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Find video protocols related to scientific articles indexed in Pubmed.
Discovery of Pentacyclic Triterpenoids as Potential Entry Inhibitors of Influenza Viruses.
J. Med. Chem.
PUBLISHED: 11-11-2014
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Entry inhibitors are of particular importance in current efforts to develop a new generation of anti-influenza virus drugs. Here we report certain pentacyclic triterpenes exhibiting conserved structure features and with in vitro anti-influenza virus activity comparable to and even higher than that of oseltamivir. Mechanistic studies indicated that these lead triterpenoids bind tightly to the viral envelope hemagglutinin (HA), disrupting the interaction of HA with the sialic acid receptor and thus the attachment of viruses to host cells. Docking studies suggest that the binding pocket within HA for sialic acid receptor potentially acts as a targeting domain, and this is supported by structure-activity data, sialic acid competition studies and broad anti-influenza spectrum as well as less induction of drug resistance. Our study might establish the importance of triterpenoids for development of entry inhibitors of influenza viruses.
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Black phosphorus radio-frequency transistors.
Nano Lett.
PUBLISHED: 11-03-2014
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Few-layer and thin film forms of layered black phosphorus (BP) have recently emerged as a promising material for applications in high performance nanoelectronics and infrared optoelectronics. Layered BP thin films offer a moderate bandgap of around 0.3 eV and high carrier mobility, which lead to transistors with decent on-off ratios and high on-state current densities. Here, we demonstrate the gigahertz frequency operation of BP field-effect transistors for the first time. The BP transistors demonstrated here show respectable current saturation with an on-off ratio that exceeds 2 × 10(3). We achieved a current density in excess of 270 mA/mm and DC transconductance above 180 mS/mm for hole conduction. Using standard high frequency characterization techniques, we measured a short-circuit current-gain cutoff frequency fT of 12 GHz and a maximum oscillation frequency fmax of 20 GHz in 300 nm channel length devices. BP devices may offer advantages over graphene transistors for high frequency electronics in terms of voltage and power gain due to the good current saturation properties arising from their finite bandgap, thus can be considered as a promising candidate for the future high performance thin film electronics technology for operation in the multi-GHz frequency range and beyond.
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Stacked Extreme Learning Machines.
IEEE Trans Cybern
PUBLISHED: 11-01-2014
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Extreme learning machine (ELM) has recently attracted many researchers' interest due to its very fast learning speed, good generalization ability, and ease of implementation. It provides a unified solution that can be used directly to solve regression, binary, and multiclass classification problems. In this paper, we propose a stacked ELMs (S-ELMs) that is specially designed for solving large and complex data problems. The S-ELMs divides a single large ELM network into multiple stacked small ELMs which are serially connected. The S-ELMs can approximate a very large ELM network with small memory requirement. To further improve the testing accuracy on big data problems, the ELM autoencoder can be implemented during each iteration of the S-ELMs algorithm. The simulation results show that the S-ELMs even with random hidden nodes can achieve similar testing accuracy to support vector machine (SVM) while having low memory requirements. With the help of ELM autoencoder, the S-ELMs can achieve much better testing accuracy than SVM and slightly better accuracy than deep belief network (DBN) with much faster training speed.
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Spectroscopic properties and continuous-wave laser operation of Yb:Bi4Si3O12 crystal.
Opt Express
PUBLISHED: 10-17-2014
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Yb3+:Bi4Si3O12 single crystal with Yb3+ concentration of 5.7 at.% has been grown successfully by the Czochralski method. The energy level positions of Yb3+ in Bi4Si3O12 crystal were determined based on the absorption and fluorescence spectra. The peak absorption cross-section is 0.98 × 10-20 cm2 at 976 nm and the peak emission cross-section is 0.57 × 10-20 cm2 at 1035 nm. The fluorescence lifetime of the excited multiplet is 1.26 ms. Diode-pumped continuous-wave laser operation around 1038 nm has been demonstrated in the Yb3+:Bi4Si3O12 crystal with a slope efficiency of 27% and maximum output power of 240 mW.
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In-syringe dispersive solid phase extraction: a novel format for electrospun fiber based microextraction.
Analyst
PUBLISHED: 10-16-2014
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A novel in-syringe dispersive solid phase extraction (dSPE) system using electrospun silica fibers as adsorbents has been developed in the current work. A few milligrams of electrospun silica fibers were incubated in sample solution in the barrel of a syringe for microextraction assisted by vortex. Due to the benefit of dispersion and the high mass transfer rate of the sub-microscale electrospun silica fibers, the extraction equilibrium was achieved in a very short time (less than 1 min). Moreover, thanks to the long fibrous properties of electrospun fibers, the separation of the adsorbent from sample solution was easily achieved by pushing out the sample solution which therefore simplified the sample pretreatment procedure. Besides, the analytical throughput was largely increased by using a multi-syringe plate to perform the extraction experiment. The performance of the in-syringe dSPE device was evaluated by extraction of endogenous cytokinins from plant tissue samples based on the hydrophilic interaction. Six endogenous cytokinins in 20 mg of Oryza sativa L. (O. sativa) leaves were successfully determined under optimized conditions using in-syringe dSPE combined with liquid chromatography-mass spectrometry analysis. The results demonstrated that the in-syringe dSPE method was a rapid and high-throughput strategy for the extraction of target compounds, which has great potential in microscale sample pretreatment using electrospun fibers.
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Molecular Characterization of the Monoclonal Antibodies Composing ZMAb: A Protective Cocktail Against Ebola Virus.
Sci Rep
PUBLISHED: 09-28-2014
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Ebola virus (EBOV) causes severe viral hemorrhagic fever in humans and non-human primates, with a case fatality rate of up to 88% in human outbreaks. Over the past 3 years, monoclonal antibody (mAb) cocktails have demonstrated high efficacy as treatments against EBOV infection. One such cocktail is ZMAb, which consists of three mouse antibodies, 1H3, 2G4, and 4G7. Here, we present the epitope binding properties of mAbs 1H3, 2G4, and 4G7. We showed that these antibodies have different variable region sequences, suggesting that the individual mAbs are not clonally related. All three antibodies were found to neutralize EBOV variant Mayinga. Additionally, 2G4 and 4G7 were shown to cross-inhibit each other in vitro and select for an escape mutation at the same position on the EBOV glycoprotein (GP), at amino acid 508. 1H3 selects an escape mutant at amino acid 273 on EBOV GP. Surface plasmon resonance studies showed that all three antibodies have dissociation constants on the order of 10(-7). In combination with previous studies evaluating the binding sites of other protective antibodies, our results suggest that antibodies targeting the GP1-GP2 interface and the glycan cap are often selected as efficacious antibodies for post-exposure interventions against EBOV.
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Sparse extreme learning machine for classification.
IEEE Trans Cybern
PUBLISHED: 09-16-2014
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Extreme learning machine (ELM) was initially proposed for single-hidden-layer feedforward neural networks (SLFNs). In the hidden layer (feature mapping), nodes are randomly generated independently of training data. Furthermore, a unified ELM was proposed, providing a single framework to simplify and unify different learning methods, such as SLFNs, least square support vector machines, proximal support vector machines, and so on. However, the solution of unified ELM is dense, and thus, usually plenty of storage space and testing time are required for large-scale applications. In this paper, a sparse ELM is proposed as an alternative solution for classification, reducing storage space and testing time. In addition, unified ELM obtains the solution by matrix inversion, whose computational complexity is between quadratic and cubic with respect to the training size. It still requires plenty of training time for large-scale problems, even though it is much faster than many other traditional methods. In this paper, an efficient training algorithm is specifically developed for sparse ELM. The quadratic programming problem involved in sparse ELM is divided into a series of smallest possible sub-problems, each of which are solved analytically. Compared with SVM, sparse ELM obtains better generalization performance with much faster training speed. Compared with unified ELM, sparse ELM achieves similar generalization performance for binary classification applications, and when dealing with large-scale binary classification problems, sparse ELM realizes even faster training speed than unified ELM.
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Muscle edema of the lower limb determined by MRI in Asian hypokalaemic periodic paralysis patients.
Neurol. Res.
