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Find video protocols related to scientific articles indexed in Pubmed.
Mechanical Circulatory Support of a Univentricular Fontan Circulation with a Continuous Axial-Flow Pump in a Piglet Model.
ASAIO J.
PUBLISHED: 11-15-2014
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Despite the significant contribution of the Fontan procedure to the therapy of complex congenital heart diseases, many patients progress to failure of their Fontan circulation. The use of ventricular assist devices (VADs) to provide circulatory support to these patients remains challenging. In the present study, a continuous axial-flow pump was used to support a univentricular Fontan circulation. A modified Fontan circulation (atrio-pulmonary connection) was constructed in 6 Yorkshire piglets (8-14?kg). A Dacron conduit (12 mm) with 2 branches was constructed to serve as a complete atrio-pulmonary connection without the use of cardiopulmonary bypass. The Impella pump was inserted into the conduit through an additional PTFE graft in 5 animals. Hemodynamic data was collected for 6 hours under the supported Fontan circulation. The control animal died after initiating the Fontan circulation independent of resuscitation. Four pump supported animals remained hemodynamically stable for 6 hours with pump speeds between 18,000 rpm to 22,000 rpm (P1-P3). Oxygen saturation was maintained between 95-100%. Normal organ perfusion was illustrated by blood gas analysis and biochemical assays. A continuous axial-flow pump can be used for temporal circulatory support to the failing Fontan circulation as "bridge" to heart transplantation or recovery.
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Lattice light-sheet microscopy: imaging molecules to embryos at high spatiotemporal resolution.
Science
PUBLISHED: 10-23-2014
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Although fluorescence microscopy provides a crucial window into the physiology of living specimens, many biological processes are too fragile, are too small, or occur too rapidly to see clearly with existing tools. We crafted ultrathin light sheets from two-dimensional optical lattices that allowed us to image three-dimensional (3D) dynamics for hundreds of volumes, often at subsecond intervals, at the diffraction limit and beyond. We applied this to systems spanning four orders of magnitude in space and time, including the diffusion of single transcription factor molecules in stem cell spheroids, the dynamic instability of mitotic microtubules, the immunological synapse, neutrophil motility in a 3D matrix, and embryogenesis in Caenorhabditis elegans and Drosophila melanogaster. The results provide a visceral reminder of the beauty and the complexity of living systems.
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Enhancement of 1.53???m emission in erbium/cerium-doped germanosilicate glass pumped by common 808??nm laser diode.
Appl Opt
PUBLISHED: 10-17-2014
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Erbium-doped germanosilicate glasses with various cerium ions contents have been prepared. Optical absorption and 1.53 ?m emission spectra were measured to characterize the spectroscopic performances of prepared samples. A detailed study of 1.53 ?m spectroscopic properties was carried out when pumped by an 808 nm laser diode. Moreover, an energy level diagram and an energy transfer mechanism between Er3+ and Ce3+ were proposed to elucidate the enhanced 1.53 ?m fluorescence. It is found that the prepared samples have optimal spectroscopic properties when the Ce3+ concentration is fixed to 0.5 mol. %. High spontaneous radiative transition probability (172.66??s-1), large effective emission bandwidth (74 nm), and emission cross section (9.49×10-21??cm2 indicate that 808 nm pumped Er3+/Ce3+ codoped germanosilicate glass might be a suitable material for a broadband optical amplifier.
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Strongly coupled magnons and cavity microwave photons.
Phys. Rev. Lett.
PUBLISHED: 10-07-2014
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We realize a cavity magnon-microwave photon system in which a magnetic dipole interaction mediates strong coupling between the collective motion of a large number of spins in a ferrimagnet and the microwave field in a three-dimensional cavity. By scaling down the cavity size and increasing the number of spins, an ultrastrong coupling regime is achieved with a cooperativity reaching 12?600. Interesting dynamic features including classical Rabi-like oscillation, magnetically induced transparency, and the Purcell effect are demonstrated in this highly versatile platform, highlighting its great potential for coherent information processing.
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[Lentiviral vector-mediated RNA interference of mouse epididymis-specific meClps gene lowers mouse sperm mobility].
Nan Fang Yi Ke Da Xue Xue Bao
PUBLISHED: 09-30-2014
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To analyze the effect of small interfering RNA (siRNA) targeting mouse epididymis-specific colipase-like (meClps) gene on mouse sperm mobility.
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Scale-Invariant Quantum Anomalous Hall Effect in Magnetic Topological Insulators beyond the Two-Dimensional Limit.
