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Find video protocols related to scientific articles indexed in Pubmed.
Multifunctional optical nanofiber polarization devices with 3D geometry.
Opt Express
PUBLISHED: 08-05-2014
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Here a reliable fabrication process enabling the integration of multiple functions in a single rod with one optical nano/microfiber (ONM) was proposed, which represents a further step in the "lab-on-a-rod" technology roadmap. With a unique 3D geometry, the all-fiber in-line devices based on lab-on-a-rod techniques have more freedom and potential for compactness and functionality than conventional fiber devices. With the hybrid polymer-metal-dielectric nanostructure, the coupling between the plasmonic and waveguide modes leads to hybridization of the fundamental mode and polarization-dependent loss. By functionalizing the rod surface with a nanoscale silver film and tuning the coil geometry, a broadband polarizer and single-polarization resonator, respectively, were demonstrated. The polarizer has an extinction ratio of more than 20 dB over a spectral range of 450 nm. The resonator has a Q factor of more than 78,000 with excellent suppression of polarization noise. This type of miniature single-polarization resonator is impossible to realize by conventional fabrication processes and has wide applications in fiber communication, lasing, and especially sensing.
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Reduced expression of SOX7 in ovarian cancer: a novel tumor suppressor through the Wnt/?-catenin signaling pathway.
J Ovarian Res
PUBLISHED: 07-02-2014
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Products of the SOX gene family play important roles in the life process. One of the members, SOX7, is associated with the development of a variety of cancers as a tumor suppression factor, but its relevance with ovarian cancer was unclear. In this study, we investigated the involvement of SOX7 in the progression and prognosis of epithelial ovarian cancer (EOC) and the involved mechanisms.
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Steroidal sapogenins and glycosides from the fibrous roots of Polygonatum odoratum with inhibitory effect on tissue factor (TF) procoagulant activity.
Steroids
PUBLISHED: 06-24-2014
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Six new spirostane glycosides (1-6), named polygodosides A-F, one new furostanol glycoside, polygodoside G (7), one new cholestane glycoside, polygodoside H (8), and one new steroidal sapogenin, polygodosin A (9), together with thirteen known compounds (10-22) were isolated from a 90% MeOH extract of the fibrous roots of Polygonatum odoratum (Mill.) Druce. The structures of new compounds were elucidated by extensive 1D and 2D NMR spectroscopic analyses and mass spectrometry. The effects on TF procoagulant activity in THP-1 cells were tested for most of the compounds.
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Design, synthesis, and fungicidal activity of novel carboxylic acid amides represented by N-benzhydryl valinamode carbamates.
Org. Biomol. Chem.
PUBLISHED: 06-18-2014
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Carboxylic acid amide (CAA) fungicides are an important class of agricultural fungicide with oomycete activity and low toxicity toward mammalian cells. To find CAA analogues with high activity against resistant pathogens, a series of substituted N-benzhydryl valinamide carbamate derivatives were designed and synthesized by introducing substituted aromatic rings into valinamide carbamate leads. Bioassays showed that some title compounds exhibited very good in vitro fungicidal activity against Phytophthora capsici and in vivo fungicidal activities against Pseudoperonospora cubensis. Topomer CoMFA was performed to explore the structure-activity relationship on the basis of the in vitro data. The dimethoxy substituted aromatic analogue 9e was found to display higher in vitro fungicidal activity against Phytophthora capsici than iprovalicarb but lower activity than mandipropamid, and higher in vivo fungicidal activity against Pseudoperonospora cubensis than dimethomorph at a dosage of 6.25 ?g mL(-1).
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Network pharmacology-based prediction and verification of the molecular targets and pathways for schisandrin against cerebrovascular disease.
Chin J Nat Med
PUBLISHED: 05-28-2014
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To illuminate the molecular targets for schisandrin against cerebrovascular disease based on the combined methods of network pharmacology prediction and experimental verification.
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Berberine inhibits LPS-induced TF procoagulant activity and expression through NF-?B/p65, Akt and MAPK pathway in THP-1 cells.
