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Find video protocols related to scientific articles indexed in Pubmed.
Trade-offs of the opto-electrical properties of a-Si:H solar cells based on MOCVD BZO films.
Phys Chem Chem Phys
PUBLISHED: 11-20-2014
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Boron-doped zinc oxide (BZO) films, deposited by metal-organic chemical vapor deposition (MOCVD), have been widely used as front electrodes in thin-film solar cells due to their native pyramidal surface structure, which results in efficient light trapping. This light trapping effect can enhance the short-circuit current density (Jsc) of solar cells. However, nanocracks or voids in the silicon active layer may form when the surface morphology of the BZO is too sharp; this usually leads to degraded electrical properties of the cells, such as open-circuit voltage (Voc) and the fill factor (FF), which in turn decreases efficiency (Eff) [Bailat et al., Photovoltaic Energy Conversion, Conference Record of the 2006 IEEE 4th World Conference on. IEEE, 2006, vol. 2, pp. 1533-1536]. In this paper, an etching and coating method was proposed to modify the sharp "pyramids" on the surface of the BZO films. As a result, an evident enhancement was achieved for these modified, BZO-based cells' Voc, FF, and Eff, although the Jsc exhibited a small decrease. In order to increase the Jsc and maintain the improved electrical properties (Voc, FF) of the cell, a thin BZO coating, deposited by MOCVD, was introduced to coat the sputtering-treated BZO film. Finally, we optimized the trade-off among the Voc, FF, and Jsc, that is, we identified a regime with an increase of the Jsc as well as a further improvement of the other electrical properties.
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Complete Nucleotide Sequence of cfr-carrying IncX4 Plasmid, pSD11, from Escherichia coli.
Antimicrob. Agents Chemother.
PUBLISHED: 11-19-2014
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We report a complete nucleotide sequence of a plasmid carrying the multi-resistance gene cfr. This plasmid was isolated from an Escherichia coli strain of swine origin in 2011. This 37,672-bp plasmid, pSD11, had an IncX4 backbone similar to that of the IncX4 plasmids obtained from the USA and Australia, in which the cfr gene was flanked by two copies of IS26, and a truncated Tn1331 inserted.
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l-Valine derived chiral N-sulfinamides as effective organocatalysts for the asymmetric hydrosilylation of N-alkyl and N-aryl protected ketimines.
Org. Biomol. Chem.
PUBLISHED: 11-08-2014
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l-Valine derived N-sulfinamides have been developed as efficient enantioselective Lewis basic organocatalysts for the asymmetric reduction of N-aryl and N-alkyl ketimines with trichlorosilane. Catalyst afforded up to 99% yield and 96% ee in the reduction of N-alkyl ketimines and up to 98% yield and 98% ee in the reduction of N-aryl ketimines.
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High-Efficiency Plasmon-Enhanced and Graphene-Supported Semiconductor/Metal Core-Satellite Hetero-Nanocrystal Photocatalysts for Visible-Light Dye Photodegradation and H2 Production from Water.
ACS Appl Mater Interfaces
PUBLISHED: 11-05-2014
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Solar-driven photocatalytic process based on electron-hole pair production in semiconductors is a long sought-after solution to a green and renewable energy and has attracted a renaissance of interest recently. The relatively low photocatalytic efficiency, however, is a main obstacle to their practical applications. A promising attempt to solve this problem is by combined use of metal nanoparticles, by taking advantage of strong and localized plasmonic near-field to enhance solar absorption and to increase the electron-hole pair generation rate at the surface of semiconductor. Here, we report a semiconductor/metal visible-light photocatalyst based on CdSe/CdS-Au (QD-Au) core-satellite heteronanocrystals, and assemble them on graphene nanosheets for better photocatalytic reaction. The as-synthesized photocatalyst exhibits excellent plasmon-enhanced photocatalytic activities toward both photodegradation of organic dye and visible-light H2 generation from water. The H2 evolution rate achieves a maximum of 3113 ?mol h(-1) g(-1) for the heteronanocrystal-graphene composites, which is about 155% enhancement compared to nonplasmonic QD-G sample and 340% enhancement compared to control QD-Au-G sample, and the apparent quantum efficiency (QE) reaches to 25.4% at wavelength of 450 nm.
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[Laser microdissection and mass spectrometry based proteomics in the diagnosis of kidney diseases].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 10-28-2014
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In recent years, laser microdissection followed by mass spectrometry (LMD/MS) has been successfully applied to the proteomic studies of formalin-fixed paraffin-embedded (FFPE) renal tissues. This new technique improves the diagnosis of kidney diseases and has a better potential for future clinical application. The review focuses on the use of this methodology for exploring the mechanisms, diagnosis and classification of kidney diseases including renal amyloidosis and membrane proliferative glomerulonephritis.
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[A pilot study of establishing course of professional English on stomatology].
Shanghai Kou Qiang Yi Xue
PUBLISHED: 10-24-2014
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The importance of specialized English on stomatology is becoming more and more significant under the new situation. It used to be focused on vocabulary and literature teaching in the original course of specialized English, which was lack of practicability. Thus, we try to establish a course of professional English on stomatology during the postgraduate stage of the seven-year students in our college, in order to complement the course of specialized English on stomatology and improve the students' practical ability to use specialized English. In this paper, the teaching content and method, teaching materials setting and the feedback from students on the course were discussed and analyzed, in order to lay a foundation for better construction of the course.
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Advances in Techniques for Probing Mechanoregulation of Tissue Morphogenesis.
J Lab Autom
PUBLISHED: 10-22-2014
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Cells process various mechanical cues in the microenvironment to self-organize into high-order architectures during tissue morphogenesis. Impairment of morphogenic processes is the underlying cause of many diseases; as such, understanding the regulatory mechanisms associated with these processes will form the foundation for the development of innovative approaches in cell therapy and tissue engineering. Nevertheless, little is known about how cells collectively respond to mechanical cues in the microenvironment, such as global geometric guidance, local cell-cell interactions, and other physicochemical factors, for the emergence of the structural hierarchy across multiple length scales. To elucidate the mechanoregulation of tissue morphogenesis, numerous approaches based on biochemical, biomaterial, and biophysical techniques have been developed in the past decades. In this review, we summarize techniques and approaches for probing the mechanoregulation of tissue morphogenesis and illustrate their applications in vasculature development. The potential and limitations of these methods are also discussed with a view toward the investigation of a wide spectrum of tissue morphogenic processes.
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?-apo-13-Carotenone Regulates Retinoid X Receptor Transcriptional Activity Through Tetramerization of the Receptor.
J. Biol. Chem.
PUBLISHED: 10-18-2014
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Retinoid X receptor (RXRa) is activated by 9-cis-retinoic acid (9cRA) and regulates transcription as a homodimer or as a heterodimer with other nuclear receptors. We have previously demonstrated that beta-apo-13-carotenone, an eccentric cleavage product of bea-carotene, antagonizes the activation of RXRa by 9cRA in mammalian cells overexpressing this receptor. However, the molecular mechanism of beta-apo-13-carotenone modulation on RXRa transcriptional activity is not understood and is the subject of this report. We performed transactivation assays using full length RXRa and reporter gene constructs (RXRE-Luc) transfected into COS-7 cells and luciferase activity was examined. beta-apo-13-Carotenone was compared with the RXR? antagonist UVI 3003. The results showed that both beta-apo-13-carotenone and UVI 3003 shifted the dose-dependent RXRa activation by 9cRA. In contrast, results of assays using a hybrid Gal4-DBD:RXRa-LBD receptor reporter cell assay that detects 9cRA-induced coactivator binding to the ligand binding domain demonstrated that UVI3003 significantly inhibited 9cRA-induced coactivator binding to RXR?LBD, but beta-apo-13-carotenone did not. However, both beta-apo-13-carotenone and UVI 3003 inhibited 9-cRA induction of caspase 9 gene expression in the mammary carcinoma cell line MCF7. In order to resolve this apparent contradiction we investigated the effect of beta-apo-13-carotenone on the oligomeric state of purified recombinant RXRa LBD. beta-apo-13-carotenone induces tetramerization of the RXRaLBD whereas UVI3003 had no effect on the oligomeric state. These observations suggest that beta-apo-13-carotenone regulates RXRa transcriptional activity through inducing the formation of the transcriptionally silent RXRa tetramer.
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A Randomized, Three-arm Study to Optimize Lamivudine Efficacy in HBeAg Positive Chronic Hepatitis B Patients.
J. Gastroenterol. Hepatol.
PUBLISHED: 10-14-2014
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To compare the efficacy at week 104 of lamivudine monotherapy (MONO), lamivudine plus adefovir dipivoxil (ADV) combination therapy (COMBO), and lamivudine optimization strategy (OPTIMIZE).
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Clinical characteristics of human infection with a novel avian-origin influenza A(H10N8) virus.
Chin. Med. J.
PUBLISHED: 10-01-2014
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Novel influenza A viruses of avian-origin may be the precursors of pandemic strains. This descriptive study aims to introduce a novel avian-origin influenza A (H10N8) virus which can infect humans and cause severe diseases.
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Role of hydrogen plasma pretreatment in improving passivation of the silicon surface for solar cells applications.