Phys. Rev. Lett.
PUBLISHED: 09-26-2014
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We investigate the quantum anomalous Hall effect (QAHE) and related chiral transport in the millimeter-size (Cr_{0.12}Bi_{0.26}Sb_{0.62})_{2}Te_{3} films. With high sample quality and robust magnetism at low temperatures, the quantized Hall conductance of e^{2}/h is found to persist even when the film thickness is beyond the two-dimensional (2D) hybridization limit. Meanwhile, the Chern insulator-featured chiral edge conduction is manifested by the nonlocal transport measurements. In contrast to the 2D hybridized thin film, an additional weakly field-dependent longitudinal resistance is observed in the ten-quintuple-layer film, suggesting the influence of the film thickness on the dissipative edge channel in the QAHE regime. The extension of the QAHE into the three-dimensional thickness region addresses the universality of this quantum transport phenomenon and motivates the exploration of new QAHE phases with tunable Chern numbers. In addition, the observation of scale-invariant dissipationless chiral propagation on a macroscopic scale makes a major stride towards ideal low-power interconnect applications.
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A Novel Wireless and Temperature-Compensated SAW Vibration Sensor.
Sensors (Basel)
PUBLISHED: 09-23-2014
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A novel wireless and passive surface acoustic wave (SAW) based temperature-compensated vibration sensor utilizing a flexible Y-cut quartz cantilever beam with a relatively substantial proof mass and two one-port resonators is developed. One resonator acts as the sensing device adjacent to the clamped end for maximum strain sensitivity, and the other one is used as the reference located on clamped end for temperature compensation for vibration sensor through the differential approach. Vibration directed to the proof mass flex the cantilever, inducing relative changes in the acoustic propagation characteristics of the SAW travelling along the sensing device, and generated output signal varies in frequency as a function of vibration.  A theoretical mode using the Rayleigh method was established to determine the optimal dimensions of the cantilever beam. Coupling of Modes (COM) model was used to extract the optimal design parameters of the SAW devices prior to fabrication. The performance of the developed SAW sensor attached to an antenna towards applied vibration was evaluated wirelessly by using the precise vibration table, programmable incubator chamber, and reader unit.  High vibration sensitivity of ~10.4 kHz/g, good temperature stability, and excellent linearity were observed in the wireless measurements.
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Single-cell analysis for BDNF and TrkB receptors in cardiac microvascular endothelial cells.
Biomed Mater Eng
PUBLISHED: 09-18-2014
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Recent studies revealed that BDNF-TrkB pathway plays an important role in cardiac microvascular endothelial cells (CMECs) mediated myocardial angiogenesis. Single-cell analysis is a powerful tool for studying gene expression in individuals since cellular heterogeneity and dynamic microenvironments which individual cell will experience. Little is currently known about the expression of BDNF and TrkB receptors at the single CMEC level. Our single-cell analysis of seven randomly selected CMECs for BDNF and TrkB receptors (FL, T1, T2) showed that under an in vitro culture environment, BDNF was expressed in two of the seven selected CMECs. None of the single CMEC expressed TrkB-FL. TrkB-T1 was expressed in all seven selected CMECs, while, TrkB-T2 was expressed in three of these. In addition, none of single CMEC was found to express both BDNF and three TrkB receptors or BDNF and TrkB-FL simultaneously. These results suggest that a stochastic or random expression pattern for BDNF and their receptors might be set in each of the CMEC to response requirement of the time and spatial change, regulation or pathophysiological change.
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[Biomechanical study on restorative methods of unilateral maxilla based on finite element analysis].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 09-16-2014
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This paper is to report our study in which the differences between prosthetic restoration and surgical reconstruction using traditional clasp retention technology were analyzed based on three-dimensional finite element methods in our laboratory. Firstly, the maxillary unilateral defect model was developed using medical image processing software MIMICS. Secondly, the prosthesis was generated by mirroring technology. The clasp was designed according to the methods raised by Aramany. Then, the stress distribution of maxilla was calculated by simulating occlusion. According to the results, after osseointegration of surgical reconstruction, stresses of unaffected abutments were reduced significantly, and less stress of junction occurred near zygoma of affected side, which were all less than stresses of prosthesis restoration. Thus, removing the clasp of surgical reconstruction increased the stresses of unaffected abutments. The stress trends of maxillary components were different between prosthetic restoration and surgical reconstruction. Surgical reconstruction is better than prosthesis restoration in protection of the abutments. Clasp can alleviate the occlusal burden of maxilla. Varieties of retentive technologies can be considered in prosthesis restoration. The surgical reconstruction is more conducive to rehabilitate unilateral maxilla biomechanically in clinic.
