JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Swelling/Deswelling-Induced Reversible Surface Wrinkling on Layer-by-Layer Multilayers.
J Phys Chem B
PUBLISHED: 11-19-2014
Show Abstract
Hide Abstract
ABSTRACT In this report, layer-by-layer (LbL) multilayer film is incorporated to fabricate the film/substrate system for investigation of swelling/deswelling-induced wrinkle evolution for the first time. As one typical example, hydrogen-bonded (PAA/PEG)n (PAA: poly(acrylic acid); PEG: poly(ethylene glycol)) is deposited on a poly(dimethyl siloxane) (PDMS) substrate via the LbL technique. Heating treatment causes the covalent crosslinking reaction occurring in the H-bonded multilayers with simultaneously spontaneous formation of labyrinth wrinkles. Subsequent water immersing leads to a series of the swelling-sensitive wrinkle evolution in the thermally-crosslinked (PAA/PEG)n/PDMS bilayer, ranging from initial labyrinth wrinkles (a) to an intermediate smooth wrinkle-free state (b), hexagonally-arranged dimples (c), and the later segmented labyrinth patterns (d). Upon deswelling by re-heating of the swollen bilayer, the reverse wrinkle evolution happens via the process of , or , or , or , which is dependent on the re-heating temperature and the swelling-induced pattern. We investigate the influences of experimental conditions on the swelling kinetics and the resulting wrinkle evolution, which include the thickness of (PAA/PEG)n, the additionally deposited outermost layer (e.g., Pt and polystyrene) and the swelling solution pH. The involved mechanism has been discussed from the viewpoint of the relation between the wrinkling behavior and the swelling/deswelling-induced stress state. The results indicate that the combined strategy of LbL assembly with introduction of additional layers endows us with considerable freedom to fabricate multifunctional film/substrate systems and to tune the instability-driven patterns for advanced properties and extended applications.
Related JoVE Video
Flexible rectangular wave-breaking-free pulse generation in actively mode-locked ytterbium-doped fiber laser.
Opt Express
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
We demonstrate nanosecond scale rectangular wave-breaking-free pulse generation in an actively mode locked Yb-doped fiber laser based on a combined action of active periodic cavity loss modulation and nonlinear polarization rotation effect. The pulse width of the laser can be controlled in the range of 890 ps to above 124 ns instantaneously by adjusting the electrical signal applied on the modulator. As high as 19.8 nJ wave-breaking-free pulse is achieved with maximum available pump power. The output pulse temporal dynamics exhibit various distinct characteristics under different modulation and polarization control. The laser presents unusually flexible tunabilities in pulse width, pulse energy and pulse shape.
Related JoVE Video
Ultra-wideband all-fiber tunable Tm/Ho-co-doped laser at 2 ?m.
Opt Express
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
We demonstrate an all-fiber tunable Tm/Ho-codoped laser operating in the 2 ?m wavelength region. The wavelength tuning range of the Tm/Ho-codoped fiber laser (THFL) with 1-m length of Tm/Ho-codoped fiber (THDF) was from 1727 nm to 2030 nm. Efficient short wavelength operation and ultra-wide wavelength tuning range of 303 nm were both achieved. To the best of our knowledge, this is the broadest tuning range that has been reported for an all-fiber rare-earth-doped laser to date. By increasing the THDF length to 2 m, the obtainable wavelength of the THFL was further red-shifted to the range from 1768 nm to 2071 nm. The output power of the THFL was scaled up from 1810 nm to 2010 nm by using a stage of Tm/Ho-codoped fiber amplifier (THFA), which exhibited the maximum slope efficiency of 42.6% with output power of 408 mW at 1910 nm.
Related JoVE Video
Propionyl-CoA Carboxylase in Haloferax mediterranei: Indispensability for Propionyl-CoA Assimilation and Impacts on Global Metabolism.
Appl. Environ. Microbiol.
PUBLISHED: 11-16-2014
Show Abstract
Hide Abstract
Propionyl-CoA is an important intermediate during biosynthesis and catabolism of intracellular carbon storage poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) in haloarchaea. However, the haloarchaeal propionyl-CoA carboxylase (PCC) and its physiological significance remain unclear. In this study, we identified a PCC that catalyzed propionyl-CoA carboxylation with an acetyl-CoA carboxylation side activity in Haloferax mediterranei. Gene knockout/complementation demonstrated that the PCC enzyme consisted of a fusion protein of a biotin carboxylase and a biotin-carboxyl carrier protein (PccA, HFX_2490), a carboxyltransferase component (PccB, HFX_2478), and an essential small subunit (PccX, HFX_2479). Knockout of pccBX led to an inability to utilize propionate and a higher intracellular propionyl-CoA level, indicating that the PCC is indispensable for propionyl-CoA utilization. Interestingly, H. mediterranei DBX (pccBX-deleted strain) displayed multiple phenotypic changes, including retarded cell growth, decreased glucose consumption, impaired PHBV biosynthesis, and wrinkled cells. A propionyl-CoA concentration equivalent to that accumulated in the DBX cells was demonstrated to inhibit succinyl-CoA synthetase of the TCA cycle in vitro. Genome-wide microarray analysis showed that many genes for glycolysis, pyruvate oxidation, PHBV accumulation, electron transport, and stress responses were affected in DBX. This study not only identified the haloarchaeal PCC for the metabolism of propionyl-CoA, an important intermediate in haloarchaea; but also demonstrated that impaired propionyl-CoA metabolism affected the global metabolism in H. mediterranei.
Related JoVE Video
Effect of Glaucoma Tube Shunt Parameters on Cornea Endothelial Cells in Patients With Ahmed Valve Implants.
Cornea
PUBLISHED: 11-14-2014
Show Abstract
Hide Abstract
The aim of this study was to assess the effect of various tube parameters on corneal endothelial cell density (ECD) after insertion of Ahmed valves.
Related JoVE Video
High-power all-fiber wavelength-tunable thulium doped fiber laser at 2 ?m.
Opt Express
PUBLISHED: 10-17-2014
Show Abstract
Hide Abstract
Power scaling of an all-fiber wavelength-tunable thulium doped fiber laser (TDFL) based on a monolithic master oscillator power amplifier (MOPA) system is presented. The whole configuration is comprised of a low-power seed oscillator and two stages of double-cladding thulium doped fiber amplifiers (TDFAs). The tuning of the operating wavelength is realized by inserting a spectral tunable filter into the seed oscillator. Maximum average output power of 115 W is obtained at 1950 nm with a linearly fitted slope efficiency of 51.7%. This laser has superior spectral characteristics with wavelength tunable from 1940 nm to 2070 nm. To the best of our knowledge, this is the first demonstration of an all-fiber wavelength-tunable TDFL at 2 ?m with output power exceeding 100 W. The results are of great interest for many application areas.
Related JoVE Video
[The assessment of ultrasonic measurement of superior vena cava blood flow for the volume responsiveness of patients with mechanical ventilation].
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue
PUBLISHED: 09-19-2014
Show Abstract
Hide Abstract
To approach the evaluative effect of respiratory variation of superior vena cava peak flow velocity measured using transthoracic echocardiography (TTE) on fluid responsiveness in patients with mechanical ventilation.
Related JoVE Video
Population Genomic Analysis Reveals Highly Conserved Mitochondrial Genomes in the Yeast Species Lachancea thermotolerans.
Genome Biol Evol
PUBLISHED: 09-13-2014
Show Abstract
Hide Abstract
The increasing availability of mitochondrial (mt) sequence data from various yeasts provides a tool to study genomic evolution within and between different species. While the genomes from a range of lineages are available, there is a lack of information concerning intraspecific mtDNA diversity. Here, we analyzed the mt genomes of 50 strains from Lachancea thermotolerans, a protoploid yeast species that has been isolated from several locations (Europe, Asia, Australia, South Africa, and North / South America) and ecological sources (fruit, tree exudate, plant material, and grape and agave fermentations). Protein-coding genes from the mtDNA were used to construct a phylogeny, which reflected a similar, yet less resolved topology than the phylogenetic tree of 50 nuclear genes. In comparison to its sister species Lachancea kluyveri, L. thermotolerans has a smaller mt genome. This is due to shorter intergenic regions and fewer introns, of which the latter are only found in COX1. We revealed that L. kluyveri and L. thermotolerans share similar levels of intraspecific divergence concerning the nuclear genomes. However, L. thermotolerans has a more highly conserved mt genome with the coding regions characterized by low rates of nonsynonymous substitution. Thus, in the mt genomes of L. thermotolerans, stronger purifying selection and lower mutation rates potentially shape genome diversity in contract to what was found for L. kluyveri, demonstrating that the factors driving mt genome evolution are different even between closely related species.
Related JoVE Video
Oral administration of recombinant Lactococcus lactis expressing HSP65 and tandemly repeated P277 reduces the incidence of type I diabetes in non-obese diabetic mice.