PUBLISHED: 09-13-2014
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Objective: To determine the pattern of muscle edema occurring in the lower limb muscles of Asian hypokalaemic periodic paralysis (hypoPP) patients using magnetic resonance imaging (MRI). Specifically, the relationship between muscle edema and muscle activity during daily use was examined by comparing the lower limb muscle MRI of healthy subjects following exercise and hypoPP patients. Methods: Twenty Asian patients (mean age: 29·3±7·53 years) clinically diagnosed with hypoPP were enrolled in the present study. Ten healthy subjects were also enrolled. Direct automated DNA sequencing of the S4 regions of CACNA1S and SCN4A in all hypoPP patients was performed. The upper and lower legs of all hypoPP patients during the time interval between attacks and healthy subjects pre- and post-exercise were examined on a 3 T system with T2-weighted fat saturation sequence. Images were evaluated by means of a region of interest analysis. A scoring from 0 to 3 was used to compare the degree of muscle edema among individual muscles. Results: Three hypoPP patients were identified with mutations in the screened genes: R1239H and R900S of CACNA1S and R672H of SCN4A. The lower leg muscles of both hypoPP patients and healthy subjects after exercise displayed significantly higher MRI signal intensities compared to healthy subjects before exercise (P < 0·0001 and P < 0·0001, respectively). In contrast, there was no significant change in the upper leg muscle signal intensities of hypoPP patients and healthy subjects following exercise compared to pre-exercise healthy subjects (P ?=? 0·7598 and P ?=? 0·9651, respectively). In the hypoPP patient group, high signal intensity in the upper leg muscles was seen only in the patient with the R1239H mutation. In the lower legs, muscle edema was most frequently seen in the gastrocnemius lateralis, soleus, and gastrocnemius medialis in the hypoPP patient group. Furthermore, the degree of muscle edema was the greatest in these muscles. This similar pattern of muscle edema was also seen in healthy subjects after exercise. Conclusions: In Asian hypoPP patients, muscle edema as well as the underlying abnormal ion distributions across the muscle membrane is present even during the time interval between attacks of muscle weakness. The muscles of the lower leg are more likely to be edematous than muscles of the upper leg since these muscles are more actively used in daily life. Thus, muscles subjected to high activity are more likely to be edematous and sodium-overloaded.
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[Primitive myxoid mesenchymal tumor of infancy: a clinicopathologic study of 3 additional cases].
Zhonghua Bing Li Xue Za Zhi
PUBLISHED: 09-12-2014
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To study the clinicopathologic characteristics, immunophenotypes and differential diagnosis of primitive myxoid mesenchymal tumor of infancy (PMMTI).
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Plasmons and screening in monolayer and multilayer black phosphorus.
Phys. Rev. Lett.
PUBLISHED: 09-04-2014
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Black phosphorus exhibits a high degree of band anisotropy. However, we find that its in-plane static screening remains relatively isotropic for momenta relevant to elastic long-range scattering processes. On the other hand, the collective electronic excitations in the system exhibit a strong anisotropy. Band nonparabolicity, due to interband couplings, leads to a plasmon frequency which scales as n?, where n is the carrier concentration, and ?<1/2. Screening and charge distribution in the out-of-plane direction are also studied using a nonlinear Thomas-Fermi model.
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Combination of platelet-rich plasma within periodontal ligament stem cell sheets enhances cell differentiation and matrix production.
J Tissue Eng Regen Med
PUBLISHED: 09-04-2014
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The longstanding goal of periodontal therapy is to regenerate periodontal tissues. Although platelet-rich plasma (PRP) has been gaining increasing popularity for use in the orofacial region, whether PRP is useful for periodontal regeneration is still unknown. The purpose of this study was to determine whether a mixture of periodontal ligament stem cell (PDLSC) sheets and PRP promoted bone regeneration, one of the most important measurement indices of periodontal tissue regenerative capability in vitro and in vivo. In this study, we evaluated the effects of different doses of PRP on the differentiation of human PDLSCs. Then cell sheet formation, extracellular matrix deposition and osteogenic gene expression in response to different doses of PRP treatment during sheet grafting was investigated. Furthermore, we implanted PDLSC sheets treated with 1% PRP subcutaneously into immunocompromised mice to evaluate their bone-regenerative capability. The results revealed that 1% PRP significantly enhanced the osteogenic differentiation of PDLSCs. Based on the production of extracellular matrix proteins, the results of scanning electron microscopy and the expression of the osteogenic genes ALP, Runx2, Col-1 and OCN, the provision of 1% PRP for PDLSC sheets was the most effective PRP administration mode for cell sheet formation. The results of in vivo transplantation showed that 1% PRP-mediated PDLSC sheets exhibited better periodontal tissue regenerative capability than those obtained without PRP intervention. These data suggest that a suitable concentration of PRP stimulation may enhance extracellular matrix production and positively affect cell behaviour in PDLSC sheets. Copyright © 2014 John Wiley & Sons, Ltd.
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Flower-like dynamics of coupled Skyrmions with dual resonant modes by a single-frequency microwave magnetic field.
Sci Rep
PUBLISHED: 08-21-2014
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Resonant excitations of confined systems have aroused much attention because of their potential application in future microwave devices and spintronics. Under resonant excitations, the motion of topo-logical objects exhibits circular, elliptical or even stadium-like dynamics. However, more complex non-linear resonant excitations of topological objects in confined systems have seldom been reported and the associated physical mechanism remains unclear. Here, we present an observation of flower-like resonant excitations for coupled skyrmions in Co/Ru/Co nanodisks activated by a single-frequency microwave magnetic field by means of numerical simulation. We find that flower-like dynamics of coupled skyrmions is always accompanied by an excitation of an eigenfrequency near 1.15?GHz, which is strongly associated with the large non-local deformation of the topological density distribution of coupled skyrmions. These results distinguish a skyrmion from other topological objects in dynamics and will be instrumental to the manipulation of skyrmions for applications.
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Acoustic devices for particle and cell manipulation and sensing.
Sensors (Basel)
PUBLISHED: 08-13-2014
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An emerging demand for the precise manipulation of cells and particles for applications in cell biology and analytical chemistry has driven rapid development of ultrasonic manipulation technology. Compared to the other manipulation technologies, such as magnetic tweezing, dielectrophoresis and optical tweezing, ultrasonic manipulation has shown potential in a variety of applications, with its advantages of versatile, inexpensive and easy integration into microfluidic systems, maintenance of cell viability, and generation of sufficient forces to handle particles, cells and their agglomerates. This article briefly reviews current practice and reports our development of various ultrasonic standing wave manipulation devices, including simple devices integrated with high frequency (>20 MHz) ultrasonic transducers for the investigation of biological cells and complex ultrasonic transducer array systems to explore the feasibility of electronically controlled 2-D and 3-D manipulation. Piezoelectric and passive materials, fabrication techniques, characterization methods and possible applications are discussed. The behavior and performance of the devices have been investigated and predicted with computer simulations, and verified experimentally. Issues met during development are highlighted and discussed. To assist long term practical adoption, approaches to low-cost, wafer level batch-production and commercialization potential are also addressed.
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Association of tagging SNPs in the MTHFR gene with risk of type 2 diabetes mellitus and serum homocysteine levels in a Chinese population.
Dis. Markers
PUBLISHED: 08-06-2014
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Diabetes is a global public health crisis, and the prevalence is increasing rapidly. Folate supplementation is proved to be effective in reducing the risk of diabetes or improving its symptoms. Methylenetetrahydrofolate reductase is an important enzyme involved in folate metabolism. The aim of this study is to examine whether polymorphisms in the MTHFR gene are associated with risk of type 2 diabetes mellitus (T2DM) and fasting total serum homocysteine (tHcy) levels. We genotyped nine tagging SNPs in the MTHFR gene in a case-control study, including 595 T2DM cases and 681 healthy controls in China. We found that C allele of rs9651118 had significant decreased risk of T2DM (adjusted odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.55-0.87, P = 0.002) compared with T allele. Haplotype analysis also showed that MTHFR CTCCGA haplotype (rs12121543-rs13306553-rs9651118-rs1801133-rs2274976-rs1801131) had significant reduced risk of T2DM (adjusted OR = 0.71, 95% CI: 0.58-0.87, P = 0.001) compared with CTTTGA haplotype. Besides, the MTHFR rs1801133 was significantly associated with serum levels of tHcy in healthy controls (P = 0.0002). These associations were still significant after Bonferroni corrections (P < 0.0056). These findings suggest that variants in the MTHFR gene may influence the risk of T2DM and tHcy levels.
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Shape recognition and classification in electro-sensing.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 07-28-2014
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This paper aims at advancing the field of electro-sensing. It exhibits physical mechanisms underlying shape perception for weakly electric fish. These fish orient themselves at night in complete darkness by using their active electrolocation system. They generate a stable, relatively high-frequency, weak electric field and perceive the transdermal potential modulations caused by a nearby target with different electromagnetic properties than the surrounding water. The main result of this paper is a scheme that explains how weakly electric fish might identify and classify a target, knowing in advance that the latter belongs to a certain collection of shapes. The scheme is designed to recognize living biological organisms. It exploits the frequency dependence of the electromagnetic properties of living organisms, which comes from the capacitive effects generated by the cell membrane structure. When measurements are taken at multiple frequencies, the fish might use the spectral content of the perceived transdermal potential modulations to classify the living target.