ACS Appl Mater Interfaces
PUBLISHED: 08-27-2014
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We have investigated the role of hydrogen plasma pretreatment in promoting silicon surface passivation, in particular examining its effects on modifying the microstructure of the subsequently deposited thin hydrogenated amorphous silicon (a-Si:H) passivation film. We demonstrate that pretreating the silicon surface with hydrogen plasma for 40 s improves the homogeneity and compactness of the a-Si:H film by enhancing precursor diffusion and thus increasing the minority carrier lifetime (?(eff)). However, excessive pretreatment also increases the density of dangling bond defects on the surface due to etching effects of the hydrogen plasma. By varying the duration of hydrogen plasma pretreatment in fabricating silicon heterojunction solar cells based on textured substrates, we also demonstrate that, although the performance of the solar cells shows a similar tendency to that of the ?(eff) on polished wafers, the optimal duration is prolonged owing to the differences in the surface morphology of the substrates. These results suggest that the hydrogen plasma condition must be carefully regulated to achieve the optimal level of surface atomic hydrogen coverage and avoid the generation of defects on the silicon wafer.
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Antioxidant and nitrite-scavenging capacities of phenolic compounds from sugarcane (Saccharum officinarum L.) tops.
Molecules
PUBLISHED: 08-26-2014
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Sugarcane tops were extracted with 50% ethanol and fractionated by petroleum ether, ethyl acetate (EtOAc), and n-butyl alcohol successively. Eight phenolic compounds in EtOAc extracts were purified through silica gel and Sephadex LH-20 column chromatographies, and then identified by nuclear magnetic resonance and electrospray ionization mass spectra. The results showed that eight phenolic compounds from EtOAc extracts were identified as caffeic acid, cis-p-hydroxycinnamic acid, quercetin, apigenin, albanin A, australone A, moracin M, and 5'-geranyl-5,7,2',4'-tetrahydroxyflavone. The antioxidant and nitrite-scavenging capacities of different solvent extracts correlated positively with their total phenolic (TP) contents. Amongst various extracts, EtOAc extracts possessed the highest TP content and presented the strongest oxygen radical absorbance capacity (ORAC), 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging capacity, 2,2'-azobis-3-ethylbenthiaazoline-6-sulfonic acid (ABTS) radical-scavenging capacity, ferric reducing antioxidant power (FRAP) and nitrite-scavenging capacity. Thus, sugarcane tops could be promoted as a source of natural antioxidant.
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Genetic landscape of esophageal squamous cell carcinoma.
Nat. Genet.
PUBLISHED: 08-24-2014
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Esophageal squamous cell carcinoma (ESCC) is one of the deadliest cancers. We performed exome sequencing on 113 tumor-normal pairs, yielding a mean of 82 non-silent mutations per tumor, and 8 cell lines. The mutational profile of ESCC closely resembles those of squamous cell carcinomas of other tissues but differs from that of esophageal adenocarcinoma. Genes involved in cell cycle and apoptosis regulation were mutated in 99% of cases by somatic alterations of TP53 (93%), CCND1 (33%), CDKN2A (20%), NFE2L2 (10%) and RB1 (9%). Histone modifier genes were frequently mutated, including KMT2D (also called MLL2; 19%), KMT2C (MLL3; 6%), KDM6A (7%), EP300 (10%) and CREBBP (6%). EP300 mutations were associated with poor survival. The Hippo and Notch pathways were dysregulated by mutations in FAT1, FAT2, FAT3 or FAT4 (27%) or AJUBA (JUB; 7%) and NOTCH1, NOTCH2 or NOTCH3 (22%) or FBXW7 (5%), respectively. These results define the mutational landscape of ESCC and highlight mutations in epigenetic modulators with prognostic and potentially therapeutic implications.
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Sodium hexadecyl sulfate as an interfacial substance adjusting the adsorption of a protein on carbon nanotubes.
ACS Appl Mater Interfaces
PUBLISHED: 08-21-2014
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Carbon nanotubes (CNTs) were functionalized with sodium hexadecyl sulfate (SHS). The lysozyme adsorbed on the SHS-CNTs exhibited a higher activity than that immobilized on the nonfunctionalized CNTs. To explain the experimental results and explore the mechanism of lysozyme adsorption, large-scale molecular dynamics simulations have been performed for a four-component system, including lysozyme, SHS, CNTs in explicit water. It has been found that the assembled SHS molecules form a soft layer on the surface of CNTs. The interactions between lysozyme and SHS induce the rearrangement of SHS molecules, forming a saddle-like structure on the CNT surface. The saddle-like structure fits the shape of the lysozyme, and the active-site cleft of the lysozyme is exposed to the water phase. Whereas, for the lysozyme adsorbed on the nonfunctionalized CNT, due to the hydrophobic interactions, the active-site cleft of the enzyme tends to face the wall of the CNT. The results of this work demonstrate that the SHS molecules as the interfacial substance have a function of adjusting the lysozyme with an appropriate orientation, which is favorable for the lysozyme having a higher activity.
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Sevoflurane postconditioning attenuates cerebral ischemia-reperfusion injury via protein kinase B/nuclear factor-erythroid 2-related factor 2 pathway activation.
Int. J. Dev. Neurosci.
PUBLISHED: 08-19-2014
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Oxidative damage plays a critical role in many diseases of the central nervous system. This study was conducted to determine the molecular mechanisms involved in the putative anti-oxidative effects of sevoflurane against experimental stroke. Focal cerebral ischemia was performed via 1h of middle cerebral artery occlusion followed by reperfusion. At the onset of reperfusion, rats were subjected to postconditioning with sevoflurane or without sevoflurane for 1h. Neurological deficit score was assessed at different time points after reperfusion. Cerebral infarct volume, oxidative stress level and the binding activity of Nrf2 to antioxidant response element were assessed, meanwhile the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), quinine oxidoreductase 1 (NQO1), protein kinase B (Akt) and phosphor-Akt was examined by Western blot at 72h after reperfusion. Sevoflurane postconditioning administration significantly reduced neurological deficit score, infarct volume and oxidative stress levels, while increased the expression of phosphorylation Akt, NQO1, Nrf2 and the binding activity of Nrf2 to ARE in middle cerebral artery occlusion rats. These neuroprotective effects were all suppressed by LY294002, a selective PI3K blocker. Taken together, these findings provided evidence that sevoflurane postconditioning protects brain against ischemic/reperfusion injury, and this neuroprotective effect involves the Akt/Nrf2 pathway.
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Lack of association between the 389C>T polymorphism (rs769217) in the catalase (CAT) gene and the risk of vitiligo: An update by meta-analysis.
Australas. J. Dermatol.
PUBLISHED: 08-19-2014
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The catalase (CAT) T/C at codon 389?in the exon 9 polymorphism has been implicated in susceptibility to vitiligo but a large number of studies have reported inconclusive results. The purpose of this study is to evaluate the association between the catalase gene polymorphism (389C>T) and the risk of vitiligo.
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New Insight into Improvement of Cardiovascular Outcomes with Intensive Glycemic Control in Patients with Metabolic Syndrome and Type 2 Diabetes Mellitus Included.
Cell Biochem. Biophys.
PUBLISHED: 08-12-2014
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The epidemiology of metabolic syndrome (MetS) is very concerning since this is a widespread chronic disease in adult and elderly population. Different epidemiological studies confirmed strong relationship between type 2 diabetes mellitus (DM2) inclusive MetS and the occurrence of microvascular and macrovascular complications in these patients. Therefore, we are discussing molecular mechanisms and pathways recently introduced and intensively researched. These molecules have been held responsible for direct and indirect correlative trends important in the assessment of potential benefit of intensive glycemic control. Novel substances may improve patient's outcome in recent future regarding cardiovascular complications though their acting mechanisms have not been completely elucidated. We are reviewing whether it would intensive glycemic control be a reasonable approach in patients with MetS when DM2 is included and which recommendations are currently widely applied. The aim was therefore to emphasize current need for further investigations in the field since the utility of intensive glycemic control in all DM/MetS patients as mean for reduction of cardiovascular complications still remains controversial.
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Association between Vitamin D level and viral load or fibrosis stage in chronic hepatitis B patients from Southern China.
J. Gastroenterol. Hepatol.
PUBLISHED: 08-05-2014
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The role vitamin D playing in patients with chronic hepatitis C has been intensively studied. However, studies on the potential interaction between vitamin D level and chronic hepatitis B are still limited. This study aimed to explore whether any association existed between serum vitamin D level and liver histology or virological parameters in patients with chronic hepatitis B infection in Southern China.
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A robust functional-data-analysis method for data recovery in multichannel sensor systems.
IEEE Trans Cybern
PUBLISHED: 07-23-2014
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Multichannel sensor systems are widely used in condition monitoring for effective failure prevention of critical equipment or processes. However, loss of sensor readings due to malfunctions of sensors and/or communication has long been a hurdle to reliable operations of such integrated systems. Moreover, asynchronous data sampling and/or limited data transmission are usually seen in multiple sensor channels. To reliably perform fault diagnosis and prognosis in such operating environments, a data recovery method based on functional principal component analysis (FPCA) can be utilized. However, traditional FPCA methods are not robust to outliers and their capabilities are limited in recovering signals with strongly skewed distributions (i.e., lack of symmetry). This paper provides a robust data-recovery method based on functional data analysis to enhance the reliability of multichannel sensor systems. The method not only considers the possibly skewed distribution of each channel of signal trajectories, but is also capable of recovering missing data for both individual and correlated sensor channels with asynchronous data that may be sparse as well. In particular, grand median functions, rather than classical grand mean functions, are utilized for robust smoothing of sensor signals. Furthermore, the relationship between the functional scores of two correlated signals is modeled using multivariate functional regression to enhance the overall data-recovery capability. An experimental flow-control loop that mimics the operation of coolant-flow loop in a multimodular integral pressurized water reactor is used to demonstrate the effectiveness and adaptability of the proposed data-recovery method. The computational results illustrate that the proposed method is robust to outliers and more capable than the existing FPCA-based method in terms of the accuracy in recovering strongly skewed signals. In addition, turbofan engine data are also analyzed to verify the capability of the proposed method in recovering non-skewed signals.
