JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth.
Physiol Meas
PUBLISHED: 11-19-2014
Show Abstract
Hide Abstract
Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth.We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38-42?weeks' gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60?min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5?min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross-validation split, comparing results to cord pH and BE at birth.The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from -0.3 to -18.7?mmol?L(-1). Our model predicted pH from 30 fHRV measures (R(2) = 0.90, P < 0.001) and BE from 21 fHRV measures (R(2) = 0.77, P < 0.001).Novel bioinformatics approach (CIMVA) applied to fHRV derived from trans-abdominal fECG during labor correlated well with acid-base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth.
Related JoVE Video
Optical binary image encryption using aperture-key and dual wavelengths.
Opt Express
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
We described a method where the secret binary image that has been encoded into a single amplitude pattern in Fresnel domain can be recovered based on phase retrieval with an aperture-key and wavelength keys, and no holographic recording is needed in the encryption. The predesigned aperture-key not only realizes the intensity modulation of the encrypted image, but also helps to retrieve the secret image with high quality. All the necessary decryption keys can be kept in digital form that facilitates data transmission and loading in image retrieval process. Numerical simulation results are given for testing the validity and security of the proposed approach.
Related JoVE Video
Developmental stage oxidoreductive States of Chlamydia and infected host cells.
MBio
PUBLISHED: 10-30-2014
Show Abstract
Hide Abstract
A defining characteristic of Chlamydia spp. is their developmental cycle characterized by outer membrane transformations of cysteine bonds among cysteine-rich outer membrane proteins. The reduction-oxidation states of host cell compartments were monitored during the developmental cycle using live fluorescence microscopy. Organelle redox states were studied using redox-sensitive green fluorescent protein (roGFP1) expressed in CF15 epithelial cells and targeted to the cytosol, mitochondria, and endoplasmic reticulum (ER). The redox properties of chlamydiae and the inclusion were monitored using roGFP expressed by Chlamydia trachomatis following transformation. Despite the large morphological changes associated with chlamydial infection, redox potentials of the cytosol (?cyto [average, -320 mV]), mitochondria (?mito [average, -345 mV]), and the ER (?ER [average, -258 mV]) and their characteristic redox regulatory abilities remained unchanged until the cells died, at which point ?cyto and ?mito became more oxidized and ?ER became more reduced. The redox status of the chamydial cytoplasm was measured following transformation and expression of the roGFP biosensor in C. trachomatis throughout the developmental cycle. The periplasmic and outer membrane redox states were assessed by the level of cysteine cross-linking of cysteine-rich envelope proteins. In both cases, the chlamydiae were highly reduced early in the developmental cycle and became oxidized late in the developmental cycle. The production of a late-developmental-stage oxidoreductase/isomerase, DsbJ, may play a key role in the regulation of the oxidoreductive developmental-stage-specific process.
Related JoVE Video
[Effects of arsenic trioxide combined with cisplatin on the growth of human nasopharyngeal carcinoma cells and reversion of RASSF1A hympermethylation].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 10-22-2014
Show Abstract
Hide Abstract
To investigate the effect of arsenic trioxide (As2O3) combined with cisplatin on expression of RASSF1A in nude mice with human nasopharyngeal carcinoma xenograft.
Related JoVE Video
Fractional Fourier domain optical image hiding using phase retrieval algorithm based on iterative nonlinear double random phase encoding.
Opt Express
PUBLISHED: 10-17-2014
Show Abstract
Hide Abstract
We present a novel image hiding method based on phase retrieval algorithm under the framework of nonlinear double random phase encoding in fractional Fourier domain. Two phase-only masks (POMs) are efficiently determined by using the phase retrieval algorithm, in which two cascaded phase-truncated fractional Fourier transforms (FrFTs) are involved. No undesired information disclosure, post-processing of the POMs or digital inverse computation appears in our proposed method. In order to achieve the reduction in key transmission, a modified image hiding method based on the modified phase retrieval algorithm and logistic map is further proposed in this paper, in which the fractional orders and the parameters with respect to the logistic map are regarded as encryption keys. Numerical results have demonstrated the feasibility and effectiveness of the proposed algorithms.
Related JoVE Video
Double-image encryption without information disclosure using phase-truncation Fourier transforms and a random amplitude mask.
Appl Opt
PUBLISHED: 10-17-2014
Show Abstract
Hide Abstract
We present a study about information disclosure in phase-truncation-based cryptosystems. The main information of the original image to be encoded can be obtained by using a decryption key in the worst case. The problem cannot be thoroughly solved by imaginary part truncating, keeping the encryption keys as private keys, or applying different phase keys for different plaintexts during each encryption process as well as the phase modulation in the frequency domain. In order to eliminate the risk of unintended information disclosure, we further propose a nonlinear spatial and spectral encoding technique using a random amplitude mask (RAM). The encryption process involving two security layers can be fully controlled by a RAM. The spatial encoding of the plaintext images and the simultaneous encryption of the plaintext images and the encryption key greatly enhance the security of system, avoiding several attacks that have cracked the phase-truncation-based cryptosystems. Besides, the hybrid encryption system retains the advantage of a trap door one-way function of phase truncation. Numerical results have demonstrated the feasibility and effectiveness of the proposed encryption algorithm.
Related JoVE Video
EPAS-1 mediates SP-1-dependent FBI-1 expression and regulates tumor cell survival and proliferation.
Int J Mol Sci
PUBLISHED: 09-04-2014
Show Abstract
Hide Abstract
Factor binding IST-1 (FBI-1) plays an important role in oncogenic transformation and tumorigenesis. As FBI-1 is over-expressed in multiple human cancers, the regulation of itself would provide new effective options for cancer intervention. In this work, we aimed to study the role that EPAS-1 plays in regulating FBI-1. We use the fact that specificity protein-1 (SP-1) is one of the crucial transcription factors of FBI-1, and that SP-1 can interact with the endothelial pas domain protein-1 (EPAS-1) for the induction of hypoxia related genes. The study showed that EPAS-1 plays an indispensible role in SP-1 transcription factor-mediated FBI-1 induction, and participated in tumor cell survival and proliferation. Thus, EPAS-1 could be a novel target for cancer therapeutics.
Related JoVE Video
Scene-specific pedestrian detection for static video surveillance.
IEEE Trans Pattern Anal Mach Intell
PUBLISHED: 08-06-2014
Show Abstract
Hide Abstract
The performance of a generic pedestrian detector may drop significantly when it is applied to a specific scene due to the mismatch between the source training set and samples from the target scene. We propose a new approach of automatically transferring a generic pedestrian detector to a scene-specific detector in static video surveillance without manually labeling samples from the target scene. The proposed transfer learning framework consists of four steps. 1) Through exploring the indegrees from target samples to source samples on a visual affinity graph, the source samples are weighted to match the distribution of target samples. 2) It explores a set of context cues to automatically select samples from the target scene, predicts their labels, and computes confidence scores to guide transfer learning. 3) The confidence scores propagate among target samples according to their underlying visual structures. 4) Target samples with higher confidence scores have larger influence on training scene-specific detectors. All these considerations are formulated under a single objective function called confidence-encoded SVM, which avoids hard thresholding on confidence scores. During test, only the appearance-based detector is used without context cues. The effectiveness is demonstrated through experiments on two video surveillance data sets. Compared with a generic detector, it improves the detection rates by 48 and 36 percent at one false positive per image (FPPI) on the two data sets, respectively. The training process converges after one or two iterations on the data sets in experiments.
Related JoVE Video
Image tracking for the high similarity drug tablets based on light intensity reflective energy and artificial neural network.
Comput Math Methods Med
PUBLISHED: 07-17-2014
Show Abstract
Hide Abstract
It is obvious that tablet image tracking exerts a notable influence on the efficiency and reliability of high-speed drug mass production, and, simultaneously, it also emerges as a big difficult problem and targeted focus during production monitoring in recent years, due to the high similarity shape and random position distribution of those objectives to be searched for. For the purpose of tracking tablets accurately in random distribution, through using surface fitting approach and transitional vector determination, the calibrated surface of light intensity reflective energy can be established, describing the shape topology and topography details of objective tablet. On this basis, the mathematical properties of these established surfaces have been proposed, and thereafter artificial neural network (ANN) has been employed for classifying those moving targeted tablets by recognizing their different surface properties; therefore, the instantaneous coordinate positions of those drug tablets on one image frame can then be determined. By repeating identical pattern recognition on the next image frame, the real-time movements of objective tablet templates were successfully tracked in sequence. This paper provides reliable references and new research ideas for the real-time objective tracking in the case of drug production practices.
Related JoVE Video
Genome editing of BmFib-H gene provides an empty Bombyx mori silk gland for a highly efficient bioreactor.