Pharmacol Rep
PUBLISHED: 04-03-2014
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Considering the key role of TF in coagulation of sepsis or acute lung injury (ALI), we investigated whether berberine (BBR) could inhibit TF expression and procoagulant activity and explored its possible mechanism.
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Bimetallic ruthenium complexes bridged by divinylphenylene bearing oligo(ethylene glycol)methylether: synthesis, (spectro)electrochemistry and the lithium cation effect.
Dalton Trans
PUBLISHED: 01-25-2014
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A series of 1,4-disubstituted ruthenium-vinyl complexes, (E,E)-[{(PMe3)3(CO)ClRu}2(?-HC=CH-Ar-CH=CH)], in which the 1,4-diethenylphenylene bridge bears two oligo(ethylene glycol)methyl ether side chains at different positions (2,5- and 2,3-positions), were prepared. The respective products were characterized by elemental analyses and NMR spectroscopy. The structures of complexes 1b and 1e were established by X-ray crystallography. The electronic properties of the complexes were investigated by cyclic voltammetry, and IR and UV-vis/NIR spectroscopies. Electrochemical studies showed that the 2,5-substituents better stabilized the mixed-valence states; the electrochemical behavior was greatly affected by lithium cations, especially complex 1g with 2,3-substituents, which was further supported by IR and UV-vis/NIR spectra changes. Spectroelectrochemical studies showed that the redox chemistry was dominated by the non-innocent character of the bridging fragment.
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7-Benzyl-3-methyl-6-phenyl-imidazo[2,1-b][1,3]thia-zol-7-ium chloride 0.75-hydrate.
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 08-01-2013
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Theasymmetric unit of the title salt, C19H17N2S(+)·Cl(-)·0.75H2O, contains two symmetrically independent formula units of the carbenium salt along with three water mol-ecules. The water mol-ecules are only 50% occupated, and one of them is positioned in a hydro-phobic pocket not forming any hydrogen bonds. The conformation of the independent cations is very similar, with dihedral angles of 61.0?(2) and 61.5?(3)° between the benzene rings. They form quasi-centrosymmetric couples via ?-? stacking inter-actions between the benzene and imidazo[2,1-b]thia-zole rings [centroid-centroid distances = 3.718?(3) and 3.663?(3)?Å]. In the crystal, O-H?Cl hydrogen bonds lead to the formation of a helical anion-water chain along the c-axis direction. The cations connect to the anion-water chain through C-H?Cl inter-actions, generating a three-dimensional supra-molecular network. O-H?S hydrogen bonds and C-H?O inter-actions also occur.
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[Applications of camera trap in wildlife population ecology].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 08-01-2013
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Population parameter estimation and spatial distribution pattern are the main issues in animal ecology and conservation biology. In recent decades, camera trap as a non-invasive technique in field survey has been widely used in wildlife ecology and conservation research, and showed its great superiority under the conditions of traditional survey methods difficult to achieve. The animal presence data collected by camera trap can provide extremely valuable quantitative information on wildlife populations. In this review, the operational principles of camera trap were introduced to provide an intuitive understanding of this technique, and then, the applications of this technique in two main fields of population ecology, i. e. , population density and abundance estimation and spatial occupancy estimation for the species with or without natural unique individual markings, were discussed, with special attention to the logic of development, assumptions, limits in application, challenges, and future directions of model development. Finally, the important aspects which should be kept in mind when using camera trap in estimating wildlife population parameters as well as the potential capacities of camera trap in the researches of population dynamics and biodiversity, were comprehensively analyzed.
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A new natural naphtho[1,2-b]furan from the leaves of Cassia fistula.
J Asian Nat Prod Res
PUBLISHED: 07-04-2013
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A new naphtho[1,2-b]furan, 2,9-dihydroxy-7-methoxy-4-methylnaphtha[1,2-b]furan-3(2H)-one (1), along with 10 known compounds vanillic acid (2), naringenin (3), glyceryl-1-tetracosanoate (4), moracin J (5), 1,3,8-trihydroxyanthraquinone (6), esculetin (7), mauritianin (8), kaempferol 3-neohesperidoside (9), ?-sitosterol (10), and ?-daucosterol (11), was isolated from the leaves of Cassia fistula. The structure of the new compound was determined by NMR and X-ray analysis. Compounds 1, 3, 5-9 were isolated from this plant for the first time. The naphtha[1,2-b]furan was firstly isolated from the natural resources.