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Highly sensitive real-time assay of inorganic pyrophosphatase activity based on the fluorescent gold nanoclusters.
Anal. Chem.
PUBLISHED: 07-23-2014
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On the basis of the competition assay approach and fluorescent 11-mercaptoundecanoic acid-capped AuNCs (AuNCs@11-MUA) with unique optical properties, a convenient, reliable and highly sensitive real-time assay of pyrophosphatase (PPase) activity is established and developed for the first time. Pyrophosphate (PPi) could recover the Cu(2+)-quenched AuNCs@11-MUA fluorescence selectively owing to the higher binding affinity between PPi and Cu(2+) than that between 11-MUA and Cu(2+). Whereas PPase could catalyze the hydrolysis of PPi, thus released Cu(2+), leading to fluorescence requenching of the AuNCs@11-MUA. In the assay, a good linearity between the fluorescence response and PPase activity within a range from 1 to 20 mU is found, with a detection limit of less than 1 mU, which is better than other PPase assays using PPi as the substrate. Additionally, we demonstrate that our AuNCs@11-MUA-based fluorescent assay can be applied to assay the PPase activity in real biological samples such as the cell lysate. This strategy paves a new avenue for exploring the sensing applications of fluorescence AuNCs and improving the development of competition assay approach.
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[Association between CHADS2 score and long-term atrial fibrillation recurrence rate after catheter ablation].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 07-22-2014
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To investigate the association between CHADS2 score and long-term ( ? 3 years) outcomes post catheter ablation in patients with atrial fibrillation (AF).
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Alternative approach to chemical accuracy: a neural networks-based first-principles method for heat of formation of molecules made of H, C, N, O, F, S, and Cl.
J Phys Chem A
PUBLISHED: 07-11-2014
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The neural network correction approach that was previously proposed to achieve the chemical accuracy for first-principles methods is further developed by a combination of the Kennard-Stone sampling and Bootstrapping methods. As a result, the accuracy of the calculated heat of formation is improved further, and moreover, the error bar of each calculated result can be determined. An enlarged database (Chen/13), which contains a total of 539 molecules made of the common elements H, C, N, O, F, S, and Cl, is constructed and is divided into the training (449 molecules) and testing (90 molecules) data sets with the Kennard-Stone sampling method. Upon the neural network correction, the mean absolute deviation (MAD) of the B3LYP/6-311+G(3df,2p) calculated heat of formation is reduced from 10.92 to 1.47 kcal mol(-1) and 14.95 to 1.31 kcal mol(-1) for the training and testing data sets, respectively. Furthermore, the Bootstrapping method, a broadly used statistical method, is employed to assess the accuracy of each neural-network prediction by determining its error bar. The average error bar for the testing data set is 1.05 kcal mol(-1), therefore achieving the chemical accuracy. When a testing molecule falls into the regions of the "Chemical Space" where the distribution density of the training molecules is high, its predicted error bar is comparatively small, and thus, the predicted value is accurate as it should be. As a challenge, the resulting neural-network is employed to discern the discrepancy among the existing experimental data.
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Oncogenic function and prognostic significance of protein tyrosine phosphatase PRL-1 in hepatocellular carcinoma.
Oncotarget
PUBLISHED: 07-09-2014
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Our SNP-Chip data demonstrated 7/60 (12%) hepatocellular carcinoma (HCC) patients had PRL-1 copy number amplification. However, its biological functions and signaling pathways in HCC are deficient. Here, we investigated its oncogenic function and prognostic significance in HCC. PRL-1 protein levels were examined in 167 HCC samples by immunohistochemisty (IHC). The relationship of PRL-1 expression and clinicopathological features was assessed by correlation, Kaplan-Meier and Cox regression analyses. The oncogenic function of PRL-1 in HCC cells and its underlying mechanism were investigated by ectopic overexpression and knockdown model. PRL-1 levels in primary HCC and metastatic intravascular cancer thrombus were also determined by IHC. PRL-1 levels were frequently elevated in HCC tissues (81%), and elevated expression of PRL-1 was significantly associated with more aggressive phenotype and poorer prognosis in HCC patients (p<0.05). Ectopic overexpression of PRL-1 markedly enhanced HCC cells migration and invasion. Furthermore, the oncogenic functions of PRL-1 were mediated by PI3K/AKT/GSK3? signaling pathway through inhibiting E-cadherin expression. Finally, PRL-1 protein levels in metastatic cancer thrombus were higher than that in primary HCC tissues (p<0.05). These data highlight the oncogenic function of PRL-1 in HCC invasion and metastasis implicating PRL-1 as a potential prognostic marker as well as therapeutic target in HCC.
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Direct band gap silicon allotropes.
J. Am. Chem. Soc.
PUBLISHED: 07-03-2014
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Elemental silicon has a large impact on the economy of the modern world and is of fundamental importance in the technological field, particularly in solar cell industry. The great demand of society for new clean energy and the shortcomings of the current silicon solar cells are calling for new materials that can make full use of the solar power. In this paper, six metastable allotropes of silicon with direct or quasidirect band gaps of 0.39-1.25 eV are predicted by ab initio calculations at ambient pressure. Five of them possess band gaps within the optimal range for high converting efficiency from solar energy to electric power and also have better optical properties than the Si-I phase. These Si structures with different band gaps could be applied to multiple p-n junction photovoltaic modules.
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[Identification of a new sildenafil analogue based on Q-TOF-MS].
Yao Xue Xue Bao
PUBLISHED: 07-01-2014
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The drugs such as sildenafil adulterated in herbal products and dietary supplements may endanger human health. The number of the new modified derivatives is increasing recently. Based on Q-TOF-MS, a new sildenafil analogue was found. It was isolated and purified by preparative liquid chromatography. Its structure was determined by NMR, as 1-[4-propoxy-3-(6, 7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4, 3-d] pyrimidin-5-yl)phenylsulfonyl]-4-methylpiperazine. Compared with sildenafil, the ethoxy group of the benzene ring moiety was moved to the propoxy group, which had not been reported in China. The mass spectrometric behavior pattern of the structure type was summarized, which can greatly accelerate the structural analysis of novel analogues.
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Co-spread of oqxAB and blaCTX-M-9G in non-Typhi Salmonella enterica isolates mediated by ST2-IncHI2 plasmids.
Int. J. Antimicrob. Agents
PUBLISHED: 06-27-2014
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In this study, 130 non-Typhi Salmonella enterica isolates from chickens were analysed for the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants as well as the co-existence of oqxAB and extended-spectrum ?-lactamase (ESBL) genes. The genes oqxAB, aac(6')-Ib-cr, blaCTX-M-9G and blaTEM were present alone or in combination in 40 (30.8%), 40 (30.8%), 55 (42.3%) and 2 (1.5%) isolates, respectively. Most of the oqxAB-blaCTX-M-9G-positive isolates (17/28) carried transferable ST2-IncHI2 plasmids containing an oqxAB cassette and blaCTX-M-14 flanked by insertion sequences IS10 or ISEcp1 upstream and IS903 downstream. The oqxAB-blaCTX-M-9G-positive isolates from a local area showed similar pulsed-field gel electrophoresis (PFGE) patterns, whilst the isolates from different areas were genetically divergent, suggesting that both clonal expansion in local areas and horizontal transmission contributed to the spread of ST2-IncHI2 plasmids containing oqxAB and blaCTX-M-14. This is the first report on the prevalence of ST2-IncHI2 plasmids concomitantly carrying oqxAB and blaCTX-M-14 in Salmonella and also the first description of the genetic environment of oqxAB-blaCTX-M. The genetic linkage of oqxAB-blaCTX-M-9G in non-Typhi Salmonella likely facilitates the spread of antibiotic-resistant Salmonella and poses a threat for clinical treatment of salmonellosis.
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Assessment of density gradient centrifugation (DGC) and sperm chromatin dispersion (SCD) measurements in couples with male factor infertility undergoing ICSI.
J. Assist. Reprod. Genet.
PUBLISHED: 06-15-2014
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To investigate how effectively density gradient centrifugation (DGC) improves sperm nuclear integrity and to determine whether the sperm chromatin dispersion (SCD) test of sperm nuclear integrity in native or DGC-treated semen can predict the outcome of assisted reproductive technology (ART) in couples undergoing intracytoplasmic sperm injection (ICSI).
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Primary diffuse large B-cell lymphoma of the ovary is of a germinal centre B-cell-like phenotype.
Virchows Arch.
PUBLISHED: 06-14-2014
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Primary ovarian lymphoma is rare. To better understand the clinicopathological and molecular features of these tumours, we studied 14 patients (age range 13 to 74 years, mean 46.9 years) with non-Hodgkin's lymphoma who initially presented with an ovarian tumour. The clinicopathological features were reviewed and tissue samples were studied by immunohistochemistry and for immunoglobulin gene rearrangement, presence of Epstein Barr virus and for MYC and BCL-2 rearrangements by fluorescence in situ hybridisation. The most common symptoms were abdominal pain and abdominal distension. Ten patients had a unilateral (7 left, 3 right) ovarian mass and 4 had bilateral ovarian masses, size range 4 to 13 cm (mean, 7.9 cm). Of the 14 lymphomas, 12 were classified as diffuse large B-cell lymphoma (DLBCL) and 2 as Burkitt lymphoma. The Burkitt lymphomas had a MYC rearrangement. The DLBCLs were of the germinal centre B-cell-like subtype. One DLBCL patient had MYC and BCL2 rearrangements. The treatment consisted of various combinations of surgery, chemotherapy and radiotherapy. The follow-up period ranged from 3 to 56 months. During the follow-up period, 8 patients died of disease, 4 were alive with disease, and 2 were alive without disease. Most primary ovarian lymphomas are of germinal centre B-cell-like subtype DLBCL, which have high proliferative activity and poor prognosis.