Sci Rep
PUBLISHED: 06-04-2014
Show Abstract
Hide Abstract
Evolution has produced some remarkable creatures, of which silk gland is a fascinating organ that exists in a variety of insects and almost half of the 34,000 spider species. The impressive ability to secrete huge amount of pure silk protein, and to store proteins at an extremely high concentration (up to 25%) make the silk gland of Bombyx mori hold great promise to be a cost-effective platform for production of recombinant proteins. However, the extremely low production yields of the numerous reported expression systems greatly hindered the exploration and application of silk gland bioreactors. Using customized zinc finger nucleases (ZFN), we successfully performed genome editing of Bmfib-H gene, which encodes the largest and most abundant silk protein, in B. mori with efficiency higher than any previously reported. The resulted Bmfib-H knocked-out B. mori showed a smaller and empty silk gland, abnormally developed posterior silk gland cells, an extremely thin cocoon that contain only sericin proteins, and a slightly heavier pupae. We also showed that removal of endogenous Bmfib-H protein could significantly increase the expression level of exogenous protein. Furthermore, we demonstrated that the bioreactor is suitable for large scale production of protein-based materials.
Related JoVE Video
Optical coherence tomography angiography of optic nerve head and parafovea in multiple sclerosis.
Br J Ophthalmol
PUBLISHED: 05-15-2014
Show Abstract
Hide Abstract
To investigate swept-source optical coherence tomography (OCT) angiography in the optic nerve head (ONH) and parafoveal regions in patients with multiple sclerosis (MS).
Related JoVE Video
Astragalus saponin attenuates the expression of fibrosis-related molecules in irradiated cardiac fibroblasts.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 04-15-2014
Show Abstract
Hide Abstract
The main pathological change of radiation-induced heart disease is fibrosis. Emerging evidence has indicated that Astragalus membranaceus and its extractant, Astragalus saponin (AST), were used for treating fibrosis diseases. In the present study, the effects of AST on fibrosis damage induced by irradiation were determined. After being irradiated with 1 or 2-Gy X-rays, obvious changes of endoplasmic reticulum morphology were observed in cardiac fibroblasts (CFs), suggesting that its protein processing function was imbalanced, which indirectly indicated that fibrosis damage was caused by irradiating CFs. The expression levels of TGF-?1 and collagen I (Col-1) were increased at 48-h post-irradiation. Administration of 20 ?g/ml AST reduced the production of reactive oxygen species in irradiated CFs and decreased the expression of Col-1, TGF-?1, and p-Smad2/3. Polymerase chain reaction (PCR)-array analysis showed that there were ~30 genes which were mainly classified into extracellular matrix, remodeling enzymes, inflammatory cytokines/chemokines, and TGF-? superfamily, were up-regulated after treatment with 1-Gy X-ray, whereas most of these genes were down-regulated when pretreated with 20 ?g/ml of AST. In addition, TIMP1 and Smad7 genes that were down-regulated after treatment with 1-Gy X-ray were up-regulated when pretreated with 20 ?g/ml of AST. In conclusion, radiation-induced fibrosis damage was observed at a cellular level. AST attenuated this fibrosis damage effect in irradiated CFs and this anti-fibrosis effect may be closely related to its antioxidant action. The involvement of fibrosis-related molecules in irradiated CFs was systematically demonstrated by a PCR array for the first time. AST reversed the expression of the majority of genes changed by irradiation, which further confirmed its anti-fibrosis effect.
Related JoVE Video
The 68-kDa telomeric repeat binding factor 1 (TRF1)-associated protein (TAP68) interacts with and recruits TRF1 to the spindle pole during mitosis.
J. Biol. Chem.
PUBLISHED: 04-01-2014
Show Abstract
Hide Abstract
The telomere capping protein TRF1 is a component of the multiprotein complex "shelterin," which organizes the telomere into a high order structure. Besides telomere maintenance, telomere-associated proteins also have nontelomeric functions. For example, tankyrase 1 and TRF1 are required for the maintenance of faithful mitotic progression. However, the functional relevance of their centrosomal localization has not been established. Here, we report the identification of a TRF1-binding protein, TAP68, that interacts with TRF1 in mitotic cells. TAP68 contains two coiled-coil domains and a structural maintenance of chromosome motifs and co-localizes with TRF1 to telomeres during interphase. Immediately after nuclear envelope breakdown, TAP68 translocates toward the spindle poles followed by TRF1. Dissociation of TAP68 from the telomere is concurrent with the Nek2A-dependent phosphorylation at Thr-221. Biochemical characterization demonstrated that the first coiled-coil domain of TAP68 binds and recruits TRF1 to the centrosome. Inhibition of TAP68 expression by siRNA blocked the localization of TRF1 and tankyrase 1 to the centrosome. Furthermore, siRNA-mediated depletion of TAP68 perturbed faithful chromosome segregation and genomic stability. These findings suggest that TAP68 functions in mediating TRF1-tankyrase 1 localization to the centrosome and in mitotic regulation.
Related JoVE Video
Comparison of anterior corneal curvature measurements using a galilei dual scheimpflug analyzer and topcon auto kerato-refractometer.
J Ophthalmol
PUBLISHED: 03-24-2014
Show Abstract
Hide Abstract
Purpose. To compare anterior corneal keratometry (K) measurements taken by a dual Scheimpflug analyzer and an auto kerato-refractometer. Methods. Sixty-four normal eyes underwent keratometric measurements with both devices. The repeatability of the auto kerato-refractometer measurements was assessed by calculating the coefficient of variation (COV). The interdevice agreement was evaluated using the Bland-Altman analysis, Pearson correlation coefficient, and paired two-tailed t-test. Results. The COV of the flat K and steep K measurements taken by the auto kerato-refractometer were 0.21% and 0.29%, respectively. There were no significant differences between the steep K and average K measurements for the Topcon and Galilei devices (P = 0.475, and P = 0.137, resp.). The Galilei flat K values were lower than those of the Topcon (P = 0.002). Both of the instruments showed good agreement for all anterior corneal keratometric values. There was a significant linear correlation between the Galilei and Topcon devices for the flat K (r = 0.989, P < 0.0001), steep K (r = 0.987, P < 0.0001), and average K values (r = 0.994, P < 0.0001). Conclusions. The anterior corneal flat keratometric values were not interchangeable between the Galilei and Topcon devices. However, the measurements of the two instruments showed significant linear correlation with each other.
Related JoVE Video
Highly efficient multiplex targeted mutagenesis and genomic structure variation in Bombyx mori cells using CRISPR/Cas9.
Insect Biochem. Mol. Biol.
PUBLISHED: 03-21-2014
Show Abstract
Hide Abstract
Bombyx mori is an economically important insect and a model organism for studying lepidopteran and arthropod biology. Using a highly efficient CRISPR/Cas9 system, we showed that this system could mediate highly efficient targeted genome editing of a single gene locus, large chromosomal deletion or inversion, and also multiplex genome editing of 6 genes simultaneously in BmNs cell line derived from B. mori. The simplicity and high efficiency of our system provide unprecedented possibilities for researchers to implement precise and sophisticated manipulation of a chosen B. mori gene in BmNs cells easily in a limited time course, and perhaps new opportunities for functional genomics of B. mori and other lepidopteran insects.
Related JoVE Video
Opposite effect of conflict context modulation on neural mechanisms of cognitive and affective control.
Psychophysiology
PUBLISHED: 03-18-2014
Show Abstract
Hide Abstract
This study investigated the neural effect of conflict context modulation of cognitive and affective conflict processing by recording evoked-response potentials in cognitive and affective versions of a flanker task. By varying the proportion of congruent and incongruent trials in a block, we found different patterns of the context effect on evoked potentials during cognitive and affective conflict processing. For posterior N1 amplitude, frequent incongruent trials produced a larger effect only in the affective task. The opposite pattern of the context effect was observed for the central N450, which was enhanced by frequent cognitive but reduced by frequent affective contexts. We found similar context effect on the parietal sustained potential in both tasks. Overall, our findings suggest that cognitive and affective conflict processing engage a context-dependent attentional control mechanism but a common conflict response system.
Related JoVE Video
CRISPR/Cas9 mediated multiplex genome editing and heritable mutagenesis of BmKu70 in Bombyx mori.