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Chemical potential of liquids and mixtures via adaptive resolution simulation.
J Chem Phys
PUBLISHED: 07-24-2014
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We employ the adaptive resolution approach AdResS, in its recently developed Grand Canonical-like version (GC-AdResS) [H. Wang, C. Hartmann, C. Schütte, and L. Delle Site, Phys. Rev. X 3, 011018 (2013)], to calculate the excess chemical potential, ?(ex), of various liquids and mixtures. We compare our results with those obtained from full atomistic simulations using the technique of thermodynamic integration and show a satisfactory agreement. In GC-AdResS, the procedure to calculate ?(ex) corresponds to the process of standard initial equilibration of the system; this implies that, independently of the specific aim of the study, ?(ex), for each molecular species, is automatically calculated every time a GC-AdResS simulation is performed.
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Microarray data classification using the spectral-feature-based TLS ensemble algorithm.
IEEE Trans Nanobioscience
PUBLISHED: 06-30-2014
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The reliable and accurate identification of cancer categories is crucial to a successful diagnosis and a proper treatment of the disease. In most existing work, samples of gene expression data are treated as one-dimensional signals, and are analyzed by means of some statistical signal processing techniques or intelligent computation algorithms. In this paper, from an image-processing viewpoint, a spectral-feature-based Tikhonov-regularized least-squares (TLS) ensemble algorithm is proposed for cancer classification using gene expression data. In the TLS model, a test sample is represented as a linear combination of the atoms of a dictionary. Two types of dictionaries, namely singular value decomposition (SVD)-based eigenassays and independent component analysis (ICA)-based eigenassays, are proposed for the TLS model, and both are extracted via a two-stage approach. The proposed algorithm is inspired by our finding that, among these eigenassays, the categories of some of the testing samples can be assigned correctly by using the TLS models formed from some of the spectral features, but not for those formed from the original samples only. In order to retain the positive characteristics of these spectral features in making correct category assignments, a strategy of classifier committee learning (CCL) is designed to combine the results obtained from the different spectral features. Experimental results on standard databases demonstrate the feasibility and effectiveness of the proposed method.
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Impact of continuous quality improvement initiatives on clinical outcomes in peritoneal dialysis.
Perit Dial Int
PUBLISHED: 06-26-2014
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We evaluated the role of a quality improvement initiative in improving clinical outcomes in peritoneal dialysis (PD).
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Uralsaponins M-Y, antiviral triterpenoid saponins from the roots of Glycyrrhiza uralensis.
J. Nat. Prod.
PUBLISHED: 06-24-2014
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Thirteen new oleanane-type triterpenoid saponins, uralsaponins M-Y (1-13), and 15 known analogues (14-28) were isolated from the roots of Glycyrrhiza uralensis Fisch. The structures of 1-13 were identified on the basis of extensive NMR and MS data analyses. The sugar residues were identified by gas chromatography and ion chromatography coupled with pulsed amperometric detection after hydrolysis. Saponins containing a galacturonic acid (1-3) or xylose (5) residue are reported from Glycyrrhiza species for the first time. Compounds 1, 7, 8, and 24 exhibited good inhibitory activities against the influenza virus A/WSN/33 (H1N1) in MDCK cells with IC50 values of 48.0, 42.7, 39.6, and 49.1 ?M, respectively, versus 45.6 ?M of the positive control oseltamivir phosphate. In addition, compounds 24 and 28 showed anti-HIV activities with IC50 values of 29.5 and 41.7 ?M, respectively.
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Positive temperature coefficient thermistors based on carbon nanotube/polymer composites.
Sci Rep
PUBLISHED: 06-16-2014
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In order to explore availability of carbon nanotube (CNT)-based positive temperature coefficient (PTC) thermistors in practical application, we prepared carbon nanotube (CNT) filled high density polyethylene (HDPE) composites by using conventional melt-mixing methods, and investigated their PTC effects in details. The CNT-based thermistors exhibit much larger hold current and higher hold voltage, increasing by 129% in comparison with the commercial carbon black (CB) filled HDPE thermistors. Such high current-bearing and voltage-bearing capacity for the CNT/HDPE thermistors is mainly attributed to high thermal conductivity and heat dissipation of entangled CNT networks. Moreover, the CNT/HDPE thermistors exhibit rapid electrical response to applied voltages, comparable to commercial CB-based thermistors. In light of their high current-bearing capacity and quick response, the CNT-based thermistors have great potential to be used as high-performance thermistors in practical application, especially in some critical circumstances of high temperature, large applied currents, and high applied voltages.
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Varicella and herpes zoster hospitalizations before and after implementation of one-dose varicella vaccination in Australia: an ecological study.
Bull. World Health Organ.
PUBLISHED: 06-13-2014
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To examine trends in varicella and herpes zoster (HZ) hospitalization following the availability and subsequent National Immunization Programme funding of one-dose varicella vaccination in Australia.
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Synergism between southern rice black-streaked dwarf virus and rice ragged stunt virus enhances their insect vector acquisition.
Phytopathology
PUBLISHED: 06-11-2014
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Southern rice black-streaked dwarf virus (SRBSDV), a tentative species in the genus Fijivirus, family Reoviridae, is a novel rice virus transmitted by the white-backed planthopper (Sogatella furcifera). Since its discovery in 2001, SRBSDV has spread rapidly throughout eastern and southeastern Asia and caused large rice losses in China and Vietnam. Rice ragged stunt virus (RRSV) (genus Oryzavirus, family Reoviridae) is a common rice virus vectored by the brown planthopper (Nilaparvata lugens). RRSV is also widely distributed in eastern and southeastern Asia but has not previously caused serious problems in China owing to its low incidence. With SRBSDV's spread, however, RRSV has become increasingly common in China, and is frequently found in co-infection with SRBSDV. In this study, we show that SRBSDV and RRSV interact synergistically, the first example of synergism between plant viruses in the family Reoviridae. Rice plants co-infected with both viruses displayed enhanced stunting, earlier symptoms, and higher virus titers compared with singly infected plants. Furthermore, white-backed and brown planthoppers acquired SRBSDV and RRSV, respectively, from co-infected plants at higher rates. We propose that increased RRSV incidence in Chinese fields is partly due to synergism between SRBSDV and RRSV.
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Bioaugmentation as a solution to increase methane production from an ammonia-rich substrate.
Environ. Sci. Technol.
PUBLISHED: 06-10-2014
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Ammonia-rich substrates inhibit the anaerobic digestion (AD) process and constitute the main reason for low energy recovery in full-scale reactors. It is estimated that many full-scale AD reactors are operating in ammonia induced "inhibited steady-state" with significant losses of the potential biogas production yield. To date there are not any reliable methods to alleviate the ammonia toxicity effect or to efficiently digest ammonia-rich waste. In the current study, bioaugmentation as a possible method to alleviate ammonia toxicity effect in a mesophilic continuously stirred-tank reactor (CSTR) operating under "inhibited steady state" was tested. A fast growing hydrogenotrophic methanogen (i.e., Methanoculleus bourgensis MS2(T)) was bioaugmented in the CSTR reactor at high ammonia levels (5 g NH4(+)-N L(-1)). A second CSTR reactor was used as control with no bioaugmentation. The results derived from this study clearly demonstrated a 31.3% increase in methane production yield in the CSTR reactor, at steady-state, after bioaugmentation. Additionally, high-throughput 16S rRNA gene sequencing analysis showed a 5-fold increase in relative abundance of Methanoculleus spp. after bioaugmentation. On the contrary to all methods used today to alleviate ammonia toxicity effect, the tested bioaugmentation process performed without interrupting the continuous operation of the reactor and without replacing the ammonia-rich feedstock.
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Mechanism of TiO2 nanoparticle-induced neurotoxicity in zebrafish (Danio rerio).
Environ. Toxicol.
PUBLISHED: 06-07-2014
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Zebrafish (Danio rerio) has been used historically for evaluating the toxicity of environmental and aqueous toxicants, and there is an emerging literature reporting toxic effects of manufactured nanoparticles (NPs) in zebrafish embryos. Few researches, however, are focused on the neurotoxicity on adult zebrafish after subchronic exposure to TiO2 NPs. This study was designed to evaluate the morphological changes, alterations of neurochemical contents, and expressions of memory behavior-related genes in zebrafish brains caused by exposures to 5, 10, 20, and 40 ?g/L TiO2 NPs for 45 consecutive days. Our data indicated that spatial recognition memory and levels of norepinephrine, dopamine, and 5-hydroxytryptamine were significantly decreased and NO levels were markedly elevated, and over proliferation of glial cells, neuron apoptosis, and TiO2 NP aggregation were observed after low dose exposures of TiO2 NPs. Furthermore, the low dose exposures of TiO2 NPs significantly activated expressions of C-fos, C-jun, and BDNF genes, and suppressed expressions of p38, NGF, CREB, NR1, NR2ab, and GluR2 genes. These findings imply that low dose exposures of TiO2 NPs may result in the brain damages in zebrafish, provide a developmental basis for evaluating the neurotoxicity of subchronic exposure, and raise the caution of aquatic application of TiO2 NPs. © 2014 Wiley Periodicals, Inc. Environ Toxicol, 2014.
