* of these novel miRNAs. In summary, we investigated expression patterns of miRNA in maize endosperm at key developmental stages and identified miRNAs that are likely to playing an important role in endosperm development.
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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.

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

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