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Electrical detection of spin-polarized surface states conduction in (Bi(0.53)Sb(0.47))2Te3 topological insulator.
Nano Lett.
PUBLISHED: 08-28-2014
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Strong spin-orbit interaction and time-reversal symmetry in topological insulators enable the spin-momentum locking for the helical surface states. To date, however, there has been little report of direct electrical spin injection/detection in topological insulator. In this Letter, we report the electrical detection of spin-polarized surface states conduction using a Co/Al2O3 ferromagnetic tunneling contact in which the compound topological insulator (Bi0.53Sb0.47)2Te3 was used to achieve low bulk carrier density. Resistance (voltage) hysteresis with the amplitude up to about 10 ? was observed when sweeping the magnetic field to change the relative orientation between the Co electrode magnetization and the spin polarization of surface states. The two resistance states were reversible by changing the electric current direction, affirming the spin-momentum locking in the topological surface states. Angle-dependent measurement was also performed to further confirm that the abrupt change in the voltage (resistance) was associated with the magnetization switching of the Co electrode. The spin voltage amplitude was quantitatively analyzed to yield an effective spin polarization of 1.02% for the surface states conduction in (Bi0.53Sb0.47)2Te3. Our results show a direct evidence of spin polarization in the topological surface states conduction. It might open up great opportunities to explore energy-efficient spintronic devices based on topological insulators.
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The mediator subunit Med23 contributes to controlling T-cell activation and prevents autoimmunity.
Nat Commun
PUBLISHED: 07-24-2014
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T-cell activation is critical for successful immune responses and is controlled at multiple levels. Although many changes of T-cell receptor-associated signalling molecules affect T-cell activation, the transcriptional mechanisms that control this process remain largely unknown. Here we find that T cell-specific deletion of the mediator subunit Med23 leads to hyperactivation of T cells and aged Med23-deficient mice exhibit an autoimmune syndrome. Med23 specifically and consistently promotes the transcription of multiple negative regulators of T-cell activation. In the absence of Med23, the T-cell activation threshold is lower, which results in enhanced antitumour T-cell function. Cumulatively, our data suggest that Med23 contributes to controlling T-cell activation at the transcriptional level and prevents the development of autoimmunity.
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[Pulmonary benign metastasizing leiomyoma: a clinicopathological study of 5 cases].
Zhongguo Fei Ai Za Zhi
PUBLISHED: 07-19-2014
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Pulmonary benign metastasizing leiomyoma (PBML) is a rare and often to be misdiagnosed disease. In this study, we want to investigate the diseased of the clinicopathological characteristics, diagnosis, treatment and prognosis. The retrospective analysis were performed on the clinicopathological data of 5 patients with PBML. All 5 cases were female, mean age 46.8 years old, and were found with single nodule. One case was found with left kidney metastasis. Surgical procedures includes: VATS biopsy (3 cases), resection of superior lobe of left lung (1 case), resection of superior lobe of right lung and wedge resection of middle and inferior lobe of right lung (1 case). The residual nodules in lung were stable in all cases with followup 3-48 mo. PBML is dominated occurring in females with history of uterine leiomyoma, preferential to metastasize to lung, and surgery is the primary therapy. Since it is hormone dependent, hormonal therapy may be suggested in these patients.
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Electric-field coupling to spin waves in a centrosymmetric ferrite.
Phys. Rev. Lett.
PUBLISHED: 07-16-2014
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We experimentally demonstrate that the spin-orbit interaction can be utilized for direct electric-field tuning of the propagation of spin waves in a single-crystal yttrium iron garnet magnonic waveguide. Magnetoelectric coupling not due to the spin-orbit interaction and, hence, an order of magnitude weaker leads to electric-field modification of the spin-wave velocity for waveguide geometries where the spin-orbit interaction will not contribute. A theory of the phase shift, validated by the experiment data, shows that, in the exchange spin wave regime, this electric tuning can have high efficiency. Our findings point to an important avenue for manipulating spin waves and developing electrically tunable magnonic devices.
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Integrin ?v promotes proliferation by activating ERK 1/2 in the human lung cancer cell line A549.