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PILR? and PILR? have a siglec fold and provide the basis of binding to sialic acid.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 05-19-2014
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Paired immunoglobulin-like type 2 receptor ? (PILR?) and ? (PILR?) belong to the PILR family and are related to innate immune regulation in various species. Despite their high sequence identity, PILR? and PILR? are shown to have variant sialic acid (SA) binding avidities. To explore the molecular basis of this interaction, we solved the crystal structures of PILR? and PILR? at resolutions of 1.6 Å and 2.2 Å, respectively. Both molecules adopt a typical siglec fold but use a hydrophobic bond to substitute the siglec-specific disulfide linkage for protein stabilization. We further used HSV-1 glycoprotein B (gB) as a representative molecule to study the PILR-SA interaction. Deploying site-directed mutagenesis, we demonstrated that three residues (Y2, R95, and W108) presented on the surface of PILR? form the SA binding site equivalent to those in siglecs but are arranged in a unique linear mode. PILR? differs from PILR? in one of these three residues (L108), explaining its inability to engage gB. Mutation of L108 to tryptophan in PILR? restored the gB-binding capacity. We further solved the structure of this PILR? mutant complexed with SA, which reveals the atomic details mediating PILR/SA recognition. In comparison with the free PILR structures, amino acid Y2 oriented variantly in the complex structure, thereby disrupting the linear arrangement of PILR residues Y2, R95, and W108. In conclusion, our study provides significant implications for the PILR-SA interaction and paves the way for understanding PILR-related ligand binding.
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Graphene/MoS2 hybrid technology for large-scale two-dimensional electronics.
Nano Lett.
PUBLISHED: 05-14-2014
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Two-dimensional (2D) materials have generated great interest in the past few years as a new toolbox for electronics. This family of materials includes, among others, metallic graphene, semiconducting transition metal dichalcogenides (such as MoS2), and insulating boron nitride. These materials and their heterostructures offer excellent mechanical flexibility, optical transparency, and favorable transport properties for realizing electronic, sensing, and optical systems on arbitrary surfaces. In this paper, we demonstrate a novel technology for constructing large-scale electronic systems based on graphene/molybdenum disulfide (MoS2) heterostructures grown by chemical vapor deposition. We have fabricated high-performance devices and circuits based on this heterostructure, where MoS2 is used as the transistor channel and graphene as contact electrodes and circuit interconnects. We provide a systematic comparison of the graphene/MoS2 heterojunction contact to more traditional MoS2-metal junctions, as well as a theoretical investigation, using density functional theory, of the origin of the Schottky barrier height. The tunability of the graphene work function with electrostatic doping significantly improves the ohmic contact to MoS2. These high-performance large-scale devices and circuits based on this 2D heterostructure pave the way for practical flexible transparent electronics.
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Sphincter electromyography in diabetes mellitus and multiple system atrophy.
Neurourol. Urodyn.
PUBLISHED: 04-24-2014
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Abnormalities of external anal sphincter electromyography (EAS-EMG) characterize multiple system atrophy (MSA) and focal cauda equina or conus medullaris lesions. This study is designed to determine whether and how diabetic polyneuropathy (DPN) affects EAS as compared to the abnormalities seen in MSA.
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[Follow-up assessment of "Technical specifications for occupational health surveillance"].
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi
PUBLISHED: 04-24-2014
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To investigate the possession of occupational health examination qualification among occupational health examination institutions in Zhejiang province, China and the application of GBZ188-2007 "Technical specifications for occupational health surveillance" among related government departments, and to provide a basis for revising and improving the specifications.
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Intussusception after monovalent human rotavirus vaccine in australia: severity and comparison of using healthcare database records versus case confirmation to assess risk.
Pediatr. Infect. Dis. J.
PUBLISHED: 04-23-2014
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Surveillance for intussusception (IS) has been recommended in countries using rotavirus vaccine, but can be resource intensive. There is little data about the relative severity of rotavirus vaccine-associated IS compared with other IS cases. We collected detailed clinical data on all cases to evaluate the validity of ICD coding for IS in routinely collected data and case severity.
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Lactobionic acid-modified dendrimer-entrapped gold nanoparticles for targeted computed tomography imaging of human hepatocellular carcinoma.
ACS Appl Mater Interfaces
PUBLISHED: 04-18-2014
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Development of novel nanomaterial-based contrast agents for targeted computed tomography (CT) imaging of tumors still remains a great challenge. Here we describe a novel approach to fabricating lactobionic acid (LA)-modified dendrimer-entrapped gold nanoparticles (LA-Au DENPs) for in vitro and in vivo targeted CT imaging of human hepatocellular carcinoma. In this study, amine-terminated poly(amidoamine) dendrimers of generation 5 pre-modified with fluorescein isothiocyanate and poly(ethylene glycol)-linked LA were employed as templates to form Au nanoparticles. The remaining dendrimer terminal amines were subjected to an acetylation reaction to form LA-Au DENPs. The prepared LA-Au DENPs were characterized via different methods. Our results reveal that the multifunctional Au DENPs with a Au core size of 2.7 nm have good stability under different pH (5-8) and temperature (4-50 °C) conditions and in different aqueous media, and are noncytotoxic to normal cells but cytotoxic to the targeted hepatocarcinoma cells in the given concentration range. In vitro flow cytometry data show that the LA-Au DENPs can be specifically uptaken by a model hepatocarcinoma cell line overexpressing asialoglycoprotein receptors through an active receptor-mediated targeting pathway. Importantly, the LA-Au DENPs can be used as a highly effective nanoprobe for specific CT imaging of hepatocarcinoma cells in vitro and the xenoplanted tumor model in vivo. The developed LA-Au DENPs with X-ray attenuation property greater than clinically employed iodine-based CT contrast agents hold a great promise to be used as a nanoprobe for targeted CT imaging of human hepatocellular carcinoma.
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Adiponectin regulates SR Ca(2+) cycling following ischemia/reperfusion via sphingosine 1-phosphate-CaMKII signaling in mice.
J. Mol. Cell. Cardiol.
PUBLISHED: 04-15-2014
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The adipocyte-secreted hormone adiponectin (APN) exerts protective effects on the heart under stress conditions. Recent studies have demonstrated that APN induces a marked Ca(2+) influx in skeletal muscle. However, whether APN modulates [Ca(2+)]i activity, especially [Ca(2+)]i transients in cardiomyocytes, is still unknown. This study was designed to determine whether APN modulates [Ca(2+)]i transients in cardiomyocytes. Adult male wild-type (WT) and APN knockout (APN KO) mice were subjected to myocardial ischemia/reperfusion (I/R, 30min/30min) injury. CaMKII-PLB phosphorylation and SR Ca(2+)-ATPase (SERCA2) activity were downregulated in I/R hearts of WT mice and further decreased in those of APN KO mice. Both the globular domain of APN and full-length APN significantly reversed the decrease in CaMKII-PLB phosphorylation and SERCA2 activity in WT and APN KO mice. Interestingly, compared with WT littermates, single myocytes isolated from APN KO mice had remarkably decreased [Ca(2+)]i transients, cell shortening, and a prolonged Ca(2+) decay rate. Further examination revealed that APN enhances SERCA2 activity via CaMKII-PLB signaling. In in vivo and in vitro experiments, both APN receptor 1/2 and S1P were necessary for the APN-stimulated CaMKII-PLB-SERCA2 activation. In addition, S1P activated CaMKII-PLB signaling in neonatal cardiomyocytes in a dose dependent manner and improved [Ca(2+)]i transients in APN KO myocytes via the S1P receptor (S1PR1/3). Further in vivo experiments revealed that pharmacological inhibition of S1PR1/3 and SERCA2 siRNA suppressed APN-mediated cardioprotection during I/R. These data demonstrate that S1P is a novel regulator of SERCA2 that activates CaMKII-PLB signaling and mediates APN-induced cardioprotection.
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[Complicated effects of Gfi-1 on proliferation and apoptosis of murine 32D cells].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 04-12-2014
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To explore the relationship between growth factor independence 1 (Gfi-1) and apoptosis as well as proliferation in 32D cell and observe the effects of Gfi-1 and N382S on 32D cell so as to further explore its possible mechanism of apoptosis and proliferation in hemopoietic stem cells.