PLoS ONE
PUBLISHED: 08-26-2014
Show Abstract
Hide Abstract
Diabetes mellitus type 1 (DM1) is an autoimmune disease that gradually destroys insulin-producing beta-cells. We have previously reported that mucosal administration of fusion protein of HSP65 with tandem repeats of P277 (HSP65-6P277) can reduce the onset of DM1 in non-obese diabetic (NOD) mice. To deliver large amounts of the fusion protein and to enhance long-term immune tolerance effects, in the present study, we investigated the efficacy of using orally administrated L. lactis expressing HSP65-6P277 to reduce the incidence of DM1 in NOD mice. L. lactis strain NZ9000 was engineered to express HSP65-6P277 either constitutively or by nisin induction. After immunization via gavage with the recombinant L. lactis strains to groups of 4-week old female NOD mice for 36 weeks, we observed that oral administration of recombinant L. Lactis resulted in the prevention of hyperglycemia, improved glucose tolerance and reduced insulitis. Immunologic analysis showed that treatment with recombinant L. lactis induced HSP65- and P277- specific T cell immuno-tolerance, as well as antigen-specific proliferation of splenocytes. The results revealed that the DM1-preventing function was in part caused by a reduction in the pro-inflammatory cytokine IFN-? and an increase in the anti-inflammatory cytokine IL-10. Orally administered recombinant L. lactis delivering HSP65-6P277 may be an effective therapeutic approach in preventing DM1.
Related JoVE Video
Flexible picosecond thulium-doped fiber laser using the active mode-locking technique.
Opt Lett
PUBLISHED: 08-15-2014
Show Abstract
Hide Abstract
An all-fiber actively mode-locked thulium-doped fiber laser (AML-TDFL) based on a 10 GHz bandwidth electro-optic intensity modulator (EOM) providing flexible picosecond pulses at 1980 nm is presented. The EOM is driven by electrical pulses rather than traditional sine-wave signals. The repetition rate of output pulses was 21.4 MHz at fundamental mode-locking, which could be scaled up to 1.498 GHz through the 70th order harmonic mode-locking, and the shortest measured output pulse width was 38 ps. Furthermore, the output pulse width could be tuned by either adjusting the modulation frequency with small detuning or changing the width of these driving electrical pulses without frequency detuning. In our work, the stability of these mode-locked pulses obtained from the AML-TDFL was superior; for instance, the measured supermode suppression ratio of 1.498 GHz pulses train was up to 48 dB.
Related JoVE Video
Mode-field adaptor between large-mode-area fiber and single-mode fiber based on fiber tapering and thermally expanded core technique.
Appl Opt
PUBLISHED: 08-05-2014
Show Abstract
Hide Abstract
We report a method to fabricate a mode-field adaptor (MFA) for a large-mode-area (LMA) fiber and single-mode fibers (SMFs) based on fiber tapering and the thermally expanded core (TEC) technique. Through adiabatically tapering a LMA fiber by an oxygen-hydrogen flame, the mode-field diameter is decreased effectively with nearly no extra loss, which makes it possible to realize mode-field adaptation between the LMA fiber and SMFs. Both numerical calculation and experimental results show it is workable to realize fundamental mode propagation in LMA fiber and get a low insertion loss by this method. For a LMA fiber (d=25???m, NA=0.06) and a SMF (d=4???m, NA=0.2), a low loss with less than 0.4 dB has been obtained both in the forward and backward directions experimentally.
Related JoVE Video
[Restriction endonuclease digest - melting curve analysis: a new SNP genotyping and its application in traditional Chinese medicine authentication].
Yao Xue Xue Bao
PUBLISHED: 07-01-2014
Show Abstract
Hide Abstract
Single nucleotide polymorphisms (SNP) is an important molecular marker in traditional Chinese medicine research, and it is widely used in TCM authentication. The present study created a new genotyping method by combining restriction endonuclease digesting with melting curve analysis, which is a stable, rapid and easy doing SNP genotyping method. The new method analyzed SNP genotyping of two chloroplast SNP which was located in or out of the endonuclease recognition site, the results showed that when attaching a 14 bp GC-clamp (cggcgggagggcgg) to 5' end of the primer and selecting suited endonuclease to digest the amplification products, the melting curve of Lonicera japonica and Atractylodes macrocephala were all of double peaks and the adulterants Shan-yin-hua and A. lancea were of single peaks. The results indicated that the method had good stability and reproducibility for identifying authentic medicines from its adulterants. It is a potential SNP genotyping method and named restriction endonuclease digest - melting curve analysis.
Related JoVE Video
T8590C polymorphism of CYP4A11 is a risk factor for hypertension: a meta-analysis.
Chin. Med. J.
PUBLISHED: 06-17-2014
Show Abstract
Hide Abstract
T8590C polymorphism of CYP4A11 has been associated with hypertension, though with conflicting results. The aim of this study was to quantitatively summarize the evidence for CYP4A11 T8590C polymorphism and hypertension risk.
Related JoVE Video
Continued decline of aqueous interleukin-8 after multiple intravitreal injections of ganciclovir for cytomegalovirus retinitis.
J Ocul Pharmacol Ther
PUBLISHED: 05-29-2014
Show Abstract
Hide Abstract
To evaluate the relationship between aqueous inflammation cytokines and cytomegalovirus (CMV) particles in patients with cytomegalovirus retinitis (CMVR), and evaluate the changes in aqueous inflammation cytokines during multiple intravitreal injections of antiviral drugs for CMVR.
Related JoVE Video
Resting-state functional connectivity abnormalities in patients with obsessive-compulsive disorder and their healthy first-degree relatives.
J Psychiatry Neurosci
PUBLISHED: 05-29-2014
Show Abstract
Hide Abstract
Obsessive-compulsive disorder (OCD) is a common, heritable neuropsychiatric disorder, hypothetically underpinned by dysfunction of brain cortical-striatal-thalamic-cortical (CSTC) circuits; however, the extent of brain functional abnormalities in individuals with OCD is unclear, and the genetic basis of this disorder is poorly understood. We determined the whole brain functional connectivity patterns in patients with OCD and their healthy first-degree relatives.
Related JoVE Video
Effect of vitamin D supplementation during pregnancy on the Th1/Th2 cell balance of rat offspring.
Pharmazie
PUBLISHED: 05-27-2014
Show Abstract
Hide Abstract
Vitamin D has important functions in the immune system, and it may suppress the proliferation of T helper (Th) cells and modulate their cytokine production. In this study, we aimed to investigate the effects of maternal supplementation with different doses of vitamin D on the allergy status of the offspring. We gave pregnant female rats a low dose (48000IU/kg, equal to 800IU/d in human) and a high dose (240000IU/kg,equal to 4000IU/d in human) of vitamin D3 intramuscular injection on gestation day (GD)17, and we used an enzyme-linked immunosorbent assay (ELISA) to determine the levels of immune responsive cytokines including IL-4, IgE, and interferon gamma (IFN-gamma) in the offspring. On postnatal day (PND) 21, plasma IL-4 levels were elevated by 10.43% (p < 0.01) in the offspring from the high dose vitamin D3 group compared with the control group. And offspring plasma IL-4 levels in the low dose group decreased by 7.27% (p < 0.05) compared with the control dose group. We found that the offspring of mothers given a low dose of vitamin D3 had a 6.17% (p < 0.01) decrease in their plasma IgE levels compared to control animals, but the high dose of vitamin D3 showed no effect. The serum 25(OH)D3 levels were negatively correlated with the IL-4 (r = -0.561, p < 0.01) and IgE (r = -0.421, p < 0.05) levels of the offspring from the low dose group. In the lung tissues of the offspring of the high dose group, we observed thickening of the alveolar septa and more inflammatory cells compared with the control group and low dose group. Thickened alveolar septa were also found in the lung tissues of the offspring from the control group. We conclude that high dose vitamin D3 maternal supplementation during pregnancy induced an imbalance of Th1 and Th2 cells in their offspring resulting allergic and inflammatory response.
Related JoVE Video
Thirteen watt all-fiber mid-infrared supercontinuum generation in a single mode ZBLAN fiber pumped by a 2 ?m MOPA system.
Opt Lett
PUBLISHED: 04-02-2014
Show Abstract
Hide Abstract
All-fiber-integrated mid-infrared (mid-IR) supercontinuum (SC) generation in a single mode ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) fiber with 13 W average output power and a spectrum extending from ?1.9 to 4.3 ?m is reported, which we believe is the highest output power for mid-IR SC generation in ZBLAN fibers. The overall optical conversion efficiency from the 790 nm pump light of the last stage Tm-doped fiber (TDF) amplifier to the total SC output was 20%, and the SC power for wavelengths longer than 2.5 ?m was 6.85 W with a power ratio of 52.69% with respect to the total SC power. The mid-IR SC generation in ZBLAN fiber was pumped by a 2 ?m master oscillator power amplifier (MOPA) system, which is also very appropriate for high power 2-2.5 ?m region SC generation. We also demonstrate high efficiency SC generation in the TDF amplifier with 62.1 W average power, 39.8% optical efficiency, and a spectrum extending from 1.9 to 2.7 ?m.
Related JoVE Video
Cascaded four-wave mixing seeded by two continuous wave signals.
Appl Opt
PUBLISHED: 03-26-2014
Show Abstract
Hide Abstract
We report on the broadband-cascaded four-wave mixing (CFWM) products generated in a photonic crystal fiber pumped by a picosecond pulse and seeded by two continuous wave (CW) signals. The equal and unequal frequency spaced CFWM products could be obtained through continuously tuning one of the CW wavelengths. Among the equally spaced CFWM products, the smallest frequency spacing was 477 GHz. The influences of the Raman scattering and the third-order dispersion on the CFWM were also discussed.
Related JoVE Video
Ectopic expression of B and T lymphocyte attenuator in gastric cancer: A potential independent prognostic factor in patients with gastric cancer.