Mol Med Rep
PUBLISHED: 07-09-2014
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Lung cancer is a leading cause of cancer-related death worldwide, and non-small cell lung cancer (NSCLC) constitutes ~85% of lung cancers. However, the mechanisms underlying the progression of NSCLC remain unclear. In this study, we found the mRNA and protein expression levels of integrin ?v are both increased in NSCLC tissues compared to healthy ones, which indicates that integrin ?v may play an important role in NSCLC progression. To further investigate the roles of integrin ?v in NSCLC, we overexpressed the integrin ?v gene in the NSCLC cell line A549, and found that the cell proliferative ability increased. The apoptosis of A549 cells was inhibited with overexpression of integrin ?v. To elucidate the molecular mechanism underlying the role of integrin ?v in promoting NSCLC progression, we studied the expression of proteins from a number of important pathways associated with tumorigenesis, and found that the extracellular signal regulated protein kinase (ERK)1/2 signaling pathway may be involved in the mediation of the observed integrin ?v effects. component of an important pathway for tumorigenesis, the ERK 1/2. Following inhibition of ERK 1/2 signaling, the proliferation of A549 cells induced by integrin ?v was reduced, while the inhibition of apoptosis was attenuated. Our findings demonstrate that integrin ?v promotes the proliferation of the human lung cancer cell line A549 by activating the ERK 1/2 signaling pathway, which suggests that this pathway may be a promising target for the treatment of human lung cancer.
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The histone demethylase PHF8 is an oncogenic protein in human non-small cell lung cancer.
Biochem. Biophys. Res. Commun.
PUBLISHED: 07-06-2014
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PHF8 is a JmjC domain-containing protein and erases repressive histone marks including H4K20me1 and H3K9me1/2. It binds to H3K4me3, an active histone mark usually located at transcription start sites (TSSs), through its plant homeo-domain, and is thus recruited and enriched in gene promoters. PHF8 is involved in the development of several types of cancer, including leukemia, prostate cancer, and esophageal squamous cell carcinoma. Herein we report that PHF8 is an oncogenic protein in human non-small cell lung cancer (NSCLC). PHF8 is up-regulated in human NSCLC tissues, and high PHF8 expression predicts poor survival. Our in vitro and in vivo evidence demonstrate that PHF8 regulates lung cancer cell proliferation and cellular transformation. We found that PHF8 knockdown induces DNA damage and apoptosis in lung cancer cells. PHF8 promotes miR-21 expression in human lung cancer, and miR-21 knockdown blocks the effects of PHF8 on proliferation and apoptosis of lung cancer cells. In summary, PHF8 promotes lung cancer cell growth and survival by regulating miR-21.
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Genetic polymorphisms and plasma levels of interleukin-22 contribute to the development of nonsmall cell lung cancer.
DNA Cell Biol.
PUBLISHED: 06-23-2014
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Interleukin (IL)-22, a relatively new member of the IL-10 family, has been implicated in inflammation and tumorigenesis. The aim of this study was to identify genetic polymorphisms in IL-22 and to measure plasma levels of IL-22 in patients with nonsmall cell lung cancer (NSCLC). Patients with NSCLC had a significantly higher frequency of IL-22 rs2227484 CT genotype (odds ratio [OR]=1.917, 95% confidence interval [CI] 1.001-3.670, p=0.038) and T allele (OR=1.878, 95% CI 1.010-3.491, p=0.049) as compared with controls. The rs2227484 genotype was associated with a 2.263-fold increased risk for advanced NSCLC (p=0.041). Among different subtypes of NSCLC, these associations were more obvious in the adenocarcinoma. Moreover, patients with high frequencies of genotypic polymorphisms had high plasma levels of IL-22. IL-22 polymorphisms and corresponding high levels of IL-22 in plasma may contribute to the development of NSCLC, especially adenocarcinoma.
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Efficacy and safety of proton pump inhibitors (PPIs) plus rebamipide for endoscopic submucosal dissection-induced ulcers: a meta-analysis.
Intern. Med.
PUBLISHED: 06-15-2014
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To compare the efficacy of proton pump inhibitors (PPIs) with rebamipide versus PPIs alone for the treatment of ulcers after endoscopic submucosal dissection (ESD).
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MiR-9 promotes microglial activation by targeting MCPIP1.
Nat Commun
PUBLISHED: 06-13-2014
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Microglia participate in innate inflammatory responses within the central nervous system. The highly conserved microRNA-9 (miR-9) plays critical roles in neurogenesis as well as axonal extension. Its role in microglial inflammatory responses, however, remains poorly understood. Here we identify a unique role of miR-9 in mediating the microglial inflammatory response via distinct signalling pathways. MiR-9-mediated regulation of cellular activation involved downregulated expression of the target protein, monocyte chemotactic protein-induced protein 1 (MCPIP1) that is crucial for controlling inflammation. Results indicate that miR-9-mediated cellular activation involved signalling via the NF-?B pathway, but not the ?-catenin pathway.