Sci Rep
PUBLISHED: 03-11-2014
Show Abstract
Hide Abstract
CRISPR/Cas9, a bacterial adaptive immune system derived genome-editing technique, has become to be one of the most compelling topics in biotechnology. Bombyx mori is an economically important insect and a model organism for studying lepidopteran and arthropod biology. Here we reported highly efficient and multiplex genome editing in B. mori cell line and heritable site-directed mutagenesis of Bmku70, which is required for NHEJ pathway and also related to antigen diversity, telomere length maintenance and subtelomeric gene silencing, using CRISPR/Cas9 system. We established a simple and practicable method and obtained several Bmku70 knockout B. mori lines, and showed that the frequency of HR was increased in embryos of the Bmku70 knockout B. mori. The mutant lines obtained in this study could be a candidate genetic resource for efficient knock-in and fundamental research of DNA repair in B. mori. We also provided a strategy and procedure to perform heritable genome editing of target genes with no significant phenotype effect.
Related JoVE Video
NiCo2S4 sub-micron spheres: an efficient non-precious metal bifunctional electrocatalyst.
Nanoscale
PUBLISHED: 03-06-2014
Show Abstract
Hide Abstract
Urchin-like NiCo2S4 sub-micron spheres integrated with nano-sized and micro-sized structures, which were synthesized via a facile one-pot method, deliver efficient electrocatalytic activities for oxygen reduction and evolution reactions. The excellent electrocatalytic property of NiCo2S4 sub-micron spheres is originated from their unique urchin-like microstructure, composition and d-electronic configurations of the transition metal ions.
Related JoVE Video
Stable locality sensitive discriminant analysis for image recognition.
Neural Netw
PUBLISHED: 02-21-2014
Show Abstract
Hide Abstract
Locality Sensitive Discriminant Analysis (LSDA) is one of the prevalent discriminant approaches based on manifold learning for dimensionality reduction. However, LSDA ignores the intra-class variation that characterizes the diversity of data, resulting in unstableness of the intra-class geometrical structure representation and not good enough performance of the algorithm. In this paper, a novel approach is proposed, namely stable locality sensitive discriminant analysis (SLSDA), for dimensionality reduction. SLSDA constructs an adjacency graph to model the diversity of data and then integrates it in the objective function of LSDA. Experimental results in five databases show the effectiveness of the proposed approach.
Related JoVE Video
Assessment of Registration Information on Methodological Design of Acupuncture RCTs: A Review of 453 Registration Records Retrieved from WHO International Clinical Trials Registry Platform.
Evid Based Complement Alternat Med
PUBLISHED: 02-12-2014
Show Abstract
Hide Abstract
Background. This review provides the first methodological information assessment of protocol of acupuncture RCTs registered in WHO International Clinical Trials Registry Platform (ICTRP). Methods. All records of acupuncture RCTs registered in the ICTRP have been collected. The methodological design assessment involved whether the randomization methods, allocation concealment, and blinding were adequate or not based on the information of registration records (protocols of acupuncture RCTs). Results. A total of 453 records, found in 11 registries, were examined. Methodological details were insufficient in registration records; there were 76.4%, 89.0%, and 21.4% records that did not provide information on randomization methods, allocation concealment, and blinding respectively. The proportions of adequate randomization methods, allocation concealment, and blinding were only 107 (23.6%), 48 (10.6%), and 210 (46.4%), respectively. The methodological design improved year by year, especially after 2007. Additionally, methodology of RCTs with ethics approval was clearly superior to those without ethics approval and different among registries. Conclusions. The overall methodological design based on registration records of acupuncture RCTs is not very well but improved year by year. The insufficient information on randomization methods, allocation concealment, and blinding maybe due to the relevant description is not taken seriously in acupuncture RCTs' registration.
Related JoVE Video
Discussion and a new attack of the optical asymmetric cryptosystem based on phase-truncated Fourier transform.
Appl Opt
PUBLISHED: 02-12-2014
Show Abstract
Hide Abstract
A discussion and a cryptanalysis of the optical phase-truncated Fourier-transform-based cryptosystem are presented in this paper. The concept of an optical asymmetric cryptosystem, which was introduced into the optical image encryption scheme based on phase-truncated Fourier transforms in 2010, is suggested to be retained in optical encryption. A new method of attack is also proposed to simultaneously obtain the main information of the original image, the two decryption keys from its cyphertext, and the public keys based on the modified amplitude-phase retrieval algorithm. The numerical results illustrate that the computing efficiency of the algorithm is improved and the number of iterations is much less than that by the specific attack, which has two iteration loops.
Related JoVE Video
Transarterial coil-augmented Onyx embolization for brain arteriovenous malformation. Technique and experience in 22 consecutive patients.
Interv Neuroradiol
PUBLISHED: 02-10-2014
Show Abstract
Hide Abstract
Onyx has been widely adopted for the treatment of arteriovenous malformations (AVMs). However, its control demands operators accumulate a considerable learning curve. We describe our initial experience using a novel injection method for the embolization of AVMs. We retrospectively reviewed the data of all 22 patients with brain AVMs (12 men, 10 women; age range, 12-68 years; mean age, 43.2 years) treated by the transarterial coil-augmented Onyx injection technique. The size of the AVMs ranged from 25 mm to 70 mm (average 35.6 mm). The technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated. In every case, endovascular treatment (EVT) was completed. A total of 31 sessions were performed, with a mean injection volume of 6.1 mL (range, 1.5-16.0 mL). An average of 96.7% (range 85%-100%) estimated size reduction was achieved, and 18 AVMs could be completely excluded by EVT alone. The results remained stable on follow-up angiograms. A procedural complication occurred in one patient, with permanent mild neurologic deficit. Our preliminary series demonstrated that the coil-augmented Onyx injection technique is a valuable adjunct achieving excellent nidal penetration and improving the safety of the procedure.
Related JoVE Video
Cucurbit[6]uril in combination with guanidinium ionic liquid as a new type of stationary phase for capillary gas chromatography.
J Chromatogr A
PUBLISHED: 01-24-2014
Show Abstract
Hide Abstract
Cucurbit[n]urils (CBs) possess unique structures and selective interactions with analytes of different variety and high thermal stability and show a great potential as stationary phases for capillary gas chromatography (GC). This work presents the first description of CB6 in combination with a new guanidinium-based ionic liquid (GBIL) as the GC stationary phase by using sol-gel coating method for the preparation of the CB6-GBIL and GBIL columns. Introduction of GBIL greatly improved the solubility of CB6 in the sol solution and successfully made the use of CBs for the intended purpose feasible. The CB6-GBIL and GBIL columns had average polarity of 179 and 280, respectively, suggesting their medium polar nature. The CB6-GBIL column achieves good resolution for a wide range of analytes and exhibits different retention behaviors and resolution for some of the analytes from the GBIL column and the commercial column. Moreover, it also shows good thermal stability up to 250°C. The proposed method integrates the full advantages of CBs, ionic liquids and sol-gel coating method and provides an efficient and feasible way for the wider application of CBs in separation science.
Related JoVE Video
Optical coherence tomography angiography of optic disc perfusion in glaucoma.
Ophthalmology
PUBLISHED: 01-14-2014
Show Abstract
Hide Abstract
To compare optic disc perfusion between normal subjects and subjects with glaucoma using optical coherence tomography (OCT) angiography and to detect optic disc perfusion changes in glaucoma.
Related JoVE Video
Multiplex genomic structure variation mediated by TALEN and ssODN.
BMC Genomics
PUBLISHED: 01-13-2014
Show Abstract
Hide Abstract
Genomic structure variation (GSV) is widely distributed in various organisms and is an important contributor to human diversity and disease susceptibility. Efficient approaches to induce targeted genomic structure variation are crucial for both analytic and therapeutic studies of GSV. Here, we presented an efficient strategy to induce targeted GSV including chromosomal deletions, duplications and inversions in a precise manner.
Related JoVE Video
Intracarotid transplantation of autologous adipose-derived mesenchymal stem cells significantly improves neurological deficits in rats after MCAo.
J Mater Sci Mater Med
PUBLISHED: 01-12-2014
Show Abstract
Hide Abstract
We aimed to evaluate whether adipose-derived mesenchymal stem cells (ADMSCs) that were transplanted via internal carotid can improve the neurological function after acute ischemic stroke and explore the underlying mechanisms. Total 40 adult Sprague-Dawley rats were subjected to transient (1.5 h) middle cerebral artery occlusion (MCAo) to induce ischemia/reperfusion injury. These rats were randomly divided into two groups with 20 ones in each group, which were intracarotid-injected with autologous ADMSCs (2.0 × 10(6)) and saline (control) at day 3 after MCAo, respectively. Behavioral tests (adhesive-removal and modified neurological severity score) were performed before and after MCAo. Histology was used to evaluate the ischemia lesion volume and pathological changes. The apoptosis and astroglial reactivity were determined by TUNEL and glial fibrillary acidic protein (GFAP) staining, respectively. Besides, we applied immunofluorescence to identify the distribution of ADMSCs and the neural makers (NeuN and GFAP) expressed by them under confocal microscope. Significant improvement of neurological deficits was observed in rats transplanted with ADMSCs when compared to controls. But there was no obvious difference on ischemia lesion volume between these two groups. The injected ADMSCs migrated to the brain infarct region and mainly localized in the ischemic core and boundary zone of the lesion, which can express NeuN and GFAP in the brain. In addition, autologous transplantation of ADMSCs significantly attenuated astroglial reactivity, inhibited cellular apoptosis and promoted cellular proliferation. Our data indicated that intracarotid transplantation of autologous ADMSCs had the potential therapeutic application for ischemic stroke.