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Ammonium 2-(3,4-di-methyl-benzo-yl)benzoate dihydrate.
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 06-01-2013
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In the anion of the title compound, NH4 (+)·C16H13O3 (-)·2H2O, the benzene rings are twisted with respect to each other by 73.56?(10)°. In the crystal, extensive N-H?O and O-H?O hydrogen bonds link the cations, anions and lattice water mol-ecules into a three dimensional supra-molecular structure.
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Diosgenin inhibits tumor necrosis factor-induced tissue factor activity and expression in THP-1 cells via down-regulation of the NF-?B, Akt, and MAPK signaling pathways.
Chin J Nat Med
PUBLISHED: 03-18-2013
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To investigate whether diosgenin could modulate tissue factor (TF) procoagulation activity, expression, and related signal transduction pathways.
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Qualitative and quantitative analysis of phenolic compounds in the leaves of aquilaria sinensis using liquid chromatography-mass spectrometry.
Phytochem Anal
PUBLISHED: 03-10-2013
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The leaves of Aquilaria sinensis traditionally have been used in China for a century. Phenolic compounds were investigated to be the major active compounds in them.
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Methylenetetrahydrofolate reductase C677T polymorphism predicts response and time to progression to gemcitabine-based chemotherapy for advanced non-small cell lung cancer in a Chinese Han population.
J Zhejiang Univ Sci B
PUBLISHED: 03-07-2013
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Objective: The aim of this study was to evaluate the association between the methylenetetrahydrofolate reductase (MTHFR) C677T excision repair cross-complementation group 1 (ERCC1) genetic polymorphisms and the clinical efficacy of gemcitabine-based chemotherapy in advanced non-small cell lung cancer (NSCLC). Methods: A total of 135 chemonaive patients with unresectable advanced NSCLC were treated with gemcitabine/platinum regimens. The polymorphisms of MTHFR C677T, ERCC1 C8092A, and ERCC1 C118T were genotyped using the TaqMan methods. Results: The overall response rate was 28.9%. Patients with MTHFR CC genotype had a higher rate of objective response than patients with variant genotype (TT or CT) (41.2% versus 19.1%, P=0.01). Median time to progression (TTP) of patients with MTHFR CC genotype was longer than that of patients with variant genotype (7.6 months versus 5.0 months, P=0.003). No significant associations were obtained between ERCC1 C118T and C8092A polymorphisms and both response and survival. Conclusions: Our data suggest the value of MTHFR C677T polymorphism as a possible predictive marker of response and TTP in advanced NSCLC patients treated with gemcitabine/platinum.
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Ruscogenin attenuates monocrotaline-induced pulmonary hypertension in rats.
Int. Immunopharmacol.
PUBLISHED: 01-24-2013
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Inflammation, endothelial dysfunction, and thrombosis contribute to the pathogenesis and development of human pulmonary arterial hypertension (PAH). The aim of this study was to investigate the effects of ruscogenin, a natural anti-inflammatory and anti-thrombotic agent, on the development of monocrotaline (MCT)-induced PAH in rats. Our results revealed that ruscogenin had favorable effects on hemodynamics and pulmonary vascular remodeling, preventing the development of PAH 3 weeks after MCT. In addition, ruscogenin resulted in markedly reduced expression of inflammatory cytokine and leukocyte infiltration via the inhibition of nuclear factor (NF)-?B activity in rat lungs. Ruscogenin also attenuated MCT-induced endothelial cell apoptosis in the remodeled pulmonary arterioles and rescued destruction of endothelial cell membrane proteins such as eNOS, caveolin-1, and CD31. Our findings suggest that ruscogenin might have therapeutic benefits for PAH patients.