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The association between smokeless tobacco use and pancreatic adenocarcinoma: A systematic review.
Cancer Epidemiol
PUBLISHED: 04-05-2014
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Smokeless tobacco is a possible risk factor for developing pancreatic adenocarcinoma. This systematic review addressed the question: Is there an association between smokeless tobacco use and pancreatic adenocarcinoma diagnosis?
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High-nuclearity silver(I) cluster-based coordination polymers assembled with multidentate oligo-?-heteroarylsulfanyl ligands.
Dalton Trans
PUBLISHED: 03-31-2014
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Two novel coordination polymers [Ag16(SO4)8][Ag4(SO4)2]3(L1)12·nH2O (n = 72) (1) and [Ag10(SO4)5(L2)4(H2O)2]·8H2O (2) based on conformationally variable oligo-?-heteroarylsulfanyl ligands 2-(pyrazin-2-ylthio)-6-(pyridin-2-ylthio)pyrazine (L1) or 2,6-bis(pyrazin-2-ylthio)pyrazine (L2) and sulfate-templated high-nuclearity Ag(I) clusters as structure-building units (SBUs) have been synthesized under mild conditions. Single-crystal X-ray analysis showed that complex 1 exhibits a porous three-dimensional framework containing Ag16(SO4)8 and Ag4(SO4)2 SBUs that are interconnected by L1 ligands, whereas 2 has a much denser network constructed from Ag10(SO4)5 SBUs and L2 linkers. To our knowledge, the Ag16(SO4)8 cluster core found in 1 is the largest sulfate-based polynuclear SBU in coordination polymers, and the 14-connected Ag10(SO4)5 in 2 is the highest-connectivity Ag(I) cluster SBU reported to date. These two complexes were fully characterized by infrared spectroscopy, elemental analysis, powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry.
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Photochemical properties and source of pollutants during continuous pollution episodes in Beijing, October, 2011.
J Environ Sci (China)
PUBLISHED: 03-22-2014
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Beijing suffered from serious air pollution in October, 2011 with the occurrence of three continuous episodes. Here we analyze the pollution status of particulate matter, the relationship between the gaseous pollutants, physical and chemical properties of single particles, and the profile of water-soluble ions in PM2.5 during the three episodes. Regional and photochemically aged air masses, which were characterized as having high values of O3 and SO2, were hypothesized to have played a dominant role in the first episode. After mixing local air masses with freshly-emitted primary pollutants, the concentration of NO(x) continued to increase and the size of SO4(2-), NO3(-) and NH4(+) in the particle population continued to become smaller. The amount of elemental carbon-rich and organic carbon-rich particles in the scaled single particles (0.2-2 microm) and water-soluble K(+) in PM2.5 also increased in the episodes. All the available information suggests that the biomass or fuel burning sources in or around Beijing may have had a huge impact on the last two episodes.
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Synthesis of PEGylated low generation dendrimer-entrapped gold nanoparticles for CT imaging applications.
Nanoscale
PUBLISHED: 03-21-2014
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Dendrimer-entrapped gold nanoparticles (Au DENPs) can be formed using low-generation dendrimers pre-modified by polyethylene glycol (PEG). The formed PEGylated Au DENPs with desirable stability, cytocompatibility, and X-ray attenuation properties enable efficient computed tomography imaging of the heart and tumor model of mice.
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Heme acts through the Bach1b/Nrf2a-MafK pathway to regulate exocrine peptidase precursor genes in porphyric zebrafish.
Dis Model Mech
PUBLISHED: 03-20-2014
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Using a zebrafish model of hepatoerythropoietic porphyria (HEP), we identify a previously unknown mechanism underlying heme-mediated regulation of exocrine zymogens. Zebrafish bach1b, nrf2a and mafK are all expressed in the zebrafish exocrine pancreas. Overexpression of bach1b or knockdown of nrf2a result in the downregulation of the expression of the exocrine zymogens, whereas overexpression of nrf2a or knockdown of bach1b cause their upregulation. In vitro luciferase assays demonstrate that heme activates the zymogens in a dosage-dependent manner and that the zymogen promoter activities require the integral Maf recognition element (MARE) motif. The Bach1b-MafK heterodimer represses the zymogen promoters, whereas the Nrf2a-MafK heterodimer activates them. Furthermore, chromatin immunoprecipitation (ChIP) assays show that MafK binds to the MARE sites in the 5' regulatory regions of the zymogens. Taken together, these data indicate that heme stimulates the exchange of Bach1b for Nrf2a at MafK-occupied MARE sites and that, particularly in heme-deficient porphyria, the repressive Bach1b-MafK heterodimer dominates, which can be exchanged for the activating Nrf2a-MafK heterodimer upon treatment with hemin. These results provide novel insights into the regulation of exocrine function, as well as the pathogenesis of porphyria, and should be useful for designing new therapies for both types of disease.
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Mitochondrial translocation of Nur77 induced by ROS contributed to cardiomyocyte apoptosis in metabolic syndrome.
Biochem. Biophys. Res. Commun.
PUBLISHED: 03-13-2014
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Metabolic syndrome is a major risk factor for cardiovascular diseases, and increased cardiomyocyte apoptosis which contributes to cardiac dysfunction after myocardial ischemia/reperfusion (MI/R) injury. Nur77, a nuclear orphan receptor, is involved in such various cellular events as apoptosis, proliferation, and glucose and lipid metabolism in several cell types. Apoptosis is positively correlated with mitochondrial translocation of Nur77 in the cancer cells. However, the roles of Nur77 on cardiac myocytes in patients with metabolic syndrome remain unclear. The objective of this study was to determine whether Nur77 may contribute to cardiac apoptosis in patients with metabolic syndrome after I/R injury, and, if so, to identify the underlying molecular mechanisms responsible. We used leptin-deficient (ob/ob) mice to make metabolic syndrome models. In this report, we observed that, accompanied by the substantial decline in apoptosis inducer Nur77, MI/R induced cardiac dysfunction was manifested as cardiomyopathy and increased ROS. Using the neonatal rat cardiac myocytes cultured in a high-glucose and high-fat medium, we found that excessive H2O2 led to the significant alteration in mitochondrial membrane potential and translocation of Nur77 from the nucleus to the mitochondria. However, inhibition of the relocation of Nur77 to mitochondria via Cyclosporin A reversed the changes in membrane potential mediated by H2O2 and reduced myocardial cell injury. Therefore, these data provide a potential underlying mechanism for cardiac dysfunction in metabolic syndrome and the suppression of Nur77 translocation may provide an effective approach to reduce cardiac injury in the process.
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Family-based association study of ZNF533, DOCK4 and IMMP2L gene polymorphisms linked to autism in a northeastern Chinese Han population.
J Zhejiang Univ Sci B
PUBLISHED: 03-07-2014
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A study in a Caucasian population has identified two single-nucleotide polymorphisms (SNPs) in ZNF533, one in DOCK4, and two in IMMP2L, which were all significantly associated with autism. They are located in AUTS1 and AUTS5, which have been identified as autism susceptibility loci in several genome-wide screens. The present study aimed to investigate whether ZNF533, DOCK4, and IMMP2L genes are also associated with autism in a northeastern Chinese Han population.
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Melaminivora alkalimesophila gen. nov., sp. nov., a melamine-degrading betaproteobacterium isolated from a melamine-producing factory.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 03-03-2014
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A taxonomic study was carried out on strain CY1(T), which is a novel bacterium isolated from wastewater sludge of a melamine-producing factory in Sanming city, Fujian, China. Strain CY1(T) was shown to rapidly and completely degrade melamine to NH3 and CO2 under aerobic conditions. The isolate was Gram-stain-negative, short-rod-shaped and motile by one unipolar flagellum. Growth was observed at salinities from 0 to 7% NaCl (optimum, 0.1%), at temperatures from 15 to 50 °C (optimum, 40-45 °C) and at pH 7-9.5 (optimum pH 9.5). Quinone-8 was detected as the major respiratory quinone. 16S rRNA gene sequence comparisons showed that strain CY1(T) was affiliated to the family Comamonadaceae in the class Betaproteobacteria. It was most closely related to members of the genera Alicycliphilus (95.5%), Diaphorobacter (94.6-95.1%), Acidovorax (92.9-95.4%), Delftia (93.0-93.6%) and Comamonas (92.6-93.9%). The average nucleotide identity (ANI) values between strain CY1(T) and those representing related genera ranged from 84.0 to 86.1% using Mummer, and from 74.9 to 81.1% using BLAST. The dominant fatty acids were C(16?:?1)?7c and/or C(16?:?1)?6c, C(16?:?0), C(10?:?0) 3-OH and C(18?:?1)?7c and/or C(18?:?1)?6c, and the major polar lipids consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid and one unidentified aminophospholipid. The G+C content of the chromosomal DNA was 69.5 mol%. On the basis of the phenotypic and phylogenetic data, strain CY1(T) represents a novel species of a new genus, for which the name Melaminivora alkalimesophila gen. nov., sp. nov. is proposed. The type strain of Melaminivora alkalimesophila is CY1(T) (?=?CCTCC AB 2012024(T)?=?DSM 26006(T)).