Related JoVE Video
Online detection of fetal acidemia during labour by testing synchronization of EEG and heart rate: a prospective study in fetal sheep.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Severe fetal acidemia during labour can result in life-lasting neurological deficits, but the timely detection of this condition is often not possible. This is because the positive predictive value (PPV) of fetal heart rate (FHR) monitoring, the mainstay of fetal health surveillance during labour, to detect concerning fetal acidemia is around 50%. In fetal sheep model of human labour, we reported that severe fetal acidemia (pH<7.00) during repetitive umbilical cord occlusions (UCOs) is preceded ?60 minutes by the synchronization of electroencephalogram (EEG) and FHR. However, EEG and FHR are cyclic and noisy, and although the synchronization might be visually evident, it is challenging to detect automatically, a necessary condition for bedside utility. Here we present and validate a novel non-parametric statistical method to detect fetal acidemia during labour by using EEG and FHR. The underlying algorithm handles non-stationary and noisy data by recording number of abnormal episodes in both EEG and FHR. A logistic regression is then deployed to test whether these episodes are significantly related to each other. We then apply the method in a prospective study of human labour using fetal sheep model (n?=?20). Our results render a PPV of 68% for detecting impending severe fetal acidemia ?60 min prior to pH drop to less than 7.00 with 100% negative predictive value. We conclude that this method has a great potential to improve PPV for detection of fetal acidemia when it is implemented at the bedside. We outline directions for further refinement of the algorithm that will be achieved by analyzing larger data sets acquired in prospective human pilot studies.
Related JoVE Video
Evaluation of anterior segment parameters and possible influencing factors in normal subjects using a dual Scheimpflug analyzer.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To investigate normal anterior segment parameters and analyze the possible influencing factors using a dual Scheimpflug system.
Related JoVE Video
Lesion Detection and Characterization With Context Driven Approximation in Thoracic FDG PET-CT Images of NSCLC Studies.
IEEE Trans Med Imaging
PUBLISHED: 10-16-2013
Show Abstract
Hide Abstract
We present a lesion detection and characterization method for 18F-fluorodeoxyglucose positron emission tomography - computed tomography (FDG PET-CT) images of the thorax in the evaluation of patients with primary non-small cell lung cancer (NSCLC) with regional nodal disease. Lesion detection can be difficult due to low contrast between lesions and normal anatomical structures. Lesion characterization is also challenging due to similar spatial characteristics between the lung tumors and abnormal lymph nodes. To tackle these problems, we propose a context driven approximation (CDA) method. There are two main components of our method. First, a sparse representation technique with region-level contexts was designed for lesion detection. To discriminate low-contrast data with sparse representation, we propose a reference consistency constraint and a spatial consistent constraint. Second, a multi-atlas technique with image-level contexts was designed to represent the spatial characteristics for lesion characterization. To accommodate inter-subject variation in a multi-atlas model, we propose an appearance constraint and a similarity constraint. The CDA method is effective with a simple feature set, and does not require parametric modeling of feature space separation. The experiments on a clinical FDG PET-CT dataset show promising performance improvement over the state-of-the-art.
Related JoVE Video
Amplitude-phase retrieval attack free cryptosystem based on direct attack to phase-truncated Fourier-transform-based encryption using a random amplitude mask.
Opt Lett
PUBLISHED: 10-10-2013
Show Abstract
Hide Abstract
We propose a simple amplitude-phase retrieval attack free cryptosystem based on direct attack to phase-truncated Fourier-transform-based encryption using a random amplitude mask (RAM). The RAM that is not saved during the encryption provides extremely high security for the two private keys, and no iterative calculations are involved in the nonlinear encryption process. Lack of enough constraints makes the specific attack based on iterative amplitude-phase retrieval algorithms unusable. Numerical simulation results are given for testing the validity and security of the proposed approach.
Related JoVE Video
Simultaneous nonlinear encryption of grayscale and color images based on phase-truncated fractional Fourier transform and optical superposition principle.
Appl Opt
PUBLISHED: 10-03-2013
Show Abstract
Hide Abstract
A nonlinear color and grayscale images cryptosystem based on phase-truncated fractional Fourier transform and optical superposition principle is proposed. In order to realize simultaneous encryption of color and grayscale images, each grayscale image is first converted into two phase masks by using an optical coherent superposition, one of which is treated as a part of input information that will be fractional Fourier transformed while the other in the form of a chaotic random phase mask (CRPM) is used as a decryption key. For the purpose of optical performance, all the processes are performed through three channels, i.e., red, green, and blue. Different from most asymmetric encryption methods, the decryption process is designed to be linear for the sake of effective decryption. The encryption level of a double random phase encryption based on phase-truncated Fourier transform is enhanced by extending it into fractional Fourier domain and the load of the keys management and transmission is lightened by using CRPMs. The security of the proposed cryptosystem is discussed and computer simulation results are presented to verify the validity of the proposed method.
Related JoVE Video
Image transformation based on learning dictionaries across image spaces.
IEEE Trans Pattern Anal Mach Intell
PUBLISHED: 08-14-2013
Show Abstract
Hide Abstract
In this paper, we propose a framework of transforming images from a source image space to a target image space, based on learning coupled dictionaries from a training set of paired images. The framework can be used for applications such as image super-resolution and estimation of image intrinsic components (shading and albedo). It is based on a local parametric regression approach, using sparse feature representations over learned coupled dictionaries across the source and target image spaces. After coupled dictionary learning, sparse coefficient vectors of training image patch pairs are partitioned into easily retrievable local clusters. For any test image patch, we can fast index into its closest local cluster and perform a local parametric regression between the learned sparse feature spaces. The obtained sparse representation (together with the learned target space dictionary) provides multiple constraints for each pixel of the target image to be estimated. The final target image is reconstructed based on these constraints. The contributions of our proposed framework are three-fold. 1) We propose a concept of coupled dictionary learning based on coupled sparse coding which requires the sparse coefficient vectors of a pair of corresponding source and target image patches to have the same support, i.e., the same indices of nonzero elements. 2) We devise a space partitioning scheme to divide the high-dimensional but sparse feature space into local clusters. The partitioning facilitates extremely fast retrieval of closest local clusters for query patches. 3) Benefiting from sparse feature-based image transformation, our method is more robust to corrupted input data, and can be considered as a simultaneous image restoration and transformation process. Experiments on intrinsic image estimation and super-resolution demonstrate the effectiveness and efficiency of our proposed method.
Related JoVE Video
[Inhibitory effect of arsenic trioxide combined with cisplatin on human nasopharyngeal carcinoma xenograft and DAPK in nude mice].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 08-01-2013
Show Abstract
Hide Abstract
To study the inhibitory effect of Arsenic Trioxide (As2O3) combined with diamminedichloroplatinum (DDP) on the growth of human nasopharyngeal carcinoma cell strain CNE-2Z xenograft in nude mice, and to explore the possible effect mechanisms of the antitumor.
Related JoVE Video
High-efficiency system for construction and evaluation of customized TALENs for silkworm genome editing.
Mol. Genet. Genomics
PUBLISHED: 07-15-2013
Show Abstract
Hide Abstract
Transcription activator-like effector nuclease (TALEN) possesses the characteristics of ease design and precise DNA targeting. In the silkworm Bombyx mori, TALEN has been successfully used to knockout an endogenous Bombyx gene, and shown the huge potential in functional genes research and improvement of the economical characteristics of silkworm. Thus, there is an urgent need to develop an applicable system that permits the efficient construction of customized TALEN with high activity that could efficiently induce the hereditable mutagenesis in the silkworm. In this study, we constructed an efficient assembly and evaluation system of the customized TALEN especiallly for silkworm genome editing by combination of a modified Golden Gate ligation strategy, a luciferase (LUC) reporter system in insect cell culture for binding activity and a surveyor nuclease assay system in silkworm embryos for cleavage efficiency. We showed the reliability of this system by assembling a pair of TALENs targeting a silkworm genome locus and assaying their binding and cleavage activities. The assembly strategy was convenient and efficient which allows the rapid construction of customized TALEN in less than 1 week, and the evaluation system was reliable and necessary for screening of the customized TALEN pair with high binding and cleavage activities. The results showed this system is a reliable and efficient tool for the construction of customized TALEN with high activity for gene targeting of silkworm, and will contribute to the wide application of TALEN technology in the functional gene research of silkworm.