Mol Med Rep
PUBLISHED: 03-19-2014
Show Abstract
Hide Abstract
It has been confirmed that B and T lymphocyte attenuator (BTLA; also known as CD272) is a novel co--inhibitory molecule that exhibits a critical role in restraining cell--mediated antitumor immunity. The present study aimed to investigate the expression and prognostic significance of BTLA in gastric adenocarcinoma. Immunohistochemical (IHC) staining was performed to investigate BTLA expression in gastric cancer tissues and normal mucosal tissues. In total, 123 pathologically confirmed specimens were obtained from stage IIIa gastric cancers. A correlation test, Kaplan-Meier curves, and a Cox proportional hazards regression model were used to analyze the data. No BTLA staining in the normal tissues was found, while BTLA-stained gastric carcinoma cells were detected in 75.6% (93/123) of the gastric cancer specimens. High expression levels of BTLA were detected in 31.7% (39/123) of the specimens, while low expression levels were detected in 68.3% (84/123) of the specimens. High BTLA expression levels were associated with shorter survival time, as confirmed by univariate and multivariate analyses. These findings provide a basis for the concept that high BTLA expression levels in gastric cancer, identified by IHC, are an independent biomarker for the poor prognosis of patients with gastric cancer.
Related JoVE Video
The function of EMSY in cancer development.
Tumour Biol.
PUBLISHED: 03-09-2014
Show Abstract
Hide Abstract
EMSY was first reported to bind BRCA2 and to inactivate the function of BRCA2, leading to the development of sporadic breast and ovarian cancers. The function of EMSY may also be involved in DNA damage repair, genomic instability, and chromatin remolding. Recent studies have shown that amplification of EMSY was also associated with other cancers such as prostate and pancreatic cancers and linked to tumor phenotypes and clinical outcomes. By reviewing literatures published since 2003, here, we have summarized the recent advances of EMSY in cancer development.
Related JoVE Video
1H-Nuclear magnetic resonance-based metabolomic analysis of brain in mice with nicotine treatment.
BMC Neurosci
PUBLISHED: 02-18-2014
Show Abstract
Hide Abstract
Nicotine is rapidly absorbed from cigarette smoke and therefore induces a number of chronic illnesses with the widespread use of tobacco products. Studies have shown a few cerebral metabolites modified by nicotine; however, endogenous metabolic profiling in brain has not been well explored.
Related JoVE Video
Chromosomal rearrangements as a major mechanism in the onset of reproductive isolation in Saccharomyces cerevisiae.
Curr. Biol.
PUBLISHED: 01-30-2014
Show Abstract
Hide Abstract
Understanding the molecular basis of how reproductive isolation evolves between individuals from the same species offers valuable insight into patterns of genetic differentiation as well as the onset of speciation [1, 2]. The yeast Saccharomyces cerevisiae constitutes an ideal model partly due to its vast ecological range, high level of genetic diversity [3-6], and laboratory-amendable sexual reproduction. Between S. cerevisiae and its sibling species in the Saccharomyces sensu stricto complex, reproductive isolation acts postzygotically and could be attributed to chromosomal rearrangements [7], cytonuclear incompatibility [8, 9], and antirecombination [10, 11], although the implication of these mechanisms at the incipient stage of speciation remains unclear due to further divergence in the nascent species. Recently, several studies assessed the onset of intraspecific reproductive isolation in S. cerevisiae by evaluating the effect of the mismatch repair system [12-14] or by fostering incipient speciation using the same initial genetic background [15-18]. Nevertheless, the overall genetic diversity within this species was largely overlooked, and no systematic evaluation has been performed. Here, we carried out the first species-wide survey for postzygotic reproductive isolation in S. cerevisiae. We crossed 60 natural isolates sampled from diverse niches with the reference strain S288c and identified 16 cases of reproductive isolation with reduced offspring viabilities ranging from 44% to 86%. Using different mapping strategies, we identified reciprocal translocations in a large fraction of all isolates surveyed, indicating that large-scale chromosomal rearrangements might play a major role in the onset of reproductive isolation in this species.
Related JoVE Video
Development of an improved time-resolved fluoroimmunoassay for simultaneous quantification of C-peptide and insulin in human serum.
Clin. Biochem.
PUBLISHED: 01-06-2014
Show Abstract
Hide Abstract
Diabetes mellitus is a chronic disease affecting millions of people globally and resulting in significant death rates each year. A fast, inexpensive alternative to traditional testing and monitoring techniques is desirable, since secretion of insulin and C-peptide is impaired in diabetes mellitus.
Related JoVE Video
Expression of tmp21 in normal adult human tissues.
Int J Clin Exp Med
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
TMP21, known as p23 protein, is one important member of the p24 protein families. The degradation of TMP21 is mediated by the ubiquitin-proteasome pathway, as with the other presenilin-associated ?-secretase complex members. NFAT plays a very important role in regulation of human TMP21 gene expression. Compared with the function of TMP21, the studies about the distribution of this protein in human tissues are limited. We collected 19 normal adult human tissues from a healthy adult man died in a traffic accident and did examination of all the tissues collected for ICH, western blot and RT-PCR. It was shown that the expression of TMP21 is at high levels in heart, liver, lung, kidney and adrenal gland; moderate levels in brain, pancreas, prostate gland, testicle, small intestine, colon, stomach, gall bladder, thyroid gland and trachea; low levels in skeletal muscle, skin and lymphonodus. TMP21 is widely existed in normal adult human tissues. The current study provided for the first time a comprehensive expression of TMP21 in normal adult human tissues. It will benefit on helping in the design and interpretation of future studies focused on expounding the function of TMP21.
Related JoVE Video
Mesenchymal stem cells contribute to the chemoresistance of hepatocellular carcinoma cells in inflammatory environment by inducing autophagy.
Cell Biosci
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Mesenchymal stem cells (MSCs) have been reported to play an important role in tumor growth. Inflammation is an important feature of hepatocellular carcinoma (HCC). Certain inflammatory cytokines produced in tumor microenvironment modulate functional activities of MSCs. At the present time, however, the role of MSCs in the development of HCC cell resistance to chemotherapy in the inflammatory microenvironment during tumor growth has not yet been identified.
Related JoVE Video
Inhibition of the K+ channel K(Ca)3.1 reduces TGF-?1-induced premature senescence, myofibroblast phenotype transition and proliferation of mesangial cells.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
K(Ca)3.1 channel participates in many important cellular functions. This study planned to investigate the potential involvement of K(Ca)3.1 channel in premature senescence, myofibroblast phenotype transition and proliferation of mesangial cells.
Related JoVE Video
Mechanisms of metabonomic for a gateway drug: nicotine priming enhances behavioral response to cocaine with modification in energy metabolism and neurotransmitter level.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Nicotine, one of the most commonly used drugs, has become a major concern because tobacco serves as a gateway drug and is linked to illicit drug abuse, such as cocaine and marijuana. However, previous studies mainly focused on certain genes or neurotransmitters which have already been known to participate in drug addiction, lacking endogenous metabolic profiling in a global view. To further explore the mechanism by which nicotine modifies the response to cocaine, we developed two conditioned place preference (CPP) models in mice. In threshold dose model, mice were pretreated with nicotine, followed by cocaine treatment at the dose of 2 mg/kg, a threshold dose of cocaine to induce CPP in mice. In high-dose model, mice were only treated with 20 mg/kg cocaine, which induced a significant CPP. (1)H nuclear magnetic resonance based on metabonomics was used to investigate metabolic profiles of the nucleus accumbens (NAc) and striatum. We found that nicotine pretreatment dramatically increased CPP induced by 2 mg/kg cocaine, which was similar to 20 mg/kg cocaine-induced CPP. Interestingly, metabolic profiles showed considerable overlap between these two models. These overlapped metabolites mainly included neurotransmitters as well as the molecules participating in energy homeostasis and cellular metabolism. Our results show that the reinforcing effect of nicotine on behavioral response to cocaine may attribute to the modification of some specific metabolites in NAc and striatum, thus creating a favorable metabolic environment for enhancing conditioned rewarding effect of cocaine. Our findings provide an insight into the effect of cigarette smoking on cocaine dependence and the underlying mechanism.
Related JoVE Video
The future of crystallography in drug discovery.
Expert Opin Drug Discov
PUBLISHED: 12-28-2013
Show Abstract
Hide Abstract
Introduction: X-ray crystallography plays an important role in structure-based drug design (SBDD), and accurate analysis of crystal structures of target macromolecules and macromolecule-ligand complexes is critical at all stages. However, whereas there has been significant progress in improving methods of structural biology, particularly in X-ray crystallography, corresponding progress in the development of computational methods (such as in silico high-throughput screening) is still on the horizon. Crystal structures can be overinterpreted and thus bias hypotheses and follow-up experiments. As in any experimental science, the models of macromolecular structures derived from X-ray diffraction data have their limitations, which need to be critically evaluated and well understood for structure-based drug discovery. Areas covered: This review describes how the validity, accuracy and precision of a protein or nucleic acid structure determined by X-ray crystallography can be evaluated from three different perspectives: i) the nature of the diffraction experiment; ii) the interpretation of an electron density map; and iii) the interpretation of the structural model in terms of function and mechanism. The strategies to optimally exploit a macromolecular structure are also discussed in the context of Big Data analysis, biochemical experimental design and structure-based drug discovery. Expert opinion: Although X-ray crystallography is one of the most detailed microscopes available today for examining macromolecular structures, the authors would like to re-emphasize that such structures are only simplified models of the target macromolecules. The authors also wish to reinforce the idea that a structure should not be thought of as a set of precise coordinates but rather as a framework for generating hypotheses to be explored. Numerous biochemical and biophysical experiments, including new diffraction experiments, can and should be performed to verify or falsify these hypotheses. X-ray crystallography will find its future application in drug discovery by the development of specific tools that would allow realistic interpretation of the outcome coordinates and/or support testing of these hypotheses.