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Characterization of Plasmids Carrying oqxAB in blaCTX-M-Negative Escherichia coli Isolates from Food-Producing Animals.
Microb. Drug Resist.
PUBLISHED: 06-14-2014
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To study the characteristics of plasmids harboring oqxAB among blaCTX-M-negative Escherichia coli isolates and search for oqxAB-harboring plasmids similar to plasmids carrying oqxAB-blaCTX-M reported previously, conjugation experiment was performed for 115 randomly selected oqxAB-positive but blaCTX-M-negative E. coli isolates from diseased animals in Guangdong, China. S1 nuclease pulsed-field gel electrophoresis (PFGE) and southern blotting experiments were performed to investigate the location of oqxAB and other resistance genes. The EcoRI digestion profiles of the plasmids with oqxAB were also analyzed. The clonal relatedness of donor isolates was investigated by PFGE. In this study, 32 oqxAB transconjugants were successfully obtained and most transconjugants showed multidrug resistances. Eleven replicon combination types were found in these transconjugants. floR and oqxAB were found on the same plasmids in all nine transconjugants resistant to florfenicol. The sequences between floR and oqxAB were identical in most transconjugants and the two genes were both linked with tnp in insertion sequences. Nine F18:A-:B1 plasmids with only oqxAB shared identical EcoRI digestion profiles and the profiles were also identical with that of a plasmid carrying oqxAB-blaCTX-M found previously. Co-transfer of plasmids carrying oqxAB and fosA3, respectively, was also observed in one isolate. This study demonstrates the dissemination of oqxAB among blaCTX-M-negative E. coli isolates was mainly mediated by identical F18:A-:B1 plasmids. A novel arrangement of regions between floR and oqxAB might play an important role in the dissemination of floR-oqxAB. This is the first description of the genetic environment of the relationship between oqxAB and floR in E. coli.
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650-nm 1 × 2 polymeric thermo-optic switch with low power consumption.
Opt Express
PUBLISHED: 06-13-2014
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In this paper, a low-power 1 × 2 polymeric thermo-optic switch operating at the polymer optical fiber low-loss window of 650 nm was studied. The characteristic parameters of the switch were carefully designed and simulated. The fabrication was done by using standard semiconductor fabrication techniques such as spin-coating, photolithography, and dry etching. The device was fabricated based on poly(methyl methacrylate) (PMMA)-based materials with the Mach-Zehnder interferometer (MZI) structure. The device shows an extinction ratio of over 23.4 dB at 650 nm with a very low-power consumption of 5.3 mW. The measured switching rise time and fall time are 464.4 and 448.0 µs, respectively.
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An NN-based SRD decomposition algorithm and its application in nonlinear compensation.
Sensors (Basel)
PUBLISHED: 06-04-2014
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In this study, a neural network-based square root of descending (SRD) order decomposition algorithm for compensating for nonlinear data generated by sensors is presented. The study aims at exploring the optimized decomposition of data 1.00,0.00,0.00 and minimizing the computational complexity and memory space of the training process. A linear decomposition algorithm, which automatically finds the optimal decomposition N and reduces the training time to 1/?N and memory cost to 1/N has been implemented on nonlinear data obtained from an encoder. Particular focus is given to the theoretical access of estimating the numbers of hidden nodes and the precision of varying the decomposition method. Numerical experiments are designed to evaluate the effect of this algorithm. Moreover, a designed device for angular sensor calibration is presented. We conduct an experiment that samples the data of an encoder and compensates for the nonlinearity of the encoder to testify this novel algorithm.
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Evaluation of MODS assay for rapid detection of Mycobacterium tuberculosis resistance to second-line drugs in a tertiary care tuberculosis hospital in China.
Tuberculosis (Edinb)
PUBLISHED: 05-30-2014
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In this study we evaluated the performance of microscopic observation drug susceptibility (MODS) assay for rapid detection of Mycobacterium tuberculosis resistance to second-line drugs. 246 multidrug-resistant M. tuberculosis clinical isolates were used to compare MODS with the agar proportion method for rapid detection of resistance to 8 second-line drugs: ofloxacin, amikacin, kanamycin, capreomycin, ethionamide, cycloserine, ciprofloxacin and para-aminosalicylic acid. The sensitivity of the MODS for different drugs ranged from 88.1% to 100%, whereas the specificity ranged from 92.3% to 100%. Results for MODS assay were obtained in a median time of 7 days (range 5-18). Thus MODS assay could be used as a fast, reliable and inexpensive method for detection of M. tuberculosis resistance to second-line drugs in resource-limited settings.
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Arthroscopic evaluation for omalgia patients undergoing the clavicular hook plate fixation of distal clavicle fractures.
J Orthop Surg Res
PUBLISHED: 05-26-2014
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The aim of this study is to investigate the anatomic changes in the shoulder joints responsible for omalgia after the clavicular hook plate fixation under arthroscope.
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Effects of grain development on formation of resistant starch in rice.
Food Chem
PUBLISHED: 05-04-2014
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Three rice mutants with different contents of resistant starch (RS) were selected to investigate the effects of grain filling process on the formation of resistant starch. During grain development, the content of RS was increased with grain maturation and showed negative correlations with the grain weight and the starch molecular weight (Mn, Mw) and a positive correlation with the distribution of molecular mass (polydispersity, Pd). The morphologies of starch granules in high-RS rice were almost uniform in single starch granules and exhibited different proliferation modes from common rice. The lower activities of ADP-glucose pyrophosphorylase and starch branching enzyme and the higher activity of starch synthase and starch de-branching enzyme observed in high-RS rice might be responsible for the formation of small irregular starch granules with large spaces between them. In addition, the lower molecular weight and the broad distribution of molecular weights lead to differences in the physiochemical properties of starch.
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Restoration of miR-193b sensitizes Hepatitis B virus-associated hepatocellular carcinoma to sorafenib.
Cancer Lett.
PUBLISHED: 05-01-2014
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Chronic infection with Hepatitis B virus (HBV) is the major risk factor of Hepatocellular Carcinoma (HCC). This study is to explore the mechanism of sorafenib resistance and find an effective strategy to sensitize HBV-associated HCC to sorafenib.
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Hierarchical structure and mechanical properties of remineralized dentin.
J Mech Behav Biomed Mater
PUBLISHED: 04-10-2014
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It is widely accepted that the mechanical properties of dentin are significantly determined by its hierarchical structure. The current correlation between the mechanical properties and the hierarchical structure was mainly established by studying altered forms of dentin, which limits the potential outcome of the research. In this study, dentins with three different hierarchical structures were obtained via two different remineralization procedures and at different remineralization stages: (1) a dentin structure with amorphous minerals incorporated into the collagen fibrils, (2) a dentin with crystallized nanominerals incorporated into the collagen fibrils, and (3) a dentin with an out-of-order mineral layer filling the collagen fibrils matrix. Nanoindentation tests were performed to investigate the mechanical behavior of the remineralized dentin slides. The results showed that the incorporation of the crystallized nanominerals into the acid-etched demineralized organic fibrils resulted in a remarkable improvement of the mechanical properties of the dentin. In contrast, for the other two structures, i.e. the amorphous minerals inside the collagen fibrils and the out-of-order mineral layer within the collagen fibrils matrix, the excellent mechanical properties of dentin could not be restored.
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Synthesis and biological evaluation of pyranoisoflavone derivatives as anti-inflammatory agents.
Fitoterapia
PUBLISHED: 04-07-2014
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In this paper, barbigerone (1a) and its twenty-seven related structural analogues were synthesized via complementary synthetic routes and their anti-inflammatory effects on the expression of TNF-? in LPS-stimulated splenocytes were evaluated. Among these compounds, 1a, 1d, 1f and 1g were found to remarkably inhibit TNF-? production. Furthermore, 1g showed the most potent and dose-dependent manner inhibitory effect on TNF-? release, with better IC50 value (3.58 ?M) than barbigerone (8.46 ?M). Oral administration of 1g at 20 mg/kg/day for two weeks obviously demonstrated protective effect in adjuvant-induced arthritis models as evaluated by clinical score of paws, and histological examination of joint tissues from rats. Mechanism studies on mRNA and protein level suggested that 1g inhibited the TNF-? production via depressing TNF-? converting enzyme (TACE) mRNA expression. In conclusion, these data show 1g with potential therapeutic effects as an anti-inflammatory agent.
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Automatic lung tumor segmentation on PET/CT images using fuzzy Markov random field model.
Comput Math Methods Med
PUBLISHED: 03-28-2014
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The combination of positron emission tomography (PET) and CT images provides complementary functional and anatomical information of human tissues and it has been used for better tumor volume definition of lung cancer. This paper proposed a robust method for automatic lung tumor segmentation on PET/CT images. The new method is based on fuzzy Markov random field (MRF) model. The combination of PET and CT image information is achieved by using a proper joint posterior probability distribution of observed features in the fuzzy MRF model which performs better than the commonly used Gaussian joint distribution. In this study, the PET and CT simulation images of 7 non-small cell lung cancer (NSCLC) patients were used to evaluate the proposed method. Tumor segmentations with the proposed method and manual method by an experienced radiation oncologist on the fused images were performed, respectively. Segmentation results obtained with the two methods were similar and Dice's similarity coefficient (DSC) was 0.85 ± 0.013. It has been shown that effective and automatic segmentations can be achieved with this method for lung tumors which locate near other organs with similar intensities in PET and CT images, such as when the tumors extend into chest wall or mediastinum.