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Development of bivalent oleanane-type triterpenes as potent HCV entry inhibitors.
Eur J Med Chem
PUBLISHED: 02-24-2014
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The development of entry inhibitors is an emerging approach to the prevention and reduction of HCV infection. Starting from echinocystic acid (EA), a ?M HCV entry inhibitor, we have developed a series of bivalent oleanane-type triterpenes which, upon optimization of the length, rigidity and hydrophobicity of the linker, exert dramatically potent enhancement of inhibition with IC50 values extending into the nM level. This study establishes the importance of triterpene natural products as new leads in the development of potential HCV entry inhibitors.
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Rediscovering black phosphorus as an anisotropic layered material for optoelectronics and electronics.
Nat Commun
PUBLISHED: 02-21-2014
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Graphene and transition metal dichalcogenides (TMDCs) are the two major types of layered materials under intensive investigation. However, the zero-bandgap nature of graphene and the relatively low mobility in TMDCs limit their applications. Here we reintroduce black phosphorus (BP), the most stable allotrope of phosphorus with strong intrinsic in-plane anisotropy, to the layered-material family. For 15-nm-thick BP, we measure a Hall mobility of 1,000 and 600 cm(2)V(-1)s(-1) for holes along the light (x) and heavy (y) effective mass directions at 120 K. BP thin films also exhibit large and anisotropic in-plane optical conductivity from 2 to 5 ?m. Field-effect transistors using 5 nm BP along x direction exhibit an on-off current ratio exceeding 10(5), a field-effect mobility of 205 cm(2)V(-1)s(-1), and good current saturation characteristics all at room temperature. BP shows great potential for thin-film electronics, infrared optoelectronics and novel devices in which anisotropic properties are desirable.
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Synthesis and anti-HCV entry activity studies of ?-cyclodextrin-pentacyclic triterpene conjugates.
ChemMedChem
PUBLISHED: 02-19-2014
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In our previous studies, oleanolic acid (OA) and echinocystic acid (EA), isolated from Dipsacus asperoides, were found to have anti-HCV entry properties. The major issue for members of this type of triterpene is their low water solubility. In this study, a series of new water-soluble triazole-bridged ?-cyclodextrin (CD)-pentacyclic triterpene conjugates were synthesized via click chemistry. Thanks to the attached ?-CD moiety, all synthesized conjugates showed lower hydrophobicity (Alog?P) than their parent compounds. Several conjugates exhibited moderate anti-HCV entry activity. With the exception of per-O-methylated ?-CD-pentacyclic triterpene conjugates, all other conjugates showed no cytotoxicity based on an alamarBlue assay carried out with HeLa, HepG2, MDCK, and 293T cells. More interestingly, the hemolytic activity of these conjugates disappeared upon the introduction of ?-CDs. Easy access to such conjugates that combine the properties of ?-CD and pentacyclic triterpenes may provide a way to obtain a new class of anti-HCV entry inhibitors.
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Increased gap density predicts weakness of the epithelial barrier in vivo by confocal laser endomicroscopy in indomethacin-induced enteropathy.
Dig. Dis. Sci.
PUBLISHED: 02-11-2014
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The intestinal epithelial barrier plays an important role in the pathogenesis of non-steroidal anti-inflammatory drug-induced enteropathy, and its disruption is often associated with increased cell shedding. The purpose of this report is to observe the gap density in indomethacin-induced small intestinal damage by confocal laser endomicroscopy (CLE) and to investigate the mechanisms involved in this process and how mucosal protectants improve intestinal epithelial barrier dysfunction. CLE is expected to provide a new way for evaluating non-steroidal anti-inflammatory drugs-induced enteropathy in humans and assessing drug efficacy.
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Intrabiliary RF heat-enhanced local chemotherapy of a cholangiocarcinoma cell line: monitoring with dual-modality imaging--preclinical study.
Radiology
PUBLISHED: 01-30-2014
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To determine whether magnetic resonance (MR) imaging heating guidewire-mediated radiofrequency (RF) hyperthermia could enhance the therapeutic effect of gemcitabine and 5-fluorouracil (5-FU) in a cholangiocarcinoma cell line and local deposit doses of chemotherapeutic drugs in swine common bile duct (CBD) walls.
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Hyperlipidaemia impairs the circadian clock and physiological homeostasis of vascular smooth muscle cells via the suppression of Smarcd1.
J. Pathol.
PUBLISHED: 01-25-2014
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Many mammalian physiological processes show diurnal oscillation and are controlled by a circadian clock. Disruption of the circadian clock has been implicated in the pathogenesis of cardiovascular disorders, but the mechanism through which clock and vessel function are integrated is unclear. Here we show that the rhythmicity of key clock genes and Smarcd1, a member of the SWI/SNF chromatin remodelling complex family, is suppressed in the layer of vascular smooth muscle cells (VSMCs) of the thoracic aorta of hyperlipidaemic rats fed a high-fat diet (HFD). Smarcd1 stimulates the transcription of clock genes, notably bmal1, through co-activation of the nuclear orphan receptor ROR? in VSMCs. The co-activation of Smarcd1 and ROR? is dependent on the mediation of PGC-1?, a transcriptional co-activator. Pathophysiologically, Smarcd1 inhibits VSMC proliferation and migration by blocking cell cycle re-entry and via the activation of kinase signalling pathways. Our results demonstrate that Smarcd1 is a critical node integrating the circadian clock and VSMC physiological homeostasis.
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IL-1?-induced activation of p38 promotes metastasis in gastric adenocarcinoma via upregulation of AP-1/c-fos, MMP2 and MMP9.
Mol. Cancer
PUBLISHED: 01-21-2014
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Interleukin-1? (IL-1?) has been implicated in the progression of gastric adenocarcinoma (GA); however, the molecular mechanisms of action of IL-1? in GA are poorly characterized. P38 and JNK are the major MAPK family members that regulate IL-1? signaling pathways. Here, we investigated the role of both p38 and JNK in IL-1?-induced GA cell migration, invasion and metastatic potential.
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Dorsal hippocampal brain receptor complexes linked to the protein synthesis-dependent late phase (LTP) in the rat.
Brain Struct Funct
PUBLISHED: 01-18-2014
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In order to link major brain receptor complex levels to in vivo electrically induced LTP, a bipolar stimulation electrode was chronically implanted into the perforant path, while two monopolar recording electrodes were implanted into the dentate gyrus of the dorsal hippocampus. The recording electrode was measuring extracellular excitatory postsynaptic potentials, while the other one measured population spikes. Immunoblotting of native receptor proteins was carried out in the DH based upon blue-native gel electrophoresis and immunoprecipitation followed by mass spectrometrical identification of the NR1-GluA1-GluA2 complex was used to provide evidence for complex formation. The induction of LTP in DH was proven and NMDA receptor complex levels containing NR1, GluA1, GluA2 and GluA3 were modulated by LTP induction. The LTP-associated changes of receptor complex levels may indicate concerted action, interaction and represent a pattern of major brain receptor complexes in the DH following electrical induction of LTP in the rat.
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Electronic transport and device prospects of monolayer molybdenum disulphide grown by chemical vapour deposition.
Nat Commun
PUBLISHED: 01-18-2014
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Layered transition metal dichalcogenides display a wide range of attractive physical and chemical properties and are potentially important for various device applications. Here we report the electronic transport and device properties of monolayer molybdenum disulphide grown by chemical vapour deposition. We show that these devices have the potential to suppress short channel effects and have high critical breakdown electric field. However, our study reveals that the electronic properties of these devices are at present severely limited by the presence of a significant amount of band tail trapping states. Through capacitance and ac conductance measurements, we systematically quantify the density-of-states and response time of these states. Because of the large amount of trapped charges, the measured effective mobility also leads to a large underestimation of the true band mobility and the potential of the material. Continual engineering efforts on improving the sample quality are needed for its potential applications.
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Left ventricular diastolic dysfunction in patients with dermatomyositis without clinically evident cardiovascular disease.
J. Rheumatol.
PUBLISHED: 01-15-2014
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To assess left ventricular (LV) diastolic function in patients with dermatomyositis (DM) without clinically evident cardiovascular (CV) disease and to estimate whether there is an association between the duration of DM and LV diastolic dysfunction (LVDD).
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Is there a third order phase transition for supercritical fluids?