Related JoVE Video
Dissection of the transcriptional regulator GlpR, the promoter elements, and the post-transcriptional processing involved in the fructose-induced activation of the phosphoenolpyruvate-dependent sugar phosphotransferase system in Haloferax mediterranei.
Appl. Environ. Microbiol.
PUBLISHED: 12-13-2013
Show Abstract
Hide Abstract
Among all known archaeal strains, the phosphoenolpyruvate-dependent phosphotransferase system (PTS) for fructose utilization is primarily used by haloarchaea that thrive in hypersaline environments, whereas the molecular details of the regulation of the archaeal PTS under fructose induction remain unclear. In this study, we present a comprehensive examination of the regulatory mechanism of the fructose-PTS (HFX_1559-HFX_1563) in the haloarchaeon Haloferax mediterranei. With gene knockout-complementation, microarray analysis and ChIP-qPCR, we revealed that GlpR (HFX_1565) is the indispensable activator, which specifically binds to the PTS promoter (PPTS) during fructose induction. Further promoter scanning mutation indicated that three sites located at the upstream of the H. mediterranei PPTS, which are conserved in most haloarchaeal PPTS, are found to be involved in this induction. Interestingly, two PTS transcripts (named T8 and T17) with different 5 UTR lengths were observed, and the promoter or 5 UTR swap experiments indicated that the shorter 5 UTR was most likely generated from the longer one. Notably, the translation efficiency of the transcript with this shorter 5 UTR was significantly higher, and the ratio of T8 (with the shorter 5 UTR) to T17 increased during fructose induction, implying that a post-transcriptional mechanism is also involved in PTS activation. With these insights into the molecular regulation of the haloarchaeal PTS, we have proposed a working model of haloarchaea in response to environmental fructose.
Related JoVE Video
High power all fiber mid-IR supercontinuum generation in a ZBLAN fiber pumped by a 2 ?m MOPA system.
Opt Express
PUBLISHED: 10-10-2013
Show Abstract
Hide Abstract
High power all fiber mid-IR supercontinuum (SC) generation in a ZBLAN fiber pumped by a 2 ?m master oscillator power amplifier (MOPA) system is demonstrated. A semiconductor saturable absorber mirror (SESAM) passively mode-locked laser with pulse width of 26 ps at 1960 nm is used as the seed of the MOPA system. A laser spectrum extending from ~1.9 ?m to beyond 2.6 ?m is generated in a subsequent thulium-doped fiber amplifier (TDFA). Then, the spectrum is further broadened to the mid-IR region in the ZBLAN fiber. A mid-IR SC extending from 1.9 to 3.9 ?m with 7.11 W average output power is obtained based on a large mode area TDFA, the SC power for wavelengths longer than 2.5 ?m is 3.52 W with a power ratio of 49.5% with respect to the total SC power. The overall optical conversion efficiency from the 790 nm pump of the large mode area TDFA to the total SC output is 10.4%. To the best of our knowledge, both the 7.11 W total average power and 3.52 W average power in wavelengths beyond 2.5 ?m are the highest power ever reported for a mid-IR SC generation in ZBLAN fiber pumped by 2 ?m fiber lasers and TDFAs.
Related JoVE Video
Electrophysiological characteristics of cardiomyocyte-like cells from rat bone marrow derived mesenchymal stem cells by four inductors.
Chin. Med. J.
PUBLISHED: 09-17-2013
Show Abstract
Hide Abstract
Bone marrow derived mesenchymal stem cells (BMdMSCs) can differentiate into cardiomyocyte-like cells induced by different inductors individually or collectively. In this study, by inducing BMdMSCs with p53 inhibitor (p-fifty three inhibitor-alpha, PFT-?), 5-azacytidine (5-AZA), angiotensin-II (Ang-II) and bone morphogenic protein-2 (BMP-2) we compared the influences of four inductors on the differentiation of rat BMdMSCs into caridomyocyte like-cells.
Related JoVE Video
PCBs levels and indicator congeners in childrens and adolescents hair.
Environ. Pollut.
PUBLISHED: 08-01-2013
Show Abstract
Hide Abstract
Thirty polychlorinated biphenyl (PCB) congeners were determined in the hair samples collected from children (4-12) and adolescents (13-18) of Changchun city, Northeastern China. The mean concentrations of total PCBs and dioxin-like PCBs (dl-PCBs) in the adolescents hair samples were 161.0 ng g(-1) and 61.7 ng g(-1), which were relatively higher than 43.7 ng g(-1) and 14.6 ng g(-1) in the childrens ones. Considering gender difference, the mean concentrations in the girls hair samples were approximately two times higher than those in the boys ones for most PCB congeners. The pentachlorinated biphenyl was the dominant homologue. It was found that the levels of total PCBs and dl-PCBs were highly correlated with PCB 118 level in the childrens hair samples, and with PCB 114 level in the adolescents ones. The result demonstrated that the two PCB congeners could be applied as the indicators to evaluate the concentrations of total PCBs and dl-PCBs in childrens and adolescents hair, respectively.
Related JoVE Video
Hidden-symmetry-protected topological semimetals on a square lattice.
Phys. Rev. Lett.
PUBLISHED: 07-22-2013
Show Abstract
Hide Abstract
We study a two-dimensional fermionic square lattice, which supports the existence of a two-dimensional Weyl semimetal, quantum anomalous Hall effect, and 2?-flux topological semimetal in different parameter ranges. We show that the band degenerate points of the two-dimensional Weyl semimetal and 2?-flux topological semimetal are protected by two distinct novel hidden symmetries, which both correspond to antiunitary composite operations. When these hidden symmetries are broken, a gap opens between the conduction and valence bands, turning the system into a insulator. With appropriate parameters, a quantum anomalous Hall effect emerges. The degenerate point at the boundary between the quantum anomalous Hall insulator and trivial band insulator is also protected by the hidden symmetry.
Related JoVE Video
Over an octave cascaded Raman scattering in short highly germanium-doped silica fiber.
Opt Express
PUBLISHED: 07-12-2013
Show Abstract
Hide Abstract
In this paper, we report on cascaded Raman scattering (RS) in a highly germanium-doped silica fiber (HGDF) pumped by a picosecond pulsed master oscillator power amplifier (MOPA) system at 1064 nm in the normal dispersion regime. Benefited by the higher Raman gain of germanium (GeO2) than silica in the core, the length of the HGDF is only several meters. The broadest output spectrum comprises of 10 orders Raman stokes waves and eventually evolves into a supercontinuum (SC) spanning from 1000 to beyond 2100 nm with an output average power up to Watt scale. To the best of our knowledge, this is the first time to obtain such a broad cascaded RS spectrum in a short length of GeO2-doped step index silica fiber. We also numerically investigate the propagation of picosecond pulses in this HGDF based on the generalized nonlinear Schrödinger equation (GNLSE) which includes most of the dispersive and nonlinear effects, and the simulation results are in fairly good agreement with our experiments. It is believed that the numerical approach adopted in this paper is very beneficial for designing customized cascaded Raman fiber lasers before experimental implementations.
Related JoVE Video
Haloarchaeal-type ?-ketothiolases involved in Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthesis in Haloferax mediterranei.
Appl. Environ. Microbiol.
PUBLISHED: 06-21-2013
Show Abstract
Hide Abstract
The key enzymes for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biosynthesis in haloarchaea have been identified except the ?-ketothiolase(s), which condense two acetyl coenzyme A (acetyl-CoA) molecules to acetoacetyl-CoA, or one acetyl-CoA and one propionyl-CoA to 3-ketovaleryl-CoA. Whole-genome analysis has revealed eight potential ?-ketothiolase genes in the haloarchaeon Haloferax mediterranei, among which the PHBV-specific BktB and PhaA were identified by gene knockout and complementation analysis. Unlike all known bacterial counterparts encoded by a single gene, the haloarchaeal PhaA that was involved in acetoacetyl-CoA generation, was composed of two different types of subunits (PhaA? and PhaA?) and encoded by the cotranscribed HFX_1023 (phaA?) and HFX_1022 (phaA?) genes. Similarly, the BktB that was involved in generation of acetoacetyl-CoA and 3-ketovaleryl-CoA, was also composed of two different types of subunits (BktB? and BktB?) and encoded by cotranscribed HFX_6004 (bktB?) and HFX_6003 (bktB?). BktB? and PhaA? were the catalytic subunits and determined substrate specificities of BktB and PhaA, respectively. Their catalytic triad "Ser-His-His" was distinct from the bacterial "Cys-His-Cys." BktB? and PhaA? both contained an oligosaccharide-binding fold domain, which was essential for the ?-ketothiolase activity. Interestingly, BktB? and PhaA? were functionally interchangeable, although PhaA? preferred functioning with PhaA?. In addition, BktB showed biotechnological potential for the production of PHBV with the desired 3-hydroxyvalerate fraction in haloarchaea. This is the first report of the haloarchaeal type of PHBV-specific ?-ketothiolases, which are distinct from their bacterial counterparts in both subunit composition and catalytic residues.