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N-(7-Dibromo-methyl-5-methyl-1,8-naphthyridin-2-yl)acetamide-pyrrolidine-2,5-dione (1/1).
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 01-04-2013
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In the title co-crystal, C(12)H(11)Br(2)N(3)O·C(4)H(5)NO(2), the naphthyridine derivative and the pyrrolidine-2,5-dione mol-ecules have crystallographic mirror-plane symmetry with all non-H atoms, except the Br atom, located on the mirror plane. In the crystal, N-H?N, N-H?O and C-H?O hydrogen bonds link the mol-ecules into heterodimers. These dimers are further linked into a one-dimensional structure along [010] by weak C-Br?O inter-actions [Br?O = 3.028?(5)?Å and C-Br?O = 158.52?(4)°].
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Demonstration of a compact temperature sensor based on first-order Bragg grating in a tapered fiber probe.
Opt Express
PUBLISHED: 09-22-2011
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We experimentally demonstrate an all-silica first-order fiber Bragg grating (FBG) for high temperature sensing by focused ion beam (FIB) machining in a fiber probe tapered to a point. This 61-period FBG is compact (~36.6 ?m long and ~6.5 ?m in diameter) with 200-nm-deep shallow grooves. We have tested the sensor from room temperature to around 500 °C and it shows a temperature sensitivity of nearly 20 pm/°C near the resonant wavelength of 1550 nm. This kind of sensor takes up little space because of its unique geometry and small size and may be integrated in devices that work in harsh environment or for detecting small objects.
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Ultra-flattened and low dispersion in engineered microfibers with highly efficient nonlinearity reduction.
Opt Express
PUBLISHED: 09-22-2011
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We propose an engineered microfiber with nano-scale slots that produce ultra-flattened and low dispersion of ±10 ps/(nm · km) over a 340 nm wavelength range. It is comparable with the results in photonic crystal fibers and planar slot waveguides, but can be hardly realized in conventional circular microfibers. By confining the light in a low nonlinearity air slot, the nonlinear coefficient can be greatly reduced. With the unique geometry and excellent performance, the slot microfiber offers large potential in miniature fiber devices for high-speed telecom applications.
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Miniature tapered photonic crystal fiber interferometer with enhanced sensitivity by acid microdroplets etching.
Appl Opt
PUBLISHED: 08-12-2011
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We fabricate a miniature tapered photonic crystal fiber (PCF) interferometer with enhanced sensitivity by acid microdroplets etching. This method is very simple and cost effective, avoiding elongating the PCF, moving and refixing the device during etching, and measuring. The refractive index sensing properties with different PCF diameters are investigated both theoretically and experimentally. The tapering velocity can be controlled by the microdroplet size and position. The sensitivity greatly increases (five times, 750?nm/RIU) and the size decreases after slightly tapering the PCF. The device keeps low temperature dependence before and after tapering. More uniformly and thinly tapered PCFs can be realized with higher sensitivity (?100 times) by optimizing the etching process.
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Broadband and highly efficient quadratic interactions in double-slot lithium niobate waveguides through phase matching.
Opt Lett
PUBLISHED: 07-05-2011
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We propose and study in detail a phase-matched quadratic optical interaction in a realizable 2D double-slot lithium niobate (LN) waveguide. As opposed to the single-slot waveguide, the field can be well confined in the nanometric nonlinear material, and it is also more flexible for birefringence and dispersion design. The proposed compact double-slot structure could not only achieve form birefringence phase matching but also effectively enhance the modal overlap integral and expand the working wavelength. The calculated results on second harmonic generation show an extremely large bandwidth of ~40 nm. The modal overlap integral up to 0.035 W(3/2)/V can be realized by optimizing the waveguide geometry, and it is much better than previous results on single-slot waveguides. Its temperature dependence is low--around 25 °C. The geometry is practical considering the current micromachining technique of LN.
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Chiral ruthenium(II) anthraquinone complexes as dual inhibitors of topoisomerases I and II.