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Enantioselective synthesis of benzazepinoindoles bearing trifluoromethylated quaternary stereocenters catalyzed by chiral spirocyclic phosphoric acids.
Chem. Commun. (Camb.)
PUBLISHED: 06-04-2014
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The first highly enantioselective iso-Pictet-Spengler reaction of C-2-linked o-aminobenzylindoles with trifluoromethyl ketones was developed using chiral spirocyclic phosphoric acids as organocatalysts, which afforded optically active benzazepinoindoles bearing trifluoromethylated quaternary stereocenters.
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The early and long-term outcomes of completion pneumonectomy: report of 56 cases.
Interact Cardiovasc Thorac Surg
PUBLISHED: 06-03-2014
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The aim of this study was to analyse the early and long-term results of completion pneumonectomy (CP).
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Mid-infrared fluorescence, energy transfer process and rate equation analysis in Er(3+) doped germanate glass.
Sci Rep
PUBLISHED: 05-30-2014
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Er(3+) doped Y2O3 and Nb2O5 modified germanate glasses with different Er(3+) concentrations were prepared. J-O intensity parameters were computed to estimate the structural changes due to the additions of Y2O3 and Nb2O5. The main mid-infrared spectroscopic features were investigated. To shed light on the observed mid-infrared radiative behavior, 975?nm and 1.53??m emission spectra along with their decay lifetimes were also discussed. Moreover, the energy transfer processes of (4)I11/2 and (4)I13/2 level were quantitatively analyzed. In view of the experimental lifetimes, the simplified rate equation was utilized to calculate the energy transfer upconversion processes of upper and lower laser level of 2.7??m emission. The theoretical calculations are in good agreement with the observed 2.7??m fluorescence phenomena. Finally, the stimulated emission and gain cross sections were calculated and the results indicate that Er(3+) doped germanate glasses have great potential for mid-infrared application.
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Fine mapping analysis confirms and strengthens linkage of four chromosomal regions in familial hypospadias.
Eur. J. Hum. Genet.
PUBLISHED: 05-27-2014
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Hypospadias is a common male genital malformation and is regarded as a complex disease affected by multiple genetic as well as environmental factors. In a previous genome-wide scan for familial hypospadias, we reported suggestive linkage in nine chromosomal regions. We have extended this analysis by including new families and additional markers using non-parametric linkage. The fine mapping analysis displayed an increased LOD score on chromosome 8q24.1 and 10p15 in altogether 82 families. On chromosome 10p15, with the highest LOD score, we further studied AKR1C2, AKR1C3 and AKR1C4 involved in steroid metabolism, as well as KLF6 expressed in preputial tissue from hypospadias patients. Mutation analysis of the AKR1C3 gene showed a new mutation, c.643G>A (p.(Ala215Thr)), in a boy with penile hypospadias. This mutation is predicted to have an impact on protein function and structure and was not found in controls. Altogether, we homed in on four chromosomal regions likely to harbor genes for hypospadias. Future studies will aim for studying regulatory sequence variants in these regions.European Journal of Human Genetics advance online publication, 2 July 2014; doi:10.1038/ejhg.2014.129.
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Proximity induced high-temperature magnetic order in topological insulator--ferrimagnetic insulator heterostructure.
Nano Lett.
PUBLISHED: 05-23-2014
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Introducing magnetic order in a topological insulator (TI) breaks time-reversal symmetry of the surface states and can thus yield a variety of interesting physics and promises for novel spintronic devices. To date, however, magnetic effects in TIs have been demonstrated only at temperatures far below those needed for practical applications. In this work, we study the magnetic properties of Bi2Se3 surface states (SS) in the proximity of a high Tc ferrimagnetic insulator (FMI), yttrium iron garnet (YIG or Y3Fe5O12). Proximity-induced butterfly and square-shaped magnetoresistance loops are observed by magneto-transport measurements with out-of-plane and in-plane fields, respectively, and can be correlated with the magnetization of the YIG substrate. More importantly, a magnetic signal from the Bi2Se3 up to 130 K is clearly observed by magneto-optical Kerr effect measurements. Our results demonstrate the proximity-induced TI magnetism at higher temperatures, an important step toward room-temperature application of TI-based spintronic devices.
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Overexpression of syntenin enhances hepatoma cell proliferation and invasion: Potential roles in human hepatoma.
Oncol. Rep.