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Nutritional compositions and bioactivities of Dacryodes species: a review.
Food Chem
PUBLISHED: 03-27-2014
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Dacryodes species are evergreen, perennial trees with fleshy fruits and belong to the family Buseraseae. Many Dacryodes species are underutilized but are widely applied in traditional folk medicine to treat malaria, fever and skin diseases. The nutritional compositions, phytochemicals and biological activities of Dacryodes edulis, Dacryodes rostrata, Dacryodes buettneri, Dacryodes klaineana and Dacryodes hexandra are presented. The edible fruits of D. edulis are rich in lipids, proteins, vitamins, fatty acids and amino acids. Its extracts (leaf, fruit and resin) exhibit antioxidant, anti-microbial, anti-carcinogenic and other bioactivities. D. rostrata fruit has significant nutrient content, and is rich in proteins, lipids and minerals. These fruits are also highly rich in polyphenols, anthocyanins and antioxidant activities. This comprehensive review will assist the reader in understanding the nutritional benefits of Dacryodes species and in identifying current research needs.
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Maxillary pain is the first indication of the presence of multiple myeloma: A case report.
Mol Clin Oncol
PUBLISHED: 03-21-2014
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Multiple myeloma is a primary malignancy of bone marrow characterized by the clonal proliferation of plasma cells and production of monoclonal immunoglobulin. The disease occurs more frequently in males, with the average age at diagnosis being ?60 years. The first manifestation of multiple myeloma is varied and depends on the sites and extent of involvement. The predominant clinical symptoms of multiple myeloma are associated with bone pain and renal dysfunction. Neoplastic cells usually produce large amounts of monoclonal immunoglobulin light or heavy chains that can be detected in serum or urine, while plasmacytoma may be identified on marrow biopsy. The present study reported on the case of a 69-year-old male patient presenting with a complaint of a painful lesion in the left maxilla. Physical examination, imaging, laboratory investigations and biopsy were conducted, confirming the diagnosis of multiple myeloma. The results obtained suggest that the dentist should address oral manifestations as first indications of multiple myeloma.
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Novel structural phases and superconductivity of iridium telluride under high pressures.
Sci Rep
PUBLISHED: 03-13-2014
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Transition metal selenide and telluride have recently receive considerable attention due to their possible structural relation to ferropnictide. Pressure is often used as an efficient way to modify the crystal or electronic structure that in many cases lead to new material states of interest. Here we search the structures of IrTe2 up to 150 GPa using crystal structure prediction techniques combining with ab initio calculations. Three new stable phases under high pressures are predicted, and their electronic structure properties, phonon spectra, and electron-phonon couplings are also investigated. Significant reconstructions of band structures and Fermi surfaces are found in these new phases. Calculated results show that while the C2/m-2 phase has bad metal behavior and very weak electron-phonon coupling, the and I4/mmm phases have relatively higher electron-phonon coupling up to ~ 1.5 and 0.7, respectively. The variable-composition searching have been performed, newly compounds with different stoichiometries, such as IrTe3, IrTe, and Ir3Te, are predicted to be thermodynamically and dynamically stable at high pressures. The pressure range investigated here is accessible in the diamond anvil cell experiments, thus our results might stimulate further experimental studies.
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Design and synthesis of thiazole derivatives as potent FabH inhibitors with antibacterial activity.
Eur J Med Chem
PUBLISHED: 02-25-2014
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Components of fatty acid biosynthetic pathway have been identified as attractive targets for the development of new antibacterial agents. Compounds of series A (4a-4 g) and series B (5a-5 g) were synthesized by the formation of an amine bond between aromatic acid and 4-phenylthiazol-2-amine or 4-(4-bromophenyl)thiazol-2-amine. These thiazole derivatives have evaluated as potent FabH inhibitors. Nineteen compounds (4b-4h, 4 k, 4 l, 5a-5h, 5k, 5l) are reported for the first time. Most of the synthesized compounds exhibited antibacterial activity in the MTT assay. The MIC value of these compounds ranged from 1.56 ?g/mL to 100 ?g/mL. Moreover, the tested compounds also showed FabH inhibition ability with IC50 value ranging from 5.8 ?M to 48.1 ?M. The IC50 values are near the MIC values. Compound 5f has exhibited the best antibacterial and Escherichia coli FabH inhibitory activity. Docking simulation and the QSAR study was conducted for learning about binding mode and the relationship between structure and activity.
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A two-enzyme immobilization approach using carbon nanotubes/silica as support.
Biotechnol. Prog.
PUBLISHED: 01-28-2014
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Multiple enzyme mixtures are attractive for the production of many compounds at an industrial level. We report a practical and novel approach for coimmobilization of two enzymes. The system consists of a silica microsphere core coated with two layers of individually immobilized enzymes. The model enzymes ?-amylase (AA) and glucoamylase (GluA) were individually immobilized on carbon nanotubes (CNTs). A CNT-GluA layer was formed by adsorbing CNT-GluA onto silica microsphere. A sol-gel layer with entrapped CNT-AA was then formed outside the CNT-GluA/silica microsphere conjugate. The coimmobilized ?-amylase and glucoamylase exhibited 95.1% of the activity of the mixture of free ?-amylase and glucoamylase. The consecutive use exhibited a good stability of the coimmobilized enzymes. The developed approach demonstrates advantages, including controlling the ratio of coimmobilized enzymes in an easy way, facilitating diffusion of small molecules in and out of the matrix, and preventing the leaching of enzymes. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 2014.
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A novel hemagglutinin with antiproliferative activity against tumor cells from the hallucinogenic mushroom Boletus speciosus.
Biomed Res Int
PUBLISHED: 01-28-2014
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Little was known about bioactive compounds from the hallucinogenic mushroom Boletus speciosus. In the present study, a hemagglutinin (BSH, B. speciosus hemagglutinin) was isolated from its fruiting bodies and enzymatic properties were also tested. The chromatographic procedure utilized comprised anion exchange chromatography on Q-Sepharose, cation exchange chromatography on CM-Cellulose, cation exchange chromatography on SP-Sepharose, and gel filtration by FPLC on Superdex 75. The hemagglutinin was a homodimer which was estimated to be approximately 31 kDa in size. The activity of BSH was stable up to 60°C, while there was a precipitous drop in activity when the temperature was elevated to 70°C. BSH retained 25% hemagglutinating activity when exposed to 100 mM NaOH and 25 mM HCl. The activity was potently inhibited by 1.25 mM?Hg(2+) and slightly inhibited by Fe(2+), Ca(2+), and Pb(2+). None of the sugars tested showed inhibition towards BSH. Its hemagglutinating activity towards human erythrocytes type A, type B, and type AB was higher than type O. The hemagglutinin showed antiproliferative activity towards hepatoma Hep G2 cells and mouse lymphocytic leukemia cells (L1210) in vitro, with IC50 of 4.7 ? M and 7.0 ? M, respectively. It also exhibited HIV-1 reverse transcriptase inhibitory activity with an IC50 of 7.1 ? M.
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Involvement of calcium-sensing receptors in hypoxia-induced vascular remodeling and pulmonary hypertension by promoting phenotypic modulation of small pulmonary arteries.
Mol. Cell. Biochem.
PUBLISHED: 01-25-2014
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Phenotype modulation of pulmonary artery smooth muscle cells (PASMCs) plays an important role during hypoxia-induced vascular remodeling and pulmonary hypertension (PAH). We had previously shown that calcium-sensing receptor (CaSR) is expressed in rat PASMCs. However, little is known about the role of CaSR in phenotypic modulation of PASMCs in hypoxia-induced PAH as well as the underlying mechanisms. In this study, we investigated whether CaSR induces the proliferation of PASMCs in small pulmonary arteries from both rats and human with PAH. PAH was induced by exposing rats to hypoxia for 7-21 days. The mean pulmonary arterial pressure (mPAP), right ventricular hypertrophy index (RVI), the percentage of medial wall thickness to the external diameter (WT %), and cross-sectional total vessel wall area to the total area (WA %) of small pulmonary arteries were determined by hematoxylin and eosin (HE), masson trichrome and Weigert's staining. The protein expressions of matrix metalloproteinase (MMP)-2 and MMP-9, the tissue inhibitors of metalloproteinase (TIMP)-3, CaSR, proliferating cell nuclear antigen (PCNA), phosphorylated extracellular signal-regulated kinase (p-ERK), and smooth muscle cell (SMC) phenotype marker proteins in rat small pulmonary arteries, including calponin, SM?-actin (SMA?), and osteopontin (OPN), were analyzed by immunohistochemistry and Western blotting, respectively. In addition, immunohistochemistry was applied to paraffin-embedded human tissues from lungs of normal human and PAH patients with chronic heart failure (PAH/CHF). Compared with the control group, mPAP, RVI, WT % and WA % in PAH rats were gradually increased with the prolonged hypoxia. At the same time, the expressions of CaSR, MMP-2, MMP-9, TIMP-3, PCNA, OPN, and p-ERK were markedly increased, while the expressions of SMA? and calponin were significantly reduced in lung tissues or small pulmonary arteries of PAH rats. Neomycin (an agonist of CaSR) enhanced but NPS2390 (an antagonist of CaSR) weakened these hypoxic effects. We further found that the expression change of CaSR, PCNA, and SMC phenotypic marker proteins in PAH/CHF lungs was similar to those in PAH rats. Our data suggest that CaSR is involved in the pulmonary vascular remodeling and PAH by promoting phenotypic modulation of small pulmonary arteries.
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Fluorescent blood glucose monitor by hemin-functionalized graphene quantum dots based sensing system.