J. Biol. Inorg. Chem.
PUBLISHED: 06-05-2011
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DNA topoisomerases (I and II) have been one of the excellent targets in anticancer drug development. Here two chiral ruthenium(II) anthraquinone complexes, ?- and ?-[Ru(bpy)(2)(ipad)](2+), where bpy is 2,2-bipyridine and ipad is 2-(anthracene-9,10-dione-2-yl)imidazo[4,5-f][1,10]phenanthroline, were synthesized and characterized. As expected, both of the Ru(II) complexes intercalate into DNA base pairs and possess an obviously greater affinity with DNA. Topoisomerase inhibition and DNA strand passage assay confirmed that the two complexes are efficient dual inhibitors of topoisomerases I and II by interference with the DNA religation. In MTT cytotoxicity studies, two Ru(II) complexes exhibited antitumor activity against HeLa, MCF-7, HepG2 and BEL-7402 tumor cell lines. Flow cytometry analysis shows an increase in the percentage of cells with apoptotic morphological features in the sub-G1 phase for Ru(II) complexes. Nuclear chromatin cleavage has also been observed from AO/EB staining assay and alkaline single-cell gel electrophoresis (comet assay). The results demonstrated that ?- and ?-[Ru(bpy)(2)(ipad)](2+) act as dual inhibitors of topoisomerases I and II, and cause DNA damage that can lead to cell cycle arrest and/or cell death by apoptosis.
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[Methods and applications of population viability analysis (PVA): a review].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 05-10-2011
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With the accelerating human consumption of natural resources, the problems associated with endangered species caused by habitat loss and fragmentation have become greater and more urgent than ever. Conceptually associated with the theories of island biogeography, population viability analysis (PVA) has been one of the most important approaches in studying and protecting endangered species, and this methodology has occupied a central place in conservation biology and ecology in the past several decades. PVA has been widely used and proven effective in many cases, but its predictive ability and accuracy are still in question. Also, its application needs expand. To overcome some of the problems, we believe that PVA needs to incorporate some principles and methods from other fields, particularly landscape ecology and sustainability science. Integrating landscape pattern and socioeconomic factors into PVA will make the approach theoretically more comprehensive and practically more useful. Here, we reviewed the history, basic conception, research methods, and modeling applications and their accuracies of PVA, and proposed the perspective in this field.
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Synthesis, DNA-binding and topoisomerase inhibitory activity of ruthenium(II) polypyridyl complexes.
Eur J Med Chem
PUBLISHED: 01-02-2011
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Two ruthenium(II) complexes [Ru(bpy)(2)(bfipH)](2+) (1) and [Ru(phen)(2)(bfipH)](2+) (2) have been synthesized and characterized. The DNA-binding behaviors of complexes were studied by using spectroscopic and viscosity measurements. Results suggested that the two complexes bind to DNA in an intercalative mode. Complexes 1 and 2 can efficiently photocleave pBR322 DNA in vitro under irradiation, singlet oxygen ((1)O(2)) was proved to contribute to the DNA photocleavage process. Topoisomerase inhibition and DNA strand passage assay confirmed that two Ru(II) complexes acted as efficient dual inhibitors of topoisomerases I and II. In MTT cytotoxicity studies, two Ru(II) complexes exhibited antitumor activity against BEL-7402, HeLa, MCF-7 tumor cells. The AO/EB staining assay indicated that Ru(II) complexes could induce the apoptosis of HeLa cells.
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Ginsenoside Rg1 protects against hydrogen peroxide-induced cell death in PC12 cells via inhibiting NF-?B activation.
Neurochem. Int.