PUBLISHED: 05-13-2014
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Hepatocellular carcinoma (HCC) ranks as the third leading cause of tumor-related mortality worldwide. Recently, syntenin was found to be upregulated in several tumors and to exert pivotal roles in the development of cancer. However, its function and the underlying mechanism in HCC remain to be defined. In the present study, the elevated expression levels of syntenin mRNA and protein were detected in four HCC cell lines. Overexpression of syntenin in hepatoma HCCLM3 cells enhanced cell proliferation. Furthermore, syntenin upregulation increased epidermal growth factor receptor (EGFR) expression, which accounted for syntenin?induced cell proliferation as precondition with EGFR siRNA clearly attenuated cell proliferation in syntenin-transfected cells. At the same time, syntenin overexpression promoted cell invasion by MMP-2, as pretreatment with anti-MMP-2 antibody blocked syntenin-induced invading cell numbers. Additionally, syntenin upregulation induced the phosphorylation of p38 MAPK contributing to the increase in MMP-2 expression, as treatment with the specific inhibitor for p38 MAPK (SB203580) clearly abrogated MMP-2 expression induced by syntenin. Collectively, our results suggest that syntenin overexpression plays a critical role in promoting the proliferation and invasion of hepatoma cells. Therefore, the present study provides new insight into how syntenin accelerates the development and progression of hepatoma, and suggests that syntenin may be a promising therapeutic agent against hepatoma.
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Validity of scalar diffraction theory and effective medium theory for analysis of a blazed grating microstructure at oblique incidence.
Appl Opt
PUBLISHED: 05-03-2014
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The accuracy of scalar diffraction theory (SDT) and effective medium theory (EMT) for analyzing a blazed grating is quantitatively demonstrated by making a comparison of diffraction efficiencies calculated by the two simplified methods to exact results from the Fourier modal method (FMM). It is found that when the normalized period is more than fivefold wavelength of incident light at normal incidence and is more than about tenfold wavelength at larger incident angle, SDT can be used to easily analyze effectively the transmittance characteristics of a blazed grating with divergence less than 1%. Particularly, for zeroth-order diffraction when the groove depth is less than threefold wavelength, the transmittance calculated by SDT with refractive index of 1.5 and normalized period of 5.0 agrees well with that of FMM at normal incidence. But, for ±1 orders, the validity of SDT is degraded from that for zeroth order. Generally, the deviation of transmittances between the SDT and the FMM increases as the incident angle and refractive index augment. Furthermore, when higher diffraction orders other than zeroth order are not propagating, the EMT is valid to evaluate the transmittance of a blazed grating at normal incidence. Similarly, the error of transmittances between the EMT and the FMM increases with the increase of incident angle and refractive index. The effectiveness of the SDT and the EMT for analyzing a blazed grating in the range of the normalized period far more than and less than the wavelength of incident light, respectively, is dependent on the parameters including incident angle, refractive index, normalized period, and normalized groove depth.
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Regulatory focus and burnout in nurses: The mediating effect of perception of transformational leadership.
Int J Nurs Pract
PUBLISHED: 04-15-2014
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This correlation study investigated the relationship between nurses' regulatory focus and burnout, as mediated by their perceptions of transformational leadership, using a cross-sectional research design with anonymous questionnaires. In July-August 2012, data were collected from 378 nurses from three hospitals in Shaanxi Province, China, using self-report questionnaires for measuring the nurses' regulatory focus, their level of burnout and their perception of whether the leadership of their supervisor was transformational. Structural equation modelling and bootstrapping procedures were used to identify the mediating effect of their perceptions of transformational leadership. The results supported our hypothesized model. The type of regulatory focus emerged as a significant predictor of burnout. Having a perception of transformational leadership partially mediated the relationship between regulatory focus and burnout. Having a promotion focus reduced burnout when the participants perceived transformational leadership, whereas having a prevention focus exhibited the opposite pattern. The mediating effect of the perception of transformational leadership suggests that a promotion focus may help diminish burnout, directly and indirectly. Nurse managers must be aware of the role of a regulatory focus and cultivate promotion focus in their followers.
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Magnetization switching through giant spin-orbit torque in a magnetically doped topological insulator heterostructure.