Related JoVE Video
Predictors of visual response to intravitreal bevacizumab for treatment of neovascular age-related macular degeneration.
J Ophthalmol
PUBLISHED: 06-20-2013
Show Abstract
Hide Abstract
Purpose. To identify the predictors of visual response to the bevacizumab treatment of neovascular age-related macular degeneration (AMD). Design. A cohort study within the Neovascular AMD Treatment Trial Using Bevacizumab (NATTB). Methods. This was a multicenter trial including 144 participants from the NATTB study. Visual outcomes measured by change in visual acuity (VA) score, proportion gaining ?15 letters, and change in central retinal thickness (CRT) were compared among groups according to the baseline, demographic, and ocular characteristics and genotypes. Results. Mean change in the VA score was 9.2 ± 2.3 SD letters with a total of 46 participants (31.9%) gaining ?15 letters. Change in median CRT was -81.5? ? m. Younger age, lower baseline VA score, shorter duration of neovascular AMD, and TT genotype in rs10490924 were significantly associated with greater VA score improvement (P = 0.028, P < 0.001, P = 0.02, and P = 0.039, resp.). Lower baseline VA score and TT genotype in rs10490924 were significantly associated with a higher likelihood of gaining ?15 letters (P = 0.028, and P = 0.021, resp.). Conclusions. Baseline VA and genotype of rs10490924 were both important predictors for visual response to bevacizumab at 6 months. This trial is registered with the Registration no. NCT01306591.
Related JoVE Video
A rapid and sensitive method based on magnetic beads for the detection of hepatitis B virus surface antigen in human serum.
Luminescence
PUBLISHED: 06-06-2013
Show Abstract
Hide Abstract
Current clinically assays, such as enzyme-linked immunosorbent assay and chemiluminescence immunoassay, for hepatitis B surface antigen (HBsAg) are inferior in terms of either sensitivity and accuracy or rapid and high-throughput analysis. A novel assay based on magnetic beads and time-resolved fluoroimmunoassay was developed for the quantitative determination of HBsAg in human serum. HBsAg was captured using two types of anti-HBsAg monoclonal antibodies (B028, S015) immobilized on to magnetic beads and detected using europium-labeled anti-HBsAg polyclonal detection antibody. Finally, the assay yielded a high sensitivity (0.02?IU/mL) and a wide dynamic range (0.02-700?IU/mL) for HBsAg when performed under optimal conditions. Satisfactory accuracy, recovery and specificity were also demonstrated. The intra- and interassay coefficients of variation were 4.7-8.7% and 3.8-7.5%, respectively. The performance of this assay was further assessed against a well-established commercial chemiluminescence immunoassay kit with 399 clinical serum samples. It was revealed that the test results for the two methods were in good correlation (Y?=?1.182X - 0.017, R?=?0.989). In the current study, we demonstrated that this novel time-resolved fluoroimmunoassay could be used: as a highly sensitive, automated and high-throughput immunoassay for the diagnosis of acute or chronic hepatitis B virus infection; for the screening of blood or organ donors; and for the surveillance of persons at risk of acquiring or transmitting hepatitis B virus. Copyright © 2013 John Wiley & Sons, Ltd.
Related JoVE Video
Theoretical models for beam quality evaluation of fiber supercontinuum sources.
Opt Express
PUBLISHED: 06-06-2013
Show Abstract
Hide Abstract
We propose three theoretical models to evaluate the beam quality of the fiber supercontinuum source as a whole. New definitions of spectral centroid and three factors to evaluate the beam quality of supercontinuum source are introduced. Based on the three factors some supercontinuum sources with different output power and spectra obtained from the experiment are calculated numerically. All the results denote that the three models are feasible and useful for the beam quality evaluation and comparison of the fiber supercontinuum sources as a whole with considering the power spectral distribution and propagation modes.
Related JoVE Video
The effects of mindfulness-based stress reduction program on the mental health of family caregivers: a randomized controlled trial.
Psychother Psychosom
PUBLISHED: 05-27-2013
Show Abstract
Hide Abstract
Background: Caregivers of people with chronic conditions are more likely than non-caregivers to have depression and emotional problems. Few studies have examined the effectiveness of mindfulness-based stress reduction (MBSR) in improving their mental well-being. Methods: Caregivers of persons with chronic conditions who scored 7 or above in the Caregiver Strain Index were randomly assigned to the 8-week MBSR group (n = 70) or the self-help control group (n = 71). Validated instruments were used to assess the changes in depressive and anxiety symptoms, quality of life, self-efficacy, self-compassion and mindfulness. Assessments were conducted at baseline, post-intervention and at the 3-month follow-up. Results: Compared to the participants in the control group, participants in the MBSR group had a significantly greater decrease in depressive symptoms at post-intervention and at 3 months post-intervention (p < 0.01). The improvement in state anxiety symptoms was significantly greater among participants in the MBSR group than those of the control group at post-intervention (p = 0.007), although this difference was not statistically significant at 3 months post-intervention (p = 0.084). There was also a statistically significant larger increase in self-efficacy (controlling negative thoughts; p = 0.041) and mindfulness (p = 0.001) among participants in the MBSR group at the 3-month follow-up compared to the participants in the control group. No statistically significant group effects (MBSR vs. control) were found in perceived stress, quality of life or self-compassion. Conclusions: MBSR appears to be a feasible and acceptable intervention to improve mental health among family caregivers with significant care burden, although further studies that include an active control group are needed to make the findings more conclusive. © 2013 S. Karger AG, Basel.
Related JoVE Video
[Accurate calculation of spectral line profiles by considering influence of varying pressure and temperature in a gas].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 05-24-2013
Show Abstract
Hide Abstract
Accurate calculation of spectral line profiles of a gas is very important for gas sensing. As we know, a variation in pressure (temperature) of a gas will result in the corresponding variation in temperature (pressure) of the gas. In the present paper we calculated spectral line profiles of a gas by considering the changes in both temperature and pressure. The authors found that in our case the Lorentzian profile has broader applicable ranges of pressure and temperature, and the Gaussian profile is only applicable in some extreme conditions. Furthermore, the authors found that the influence of variations in pressure and temperature has to be considered in calculating the peak values of the spectral line profiles such as Gaussian, Lorentzian, and Voigt; otherwise the resultant relative errors of the calculated peak values can exceed 0.1. The similar observations were also found for other gases such as CH4, CO2, CO, and NO, although the parameters such as wavelength, coefficient of pressure-broadening, relative molecular mass, and temperature were different.
Related JoVE Video
Magnetic particle-based time-resolved fluoroimmunoassay for the simultaneous determination of ?-fetoprotein and the free ?-subunit of human chorionic gonadotropin.
Analyst
PUBLISHED: 05-15-2013
Show Abstract
Hide Abstract
In this paper, a novel time-resolved fluoroimmunoassay (TRFIA) protocol using magnetic particles for the simultaneous determination of ?-fetoprotein (AFP) and the free ?-subunit of human chorionic gonadotropin (free ?-hCG) in human serum is described. The new approach uses magnetic particles as an immobilization matrix and means of separation, while the luminescent europium and samarium chelates are used as probes. The proposed method was evaluated via a single-step, sandwich-type TRFIA immunoassay of AFP and free ?-hCG as model analytes in serum. With the advantages of magnetic particles, the TRFIA immunoassay exhibited a wide dynamic range for AFP of 0.1-750 ng mL(-1), with a lower detection limit of 0.05 ng mL(-1). The dynamic range for free ?-hCG was 0.16-450 ng mL(-1), with a lower detection limit of 0.08 ng mL(-1). Satisfactory specificity, reproducibility, and recovery of the immunoassay were demonstrated. Good correlations were obtained in the analysis of 446 human serum samples between the proposed method and a commercial TRFIA kit. These results demonstrate the feasibility and potential of the new method as a rapid and highly sensitive immunoassay that could be developed into a platform for multi-analyte determinations in clinical practice.
Related JoVE Video
Teratogenic effects of organic extracts from the Pearl River sediments on Xenopus laevis embryos.
Environ. Toxicol. Pharmacol.
PUBLISHED: 04-26-2013
Show Abstract
Hide Abstract
Toxicity of organic extracts from the Pearl River sediments was investigated with Xenopus laevis embryos. The effects of sediment organic extracts on the mortality, body length and malformation of X. laevis embryos were tested by the Frog Embryo Teratogenesis Assay-Xenopus (FETAX). The 96-h LC50 values for X. laevis embryos ranged from 62 to 137g/L (g extracted sediment per L), and the toxicity effect on body length of larvae was not significant under 20g/L. However, the teratogenic effects produced by sediment organic extracts were diverse, including edema, hypopigmentation, cardiac and ocular malformations, abdomen recurved and curved spine. The percentage of malformations increased with increasing sediment organic extracts, and even reached almost 100% at 10 and 20g/L in Guangzhou district. A gradient of pollution in the Pearl River sediments was discerned from the teratogenic toxicity. Guangzhou district showed higher teratogenic toxicity compared with Panyu and Nansha districts as a possible consequence of high levels of PAHs, PCBs, OCPs and NP in the sediments. The teratogenic effects of organic extracts from the Pearl River sediments were successfully assessed which indicated the feasibility of teratogenic potential studies of sediments using X. laevis embryos.