Anal. Chim. Acta
PUBLISHED: 01-21-2014
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In the present work, a highly sensitive and specific fluorescent biosensor for blood glucose monitoring is developed based on hemin-functionalized graphene quantum dots (GQDs) and glucose oxidase (GOx) system. The GQDs which are simply prepared by pyrolyzing citric acid exhibit strong fluorescence and good water-solubility. Due to the noncovalent assembly between hemin and GQDs, the addition of hemin can make hydrogen peroxide (H2O2) to destroy the passivated surface of GQDs, leading to significant fluorescence quenching of GQDs. Based on this effect, a novel fluorescent platform is proposed for the sensing of glucose. Under the optimized conditions, the linear range of glucose is from 9 to 300?M, and the limit of detection is 0.1?M. As unique properties of GQDs, the proposed biosensor is green, simple, cost-efficient, and it is successfully applied to the determination of glucose in human serum. In addition, the proposed method provides a new pathway to further design the biosensors based on the assembly of GQDs with hemin for detection of biomolecules.
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Development of aminoglycoside and ?-lactamase resistance among intestinal microbiota of swine treated with lincomycin, chlortetracycline, and amoxicillin.
Front Microbiol
PUBLISHED: 01-01-2014
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Lincomycin, chlortetracycline, and amoxicillin are commonly used antimicrobials for growth promotion and infectious disease prophylaxis in swine production. In this study, we investigated the shifts and resistance development among intestinal microbiota in pregnant sows before and after lincomycin, chlortetracycline, and amoxicillin treatment by using phylogenetic analysis, bacterial enumeration, and PCR. After the antimicrobial treatment, shifts in microbial community, an increased proportion of resistant bacteria, and genes related to antimicrobial resistance as compared to the day before antimicrobial administration (day 0) were observed. Importantly, a positive correlation between antimicrobial resistance gene expression in different categories, especially those encoding aminoglycoside and ?-lactamase and antimicrobial resistance, was observed. These findings demonstrate an important role of antimicrobial usage in animals in the development of antimicrobial resistance, and support the notion that prudent use of antimicrobials in swine is needed to reduce the risk of the emergence of multi-drug resistant zoonotic pathogens.
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Illumina Amplicon Sequencing of 16S rRNA Tag Reveals Bacterial Community Development in the Rhizosphere of Apple Nurseries at a Replant Disease Site and a New Planting Site.
PLoS ONE
PUBLISHED: 01-01-2014
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We used a next-generation, Illumina-based sequencing approach to characterize the bacterial community development of apple rhizosphere soil in a replant site (RePlant) and a new planting site (NewPlant) in Beijing. Dwarfing apple nurseries of 'Fuji'/SH6/Pingyitiancha trees were planted in the spring of 2013. Before planting, soil from the apple rhizosphere of the replant site (ReSoil) and from the new planting site (NewSoil) was sampled for analysis on the Illumina MiSeq platform. In late September, the rhizosphere soil from both sites was resampled (RePlant and NewPlant). More than 16,000 valid reads were obtained for each replicate, and the community was composed of five dominant groups (Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria). The bacterial diversity decreased after apple planting. Principal component analyses revealed that the rhizosphere samples were significantly different among treatments. Apple nursery planting showed a large impact on the soil bacterial community, and the community development was significantly different between the replanted and newly planted soils. Verrucomicrobia were less abundant in RePlant soil, while Pseudomonas and Lysobacter were increased in RePlant compared with ReSoil and NewPlant. Both RePlant and ReSoil showed relatively higher invertase and cellulase activities than NewPlant and NewSoil, but only NewPlant soil showed higher urease activity, and this soil also had the higher plant growth. Our experimental results suggest that planting apple nurseries has a significant impact on soil bacterial community development at both replant and new planting sites, and planting on new site resulted in significantly higher soil urease activity and a different bacterial community composition.
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Effects of grazing regimes on plant traits and soil nutrients in an alpine steppe, Northern Tibetan Plateau.
PLoS ONE
PUBLISHED: 01-01-2014
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Understanding the impact of grazing intensity on grassland production and soil fertility is of fundamental importance for grassland conservation and management. We thus compared three types of alpine steppe management by studying vegetation traits and soil properties in response to three levels of grazing pressure: permanent grazing (M1), seasonal grazing (M2), and grazing exclusion (M3) in the alpine steppe in Xainza County, Tibetan Plateau. The results showed that community biomass allocation did not support the isometric hypothesis under different grassland management types. Plants in M1 had less aboveground biomass but more belowground biomass in the top soil layer than those in M2 and M3, which was largely due to that root/shoot ratios of dominant plants in M1 were far greater than those in M2 and M3. The interramet distance and the tiller size of the dominant clonal plants were greater in M3 than in M1 and M2, while the resprouting from rhizome buds did not differ significantly among the three greezing regimes. Both soil bulk density and soil available nitrogen in M3 were greater than in M1 at the 15-30 cm soil depth (P?=?0.05). Soil organic carbon and soil total nitrogen were greater in M3 than in M1 and M2 (P?=?0.05). We conclude that the isometric hypothesis is not supported in this study and fencing is a helpful grassland management in terms of plant growth and soil nutrient retention in alpine steppe. The extreme cold, scarce precipitation and short growing period may be the causation of the unique plant and soil responses to different management regimes.
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Association of UGT1A1 variants and hyperbilirubinemia in breast-fed full-term Chinese infants.
PLoS ONE
PUBLISHED: 01-01-2014
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A retrospective case control study of breast-fed full-term infants was carried out to determine whether variants in Uridine Diphosphate Glucuronosyl Transferase 1A1 (UGT1A1) and Heme Oxygenase-1 (HMOX1) were associated with neonatal hyperbilirubinemia. Eight genetic variants of UGT1A1 and 3 genetic variants of HMOX1 were genotyped in 170 hyperbilirubinemic newborns and 779 controls. Five significant associations with breast-fed hyperbilirubinemia were detected after adjusting for gender, birth season, birth weight, delivery mode, gestational age and False Discovery Rate (FDR) correction: the dominant effect of rs887829 (c-364t) (Odds Ratio (OR): 0.55; 95% Confidence Interval (CI): 0.34-0.89; p?=?0.014), the additive effect of (TA)n repeat (OR: 0.59; 95%CI: 0.38-0.91; p?=?0.017), the dominant effect of rs4148323 (Gly71Arg, G211A) (OR: 2.02; 95%CI: 1.44-2.85; p?=?5.0×10-5), the recessive effect of rs6717546 (g+914a) (OR: 0.30; 95%CI: 0.11-0.83; p?=?0.021) and rs6719561 (t+2558c) (OR: 0.38; 95%CI: 0.20-0.75; p?=?0.005). Neonates carrying the minor allele of rs887829 (TA)n repeat had significantly lower peak bilirubin than wild types, while the minor allele carriers of rs4148323 had significantly higher peak bilirubin than wild types. No association was found in HMOX1. Our findings added to the understanding of the significance of UGT1A1 in association with neonatal hyperbilirubinemia in East Asian population. Additional studies were required to investigate the mechanisms of the protective effects.
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Identification of the multi-resistance gene cfr in Escherichia coli isolates of animal origin.
PLoS ONE
PUBLISHED: 01-01-2014
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Previous study indicated that the multi-resistance gene cfr was mainly found in gram-positive bacteria, such as Staphylococcus and Enterococcus, and was sporadically detected in Escherichia coli. Little is known about the prevalence and transmission mechanism of cfr in E. coli. In this study, the presence of cfr in E. coli isolates collected during 2010-2012 from food-producing animals in Guangdong Province of China was investigated, and the cfr-positive E. coli isolates were characterized by PFGE, plasmid profiling, and genetic environment analysis. Of the 839 E. coli isolates, 10 isolates from pig were cfr positive. All the cfr-positive isolates presented a multi-resistance phenotype and were genetically divergent as determined by PFGE. In 8 out of the 10 strains, the cfr gene was located on plasmids of ?30 kb. Restriction digestion of the plasmids with EcoRI and sequence hybridization with a cfr-specific probe revealed that the cfr-harboring fragments ranged from 6 to 23 kb and a ?18 kb cfr-carrying fragment was common for the plasmids that were ?30 kb. Four different genetic environments of cfr were detected, in which cfr is flanked by two identical copies of IS26, which may loop out the intervening sequence through homologous recombination. Among the 8 plasmids of ?30 kb, 7 plasmids shared the same genetic environment. These results demonstrate plasmid-carried cfr in E. coli and suggest that transposition and homologous recombination mediated by IS26 might have played a rule in the transfer of the cfr gene in E. coli.
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Relationships of biomass with environmental factors in the grassland area of Hulunbuir, China.
PLoS ONE
PUBLISHED: 01-01-2014
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Many studies have focused on the relationship between vegetation biomass and environmental factors in grassland. However, several questions remain to be answered, especially with regards to the spatial pattern of vegetation biomass. Thus, the distributed mechanism will be explored in the present study. Here, plant biomass was measured at 23 sites along a transect survey during the peak growing season in 2006. The data were analyzed with a classification and regression tree (CART) model. The structural equation modeling (SEM) was conducted to explicitly evaluate the both direct and indirect effects of these critical environmental elements on vegetation biomass. The results demonstrated that mean annual temperature (MAT) affected aboveground biomass (AGB) scored at -0.811 (P<0.05). The direct effect of MAT on belowground biomass (BGB) was -0.490 (P<0.05). The results were determined by SEM. Our results indicate that AGB and BGB in semi-arid ecosystems is strongly affected by precipitation and temperature. Future work shall attempt to take into account the integrated effects of precipitation and temperature. Meanwhile, partitioning the influences of environmental variations and vegetation types are helpful in illuminating the internal mechanism of biomass distribution.