Nat Mater
PUBLISHED: 04-02-2014
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Recent demonstrations of magnetization switching induced by in-plane current in heavy metal/ferromagnetic heterostructures (HMFHs) have drawn great attention to spin torques arising from large spin-orbit coupling (SOC). Given the intrinsic strong SOC, topological insulators (TIs) are expected to be promising candidates for exploring spin-orbit torque (SOT)-related physics. Here we demonstrate experimentally the magnetization switching through giant SOT induced by an in-plane current in a chromium-doped TI bilayer heterostructure. The critical current density required for switching is below 8.9 × 10(4) A cm(-2) at 1.9 K. Moreover, the SOT is calibrated by measuring the effective spin-orbit field using second-harmonic methods. The effective field to current ratio and the spin-Hall angle tangent are almost three orders of magnitude larger than those reported for HMFHs. The giant SOT and efficient current-induced magnetization switching exhibited by the bilayer heterostructure may lead to innovative spintronics applications such as ultralow power dissipation memory and logic devices.
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Wide-field in vivo background free imaging by selective magnetic modulation of nanodiamond fluorescence.
Biomed Opt Express
PUBLISHED: 04-01-2014
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The sensitivity and resolution of fluorescence-based imaging in vivo is often limited by autofluorescence and other background noise. To overcome these limitations, we have developed a wide-field background-free imaging technique based on magnetic modulation of fluorescent nanodiamond emission. Fluorescent nanodiamonds are bright, photo-stable, biocompatible nanoparticles that are promising probes for a wide range of in vitro and in vivo imaging applications. Our readily applied background-free imaging technique improves the signal-to-background ratio for in vivo imaging up to 100-fold. This technique has the potential to significantly improve and extend fluorescent nanodiamond imaging capabilities on diverse fluorescence imaging platforms.
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Organelle interactions: melanosomes and mitochondria get cozy.
Curr. Biol.
PUBLISHED: 03-22-2014
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Melanosomes make pigments and mitochondria make ATP. A recent study has shown that these two organelles are connected by fibrillar bridges and that their close physical contact may promote the biogenesis of the melanosome by providing it with ATP.
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Differential co-expression analysis of a microarray gene expression profiles of pulmonary adenocarcinoma.
Mol Med Rep
PUBLISHED: 03-17-2014
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Lung cancer severely reduces the quality of life worldwide and causes high socioeconomic burdens. However, key genes leading to the generation of pulmonary adenocarcinoma remain elusive despite intensive research efforts. The present study aimed to identify the potential associations between transcription factors (TFs) and differentially co?expressed genes (DCGs) in the regulation of transcription in pulmonary adenocarcinoma. Gene expression profiles of pulmonary adenocarcinoma were downloaded from the Gene Expression Omnibus, and gene expression was analyzed using a computational method. A total of 37,094 differentially co?expressed links (DCLs) and 251 DCGs were identified, which were significantly enriched in 10 pathways. The construction of the regulatory network and the analysis of the regulatory impact factors revealed eight crucial TFs in the regulatory network. These TFs regulated the expression of DCGs by promoting or inhibiting their expression. In addition, certain TFs and target genes associated with DCGs did not appear in the DCLs, which indicated that those TFs could be synergistic with other factors. This is likely to provide novel insights for research into pulmonary adenocarcinoma. In conclusion, the present study may enhance the understanding of disease mechanisms and lead to an improved diagnosis of lung cancer. However, further studies are required to confirm these observations.
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The effect of bumetanide on photodynamic therapy-induced peri-tumor edema of C6 glioma xenografts.
Lasers Surg Med
PUBLISHED: 03-13-2014
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The aim of this study was to investigate the effect of bumetanide on peri-tumor edema caused by photodynamic therapy (PDT) of intraparenchymal C6 glioma xenografts.
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?1 integrin modulates tumor growth and apoptosis of human colorectal cancer.
Oncol. Rep.
PUBLISHED: 03-12-2014
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We aimed to ascertain whether ?1 integrin (ITGB1) induces apoptosis of colorectal cancer (CRC) through regulation of the mitochondrial pathway in vitro and in vivo. We generated lentiviral vectors expressing ITGB1 or ITGB1-specific RNAi and an unrelated control vector. After infection of the HT29 cells, we used western blot analysis and flow cytometric analysis to validate the patterns of ITGB1 expression. Proliferation and apoptosis were evaluated by colony formation assay, flow cytometry and western blot analysis. Upregulation of ITGB1 significantly increased the proliferation of HT29 cells; however, the levels of Bcl-2 and cyclin D1 proteins were upregulated while Bax, caspase-3, caspase-9 and p21 were downregulated in the HT29-ITGB1 cells compared to these levels in the controls. Hoechst 33258 staining and flow cytometric analysis showed that ITGB1 may play a significant role in the apoptosis of CRC cells. Moreover, ITGB1 promoted the proliferation of cells in a xenograft tumor mouse model. TUNEL staining revealed a marked increase in the percentage of positive cells in the HT29-RNAi group (84.3 ± 4.0%), which were more significant than in the HT29-ITGB1 group (48.3 ± 2.9%) and the other two control groups, HT29 (52.0 ± 3.6%) and HT29-NC (49.7 ± 4.5%). These results suggest that ITGB1 regulates the growth and apoptosis of human colorectal cancer cells.