Related JoVE Video
Scene-Specific Pedestrian Detection for Static Video Surveillance.
IEEE Trans Pattern Anal Mach Intell
PUBLISHED: 06-27-2013
Show Abstract
Hide Abstract
The performance of a generic pedestrian detector may drop significantly when it is applied to a specific scene due to the mismatch between the source training set and samples from the target scene. We propose a new approach of automatically transferring a generic pedestrian detector to a scene-specific detector in static video surveillance without manually labeling samples from the target scene. The proposed transfer learning framework consists of four steps. (1) Through exploring the indegrees from target samples to source samples on a visual affinity graph, the source samples are weighted to match the distribution of target samples. (2) It explores a set of context cues to automatically select samples from the target scene, predicts their labels, and computes confidence scores to guide transfer learning. (3) The confidence scores propagate among target samples according to their underlying visual structures. (4) Target samples with higher confidence scores have larger influence on training scene-specific detectors. All these considerations are formulated under a single objective function called Confidence-Encoded SVM, which avoids hard thresholding on confidence scores. During test, only the appearance-based detector is used without context cues. The effectiveness is demonstrated through experiments on two video surveillance datasets.
Related JoVE Video
Two-dimensional maximum local variation based on image euclidean distance for face recognition.
IEEE Trans Image Process
PUBLISHED: 05-13-2013
Show Abstract
Hide Abstract
Manifold learning concerns the local manifold structure of high dimensional data, and many related algorithms are developed to improve image classification performance. None of them, however, consider both the relationships among pixels in images and the geometrical properties of various images during learning the reduced space. In this paper, we propose a linear approach, called two-dimensional maximum local variation (2DMLV), for face recognition. In 2DMLV, we encode the relationships among pixels in images using the image Euclidean distance instead of conventional Euclidean distance in estimating the variation of values of images, and then incorporate the local variation, which characterizes the diversity of images and discriminating information, into the objective function of dimensionality reduction. Extensive experiments demonstrate the effectiveness of our approach.
Related JoVE Video
Coaxial Ni(x)Co(2x)(OH)(6x)/TiN nanotube arrays as supercapacitor electrodes.
ACS Nano
PUBLISHED: 05-09-2013
Show Abstract
Hide Abstract
NixCo2x(OH)6x, as a precursor of intensively studied NiCo2O4, has been directly deposited into self-standing titanium nitride nanotube array (TiN NTA) grid monolithic supports to form a coaxial nanostructured electrode for supercapacitors. With TiN NTA substrates providing a large surface area, fast electron transport, and enhanced structure stability, this NixCo2x(OH)6x/TiN electrode exhibits superior pseudocapacitive performance with a high specific capacitance of 2543 F g(-1) at 5 mV s(-1), remarkable rate performance of 660 F g(-1) even at 500 mV s(-1), and promising cycle performance (about 6.25% capacitance loss for 5000 cycles). Interestingly, the NixCo2x(OH)6x/TiN NTA electrode outperforms the NiCo2O4/TiN NTA electrode, indicating that this self-standing NixCo2x(OH)6x/TiN NTA monolith is a promising candidate for high-performance supercapacitor applications.
Related JoVE Video
Molybdenum nitride/N-doped carbon nanospheres for lithium-O? battery cathode electrocatalyst.
ACS Appl Mater Interfaces
PUBLISHED: 04-16-2013
Show Abstract
Hide Abstract
Molybdenum nitride/N-doped carbon nanospheres (MoN/N-C) are synthesized by hydrothermal method followed by ammonia annealing. The as-prepared MoN/N-C nanospheres manifest considerable electrocatalytic activity toward oxygen reduction reaction in nonaqueous electrolytes because of its nanostructure and the synergetic effect between MoN and N-C. Furthermore, the MoN/N-C nanospheres are explored as cathode catalyst for Li-O2 batteries with tetra-(ethylene glycol) dimethyl ether as the electrolyte. The assembled batteries deliver alleviated overpotentials and improved battery lifespan, and their excellent performances should be attributed to the unique hierarchical structure and high fraction of surface active sites of cathode catalyst.
Related JoVE Video
Mean central corneal thickness and corneal power measurements in pigmented and white rabbits using Visante optical coherence tomography and ATLAS corneal topography.
Vet Ophthalmol
PUBLISHED: 03-27-2013
Show Abstract
Hide Abstract
OBJECTIVE: To document central corneal thickness (CCT) and power measurements in pigmented and white rabbits using Visante anterior segment optical coherence tomography (AS-OCT) and the Humphrey ATLAS Corneal Topography System (HACTS). ANIMAL STUDIED: Fourteen female rabbits (seven pigmented and seven white rabbits) were involved in this study. PROCEDURE: Twenty-eight eyes underwent AS-OCT and HACTS examination. Central corneal thickness, corneal power in the steepest and flattest meridians, astigmatism, pupil diameter (PD), and white-to-white (WTW) were calculated. RESULTS: The CCT was 390 ± 14.2 and 373 ± 7.2 ?m for pigmented and white rabbits, respectively. The CCT values showed statistical difference between the two breeds (P = 0.017). The corneal power in the steepest meridian was 44.6 ± 1.9 Diopter (D) in pigmented rabbits and 47.8 ± 1.5 D in white rabbits. The corneal power in the flattest meridian was 44.0 ± 2.1 D in pigmented rabbits and 47.4 ± 1.5 D in white rabbits. The astigmatism, PD, and WTW values were 0.6 ± 0.22 D, 7.9 ± 0.9, and 14.5 ± 0.1 mm in pigmented rabbits, respectively. The corresponding values in white rabbits were 0.4 ± 0.23 D, 7.5 ± 0.5, and 13.5 ± 0.2 mm. There was a statistically significant difference in corneal power in the steepest and flattest meridians and for WTW. No such difference was observed for astigmatism or PD between them. CONCLUSIONS: Differences exist in the CCT, corneal power, and WTW between 5-month-old pigmented and white rabbits. Such difference should be considered when designing cornea-related experiments in rabbits.
Related JoVE Video
Genetic marking of sex using a W chromosome-linked transgene.
Insect Biochem. Mol. Biol.
PUBLISHED: 02-23-2013
Show Abstract
Hide Abstract
Many species belonging to the order Lepidoptera are major pests in agriculture and arboriculture. The sterile insect technique (SIT) is an eco-friendly and highly efficient genetically targeted pest management approach. In many cases, it is preferable to release only sterile males in an SIT program, and efficient sexing strategies are crucial to the successful large-scale implementation of SIT. In the present study, we established 160 transgenic silkworm (Bombyx mori) lines to test the possibility of genetic sexing using a W chromosome-linked transgene, which is thought to be the best sexing strategy for lepidopteran species. One transgenic line with a female-specific expression pattern of reporter gene was obtained. The expression level of the W-linked transgene was comparable with autosomal insertions and was stable for 17 continuous generations. Molecular characterization showed this line contained a single copy of the reporter gene on the W chromosome, and the integration site was TTAG in contig W-BAC-522N19-C9. The feasibility of using a W chromosome-linked transgene demonstrated here and the possible improvements discussed will provide valuable information for other lepidopteran pests. The novel W chromosome-linked transgenic line established in this study will serve as an important resource for fundamental research with the silkworm B. mori.
Related JoVE Video
Three new nor-dammarane triterpenoids from Dysoxylum hainanense with particular cytotoxicity against glioma cell line.
Arch. Pharm. Res.
PUBLISHED: 02-22-2013
Show Abstract
Hide Abstract
Three new nor-dammarane triterpenoids, 12?-O-acetyl-15?-hydoxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanran (1), 12?,28-O-diacetyl-15?-hydoxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanran (2), 12?-hydoxy-3,15-dioxo-20,21,22-23,24,25,26,27-octanordammanran (3), together with one known compound, 12?-O-acetyl-15?,28-dihydoxy-3-oxo-17-en-20,21,22-23,24,25,26,27-octanordammanran (4), were isolated from the 95 % EtOH extract of Dysoxylum hainanense. The structures of the new compounds were elucidated by spectral methods. All the triterpenoids were in vitro evaluated for their cytotoxic activities against four tumor cell lines (BGC-823, U251, HepG2 and SGC-7901). All the three nor-dammarane triterpenoids exhibited particular significant cytotoxic activities against glioma cell line.
Related JoVE Video
Endovascular treatment for dural arteriovenous fistula at the foramen magnum: report of five consecutive patients and experience with balloon-augmented transarterial Onyx injection.