PUBLISHED: 10-08-2010
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Oxidative stress is a major cause in neurodegenerative diseases including Alzheimers disease (AD), Parkinsons disease (PD), and cerebral ischemia. Ginsenoside Rg1, a natural product extracted from Panax ginseng C.A. Meyer, has been reported to exert notable neuroprotective activities, which partly ascribed to its antioxidative activity. However, its molecular mechanism against oxidative stress induced by exogenous hydrogen peroxide (H(2)O(2)) remained unclear. In this study, we investigated its effect on H(2)O(2)-induced cell death and explored possible signaling pathway in PC12 cells. We proved that pretreatment with Rg1 at concentrations of 0.1-10 ?M remarkably reduced the cytotoxicity induced by 400 ?M of H(2)O(2) in PC12 cells by MTT and Hoechst and PI double staining assay. Of note, we demonstrated the activation of NF-?B signaling pathway induced by H(2)O(2) thoroughly in PC12 cells, and Rg1 suppressed phosphorylation and nuclear translocation of NF-?B/p65, phosphorylation and degradation of inhibitor protein of ?B (I?B) as well as the phosphorylation of I?B-kinase complex (IKK) by western blotting or indirect immunofluorescence assay. Besides, Rg1 also inhibited the activation of Akt and the extracellular signal-regulated kinase 1/2 (ERK1/2). Furthermore, the protection of Rg1 on H(2)O(2)-injured PC12 cells was attenuated by pretreatment with two NF-?B pathway inhibitors (JSH-23 or BOT-64). In conclusion, our results suggest that Rg1 could rescue the cell injury by H(2)O(2) via down-regulation NF-?B signaling pathway as well as Akt and ERK1/2 activation, which put new evidence on the neuroprotective mechanism of Rg1 against the oxidative stress and the regulatory role of H(2)O(2) in NF-?B pathway in PC12 cells.
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Controlled light-pulse propagation via dynamically induced double photonic band gaps.
Opt Express
PUBLISHED: 08-20-2010
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We analyze the optical response of a standing-wave driven four-level atomic system with double dark resonances. Fully developed double photonic band gaps arise as a result of periodically modulated refractive index within the two electromagnetically induced transparency widows. We anticipate that the dynamically induced band gaps can be used to coherently control the propagation of light-pulses with different center frequencies and may have applications in all-optical switching and routing for quantum information networks.
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Microfiber-probe-based ultrasmall interferometric sensor.
Opt Lett
PUBLISHED: 07-03-2010
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We report an ultrasmall microfiber-probe-based reflective interferometer for highly sensitive liquid refractive index measurement. It has a 3.5 microm micronotch cavity fabricated by focused ion beam micromachining. A sensitivity of 110 nm/RIU (refractive index unit) in liquid is achieved with over 20 dB extinction ratio. Theoretical analysis shows this kind of device is a hybrid of Fabry-Perot and modal interferometers. In comparison with normal fiber interferometers, this probe sensor is very compact, stable, and cheap, offering great potentials for detecting inside sub-wavelength bubbles, droplets, or biocells.
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Miniaturized fiber taper reflective interferometer for high temperature measurement.
Opt Express
PUBLISHED: 07-01-2010
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We present an ultra-small all-silica high temperature sensor based on a reflective Fabry-Perot modal interferometer (FPMI). Our FPMI is made of a micro-cavity (approximately 4.4 microm) directly fabricated into a fiber taper probe less than 10 mum in diameter. Its sensing head is a miniaturized single mode-multimode fiber configuration without splicing. The sensing mechanism of FPMI is the interference among reflected fundamental mode and excited high-order modes at the end-faces. Its temperature sensitivity is approximately 20 pm/degrees C near the wavelength of 1550 nm. This kind of sensor can work in harsh environments with ultra-large temperature gradient, but takes up little space because of its unique geometry and small size.
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One unique steroidal sapogenin obtained through the microbial transformation of ruscogenin by Phytophthora cactorum ATCC 32134 and its potential inhibitory effect on tissue factor (TF) procoagulant activity.
Bioorg. Med. Chem. Lett.
PUBLISHED: 04-01-2010
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With the aim to obtain more effective tissue factor (TF) inhibitors, the microbial transformation of three steroidal sapogenins, ruscogenin (1), diosgenin (2) and sarsasapogenin (3), was carried out and only ruscogenin was selectivity converted to 1-hydroxy-spirost-4-en-3-one (4) by Phytophthora cactorum ATCC 32134. The in vitro anti-TF procoagulant activity of this metabolite was enhanced almost 10 times to an IC(50) value of 0.29 microM. The chemical assignments of compound 4 were made unambiguously using ESI-MS, IR and 2D NMR spectroscopy.