Related JoVE Video
RecJ-like protein from Pyrococcus furiosus has 3-5 exonuclease activity on RNA: implications for proofreading of 3-mismatched RNA primers in DNA replication.
Nucleic Acids Res.
PUBLISHED: 04-19-2013
Show Abstract
Hide Abstract
Replicative DNA polymerases require an RNA primer for leading and lagging strand DNA synthesis, and primase is responsible for the de novo synthesis of this RNA primer. However, the archaeal primase from Pyrococcus furiosus (Pfu) frequently incorporates mismatched nucleoside monophosphate, which stops RNA synthesis. Pfu DNA polymerase (PolB) cannot elongate the resulting 3-mismatched RNA primer because it cannot remove the 3-mismatched ribonucleotide. This study demonstrates the potential role of a RecJ-like protein from P. furiosus (PfRecJ) in proofreading 3-mismatched ribonucleotides. PfRecJ hydrolyzes single-stranded RNA and the RNA strand of RNA/DNA hybrids in the 3-5 direction, and the kinetic parameters (Km and Kcat) of PfRecJ during RNA strand digestion are consistent with a role in proofreading 3-mismatched RNA primers. Replication protein A, the single-stranded DNA-binding protein, stimulates the removal of 3-mismatched ribonucleotides of the RNA strand in RNA/DNA hybrids, and Pfu DNA polymerase can extend the 3-mismatched RNA primer after the 3-mismatched ribonucleotide is removed by PfRecJ. Finally, we reconstituted the primer-proofreading reaction of a 3-mismatched ribonucleotide RNA/DNA hybrid using PfRecJ, replication protein A, Proliferating cell nuclear antigen (PCNA) and PolB. Given that PfRecJ is associated with the GINS complex, a central nexus in archaeal DNA replication fork, we speculate that PfRecJ proofreads the RNA primer in vivo.
Related JoVE Video
Validation of a Chinese Version of the Five Facet Mindfulness Questionnaire in Hong Kong and Development of a Short Form.
Assessment
PUBLISHED: 04-16-2013
Show Abstract
Hide Abstract
Mindfulness-based interventions are increasingly being used in various populations to improve well-being and reduce psychological afflictions. However, there is lack of a validated mindfulness measurement in the Chinese language. This study validated the Chinese version of the Five Facet Mindfulness Questionnaire (FFMQ-C) in both a community sample of 230 adults and a clinical sample of 156 patients with significant psychological distress. Results showed a good test-retest reliability (.88) and a high internal consistency (.83 in the community sample and .80 in the clinical sample). Mindfulness as measured by FFMQ-C has moderate to large correlations with psychological distress and mental well-being. Two of the five subscales (describing and acting with awareness) showed incremental validity over the others in predicting psychological symptoms and mental health. Confirmatory factor analysis confirmed the five-factor structure of the FFMQ-C and demonstrated adequate model fit. A 20-item short form scale (FFMQ-SF) was developed using the proposed comprehensive criteria. These findings indicate that the FFMQ-C is reliable and valid to measure mindfulness in a Chinese population. Further study is needed to evaluate the psychometric properties of FFMQ-SF.
Related JoVE Video
Imbalance between circulating CD4+ regulatory T and conventional T lymphocytes in patients with HBV-related acute-on-chronic liver failure.
Liver Int.
PUBLISHED: 04-11-2013
Show Abstract
Hide Abstract
The important pathophysiological role of immune dysfunction, especially innate immune dysfunction in patients with acute-on-chronic liver failure (ACLF), has been investigated in recent years, but dysregulation of adaptive immunity remains poorly elucidated. The aim of this study was to (i) determine the CD3(+) T-lymphocyte count and the balance between CD4(+) regulatory T (Tregs) and conventional T cells (Tconv) in hepatitis B virus (HBV)-related ACLF patients; (ii) analyse the frequencies of Tregs subpopulations; and (iii) assess the suppressive potency of CD4(+) Tregs and each fraction.
Related JoVE Video
The MTHFR C677T Polymorphism and Risk of Acute Lymphoblastic Leukemia: an Updated Meta-analysis Based on 37 Case-control Studies.
Asian Pac. J. Cancer Prev.
PUBLISHED: 04-09-2013
Show Abstract
Hide Abstract
Background: The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) has been associated with acute lymphoblastic leukemia (ALL). However, results were conflicting. The aim of this study was to quantitatively summarize the evidence for the MTHFRC677T polymorphism and ALL risk. Methods: Electronic searches of PubMed and the Chinese Biomedicine database were conducted to select case-control studies containing available genotype frequencies of C677T and the odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of any association. Results: Case-control studies including 6,371 cases and 10,850 controls were identified. The meta-analysis stratified by ethnicity showed that individuals with the homozygous TT genotype had decreased risk of ALL (OR= 0.776, 95% CI: 0.687~0.877, p< 0.001) in Caucasians (OR= 0.715, 95% CI: 0.655~0.781, p= 0.000). However, results among Asians (OR=0.711, 95% CI: 0.591~1.005, p= 0.055) and others (OR=0.913, 95% CI: 0.656~1.271, p= 0. 590) did not suggest an association. A symmetric funnel plot, the Eggers test (P=0.093), and the Begg- test (P=0.072) were all suggestive of the lack of publication bias. Conclusion: This meta-analysis supports the idea that the MTHFR C677T genotype is associated with risk of ALL in Caucasians. To draw comprehensive and true conclusions, further prospective studies with larger numbers of participants worldwide are needed to examine associations between the MTHFRC677T polymorphism and ALL.
Related JoVE Video
Efficient generation of broad Raman sidebands in an index-guided photonic crystal fiber.
Appl Opt
PUBLISHED: 04-03-2013
Show Abstract
Hide Abstract
The efficient generation of broad Raman sidebands is experimentally demonstrated in a short piece of index-guided photonic crystal fiber, which is pumped by a high-peak-power pulse near the zero-dispersion wavelength and seeded by a continuous-wave Stokes signal centered at 1117 nm. The Raman sidebands generated via stimulated Raman scattering and cascaded four-wave mixing contain five Stokes and six anti-Stokes peaks and span from 827 to 1398 nm, and the 3 dB linewidth for each peak is smaller than 1 nm. However, the pure Raman sidebands are largely dependent on the pulse pump power as well as the fiber length.
Related JoVE Video
AlphaLISA for the determination of median levels of the free ? subunit of human chorionic gonadotropin in the serum of pregnant women.
J Immunoassay Immunochem
PUBLISHED: 03-30-2013
Show Abstract
Hide Abstract
Measurement of the free ? subunit of human chorionic gonadotropin (free ?-hCG) in serum is useful for prenatal screening. Concentrations of free ?-hCG vary in different races. Conventional assays used for such measurements have limitations. We applied the AlphaLISA to measure levels of free ?-hCG in maternal serum during 8-20 weeks of gestation in women from southern China. Two anti-free ?-hCG antibodies were used: one was coated on AlphaLISA acceptor beads and the one was biotinylated. The assay also contained donor beads coated with streptavidin. The AlphaLISA assay detection limit was 0.11 ng/mL, and the analytical range was 0.11-200 ng/mL. The intra- and interassay coefficients of variation were 1.32%-2.50% and 3.44%-5.45%, respectively. The correlation with commercial Eu(3+)-labeled free ?-HCG-TRFIA assay was good (y = 1.045x + 1.580, r(2) = 0.978). Median levels of free ?-hCG in maternal serum at 8-20 weeks gestation were higher in women from southern China compared with those reported in women from other countries. The AlphaLISA for free ?-HCG could become the assay of choice for applications in clinical diagnostics. The established median value of free ?-HCG is helpful in clinical diagnosis specific for southern Chinese women.
Related JoVE Video
Characterization of genes for chitin catabolism in Haloferax mediterranei.
Appl. Microbiol. Biotechnol.
PUBLISHED: 03-21-2013
Show Abstract
Hide Abstract
Chitin is the second most abundant natural polysaccharide after cellulose. But degradation of chitin has never been reported in haloarchaea. In this study, we revealed that Haloferax mediterranei, a metabolically versatile haloarchaeon, could utilize colloidal or powdered chitin for growth and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) accumulation, and the gene cluster (HFX_5025-5039) for the chitin catabolism pathway was experimentally identified. First, reverse transcription polymerase chain reaction results showed that the expression of the genes encoding the four putative chitinases (ChiAHme, ChiBHme, ChiCHme, and ChiDHme, HFX_5036-5039), the LmbE-like deacetylase (DacHme, HFX_5027), and the glycosidase (GlyAHme, HFX_5029) was induced by colloidal or powdered chitin, and chiA Hme, chiB Hme, and chiC Hme were cotranscribed. Knockout of chiABC Hme or chiD Hme had a significant effect on cell growth and PHBV production when chitin was used as the sole carbon source, and the chiABCD Hme knockout mutant lost the capability to utilize chitin. Knockout of dac Hme or glyA Hme also decreased PHBV accumulation on chitin. These results suggested that ChiABCDHme, DacHme, and GlyAHme were indeed involved in chitin degradation in H. mediterranei. Additionally, the chitinase assay showed that each chitinase possessed hydrolytic activity toward colloidal or powdered chitin, and the major product of colloidal chitin hydrolysis by ChiABCDHme was diacetylchitobiose, which was likely further degraded to monosaccharides by DacHme, GlyAHme, and other related enzymes for both cell growth and PHBV biosynthesis. Taken together, this study revealed the genes and enzymes involved in chitin catabolism in haloarchaea for the first time and indicated the potential of H. mediterranei as a whole-cell biocatalyst in chitin bioconversion.