J Neuroradiol
PUBLISHED: 02-19-2013
Show Abstract
Hide Abstract
Foramen magnum dural arteriovenous fistulas (DAVF) with perimedullary venous drainage represent a small minority of intracranial DAVF, and only a number of small series with limited cases have been reported. The purpose of this retrospective study is to summarize experience of transarterial Onyx embolisation in the treatment of these lesions, with emphasis on the balloon-augmented technique.
Related JoVE Video
Registration quality assessment of acupuncture clinical trials.
PLoS ONE
PUBLISHED: 02-14-2013
Show Abstract
Hide Abstract
Registration can help with transparency of acupuncture clinical trials (ACTs) by making protocol information and results available to the public. Recently, the number of registered ACTs has increased greatly, but only a few researchers have focused on the quality of ACTs registration. This review provides the first assessment of the registration quality of ACTs and the baseline information for future development.
Related JoVE Video
IOL tilt and decentration estimation from 3 dimensional reconstruction of OCT image.
PLoS ONE
PUBLISHED: 02-11-2013
Show Abstract
Hide Abstract
To evaluate intraocular lens (IOL) tilt and decentration by anterior segment optical coherence tomography (AS-OCT) using 3-dimensional (3D) reconstruction method.
Related JoVE Video
NleB, a bacterial effector with glycosyltransferase activity, targets GAPDH function to inhibit NF-?B activation.
Cell Host Microbe
PUBLISHED: 01-16-2013
Show Abstract
Hide Abstract
Modulation of NF-?B-dependent responses is critical to the success of attaching/effacing (A/E) human pathogenic E. coli (EPEC and EHEC) and the natural mouse pathogen Citrobacter rodentium. NleB, a highly conserved type III secretion system effector of A/E pathogens, suppresses NF-?B activation, but the underlying mechanisms are unknown. We identified the mammalian glycolysis enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as an NleB-interacting protein. Further, we discovered that GAPDH interacts with the TNF receptor-associated factor 2 (TRAF2), a protein required for TNF-?-mediated NF-?B activation, and regulates TRAF2 polyubiquitination. During infection, NleB functions as a translocated N-acetyl-D-glucosamine (O-GlcNAc) transferase that modifies GAPDH. NleB-mediated GAPDH O-GlcNAcylation disrupts the TRAF2-GAPDH interaction to suppress TRAF2 polyubiquitination and NF-?B activation. Eliminating NleB O-GlcNAcylation activity attenuates C. rodentium colonization of mice. These data identify GAPDH as a TRAF2 signaling cofactor and reveal a virulence strategy employed by A/E pathogens to inhibit NF-?B-dependent host innate immune responses.
Related JoVE Video
Neural correlates of self-appraisals in the near and distant future: an event-related potential study.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
To investigate perceptual and neural correlates of future self-appraisals as a function of temporal distance, event-related potentials (ERPs) were recorded while participants (11 women, eight men) made judgments about the applicability of trait adjectives to their near future selves (i.e., one month from now) and their distant future selves (i.e., three years from now). Behavioral results indicated people used fewer positive adjectives, more negative adjectives, recalled more specific events coming to mind and felt more psychologically connected to the near future self than the distant future self. Electrophysiological results demonstrated that negative trait adjectives elicited more positive ERP deflections than did positive trait adjectives in the interval between 550 and 800 ms (late positive component) within the near future self condition. However, within the same interval, there were no significant differences between negative and positive traits adjectives in the distant future self condition. The results suggest that negative emotional processing in future self-appraisals is modulated by temporal distance, consistent with predictions of construal level theory.
Related JoVE Video
Twenty-four-hour measurement of IOP in rabbits using rebound tonometer.
Vet Ophthalmol
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
PURPOSE: To observe the Intraocular pressure (IOP) measurements over a 24-h period in New Zealand white rabbits. METHODS: Thirty-four normal New Zealand white rabbits (68 eyes) were included in this study. The IOP values were determined with a rebound tonometer (RBT, Icare VET). Measurements were always obtained in the right eye first. RESULTS: The data showed that there was no significant difference in IOP between measurements, which indicated that the RBT showed good repeatability in this study (P = 0.920). There was no statistically significant difference between genders (P = 0.943). The IOP in right eyes was a little higher than left eyes (F = 45.96, P < 0.001). Comparison of the true IOP and RBT results over the entire pressure range (8-100 mmHg) revealed a statistically significant difference between them (P < 0.001). The mean difference between the RBT and true IOP (RBT-True IOP) was -22.65 ± 9.52 mmHg with 95% confidence interval (-27.1, -18.2 mmHg). In the light period (7 AM to 7 PM), the IOP was a little lower than during the dark period (8 PM to 6 AM); 9 AM and 2 PM were the lowest measurements (10 mmHg, 9.625 mmHg), and 10 AM (14.125 mmHg)was the highest measurement during the 24-h period. CONCLUSIONS: The IOP obtained by RBT underestimated the true IOP but the RBT had a good repeatability in IOP measurements. In the light period (7 AM to 7 PM), the IOP was a little lower than during the dark period (8 PM to 6 AM), which may be beneficial to the intervention therapy observation of glaucoma research in rabbits.
Related JoVE Video
Security enhancement of a phase-truncation based image encryption algorithm.
Appl Opt
PUBLISHED: 12-24-2011
Show Abstract
Hide Abstract
The asymmetric cryptosystem, which is based on phase-truncated Fourier transforms (PTFTs), can break the linearity of conventional systems. However, it has been proven to be vulnerable to a specific attack based on iterative Fourier transforms when the two random phase masks are used as public keys to encrypt different plaintexts. An improvement from the asymmetric cryptosystem may be taken by relocating the amplitude values in the output plane. In this paper, two different methods are adopted to realize the amplitude modulation of the output image. The first one is to extend the PTFT-based asymmetrical cryptosystem into the anamorphic fractional Fourier transform domain directly, and the second is to add an amplitude mask in the Fourier plane of the encryption scheme. Some numerical simulations are presented to prove the good performance of the proposed cryptosystems.
Related JoVE Video
IntentSearch:Capturing User Intention for One-Click Internet Image Search.
IEEE Trans Pattern Anal Mach Intell
PUBLISHED: 12-14-2011
Show Abstract
Hide Abstract
Web-scale image search engines mostly rely on surrounding text features. It is difficult for them to interpret users search intention only by query keywords and this leads to ambiguous and noisy search results. We propose a novel Internet image search approach. It only requires the user to click on one query image with the minimum effort and images from a pool retrieved by text-based search are re-ranked based on both visual and textual content. Our key contribution is to capture the users search intention from this one-click query image in four steps. (1) The query image is categorized into one of the predefined adaptive weight categories. Inside each category, a specific weight schema is used to combine visual features adaptive to this kind of images to better re-rank the text-based search result. (2) Based on the visual content of the query image selected by the user, query keywords are expanded to capture user intention. (3) Expanded keywords are used to enlarge the image pool to contain more relevant images. (4) Expanded keywords are also used to expand the query image to multiple positive visual examples from which new query specific visual and textual similarity metrics are learned.
Related JoVE Video
[Exploration and practice of open experiment in molecular pharmacognosy].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 05-19-2011
Show Abstract
Hide Abstract
In order to improve quality of molecular pharmacognosy teaching, the open experiment is applied. Under the guidance of tutors, students conduct the whole experiment independently. Students abilities of independent thinking and comprehensive-experimental conduction were enhanced in the open experiment. Meanwhile, the authors discuss the problems of open experiment and propose some reflection and suggestions.
Related JoVE Video
An engineered superantigen SEC2 exhibits promising antitumor activity and low toxicity.
Cancer Immunol. Immunother.
PUBLISHED: 01-28-2011
Show Abstract
Hide Abstract
Recent studies suggested that the histidine residues at 118 and 122 play an important role for the toxicity of staphylococcal enterotoxin C subtype 2 (SEC2), and the substitutions of both histidines with alanine can severely impair the fever activity of SEC2. We hypothesized that promising SEC2 antitumor agent with low toxicity and enhanced superantigen activity can be constructed by introducing related mutations at protein functional sites of SEC2. We showed that the SEC2 mutants H122A and H118A/H122A exhibited improved superantigen activity after introducing the point mutations at Thr20 and Gly22. A resultant mutant, named as SAM-3, has considerable abilities to inhibit the growth of H22 and Hepa1-6 tumor cells in vitro and colon 26 solid tumor in vivo. Furthermore, SAM-3 also exhibits significantly reduced toxicity compared with native SEC2. The study provides a novel strategy for designing promising superantigen immunotherapeutic agent. The constructed SEC2 mutant SAM-3 can be used as a powerful candidate for cancer immunotherapy and could compensate the deficiency caused by toxicity of native SEC2 in clinic.