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[Land use pattern and its dynamic changes in Amur tiger distribution region].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 07-30-2009
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Land use and land cover change has been the primary cause for the habitat loss and fragmentation in the distribution region of Amur tiger (Panthera tigris altaica). Based on the spatiotemporal changes of land use and land cover in the distribution region, as well as their effects on the population dynamics of Amur tiger, this paper analyzed the development process and its characteristics of the main land use types (agricultural land, forest land, and construction land) in this region, with the land use change history being divided chronically into three distinctive periods, i.e., ancient times (prior to 1860), modern times (1860-1949), and contemporary times (after 1949). The results showed that the sporadic land use in ancient times had no significant effects on the survival of Amur tiger, while the extensive and intensive land use after the 1860s was mainly responsible for the decrease of Amur tiger population and its living space. Since 1949, the Amur tiger distribution region has been divided into two parts, i.e., Northeast China and Russia Far East. The differences in land use pattern, policy, and intensity between these two parts led to different survival status of Amur tiger. The key driving forces for the land use change in Amur tiger distribution region were human population increase, policy change, and increased productivity.
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DNA condensation induced by ruthenium(II) polypyridyl complexes [Ru(bpy)(2)(PIPSH)](2+) and [Ru(bpy)(2)(PIPNH)](2+).
Inorg Chem
PUBLISHED: 04-14-2009
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Two novel DNA-intercalating ruthenium(II) complexes, [Ru(bpy)(2)(PIPSH)](2+) and [Ru(bpy)(2)(PIPNH)](2+), have been synthesized and characterized. Gel retardation assay, atomic force microscopy, and dynamic light scattering studies show that both complexes can induce the condensation of originally circular plasmid pBR322 DNA to particulate structures under neutral conditions.
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Miniaturized broadband highly birefringent device with stereo rod-microfiber-air structure.
Opt Express
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A wrapping-on-a-rod technique is presented and demonstrated successfully to realize broadband microfiber-based highly birefringent (Hi-Bi) devices with 3D geometry. By wrapping a circular microfiber (MF) on a Teflon-coated rod (2 mm in diameter), a large and broadband birefringence can be obtained utilizing a rod-microfiber-air (RMA) structure. Wavelength scanning method is used to measure the birefringence of the device. Results show that group birefringence as high as 10(-3) can be achieved over 400 nm wavelength range. This compact element presents great potential in sensing and communication applications, as well as lab-on-a-rod devices.
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Chemical and microbial semi-synthesis of tetrahydroprotoberberines as inhibitors on tissue factor procoagulant activity.
Bioorg. Med. Chem.
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To discover new inhibitors on tissue factor procoagulant activity, 21 tetrahydroprotoberberines were screened on the model of human THP-1 cells stimulated by lipopolysaccharide. Among these tetrahydroprotoberberines, several unique compounds were synthesized through microbial transformation: compound 6 (l-corydalmine) was obtained through regio-selective demethylation by Streptomyces griseus ATCC 13273, whereas compounds 4a, 4b, 5h, and 5i were microbial glycosylation products by Gliocladium deliquescens NRRL1086. The bioassay results showed that compounds 3 (tetrahydroberberine), 10 (tetrahydroberberrubine), and 5f (cinnamyl ester of 5) and 5i (glycosidic product of 5), exhibited the most potential effects, with IC(50) values of 8.35, 6.75, 3.75, and 8.79 nM, respectively. The preliminary structure and activity relationship analysis revealed that the 2,3-methylenedioxy group of the A ring was essential for the strong inhibitory effects, and the R configuration of the chiral center C-14 showed higher activity than S-form products. The formation of fatty acid or aromatic acid esters of compound 5, except the cinnamyl esters, would weaken its effects. It is also interesting to note that the glycosylation of tetrahydroprotoberberines will maintain and even enhance the inhibitory effects. Because of the importance of glycochemistry in new drug discovery and development, this deserves further exploration and may provide some guide on the semi-synthesis of tetrahydroprotoberberines as tissue factor pathway inhibitors. Our findings also provide some potential leading compounds for tissue factor-related diseases, such as cancer and cardiovascular diseases.