Related JoVE Video
Clinicopathologic significance of putative stem cell marker, CD44 and CD133, in human gastric carcinoma.
J Surg Oncol
PUBLISHED: 03-06-2013
Show Abstract
Hide Abstract
CD44 and CD133 have been reported as putative stem cell markers. However, the clinicopathologic significance of CD44 and CD133 expression in patients with gastric carcinoma (GC) has not been clearly elucidated.
Related JoVE Video
A novel homogeneous time-resolved fluoroimmunoassay for carcinoembryonic antigen based on water-soluble quantum dots.
J Fluoresc
PUBLISHED: 02-24-2013
Show Abstract
Hide Abstract
Quantum dots are not widely used in clinical diagnosis. However, the homogeneous time-resolved fluorescence assay possesses many advantages over current methods for the detection of carcinoembryonic antigen (CEA), a primary marker for many cancers and diseases. Therefore, a novel luminescent terbium chelates- (LTCs) and quantum dots-based homogeneous time-resolved fluorescence assay was developed to detect CEA. Glutathione-capped quantum dots (QDs) were prepared from oil-soluble QDs with a 565 nm emission peak. Conjugates (QDs-6 F11) were prepared with QDs and anti-CEA monoclonal antibody. LTCs were prepared and conjugates (LTCs-S001) were prepared with another anti-CEA monoclonal antibody. The fluorescence lifetime of QDs was optimized for sequential analysis. The Förster distance (R0) was calculated as 61.9 Å based on the overlap of the spectra of QDs-6 F11 and LTCs-S001. Using a double-antibody sandwich approach, the above antibody conjugates were used as energy acceptor and donor, respectively. The signals from QDs were collected in time-resolved mode and analyzed for the detection of CEA. The results show that the QDs were suitable for time-resolved fluoroassays. The spatial distance of the donor-acceptor pair was calculated to be 61.9 Å. The signals from QDs were proportional to CEA concentration. The standard curve was LogY?=?2.75566?+?0.94457 LogX (R?=?0.998) using the fluorescence counts (Y) of QDs and the concentrations of CEA (X). The calculated sensitivity was 0.4 ng/mL. The results indicate that water-soluble QDs are suitable for the homogenous immunoassay. This work has expanded future applications of QDs in homogeneous clinical bioassays. Furthermore, a QDs-based homogeneous multiplex immunoassay will be investigated as a biomarker for infectious diseases in future research.
Related JoVE Video
Combination of BMP-2 and 5-AZA is advantageous in rat bone marrow-derived mesenchymal stem cells differentiation into cardiomyocytes.
Cell Biol. Int.
PUBLISHED: 02-23-2013
Show Abstract
Hide Abstract
Bone morphogenetic protein-2 (BMP-2) has a crucial role in the development of cardiogenesis, and is used in inducing bone marrow mesenchymal stem cells (BMMSCs) to differentiate into cardiomyocytes. We have examined a combination of BMP-2 and 5-azacytidine (5-AZA) in inducing these differentiation effects. BMMSCs were collected and purified from bone marrow of 4-week-old Sprague-Dawley (SD) rats by density-gradient centrifugation and differential attachment. The fourth passage subculture of BMMSCs, selected by cytometry for purity and identification, was divided into four groups: a control group, BMP-2 treated, 5-AZA treated, and a combination of BMP-2 and 5-AZA treatment. Expression of cardiac Troponin I (cTnI) and Connexin 43 (CX-43) in BMMSCs after induction were detected by immunofluorescence and Western blot. Flow cytometry analysis was used for differentiation rates and apoptosis of induced BMMSCs, through the expression of cardiac Troponin T (cTnT) and Annexin V-FITC & PI kit, respectively. BMP-2 can ameliorate apoptosis of BMMSCs caused by 5-AZA and promote the differentiation of BMMSCs into cardiomyocyte-like cells. Thus a combination of BMP-2 and 5-AZA can significantly improve the cardiac differentiation with fewer cell damage effects, making it a safe and effective method of induction in vitro.
Related JoVE Video
Multiple propionyl coenzyme A-supplying pathways for production of the bioplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in Haloferax mediterranei.
Appl. Environ. Microbiol.
PUBLISHED: 02-22-2013
Show Abstract
Hide Abstract
Haloferax mediterranei is able to accumulate the bioplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with more than 10 mol% 3-hydroxyvalerate (3HV) from unrelated carbon sources. However, the pathways that produce propionyl coenzyme A (propionyl-CoA), an important precursor of 3HV monomer, have not yet been determined. Bioinformatic analysis of H. mediterranei genome indicated that this strain uses multiple pathways for propionyl-CoA biosynthesis, including the citramalate/2-oxobutyrate pathway, the aspartate/2-oxobutyrate pathway, the methylmalonyl-CoA pathway, and a novel 3-hydroxypropionate pathway. Cofeeding of pathway intermediates and inactivating pathway-specific genes supported that these four pathways were indeed involved in the biosynthesis of 3HV monomer. The novel 3-hydroxypropionate pathway that couples CO2 assimilation with PHBV biosynthesis was further confirmed by analysis of (13)C positional enrichment in 3HV. Notably, (13)C metabolic flux analysis showed that the citramalate/2-oxobutyrate pathway (53.0% flux) and the 3-hydroxypropionate pathway (30.6% flux) were the two main generators of propionyl-CoA from glucose. In addition, genetic perturbation on the transcriptome of the ?phaEC mutant (deficient in PHBV accumulation) revealed that a considerable number of genes in the four propionyl-CoA synthetic pathways were significantly downregulated. We determined for the first time four propionyl-CoA-supplying pathways for PHBV production in haloarchaea, particularly including a new 3-hydroxypropionate pathway. These results would provide novel strategies for the production of PHBV with controllable 3HV molar fraction.
Related JoVE Video
Risk factors for human papillomavirus infection in Shanghai suburbs: a population-based study with 10,000 women.
J. Clin. Virol.
PUBLISHED: 02-12-2013
Show Abstract
Hide Abstract
High risk human papillomavirus (HPV) infection is the major cause of cervical cancer. Several epidemiological studies have performed HPV screening in Chinese women, but no report was for Shanghai suburb women.
Related JoVE Video
Temperature sensing using the bandgap-like effect in a selectively liquid-filled photonic crystal fiber.
Opt Lett
PUBLISHED: 02-06-2013
Show Abstract
Hide Abstract
A compact temperature sensor based on a selectively liquid-filled photonic crystal fiber (PCF) is proposed using controlled hole collapse in PCF post-processing. The first ring around the core is filled with liquid of higher refractive index than the matrix, while the outer rings of holes are filled with air. The bandgap (BG)-like effect of the high refractive index ring is analyzed. Absorption loss spectra of the fiber are found to be quite sensitive to the refractive index of liquid when the liquid is lossy. Using the BG-like effect, a fiber temperature sensor is fabricated by selectively injecting a mixture of dimethyl sulfoxide and aqueous gold colloids with a high thermo-optic coefficient to the PCF. Temperature sensitivity up to -5.5 nm/°C is experimentally confirmed.
Related JoVE Video
A novel immunoassay for the quantization of CYFRA 21-1 in human serum.
J. Clin. Lab. Anal.
PUBLISHED: 02-04-2013
Show Abstract
Hide Abstract
Cytokeratin 19 fragment antigen (CYFRA 21-1) is used to diagnose and monitor neoplasms. However, the main disadvantages of the currently available CYFRA 21-1 assays include heterogenous technology, being time-consuming, and having low through-put with low insensitivity. This study investigated the use of amplified luminescent proximity homogeneous immunoassay (AlphaLISA) for the quantization of CYFRA 21-1 in human serum.
Related JoVE Video
One cell, multiple roles: contribution of mesenchymal stem cells to tumor development in tumor microenvironment.
Cell Biosci
PUBLISHED: 01-21-2013
Show Abstract
Hide Abstract
The discovery of tissue reparative and immunosuppressive abilities of mesenchymal stem cells (MSCs) has drawn more attention to tumor microenvironment and its role in providing the soil for the tumor cell growth. MSCs are recruited to tumor which is referred as the never healing wound and altered by the inflammation environment, thereby helping to construct the tumor microenvironment. The environment orchestrated by MSCs and other factors can be associated with angiogenesis, immunosuppression, inhibition of apoptosis, epithelial-mesenchymal transition (EMT), survival of cancer stem cells, which all contribute to tumor growth and progression. In this review, we will discuss how MSCs are recruited to the tumor microenvironment and what effects they have on tumor progression.
Related JoVE Video
Pharmacist-conducted medication reconciliation at hospital admission using information technology in Taiwan.
Int J Med Inform
PUBLISHED: 01-16-2013
Show Abstract
Hide Abstract
Obtaining an accurate medication history upon admission to the hospital can be challenging and time-consuming. This study evaluated the efficacy of a medication reconciliation program, conducted by pharmacists, with the assistance of medication usage data from the Taiwan National Health Insurance (NHI). Characteristics of patients at high risk for drug discrepancies were also determined.
Related JoVE Video
p53 codon 72 polymorphism and breast cancer risk: A meta-analysis.