J Chem Phys
PUBLISHED: 01-14-2014
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We prove that according to Molecular Dynamics (MD) simulations of liquid mixtures of Lennard-Jones (L-J) particles, there is no third order phase transition in the supercritical regime beyond Andrew's critical point. This result is in open contrast with recent theoretical studies and experiments which instead suggest not only its existence but also its universality regarding the chemical nature of the fluid. We argue that our results are solid enough to go beyond the limitations of MD and the generic character of L-J models, thus suggesting a rather smooth liquid-vapor thermodynamic behavior of fluids in supercritical regime.
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Neutrophil-to-Lymphocyte Ratio Positively Correlates to Age in Healthy Population.
J. Clin. Lab. Anal.
PUBLISHED: 01-12-2014
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Neutrophil to lymphocyte ratio (NLR) was reported to be an independent easy-to-measure marker for many diseases, while the distribution of NLR in healthy population was not formally studied. So we investigated NLR in healthy people in this study.
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Therapeutic effect of deferoxamine on iron overload-induced inhibition of osteogenesis in a zebrafish model.
Calcif. Tissue Int.
PUBLISHED: 01-12-2014
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Osteoporosis results from an imbalance in bone remodeling, in which osteoclastic bone resorption exceeds osteoblastic bone formation. Iron has recently been recognized as an independent risk factor for osteoporosis. Reportedly, excess iron could promote osteoclast differentiation and bone resorption through the production of reactive oxygen species (ROS). We evaluated the effect of iron on osteoblast differentiation and bone formation in zebrafish and further investigated the potential benefits of deferoxamine (DFO), a powerful iron chelator, in iron-overloaded zebrafish. The zebrafish model of iron overload described in this study demonstrated an apparent inhibition of bone formation, accompanied by decreased expression of osteoblast-specific genes (runx2a, runx2b, osteocalcin, osteopontin, ALP, and collagen type I). The negative effect of iron on osteoblastic activity and bone formation could be attributed to increased ROS generation and oxidative stress. Most importantly, we revealed that DFO was capable of removing whole-body iron and attenuating oxidative stress in iron-overloaded larval zebrafish, which facilitated larval recovery from the reductions in bone formation and osteogenesis induced by iron overload.
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Adsorption of phthalic acid esters (PAEs) by amphiphilic polypropylene nonwoven from aqueous solution: the study of hydrophilic and hydrophobic microdomain.
J. Hazard. Mater.
PUBLISHED: 01-10-2014
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A kind of amphiphilic polypropylene nonwoven with hydrophilic and hydrophobic microdomain was prepared through electron beam induced graft polymerization and subsequent ring opening reaction and then utilized in the adsorption of phthalic acid esters (PAEs). To elucidate the superiority of such amphiphilic microdomain, a unique structure without hydrophilic part was constructed as comparison. In addition, the adsorption behaviors including adsorption kinetics, isotherms and pH effect were systematically investigated. The result indicated that the amphiphilic structure and the synergy between hydrophilic and hydrophobic microdomain could considerably improve the adsorption capacities, rate and affinity. Particularly the existence of hydrophilic microdomain could reduce the diffusion resistance and energy barrier in the adsorption process. These adsorption results showed that the amphiphilic PP nonwoven have the potential to be used in environmental application.
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Microfluidic acoustophoretic force based low-concentration oil separation and detection from the environment.
Lab Chip
PUBLISHED: 01-10-2014
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Detecting and quantifying extremely low concentrations of oil from the environment have broad applications in oil spill monitoring in ocean and coastal areas as well as in oil leakage monitoring on land. Currently available methods for low-concentration oil detection are bulky or costly with limited sensitivities. Thus they are difficult to be used as portable and field-deployable detectors in the case of oil spills or for monitoring the long-term effects of dispersed oil on marine and coastal ecosystems. Here, we present a low-concentration oil droplet trapping and detection microfluidic system based on the acoustophoresis phenomenon where oil droplets in water having a negative acoustic contrast factor move towards acoustic pressure anti-nodes. By trapping oil droplets from water samples flowing through a microfluidic channel, even very low concentrations of oil droplets can be concentrated to a detectable level for further analyses, which is a significant improvement over currently available oil detection systems. Oil droplets in water were successfully trapped and accumulated in a circular acoustophoretic trapping chamber of the microfluidic device and detected using a custom-built compact fluorescent detector based on the natural fluorescence of the trapped crude oil droplets. After the on-line detection, crude oil droplets released from the trapping chamber were successfully separated into a collection outlet by acoustophoretic force for further off-chip analyses. The developed microfluidic system provides a new way of trapping, detecting, and separating low-concentration crude oil from environmental water samples and holds promise as a low-cost field-deployable oil detector with extremely high sensitivity. The microfluidic system and operation principle are expected to be utilized in a wide range of applications where separating, concentrating, and detecting small particles having a negative acoustic contrast factor are required.
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The value of magnetic resonance imaging in the detection of prostate cancer in patients with previous negative biopsies and elevated prostate-specific antigen levels: a meta-analysis.
Acad Radiol
PUBLISHED: 01-07-2014
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To assess the diagnostic performance of magnetic resonance imaging (MRI) for targeting prostate cancer in patients with previous negative biopsies and elevated prostate-specific antigen (PSA) levels.
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Could abiotic stress tolerance in wild relatives of rice be used to improve Oryza sativa?
Plant Sci.
PUBLISHED: 01-07-2014
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Oryza sativa and Oryza glaberrima have been selected to acquire and partition resources efficiently as part of the process of domestication. However, genetic diversity in cultivated rice is limited compared to wild Oryza species, in spite of 120,000 genotypes being held in gene banks. By contrast, there is untapped diversity in the more than 20 wild species of Oryza, some having been collected from just a few coastal locations (e.g. Oryza schlechteri), while others are widely distributed (e.g. Oryza nivara and Oryza rufipogon). The extent of DNA sequence diversity and phenotypic variation is still being established in wild Oryza, with genetic barriers suggesting a vast range of morphologies and function even within species, such as has been demonstrated for Oryza meridionalis. With increasing climate variability and attempts to make more marginal land arable, abiotic and biotic stresses will be managed over the coming decades by tapping into the genetic diversity of wild relatives of O. sativa. To help create a more targeted approach to sourcing wild rice germplasm for abiotic stress tolerance, we have created a climate distribution map by plotting the natural occurrence of all Oryza species against corresponding temperature and moisture data. We then discuss interspecific variation in phenotype and its significance for rice, followed by a discussion of ways to integrate germplasm from wild relatives into domesticated rice.
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Inpatient survival after gastrectomy for gastric cancer in the 21st century.
J. Surg. Res.
PUBLISHED: 01-04-2014
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Surgical treatment for gastric cancer has evolved substantially. To understand how changes in patient- and hospital-level factors are associated with outcomes over the last decade, we examined a nationally representative sample.
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US emergency department visits for fireworks injuries, 2006-2010.
J. Surg. Res.
PUBLISHED: 01-03-2014
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Most literature regarding fireworks injuries are from outside the United States, whereas US-based reports focus primarily on children and are based on datasets which cannot provide accurate estimates for subgroups of the US population.
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Biodegradation of high concentrations of halomethanes by a fermentative enrichment culture.
AMB Express
PUBLISHED: 01-01-2014
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A fermentative enrichment culture (designated DHM-1) that grows on corn syrup was evaluated for its ability to cometabolically biodegrade high concentrations of chloroform (CF), carbon tetrachloride (CT), and trichlorofluoromethane (CFC-11). When provided with corn syrup and vitamin B12 (0.03 mol B12 per mol CF), DHM-1 grew and biodegraded up to 2,000 mg/L of CF in 180 days, with only minor transient accumulation of dichloromethane and chloromethane. CT (15 mg/L) and CFC-11 (25 mg/L) were also biodegraded without significant accumulation of halomethane daughter products. The rate of CF biodegradation followed a Michaelis-Menten-like pattern with respect to the B12 concentration; one-half the maximum rate (66 mg CF/L/d) occurred at 0.005 mol B12 per mol CF. DHM-1 was able to biodegrade 500 mg/L of CF at an inoculum level as low as 10(-8) mg protein/L. The highest rate of CF biodegradation occurred at pH 7.7; activity decreased substantially below pH 6.0. DHM-1 biodegraded mixtures of CT, CFC-11, and CF, although CFC-11 inhibited CF biodegradation. Evidence for compete defluorination of CFC-11 was obtained based on a fluoride mass balance. Overall, the results suggest that DHM-1 may be effective for bioaugmentation in source zones contaminated with thousands of milligrams per liter of CF and tens of milligrams per liter of CT and CFC-11.
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Adult-Onset Still's Disease Associated with Thyroid Dysfunction: Case Report and Review of the Literature.