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Enhancing the light absorbance of polymer solar cells by introducing pulsed laser-deposited CuIn0.8Ga0.2Se2 nanoparticles.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
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Evenly separated crystalline CuIn0.8Ga0.2Se2 (CIGS) nanoparticles are deposited on ITO-glass substrate by pulsed laser deposition. Such CIGS layers are introduced between conjugated polymer layers and ITO-glass substrates for enhancing light absorbance of polymer solar cells. The P3HT:PCBM absorbance between 300 and 650 nm is enhanced obviously due to the introduction of CIGS nanoparticles. The current density-voltage curves of a P3HT:PCBM/CIGS solar cell demonstrate that the short-circuit current density is improved from 0.77 to 1.20 mA/cm(2). The photoluminescence spectra show that the excitons in the polymer are obviously quenched, suggesting that the charge transfer between the P3HT:PCBM and CIGS occurred. The results reveal that the CIGS nanoparticles may exhibit the localized surface plasmon resonance effect just as metallic nanostructures.
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Optimized Product Quantization.
IEEE Trans Pattern Anal Mach Intell
PUBLISHED: 12-11-2013
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Product quantization (PQ) is an effective vector quantization method. A product quantizer can generate an exponentially large codebook at very low memory/time cost. The essence of PQ is to decompose the high-dimensional vector space into the Cartesian product of subspaces and then quantize these subspaces separately. The optimal space decomposition is important for the PQ performance, but still remains an unaddressed issue. In this paper, we optimize PQ by minimizing quantization distortions wrt the space decomposition and the quantization codebooks. We present two novel solutions to this challenging optimization problem. The first solution iteratively solves two simpler sub-problems. The second solution is based on a Gaussian assumption and provides theoretical analysis of the optimality. We evaluate our optimized product quantizers in three applications: (i) compact encoding for exhaustive ranking cite{Jegou2011a}, (ii) building inverted multi-indexing for non-exhaustive search cite{Babenko2012}, and (iii) compacting image representations for image retrieval cite{Jegou2010a}. In all applications our optimized product quantizers outperform existing solutions.
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Comparison of Plasmids Coharboring 16S rRNA Methylase and Extended-Spectrum ?-Lactamase Genes among Escherichia coli Isolates from Pets and Poultry.
J. Food Prot.
PUBLISHED: 12-03-2013
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A total of 247 Escherichia coli isolates (148 from diseased or dead poultry and 99 from diseased pets in the Peoples Republic of China) were screened for extended-spectrum ?-lactamase (ESBL) determinants by PCR and sequencing. Then, 16S rRNA methylase genes were detected among ESBL-producing isolates. Clonal relatedness of the E. coli isolates was examined by pulsed-field gel electrophoresis. Conjugation experiments were performed to investigate the association of 16S rRNA methylases and ESBLs, and plasmid contents were also characterized. Among 247 E. coli isolates, 74 (29.96%) isolates were positive for blaCTX-M genes, 42 from pets (12 from cats and 30 from dogs) and 32 from poultry (12 from chickens and 20 from ducks). The most common CTX-M type in isolates from pets was blaCTX-M-14, whereas blaCTX-M-27 was the most common for poultry. rmtB was dectected in 39 of the 74 blaCTX-M-positive isolates, 18 from pets and 21 from poultry. One strain from a pet was found to harbor blaCTX-M-14, blaCTX-M-15, and rmtB. blaCTX-M and rmtB were found to be colocated on the same transferable plasmid in 16 isolates. These genes were on the same or similar plasmids (eight F2:A-:B- and two IncN) in isolates from ducks, whereas they were colocated on the similar F2:A-:B- or similar F33:A-:B- plasmids in isolates of pets origin. In conclusion, similar F2:A-:B- plasmids and similar F33:A-:B- plasmids are responsible for the dissemination of both rmtB and blaCTX-Mgenes in E. coli isolates from poultry and pets, respectively.
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Limited Correlation between Conventional Pathologist and Automatic Computer-assisted Quantification of Hepatic Steatosis due to Difference between Event-based and Surface-based Analysis.
IEEE J Biomed Health Inform
PUBLISHED: 11-05-2013
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Computer-assisted automatic quantification (CAQ) was developed as an alternative method for diagnosis of hepatic steatosis in order to compensate for observer-dependent bias Here we aim to demonstrate that CAQ can provide an accurate and precise result in analysis of fatty content, but that it is inappropriate to validate CAQ by comparison with a conventional pathologist estimation (PE). Male rats were fed with a methionine-choline-deficient plus high-fat (MCD+HF) diet for 3days, 1week or 2weeks to induce mild, moderate or severe steatosis. Samples were collected from all liver lobes. Severity of hepatic steatosis was assessed by an experienced pathologist who estimated the percentage of hepatocytes containing lipid droplets. Fatty content was quantified by PE, CAQ, and biochemical analysis (BA). CAQ, PE and BA can correctly reflect severe fatty change. However, in the case of mild and moderate steatosis, PE could not reflect the true fatty content (r between PE and BA was <0). The result of CAQ correlated well with that of BA amongst the various degrees of severity of hepatic steatosis. In conclusion, due to a difference between event-based and surface-based analysis, it is inappropriate to validate the CAQ of hepatic steatosis by comparison with PE.
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Discovery of 4,6-substituted-(diaphenylamino)quinazolines as potent c-Src inhibitors.
Org. Biomol. Chem.
PUBLISHED: 10-31-2013
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A series of 4,6-substituted-(diaphenylamino)quinazolines as c-Src inhibitors have been prepared and their biological activity has also been evaluated. All the compounds displayed potential antiproliferation activities, with IC50 values ranging from 3.42 ?M to 118.81 ?M in five human tumor cell lines. Particularly, compound 15 exhibited higher cytotoxicity against the tested five tumor cell lines compared to the other small molecules. Generally, most of these compounds showed selectivity between the A549 cells and the other four cells, according to their corresponding IC50 values. The results obtained from the in vitro enzyme assay indicated compound 15 has remarkable inhibitory activity against c-Src kinase with an IC50 value of 27.3 nM, which is comparable to the control compounds. Furthermore, molecular docking and QSAR study by means of DS 3.5 (Discovery Studio 3.5, Accelrys, Co. Ltd) explored the binding modes and the structure and activity relationship (SAR) of these derivatives.
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Comparative analysis of dental implant treatment outcomes following mandibular reconstruction with double-barrel fibula bone grafting or vertical distraction osteogenesis fibula: a retrospective study.
Clin Oral Implants Res
PUBLISHED: 10-25-2013
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The purpose of this study was twofold: (i) to compare vertical bone height (VBH) after tumor resection through grafting with either a double-barrel fibula (DBF) technique or vertical distraction osteogenesis of the fibula (VDOF); (ii) to compare the performance of loaded dental implants following either DBF or VDOF with special focus on implant survival, implant success, and bone resorption.
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Accumulation of Fascin+ cells during experimental autoimmune neuritis.
Diagn Pathol
PUBLISHED: 10-24-2013
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Experimental autoimmune neuritis (EAN) is a well-known animal model of human demyelinating polyneuropathies and is characterized by inflammation and demyelination in the peripheral nervous system. Fascin is an evolutionarily highly conserved cytoskeletal protein of 55 kDa containing two actin binding domains that cross-link filamentous actin to hexagonal bundles.
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Identification and Characterization of FGF2-Dependent mRNA: microRNA Networks During Lens Fiber Cell Differentiation.
G3 (Bethesda)
PUBLISHED: 10-22-2013
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MicroRNAs (miRNAs) and fibroblast growth factor (FGF) signaling regulate a wide range of cellular functions, including cell specification, proliferation, migration, differentiation, and survival. In lens, both these systems control lens fiber cell differentiation; however, a possible link between these processes remains to be examined. Herein, the functional requirement for miRNAs in differentiating lens fiber cells was demonstrated via conditional inactivation of Dicer1 in mouse (Mus musculus) lens. To dissect the miRNA-dependent pathways during lens differentiation, we used a rat (Rattus norvegicus) lens epithelial explant system, induced by FGF2 to differentiate, followed by mRNA and miRNA expression profiling. Transcriptome and miRNome analysis identified extensive FGF2-regulated cellular responses that were both independent and dependent on miRNAs. We identified 131 FGF2-regulated miRNAs. Seventy-six of these miRNAs had at least two in silico predicted and inversely regulated target mRNAs. Genes modulated by the greatest number of FGF-regulated miRNAs include DNA-binding transcription factors Nfib, Nfat5/OREBP, c-Maf, Ets1, and N-Myc. Activated FGF signaling influenced bone morphogenetic factor/transforming growth factor-?, Notch, and Wnt signaling cascades implicated earlier in lens differentiation. Specific miRNA:mRNA interaction networks were predicted for c-Maf, N-Myc, and Nfib (DNA-binding transcription factors); Cnot6, Cpsf6, Dicer1, and Tnrc6b (RNA to miRNA processing); and Ash1l, Med1/PBP, and Kdm5b/Jarid1b/Plu1 (chromatin remodeling). Three miRNAs, including miR-143, miR-155, and miR-301a, down-regulated expression of c-Maf in the 3-UTR luciferase reporter assays. These present studies demonstrate for the first time global impact of activated FGF signaling in lens cell culture system and predicted novel gene regulatory networks connected by multiple miRNAs that regulate lens differentiation.
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[Histological observations of Medaka(Oryzias latipes)gonad sexual differentiation and development].
Zool. Res.