Related JoVE Video
Adenovirus-mediated sphingomyelin synthase 2 increases atherosclerotic lesions in ApoE KO mice.
Lipids Health Dis
PUBLISHED: 01-17-2011
Show Abstract
Hide Abstract
Sphingomyelin synthase 2 (SMS2) contributes to de novo sphingomyelin (SM) biosynthesis. Its activity is related to SM levels in the plasma and the cell membrane. In this study, we investigated the possibility of a direct relationship between SMS and atherosclerosis.
Related JoVE Video
[A meta analysis of aidi injection plus taxotere and cisplatin in the treatment of non-small cell lung cancer].
Zhongguo Fei Ai Za Zhi
PUBLISHED: 11-18-2010
Show Abstract
Hide Abstract
Compared with chemotherapy, whether aidi injection can improve the patients quality of life is not definite. The aim of this study is to evaluate the efficacy and safety of axotere plus eisplatin chemotherapy combining aidi injection for patients with non-small cell lung cancer (NSCLC).
Related JoVE Video
Redox regulation of actin by thioredoxin-1 is mediated by the interaction of the proteins via cysteine 62.
Antioxid. Redox Signal.
PUBLISHED: 03-12-2010
Show Abstract
Hide Abstract
Actin is a highly conserved protein in eukaryotic cells, and has been identified as one of the main redox targets by redox proteomics under oxidative stress. However, little is known about the mechanisms of regulation of the redox state of actin. In this study, we investigated how thioredoxin-1 (Trx1) affected the redox state of actin and its polymerization under oxidative stress in SH-SY5Y cells. Trx1 decreased the levels of reactive oxygen species (ROS) in the cells, and cysteine residues at positions 32, 35, and 69 of the Trx1 protein were active sites for redox regulation. Actin could be kept in a reduced state by Trx1 under H(2)O(2) stimulation. A physical interaction was found to exist between actin and Trx1. Cysteine 62 in Trx1 was the key site that interacted with actin, and it was required to maintain cellular viability and anti-apoptotic function. Taken together, these results suggested that Trx1 could protect cells from apoptosis under oxidative stress not only by increasing the total antioxidant capability and decreasing the ROS levels, but also by stabilizing the actin cytoskeletal system, which cooperatively contributed to the enhancement of cell viability and worked against apoptosis.
Related JoVE Video
Tractography segmentation using a hierarchical Dirichlet processes mixture model.
Neuroimage
PUBLISHED: 03-02-2010
Show Abstract
Hide Abstract
In this paper, we propose a new nonparametric Bayesian framework to cluster white matter fiber tracts into bundles using a hierarchical Dirichlet processes mixture (HDPM) model. The number of clusters is automatically learned driven by data with a Dirichlet process (DP) prior instead of being manually specified. After the models of bundles have been learned from training data without supervision, they can be used as priors to cluster/classify fibers of new subjects for comparison across subjects. When clustering fibers of new subjects, new clusters can be created for structures not observed in the training data. Our approach does not require computing pairwise distances between fibers and can cluster a huge set of fibers across multiple subjects. We present results on several data sets, the largest of which has more than 120,000 fibers.
Related JoVE Video
Comparison of phenotypic methods in predicting methicillin resistance in coagulase-negative Staphylococcus (CoNS) from animals.
Res. Vet. Sci.
PUBLISHED: 02-26-2010
Show Abstract
Hide Abstract
Phenotypic detection of methicillin resistance in coagulase-negative Staphylococcus (CoNS) of animal origin has been challenging due to the heterogeneous expression of mecA. To compare different phenotypic methods in predicting the mecA presence in CoNS, a total of 87 CoNS isolates from agricultural animals were analyzed in this study by agar dilution, disk diffusion, and broth microdilution. mecA was present in 81 CoNS isolates. Broth microdilution demonstrated the highest sensitivity of 100% in predicting the mecA presence, followed by 72.8% by agar dilution and 70.4% by disk diffusion. The results indicate that broth microdilution may be more suitable for predicting the presence of mecA in CoNS from animals than the other two methods, although staphylococcal species may also be a factor affecting the sensitivities of the methods as the top three staphylococcal species in this study were Staphylococcus lentus, Staphylococcus sciuri, and Staphylococcus xylosus (a total of 75 of 87).
Related JoVE Video
Inhibition of proteasomal degradation of rpn4 impairs nonhomologous end-joining repair of DNA double-strand breaks.
PLoS ONE
PUBLISHED: 02-03-2010
Show Abstract
Hide Abstract
The proteasome homeostasis in Saccharomyces cerevisiae is regulated by a negative feedback circuit in which the transcription factor Rpn4 induces the proteasome genes and is rapidly degraded by the assembled proteasome. The integrity of the Rpn4-proteasome feedback loop is critical for cell viability under stressed conditions. We have demonstrated that inhibition of Rpn4 degradation sensitizes cells to DNA damage, particularly in response to high doses of DNA damaging agents. The underlying mechanism, however, remains unclear.
Related JoVE Video
[Callus induction and plant regeneration of Liriope spicata var. prolifera anther].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 12-01-2009
Show Abstract
Hide Abstract
To study the technique of the callus induction from anther and plant regeneration of medicinal plants Liriope spicata var. prolifera.
Related JoVE Video
Proteasomal degradation of Rpn4 in Saccharomyces cerevisiae is critical for cell viability under stressed conditions.
Genetics
PUBLISHED: 11-23-2009
Show Abstract
Hide Abstract
The proteasome homeostasis in Saccharomyces cerevisiae is regulated by a negative feedback loop in which the transcription factor Rpn4 induces the proteasome genes and is rapidly degraded by the assembled proteasome. In addition to the proteasome genes, Rpn4 regulates numerous other genes involved in a wide range of cellular pathways. Therefore, the Rpn4-proteasome negative feedback circuit not only controls proteasome abundance, but also gauges the expression of other Rpn4 target genes. Our previous work has shown that Rpn4-induced gene expression is critical for cell viability under stressed conditions. Here we investigate whether proteasomal degradation of Rpn4 is also important for cell survival in response to stress. To this end, we generate a stabilized Rpn4 mutant (Rpn4*) that retains its transcription activity. We find that expression of Rpn4* severely reduces cell viability in response to various genotoxic and proteotoxic agents. This detrimental effect can be eliminated by a point mutation that abolishes the transcription activity of Rpn4*, suggesting that overexpression of some Rpn4 target genes weakens the cells ability to cope with stress. Moreover, we demonstrate that inhibition of Rpn4 degradation causes synthetic growth defects when combined with proteasome impairment resulting from mutation of a proteasome gene or accumulation of misfolded endoplasmic reticulum membrane proteins. Rpn4 thus represents an important stress-responsive mediator whose degradation as well as availability are critical for cell survival under stressed conditions.
Related JoVE Video
Face photo-sketch synthesis and recognition.
IEEE Trans Pattern Anal Mach Intell
PUBLISHED: 09-19-2009
Show Abstract
Hide Abstract
In this paper, we propose a novel face photo-sketch synthesis and recognition method using a multiscale Markov Random Fields (MRF) model. Our system has three components: 1) given a face photo, synthesizing a sketch drawing; 2) given a face sketch drawing, synthesizing a photo; and 3) searching for face photos in the database based on a query sketch drawn by an artist. It has useful applications for both digital entertainment and law enforcement. We assume that faces to be studied are in a frontal pose, with normal lighting and neutral expression, and have no occlusions. To synthesize sketch/photo images, the face region is divided into overlapping patches for learning. The size of the patches decides the scale of local face structures to be learned. From a training set which contains photo-sketch pairs, the joint photo-sketch model is learned at multiple scales using a multiscale MRF model. By transforming a face photo to a sketch (or transforming a sketch to a photo), the difference between photos and sketches is significantly reduced, thus allowing effective matching between the two in face sketch recognition. After the photo-sketch transformation, in principle, most of the proposed face photo recognition approaches can be applied to face sketch recognition in a straightforward way. Extensive experiments are conducted on a face sketch database including 606 faces, which can be downloaded from our Web site (http://mmlab.ie.cuhk.edu.hk/facesketch.html).
Related JoVE Video
The transcription activation domain of Rpn4 is separate from its degrons.
Int. J. Biochem. Cell Biol.
PUBLISHED: 08-25-2009
Show Abstract
Hide Abstract
The proteasome homeostasis in Saccharomyces cerevisiae is regulated by a negative feedback circuit in which the transcription activator Rpn4 upregulates the proteasome genes and is rapidly degraded by the assembled proteasome. In addition to the proteasome genes, Rpn4 regulates numerous other genes involved in a wide variety of cellular processes. However, the transcription activation domain of Rpn4 remains largely unclear. Here we locate a major transactivation domain of Rpn4 in the N-terminal region between residues 118 and 210. Interestingly, this domain is separate from its degradation signals (degrons), suggesting that functional overlap of sequences that activate transcription and signal degradation may not be as common as previously thought. We further demonstrate that the intracellular proteasome activity is correlated with the transactivation potency of Rpn4. This study provides important information for further understanding the biological functions of Rpn4 and the proteasome system.