Open Rheumatol J
PUBLISHED: 01-01-2014
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To our knowledge, the possible unveiled interaction between adult-onset Still's disease (AOSD) with autoimmune thyroid disease (AITD) has never been reported although it is well established that systemic autoimmune disease may usually occur in relation to AITD. As increasingly clear links of AITD with other autoimmune disease such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and primary Sjögren's syndrome (pSS) have been reported, and the incidence of AOSD concurrent AITD draws our attention rapidly. In this study, we searched relevant literatures published in the past 30 years to explore that condition.
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Rhinitis symptoms and asthma among parents of preschool children in relation to the home environment in Chongqing, China.
PLoS ONE
PUBLISHED: 01-01-2014
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Risk factors for rhinitis and asthma in the home environment were studied by a questionnaire survey. Parents of 4530 1-8 year old children (one parent per child) from randomly selected kindergartens in Chongqing, China participated. 70.4% were females; 47.1% had rhinitis symptoms in the last three months (current rhinitis, CR); 1.6% reported a history of allergic asthma (AA); 2.7% reported a history of allergic rhinitis (AR); 16.4% were current smokers; 50.8% males and 2.4% females were current smokers. Stuffy odor, unpleasant odor, tobacco smoke odor and dry air were associated with CR (adjustment for gender, current smoking and other perceptions of odor or humidity). Associations between home environment and CR, AR, and AA were studied by multiple logistic regression analyses, adjusting for gender, current smoking and other significant home factors. Living near a main road or highway was a risk factor for both CR (OR(95%CI): 1.31(1.13,1.52)) and AR (OR(95%CI): 2.44(1.48,4.03)). Other risk factors for CR included living in rural areas (OR(95%CI): 1.43(1.10,1.85)), new furniture (OR(95%CI): 1.28(1.11,1.49)), water damage (OR(95%CI): 1.68(1.29,2.18)), cockroaches (OR(95%CI): 1.46(1.23,1.73)), and keeping pets (OR(95%CI): 1.24(1.04,1.49)). Other risk factors for AR included redecoration (OR(95%CI): 2.14(1.34,3.41)), mold spots (OR(95%CI): 2.23(1.06,4.68)), window pane condensation (OR(95%CI): 2.04(1.28,3.26)). Water damage was the only home factor associated with AA (2.56(1.34,4.86)). Frequently put bedding to sunshine was protective for CR (OR(95%CI): 0.79(0.68,0.92); cleaning every day was protective for AR (OR(95%CI): 0.40(0.22,0.71)). In conclusion, parents' CR and AR were related to a number of factors of the home environment.
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Altered lipid levels in untreated patients with early polymyositis.
PLoS ONE
PUBLISHED: 01-01-2014
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Little is known so far on the lipid profile in polymyositis (PM) patients. Our aim is to identify lipid profiles in untreated patients with early PM, to assess the association between lipid profiles and C-reactive protein (a sensitive marker of inflammation) in these patients.
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[Research on allelopathic effects of phellamurine].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 12-31-2013
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Conducted research on new allelochemicals phellamurine extracted from deciduous of Phellodendron amurense, which worked in allelopathy effect to seed germination and growth process of P. amurense and P. chinense in order to interpret the causes of rare seedlings of wild populations of P. amurense. Extracted and separated phellamurine from P. amurense deciduous, and treated the seeds of P. amurense and P. chinense in after-ripening stage and germination stage with different concentrations of phellamurine solution, then detection of the seed germination rate, germination index, seedling height, root length and seed vigor index to evaluate the allelopathic effect of phellamurine. The results show that: phellamurine solution at 0.30 g x L(-1) produce significant inhibition to seed after-ripening of P. amurense, and also the solution at 0.15 g x L(-1) produce significant inhibition to seeds germination of P. amurense; the solution at 0.15 g x L(-1) produce significant inhibition to seeds after-ripening and seeds germination of P. chinense, inhibition intensity increased with the concentration and enhanced. For both species, the presence of phellamurine can lower the seed germination rate, extend the germination time, reduce the ability of seedlings to adapt to the environment, thus the phellamurine may be one of the causes of rare seedlings in the wild population of P. amurense.
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3-(3-Methyl-phen-yl)-5-(quinolin-8-yl-meth-oxy)-1,2,4-oxa-diazole monohydrate.
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 10-01-2013
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In the title compound, C19H15N3O2·H2O, the oxa-diazole ring and the quinoline unit are almost coplanar, making a dihedral angle of 7.66?(8)°. The dihedral angle between the benzene ring and the quinoline system is 25.95?(8)° while that between the benzene and the oxa-diazole rings is 18.88?(9)°. The water mol-ecule is hydrogen bonded to an oxa-diazole N atom and to the quinoline N atom. In the crystal, these units are linked via C-H?O hydrogen bonds, forming two-dimensional net-works lying parallel to the ab plane.
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[Expression of hippocampus Klotho protein and insulin-like growth factor-1 in rats with dementia].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 09-25-2013
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This study aims to assess the expression of Klotho and insulin-like growth factor-1 (IGF-1) and the association between Klotho and IGF-1 in rats with dementia model. Thirty rats were randomly divided into three groups. Morris water maze was used to investigate the learning and memory functions, and enzyme linked immunosorbent assay was used to analyze the levels of Klotho and IGF-1. Klotho and IGF-1 levels in the model group were lower than those in other 2 groups. Morris water maze test showed that the model group had longer escape latency times and shorter step platform times compared to other groups. Line correlation model demonstrated that Klotho level was positively correlated with IGF-1 level in rats with dementia (P= 0. 029). The levels of Klotho and IGF-1 both reduced at hippocampus in rats with dementia model, suggesting that it may be a close relationship between Klotho and IGF-1 in the pathogenesis of dementia.
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Characterization of a novel melamine-degrading bacterium isolated from a melamine-manufacturing factory in China.
Appl. Microbiol. Biotechnol.
PUBLISHED: 09-08-2013
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Melamine (2,4,6-triamino-1,3,5-triazine, C3H6N6), belonging to the s-triazine family, is an anthropogenic and versatile raw material for a large number of consumer products and its extensive use has resulted in the contamination of melamine in the environment. A novel melamine-degrading bacterium strain CY1 was isolated from a melamine-manufacturing factory in China. The strain is phylogenetically different from the known melamine-degrading bacteria. Approximately, 94 % melamine (initial melamine concentration 4.0 mM, initial cell OD 0.05) was degraded in 10 days without the addition of additional carbon source. High-performance liquid chromatography showed the production of degradation intermediates including ammeline, ammelide, cyanuric acid, biuret, and urea. Kinetic simulation analysis indicated that transformation of urea into ammonia was the rate-limiting step for the degradation process. The melamine-cyanurate complex was formed due to self-assembly of melamine and cyanuric acid during the degradation. The tracking experiment using CY1 cells and (13)C3-melamine showed that the CY1 could mineralize s-triazine ring carbon to CO2. The strain CY1 could also catalyze partial transformation of cyromazine, a cyclopropyl derivative of melamine, to 6-(cyclopropylamino)-[1,3,5]triazine-2,4-diol.
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PKA controls calcium influx into motor neurons during a rhythmic behavior.
PLoS Genet.
PUBLISHED: 09-01-2013
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Cyclic adenosine monophosphate (cAMP) has been implicated in the execution of diverse rhythmic behaviors, but how cAMP functions in neurons to generate behavioral outputs remains unclear. During the defecation motor program in C. elegans, a peptide released from the pacemaker (the intestine) rhythmically excites the GABAergic neurons that control enteric muscle contractions by activating a G protein-coupled receptor (GPCR) signaling pathway that is dependent on cAMP. Here, we show that the C. elegans PKA catalytic subunit, KIN-1, is the sole cAMP target in this pathway and that PKA is essential for enteric muscle contractions. Genetic analysis using cell-specific expression of dominant negative or constitutively active PKA transgenes reveals that knockdown of PKA activity in the GABAergic neurons blocks enteric muscle contractions, whereas constitutive PKA activation restores enteric muscle contractions to mutants defective in the peptidergic signaling pathway. Using real-time, in vivo calcium imaging, we find that PKA activity in the GABAergic neurons is essential for the generation of synaptic calcium transients that drive GABA release. In addition, constitutively active PKA increases the duration of calcium transients and causes ectopic calcium transients that can trigger out-of-phase enteric muscle contractions. Finally, we show that the voltage-gated calcium channels UNC-2 and EGL-19, but not CCA-1 function downstream of PKA to promote enteric muscle contractions and rhythmic calcium influx in the GABAergic neurons. Thus, our results suggest that PKA activates neurons during a rhythmic behavior by promoting presynaptic calcium influx through specific voltage-gated calcium channels.
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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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