Exp Ther Med
PUBLISHED: 01-04-2013
Show Abstract
Hide Abstract
p53 is a tumor suppressor gene and plays important roles in the etiology of breast cancer. Studies have produced conflicting results concerning the role of p53 codon 72 polymorphism (G>C) on the risk of breast cancer; therefore, a meta-analysis was performed to estimate the association between the p53 codon 72 polymorphism and breast cancer. Screening of the PubMed database was conducted to identify relevant studies. Studies containing available genotype frequencies of the p53 codon 72 polymorphism were selected and a pooled odds ratio (OR) with 95% confidence interval (CI) was used to assess the association. Sixty-one published studies, including 28,539 breast cancer patients and 32,788 controls were identified. The results suggest that variant genotypes are not associated with breast cancer risk (Pro/Pro + Arg/Pro vs. Arg/Arg: OR=1.016, 95% CI=0.931-1.11, P=0.722). The symmetric funnel plot, Eggers test (P=0.506) and Beggs test (P=0.921) were all suggestive of the lack of publication bias. This meta-analysis suggests that the p53 codon 72 Pro/Pro + Arg/Pro genotypes are not associated with an increased risk of breast cancer. To validate the association between the p53 codon 72 polymorphism and breast cancer, further studies with larger numbers of participants worldwide are required.
Related JoVE Video
Chlamydophila pneumoniae endonuclease IV prefers to remove mismatched 3 ribonucleotides: implication in proofreading mismatched 3-terminal nucleotides in short-patch repair synthesis.
DNA Repair (Amst.)
PUBLISHED: 01-04-2013
Show Abstract
Hide Abstract
DNA polymerase I (DNApolI) catalyzes DNA synthesis during Okazaki fragment maturation, base excision repair, and nucleotide excision repair. Some bacterial DNApolIs are deficient in 3-5 exonuclease, which is required for removing an incorrectly incorporated 3-terminal nucleotide during DNA elongation by DNA polymerase activity. The key amino acid residues in the exonuclease center of Chlamydophila pneumoniae DNApolI (CpDNApolI) are naturally mutated, resulting in the loss of 3-5 exonuclease. Hence, the manner by which CpDNApolI proofreads the incorrectly incorporated nucleotide during DNA synthesis warrants clarification. C. pneumoniae encodes three 3-5 exonuclease activities: one endonuclease IV and two homologs of the epsilon subunit of replicative DNA polymerase III. The three proteins were biochemically characterized using single- and double-stranded DNA substrate. Among them, C. pneumoniae endonuclease IV (CpendoIV) possesses 3-5 exonuclease activity that prefers to remove mismatched 3-terminal nucleotides in the nick, gap, and 3 recess of a double-stranded DNA (dsDNA). Finally, we reconstituted the proofreading reaction of the mismatched 3-terminal nucleotide using the dsDNA with a nick or 3 recess as substrate. Upon proofreading of the mismatched 3-terminal nucleotide by CpendoIV, CpDNApolI can correctly reincorporate the matched nucleotide and the nick is further sealed by DNA ligase. Based on our biochemical results, we proposed that CpendoIV was responsible for proofreading the replication errors of CpDNApolI.
Related JoVE Video
Small Ribosomal Protein Subunit S7 Suppresses Ovarian Tumorigenesis through Regulation of the PI3K/AKT and MAPK Pathways.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Small ribosomal protein subunit S7 (RPS7) has been reported to be associated with various malignancies, but the role of RPS7 in ovarian cancer remains unclear. In this study, we found that silencing of RPS7 by a specific shRNA promoted ovarian cancer cell proliferation, accelerated cell cycle progression, and slightly reduced cell apoptosis and response to cisplatin treatment. Knockdown of RPS7 resulted in increased expression of P85?, P110?, and AKT2. Although the basal levels of ERK1/2, MEK1/2, and P38 were inconsistently altered in ovarian cancer cells, the phosphorylated forms of MEK1/2 (Ser217/221), ERK1/2 (Thr202/Tyr204), JNK1/2 (Thr183/Tyr185), and P38 (Thr180/Tyr182) were consistently reduced after RPS7 was silenced. Both the in vitro anchorage-independent colony formation and in vivo animal tumor formation capability of cells were enhanced after RPS7 was depleted. We also showed that silencing of RPS7 enhanced ovarian cancer cell migration and invasion. In sum, our results suggest that RPS7 suppresses ovarian tumorigenesis and metastasis through PI3K/AKT and MAPK signal pathways. Thus, RPS7 may be used as a potential marker for diagnosis and treatment of ovarian cancer.
Related JoVE Video
Glycyrrhizin attenuates rat ischemic spinal cord injury by suppressing inflammatory cytokines and HMGB1.
Acta Pharmacol. Sin.
PUBLISHED: 12-12-2011
Show Abstract
Hide Abstract
To investigate the neuroprotective effect of glycyrrhizin (Gly) against the ischemic injury of rat spinal cord and the possible role of the nuclear protein high-mobility group box 1 (HMGB1) in the process.
Related JoVE Video
[Correlation analysis between the expression of aquaporin 4 and magnetic resonance imaging of brain tissue in severely scalded rabbit with brain edema during early stage].
Zhonghua Shao Shang Za Zhi
PUBLISHED: 10-26-2011
Show Abstract
Hide Abstract
To observe expression pattern of aquaporin 4 (AQP4) in brain tissue of severely scalded rabbit during early stage of brain edema and its relationship with signal changes in magnetic resonance imaging (MRI), and to explore the feature of water transmembrane transportation in brain edema at early stage after severe scald.
Related JoVE Video
[The effects of administration of valproic acid on organ function and outcome in a canine lethal hemorrhagic shock model].
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue
PUBLISHED: 09-01-2011
Show Abstract
Hide Abstract
To investigate the effects of valproic acid (histone deacetylase inhibitor) on visceral function and outcome in a canine lethal hemorrhage model.
Related JoVE Video
Continuous wave, dual-wavelength-pumped supercontinuum generation in an all-fiber device.
Appl Opt
PUBLISHED: 06-16-2011
Show Abstract
Hide Abstract
We propose a continuous wave dual-wavelength-pumped scheme for visible supercontinuum (SC) generation. The scheme is numerically studied in this paper. In the scheme, the dual-wavelength pump source is produced through a four-wave mixing process in a photonic crystal fiber. SC generation is numerically investigated by solving the generalized nonlinear Schrödinger equation. The results verify that the visible SC can be generated by the scheme, which implies that the scheme is promising for generating visible SC with high spectral power densities.
Related JoVE Video
No relationship between the distribution of mast cells and the survival of stage IIIB colon cancer patients.
J Transl Med
PUBLISHED: 06-09-2011
Show Abstract
Hide Abstract
Mast cells promote the progression of experimental tumors and might be a valuable therapeutic target. However, the relevant clinical evidence is still controversial. This study analyzed the relationship between the distribution of mast cells and the survival of patients with colon cancer to study whether mast cells contribute to tumor progression.
Related JoVE Video
[Observation on immediate analgesic effect of acupuncture at Shiqizhui (EX-B 8) only or multi-acupoints in patients with dysmenorrhea: a randomized controlled trial].
Zhongguo Zhen Jiu
PUBLISHED: 06-08-2011
Show Abstract
Hide Abstract
To compare the different therapeutic effect between acupuncture at Shiqizhui (EX-B 8) only and multi acupoints on dysmenorrhea.
Related JoVE Video
Mast Cells in Adjacent Normal Colon Mucosa rather than Those in Invasive Margin are Related to Progression of Colon Cancer.
Chin. J. Cancer Res.
PUBLISHED: 04-27-2011
Show Abstract
Hide Abstract
Mast cells (MC) reside in the mucosa of the digestive tract as the first line against bacteria and toxins. Clinical evidence has implied that the infiltration of mast cells in colorectal cancers is related to malignant phenotypes and a poor prognosis. This study compared the role of mast cells in adjacent normal colon mucosa and in the invasive margin during the progression of colon cancer.
Related JoVE Video
Effects of amphiphilic PCL-PEG-PCL copolymer addition on 5-fluorouracil release from biodegradable PCL films for stent application.
Int J Pharm
PUBLISHED: 04-26-2011
Show Abstract
Hide Abstract
Biodegradable film-based stents emerged as a promising medical platform for drug delivery to resolve stenosis encountered in physiological conduits (e.g. blood vessels, biliary and urethral tracts). Drug release kinetics significantly affects the pharmacological effects of a stent, thus it is desirable for a stent to possess highly adjustable drug release kinetics. In this study, a series of amphiphilic poly(?-caprolactone)-poly(ethylene glycol)-poly(?-caprolactone) (PCL-PEG-PCL) copolymers were used as additives to adjust 5-fluorouracil (5-FU) release from PCL films. The effects of the copolymer addition on drug release behavior, drug permeability, crystalline states, and surface and internal morphologies of the films were investigated. It was found that, the addition of PCL-PEG-PCL could accelerate 5-FU release. The release rate of 5-FU increased with increasing content of PCL-PEG-PCL in the film, but it decreased with the ratio of PCL blocks in the PCL-PEG-PCL copolymer. The diffusion test results showed that 5-FU diffused through the film containing PCL-PEG-PCL faster than it permeated through the pure PCL film, indicating that the addition of PCL-PEG-PCL can improve the permeability of 5-FU in PCL film. The addition of PCL-PEG-PCL copolymer showed high drug-release-regulating ability in the 5-FU-loaded PCL films.
Related JoVE Video

What is Visualize?

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

How does it work?

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

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

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