PUBLISHED: 10-12-2013
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Over the past few decades, Medaka (Oryzias latipes) has become a model animal in teleost species research due both to its short reproductive cycle and efficient proliferate capacity. Unfortunately, however, systematic data of its sexual differentiation and development have yet to be obtained. In the present study, we observed Medaka gonad development from the earliest recognizable stages through differentiation to maturation under a light microscope, after paraffin sectioning and hematoxylin-eosin staining. The results showed that among juveniles aged 5 to 10 days, the gonad located on the right side of the dorsal abdominal cavity and the germ cells was significantly larger than the surrounding somatic cells. Ten days after hatching, sexual differences between females and males became obvious, and germline cysts derived from oogonium division were present in the gonad. At 50 days after hatching, ovarian cavities and mature sperm were observed. Moreover, during the study we also observed the coexistence of two sexual characteristics during a males development. Together, these observations fill current gaps in developmental and genetic biology that will allow a more efficient use of Medaka as an experimental model.
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Design, synthesis, biological evaluation, and molecular modeling study of 4-alkoxyquinazoline derivatives as potential VEGFR2 kinase inhibitors.
Org. Biomol. Chem.
PUBLISHED: 10-09-2013
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A series of novel 4-alkoxyquinazoline derivatives were prepared and synthesized and their biological activities were evaluated as potential inhibitors of vascular endothelial growth factor receptor 2 (VEGFR2). Of these compounds, compound 3j demonstrated the most potent inhibitory activities against VEGFR2 tyrosine kinase and cell proliferation, the IC50 values of this compound reaching up to 2.72 nM and 0.35 ?M, respectively, compared with Tivozanib (3.40 nM and 0.38 ?M). The obtained results, along with a 3D-QSAR study and molecular docking that was used for investigating the probable binding mode, could provide an important basis for further optimization of compound 3j as a potential tyrosine kinase inhibitor.
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Profiles of Mycobacterium communities under polycyclic aromatic hydrocarbon contamination stress in the Shenfu Irrigation Area, northeast China.
Can. J. Microbiol.
PUBLISHED: 10-03-2013
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Indigenous Mycobacterium communities play an important role in the degradation of polycyclic aromatic hydrocarbons (PAHs), but little is known about Mycobacterium distribution in situ at PAH-contaminated sites. In this study, the diversity and distribution of Mycobacterium communities were investigated in sediments and soils at sites upstream, midstream, and downstream of an oil-sewage irrigation channel, using denaturing gradient gel electrophoresis (DGGE). The results show that heavy PAH contamination in upstream sites negatively affected Mycobacterium community diversity compared with midstream and downstream sites in all 3 sample types (sediments, corn field soils, and rice field soils). There was a correlation between the distribution of Mycobacterium communities and PAH contamination, as indicated by canonical correspondence analysis. Mycobacterium diversity and distribution was found to vary between the 3 sample types.
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Populus euphratica XTH overexpression enhances salinity tolerance by the development of leaf succulence in transgenic tobacco plants.
J. Exp. Bot.
PUBLISHED: 10-01-2013
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Populus euphratica is a salt-tolerant tree species that develops leaf succulence after a prolonged period of salinity stress. In the present study, a putative xyloglucan endotransglucosylase/hydrolase gene (PeXTH) from P. euphratica was isolated and transferred to tobacco plants. PeXTH localized exclusively to the endoplasmic reticulum and cell wall. Plants overexpressing PeXTH were more salt tolerant than wild-type tobacco with respect to root and leaf growth, and survival. The increased capacity for salt tolerance was due mainly to the anatomical and physiological alterations caused by PeXTH overexpression. Compared with the wild type, PeXTH-transgenic plants contained 36% higher water content per unit area and 39% higher ratio of fresh weight to dry weight, a hallmark of leaf succulence. However, the increased water storage in the leaves in PeXTH-transgenic plants was not accompanied by greater leaf thickness but was due to highly packed palisade parenchyma cells and fewer intercellular air spaces between mesophyll cells. In addition to the salt dilution effect in response to NaCl, these anatomical changes increased leaf water-retaining capacity, which lowered the increase of salt concentration in the succulent tissues and mesophyll cells. Moreover, the increased number of mesophyll cells reduced the intercellular air space, which improved carbon economy and resulted in a 47-78% greater net photosynthesis under control and salt treatments (100-150 mM NaCl). Taken together, the results indicate that PeXTH overexpression enhanced salt tolerance by the development of succulent leaves in tobacco plants without swelling.
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[Chemical constituents from seeds of Vigna umbellata].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-27-2013
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Phytochemical investigation was carried out on the seeds of Vigna umbellata. The 70% ethanol extract of the seeds of V. umbellata was subjected to silica gel, Sephadex LH-20, ODS column chromatographies and preparative HPLC. The structures of the isolated compounds were elucidated on the basis of NMR and ESI-MS spectroscopic data Eight compounds were obtained and identified as carboxyatractyligenin (1), 2beta-O-beta-D-glucopyranosyl-15alpha-hydroxy-kaur-16-ene-18,19-dicarboxylic acid (2), 2beta-O-(beta-D-glucopyranosyl) atractyligenin (3), 3R-O-[beta-L-arabinopyranosyl-(1-6) -beta-D-glucopyranosyl] oct-1-ene-3-ol (4), (6S, 7E, 9R) -roseoside (5), liriodendrin (6), resveratrol (7) and maltol (8). Compounds 1-7 were isolated from Vigna genus for the first time, and compound 8 was isolated from V. umbellata for the first time.
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[Current situation of awareness and use of banned pesticides among vegetable greenhouse farmers in a town of Ledu County, China].
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi
PUBLISHED: 09-26-2013
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To investigate the awareness and use of banned pesticides among vegetable greenhouse farmers in a town of Ledu County, Qinghai Province, China and to provide a basis for the management and control of banned pesticides.
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[Enhanced SEC2 mutants and their superantigen activities].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 09-26-2013
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As a superantigen protein, Staphylococcal enterotoxin C2 (SEC2) activates the immune system effectively even in extremely low concentrations, and this property could be applied in adjuvant therapy against tumors and infectious diseases. In order to enhance the superantigen activity of SEC2, the residues at position 102-106 of native SEC2 were substituted for WWH, WWT and WWP by over-lap PCR, and three mutants named ST-1, ST-2 and ST-3 were obtained. Stimulating activity to murine lymphocytes proliferation and inhibiting activity to tumor cell growth of the three mutants were significantly improved compared with the native SEC2. Febrile activities of ST-1 and ST-3 were comparable with the native SEC2, but ST-2 showed markedly increased febrile activity than native SEC2. Moreover, the levels of IL-2, IFN-gamma and TNF-alpha secreted by T cells stimulated with the three mutants were significantly improved, which might be the possible reason for enhanced tumor cell growth inhibition activities. Furthermore, mVbeta8.2 gene transcription levels of murine splenocytes stimulated by the three mutants were dramatically increased compared with native SEC2, suggesting their increased affinities to TCR mVbeta8.2 molecular, which might be the main reason for their enhanced superantigen activities.
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Area-preservation mapping using optimal mass transport.
IEEE Trans Vis Comput Graph
PUBLISHED: 09-21-2013
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We present a novel area-preservation mapping/flattening method using the optimal mass transport technique, based on the Monge-Brenier theory. Our optimal transport map approach is rigorous and solid in theory, efficient and parallel in computation, yet general for various applications. By comparison with the conventional Monge-Kantorovich approach, our method reduces the number of variables from O(n2) to O(n), and converts the optimal mass transport problem to a convex optimization problem, which can now be efficiently carried out by Newtons method. Furthermore, our framework includes the area weighting strategy that enables users to completely control and adjust the size of areas everywhere in an accurate and quantitative way. Our method significantly reduces the complexity of the problem, and improves the efficiency, flexibility and scalability during visualization. Our framework, by combining conformal mapping and optimal mass transport mapping, serves as a powerful tool for a broad range of applications in visualization and graphics, especially for medical imaging. We provide a variety of experimental results to demonstrate the efficiency, robustness and efficacy of our novel framework.
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A sensitive UPLC-MS/MS method for simultaneous determination of eleven bioactive components of Tong-Xie-Yao-Fang decoction in rat biological matrices.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 09-16-2013
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There is a growing concern for the sensitive quantification of multiple components using advanced data acquisition method in herbal medicines (HMs). An improved and rugged UPLC-MS/MS method has been developed and validated for sensitive and rapid determination of multiply analytes from Tong-Xie-Yao-Fang (TXYF) decoction in three biological matrices (plasma/brain tissue/urine) using geniposide and formononetin as internal standards. After solid-phase extraction, chromatographic separation was performed on a C18 column using gradient elution. Quantifier and qualifier transitions were monitored using novel Triggered Dynamic multiple reaction monitoring (TdMRM) in the positive ionization mode. A significant peak symmetry and sensitivity improvement in the TdMRM mode was achieved as compared to conventional MRM. The reproducibility (RSD%) was ?7.9% by applying TdMRM transition while the values were 6.8-20.6% for MRM. Excellent linear calibration curves were obtained under TdMRM transitions over the tested concentration ranges. Intra- and inter-day precisions (RSD%) were ?14.2% and accuracies (RE%) ranged from -9.6% to 10.6%. The validation data of specificity, carryover, recovery, matrix effect and stability were within the required limits. The method was effectively applied to simultaneously detect and quantify 1 lactone, 2 monoterpene glucosides, 1 alkaloid, 5 flavonoids and 2 chromones in plasma, brain tissue and urine after oral administration of TXYF decoction. In conclusion, this new and reliable method is beneficial for quantification and confirmation assays of multiply components in complex biological samples.
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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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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.