Related JoVE Video
Tractography segmentation using a hierarchical Dirichlet processes mixture model.
Inf Process Med Imaging
PUBLISHED: 08-22-2009
Show Abstract
Hide Abstract
In this paper, we propose a new nonparametric Bayesian framework to cluster white matter fiber tracts into bundles using a hierarchical Dirichlet processes mixture (HDPM) model. The number of clusters is automatically learnt from data with a Dirichlet process (DP) prior instead of being manually specified. After the models of bundles have been learnt from training data without supervision, they can be used as priors to cluster/classify fibers of new subjects. When clustering fibers of new subjects, new clusters can be created for structures not observed in the training data. Our approach does not require computing pairwise distances between fibers and can cluster a huge set of fibers across multiple subjects without subsampling. We present results on multiple data sets, the largest of which has more than 120, 000 fibers.
Related JoVE Video
Efficient layered density-based clustering of categorical data.
J Biomed Inform
PUBLISHED: 08-18-2009
Show Abstract
Hide Abstract
A challenge involved in applying density-based clustering to categorical biomedical data is that the "cube" of attribute values has no ordering defined, making the search for dense subspaces slow. We propose the HIERDENC algorithm for hierarchical density-based clustering of categorical data, and a complementary index for searching for dense subspaces efficiently. The HIERDENC index is updated when new objects are introduced, such that clustering does not need to be repeated on all objects. The updating and cluster retrieval are efficient. Comparisons with several other clustering algorithms showed that on large datasets HIERDENC achieved better runtime scalability on the number of objects, as well as cluster quality. By fast collapsing the bicliques in large networks we achieved an edge reduction of as much as 86.5%. HIERDENC is suitable for large and quickly growing datasets, since it is independent of object ordering, does not require re-clustering when new data emerges, and requires no user-specified input parameters.
Related JoVE Video
[Comparative study on meiotic behavior and pollen development of medicinal plants Liriope spicata var. prolifera and L. spicata].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 08-14-2009
Show Abstract
Hide Abstract
To reveal the mechanism of sterility of Liriope spicata var. prolifera.
Related JoVE Video
Functional analysis of the disulphide loop mutant of staphylococcal enterotoxin C2.
Appl. Microbiol. Biotechnol.
PUBLISHED: 05-14-2009
Show Abstract
Hide Abstract
The superantigen staphylococcal enterotoxin C2 (SEC2) tremendously activate T lymphocytes bearing certain T-cell receptor Vbeta domains when binding to MHC II molecules, which launches a powerful response of tumour inhibition in vitro as well as in vivo. However, the toxicity of SEC2 performed in clinic limited its broad application for immunotherapy. The previous studies suggested that the disulphide loop may be important for the toxicity of some SEs, which prompted us to investigate the potential roles of the disulphide loop in biological activity of SEC2. Site-directed mutagenesis was used to disturb the formation of the disulphide bond by substituting Ala or Ser for Cys-93 and Cys-110. The expressed mutants in Escherichia coli were used to determine their superantigen activity and toxicity. Results showed that all of the mutated proteins exhibited reduced abilities to induce T-cell proliferation and cytotoxic effects on tumour cells L929 and Hepa1-6, suggesting that the disulphide loop plays functional role in maintaining the maximal superantigen activity of SEC2. Furthermore, the toxicity assays in vivo showed that all of the mutants induced a reduced emetic and pyrogenic responses compared with native SEC2, which might be important for further construction of lowly toxic superantigen agent.
Related JoVE Video
Computational prediction of the specificities of proteasome interaction with antigen protein.
Cell. Mol. Immunol.
PUBLISHED: 05-01-2009
Show Abstract
Hide Abstract
In the processing and presentation of antigenic peptides bound by the major histocompatibility complex (MHC) class I molecule, the ubiquitin-proteasome system of the eukaryotic cells plays an important role in proteolysis and degradation. The ubiquitinated protein substrate is delivered into the 26S proteasome to be digested and degraded. The proteasome degrading substrate is actually protein-protein interactions. Some researches of predicting proteasome cleave site rarely gave the information of the proteasome interacting with its substrate, and so the accuracy and reliability of these proteasome cleavage predictive methods still need to be improved. This paper used support vector machine method (SVM) to predict the proteasomal cleavage sites, and the predictive accuracy of the model was 82.8%. We showed analytically that the cleavage specificities of the cleavage sites "|" and its adjacent positions, and gave the information about the proteasome interacting with its substrate from our research results. It demonstrates that the proteasome cleaving to target protein is selective, but not random.
Related JoVE Video
Enhancement of superantigen activity and antitumor response of staphylococcal enterotoxin C2 by site-directed mutagenesis.
Cancer Immunol. Immunother.
PUBLISHED: 04-02-2009
Show Abstract
Hide Abstract
Bacterial superantigen staphylococcal enterotoxins (SEs) tremendously stimulate polyclonal T cells bearing particular TCR Vbeta domains when binding to MHC II molecules, suggesting that they could be a candidate of new antitumor agent. SEC2, an important member of superantigen family, has been used in clinical trial as an immunotherapy agent for cancer treatment in China, and obtained some encouraging effects. However, the presence of immunosuppression and endotoxic activity limits the therapeutic dosage of SEC2, and influences its antitumor effect in clinic. Therefore, the enhancement of superantigen activity and antitumor effect of SEC2 could effectively make compensation for the disadvantages mentioned above. In this study, a superantigen SEC2(T20L/G22E) mutant was generated by site-directed mutagenesis, and efficiently expressed in E. coli BL21(DE3). The results showed that SEC2(T20L/G22E) mutant exhibited a significantly enhanced superantigen activity and antitumor response, compared with native SEC2 in vitro. Further toxicity assay in vivo indicated that SEC2(T20L/G22E) mutant had no significant increase in emetic and pyrogenic activity compared with SEC2, which suggested that the mutant SEC2(T20L/G22E) could be used as a potentially powerful candidate for cancer immunotherapy, and could make compensation for the deficiency of native SEC2 in clinic.
Related JoVE Video
Biological characterization of the zinc site coordinating histidine residues of staphylococcal enterotoxin C2.
Microbiology (Reading, Engl.)
PUBLISHED: 02-28-2009
Show Abstract
Hide Abstract
The bacterial toxin staphylococcal enterotoxin C2 (SEC2) can cause staphylococcal toxic shock syndrome and food poisoning. Although the previously determined crystal structure of SEC2 revealed that some histidine residues (His47, His118 and His122) contribute to the binding of zinc ions, little is known about their biological roles in SEC2. This prompted us to investigate the role of the zinc site coordinating histidine residues in the biological activities of SEC2. The mutants with substitutions at positions 118 and 122 all retained T-cell stimulatory activity, whereas the histidine mutants at position 47 were defective in the ability to stimulate T-cell proliferation. Further toxicity assays in vivo indicated that mutants SEC2-H118A and SEC2-H122A were defective in emetic and febrile activities. However, mutant SEC2-H47A could cause significant emetic and febrile responses in comparison with the other two histidine mutants. These findings suggested that the zinc-coordinating histidine residues play significant roles in superantigen and toxic activities of SEC2 and further implied that superantigen and febrile activities could be separable in staphylococcal enterotoxins. The results also show that it should be possible to design new SEC2 immunotherapeutic agents that have superantigen activity and low toxicity.
Related JoVE Video
Biological analysis of the deletion mutants of Staphylococcal enterotoxin C2.
Appl. Microbiol. Biotechnol.
PUBLISHED: 02-27-2009
Show Abstract
Hide Abstract
To investigate the functional domains involved in the biological activity of staphylococcal enterotoxin (SEC2), a series of SEC2 mutants were constructed. Deletion of the last 77 amino acids at the C-terminus of SEC2 did not affect its native superantigen and fever activities, and further removal of the C-terminal residues reduced SEC2 activities significantly. On the other hand, the mutants lacking 18 or more N-terminal residues severely impaired superantigen activity. These data indicated that the functional regions for the biological activities of SEC2 were confined to N-terminal domain, further implied that the proper three-dimensional structure of SEC2 is not needed for its biological activities. Our results deliver valuable information that it is possible to design new SEC2 immunotherapeutic agents which have the superantigen activity and low molecular weight for permeability.
Related JoVE Video

What is Visualize?

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

How does it work?

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

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

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