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Synthesis, crystal structure, DNA interaction and anticancer activity of tridentate copper(II) complexes.
J. Inorg. Biochem.
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Three new tridentate copper(II) complexes [Cu(dthp)Cl(2)] (1) (dthp=2,6-di(thiazol-2-yl)pyridine), [Cu(dmtp)Cl(2)] (2) (dmtp=2,6-di(5-methyl-4H-1,2,4-triazol-3-yl)pyridine) and [Cu(dtp)Cl(2)] (3) (dtp=2,6-di(4H-1,2,4-triazol-3-yl)pyridine) have been synthesized and characterized. Crystal structure of complex 1 shows that the complex existed as distorted square pyramid with five co-ordination sites occupied by the tridentate ligand and the two chlorine anions. Ethidium bromide displacement assay, viscosity measurements, circular dichroism studies and cyclic voltammetric experiments suggested that these complexes bound to DNA via an intercalative mode. Three Cu(II) complexes were found to efficiently cleave DNA in the presence of sodium ascorbate, and singlet oxygen ((1)O(2)) and hydrogen peroxide were proved to contribute to the DNA cleavage process. They exhibited anticancer activity against HeLa, Hep-G2 and BEL-7402 cell lines. Nuclear chromatin cleavage has also been observed with AO/EB staining assay and the alkaline single-cell gel electrophoresis (comet assay). The results demonstrated that three Cu(II) complexes cause DNA damage that can induce the apoptosis of BEL-7402 cells.
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Microfiber-based Bragg gratings for sensing applications: a review.
Sensors (Basel)
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Microfiber-based Bragg gratings (MFBGs) are an emerging concept in ultra-small optical fiber sensors. They have attracted great attention among researchers in the fiber sensing area because of their large evanescent field and compactness. In this review, the basic techniques for the fabrication of MFBGs are introduced first. Then, the sensing properties and applications of MFBGs are discussed, including measurement of refractive index (RI), temperature, and strain/force. Finally a summary of selected MFBG sensing elements from previous literature are tabulated.
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Selection and validation of suitable reference genes for miRNA expression normalization by quantitative RT-PCR in citrus somatic embryogenic and adult tissues.
Plant Cell Rep.
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miRNAs have recently been reported to modulate somatic embryogenesis (SE), a key pathway of plant regeneration in vitro. For expression level detection and subsequent function dissection of miRNAs in certain biological processes, qRT-PCR is one of the most effective and sensitive techniques, for which suitable reference gene selection is a prerequisite. In this study, three miRNAs and eight non-coding RNAs (ncRNA) were selected as reference candidates, and their expression stability was inspected in developing citrus SE tissues cultured at 20, 25, and 30 °C. Stability of the eight non-miRNA ncRNAs was further validated in five adult tissues without temperature treatment. The best single reference gene for SE tissues was snoR14 or snoRD25, while for the adult tissues the best one was U4; although they were not as stable as the optimal multiple references snoR14 + U6 for SE tissues and snoR14 + U5 for adult tissues. For expression normalization of less abundant miRNAs in SE tissues, miR3954 was assessed as a viable reference. Single reference gene snoR14 outperformed multiple references for the overall SE and adult tissues. As one of the pioneer systematic studies on reference gene identification for plant miRNA normalization, this study benefits future exploration on miRNA function in citrus and provides valuable information for similar studies in other higher plants.
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The T393C polymorphism of GNAS1 as a predictor for chemotherapy sensitivity and survival in advanced non-small-cell lung cancer patients treated with gemcitabine plus platinum.
Cancer Chemother. Pharmacol.
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The GNAS1 gene is linked to proapoptotic signaling and correlates closely with clinical outcomes in many human cancers. The aim of this study was to evaluate whether the T393C polymorphism of the GNAS1 gene could be used as a chemotherapy sensitivity and prognosis predictive marker of advanced non-small-cell lung cancer (NSCLC) treated with gemcitabine plus platinum (GP).
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What is Visualize?

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

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.