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Androgen-deprivation therapy-induced aggressive prostate cancer with neuroendocrine differentiation.
Asian J. Androl.
PUBLISHED: 03-05-2014
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Most prostate cancers (PCas) are classified as acinar type (conventional) adenocarcinoma which are composed of tumor cells with luminal differentiation including the expression of androgen receptor (AR) and prostate-specific antigen (PSA). There are also scattered neuroendocrine (NE) cells in every case of adenocarcinoma. The NE cells are quiesecent, do not express AR or PSA, and their function remains unclear. We have demonstrated that IL8-CXCR2-P53 pathway provides a growth-inhibitory signal and keeps the NE cells in benign prostate and adenocarcinoma quiescent. Interestingly, some patients with a history of adenocarcinoma recur with small cell neuroendocrine carcinoma (SCNC) after hormonal therapy, and such tumors are composed of pure NE cells that are highly proliferative and aggressive, due to P53 mutation and inactivation of the IL8-CXCR2-P53 pathway. The incidence of SCNC will likely increase due to the widespread use of novel drugs that further inhibit AR function or intratumoral androgen synthesis. A phase II trial has demonstrated that platinum-based chemotherapy may be useful for such therapy-induced tumors.
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?1 integrin mediates colorectal cancer cell proliferation and migration through regulation of the Hedgehog pathway.
Tumour Biol.
PUBLISHED: 02-27-2014
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?1 integrin (ITGB1) is the major expressed integrin protein of normal cells and tumor-associated cells. It is often up-regulated in human malignancies and is involved in many developmental processes, such as tumor progression and metastasis. However, little is known about the function of ITGB1 in colorectal cancer. We constructed lentiviral vectors expressing ITGB1 or ITGB1-specific RNA interference (RNAi) and an unrelated control vector. After infecting HT29 cells in vitro, proliferation and migration were evaluated by Cell Counting Kit 8 (CCK-8) assays, transwell invasion assays, and Western blots. The influence of lentivirus infection on the tumor development capacity of HT29 cells in vivo was examined by xenografting the tumor cells. The expression of ITGB1 in the xenografted tumor cells was analyzed by immunohistochemistry. The up-regulation of ITGB1 significantly increased the proliferation in HT29 cells in vitro. Moreover, we found that the overexpression of ITGB1 up-regulated sonic hedgehog (Shh) while down-regulating Gli1 and SuFu in HT29-ITGB1 cells compared to controls. Moreover, the levels of c-myc and cyclin D1 proteins were up-regulated. Transwell assays showed that the number of migrating HT29-RNAi cells was lower than that in the other cell groups, indicating that ITGB1 significantly enhances the invasive ability of HT29 cells. In addition to these in vitro results, ITGB1 was found to be a significantly effective growth factor in a xenografted tumor mouse model. These results suggest that ITGB1 induces growth and invasion in a human colorectal cancer cell line through the hedgehog (Hh) signaling pathway in vitro and in vivo.
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A risk evaluation model of cervical cancer based on etiology and human leukocyte antigen allele susceptibility.
Int. J. Infect. Dis.
PUBLISHED: 02-27-2014
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There are no reliable risk factors to accurately predict progression to cervical cancer in patients with chronic cervicitis infected with human papillomavirus (HPV). The aim of this study was to create a validated predictive model based on the risk factors for cervical cancer. A model to estimate the risk of cervical cancer may help select patients for intervention therapy in order to reduce the occurrence of cervical cancer after HPV infection.
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Aqueous batteries based on mixed monovalence metal ions: a new battery family.
ChemSusChem
PUBLISHED: 02-21-2014
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As existing battery technologies struggle to meet the requirements for widespread use in the field of large-scale energy storage, new concepts are urgently needed to build batteries with high energy density, low cost, and good safety. Here, we demonstrate two new aqueous batteries based on two monovalence metal ions (Li(+) /K(+) and Na(+) /K(+) ) as charge-transfer ions, Ni1 Zn1 HCF/TiP2 O7 and Ni1 Zn1 HCF/NaTi2 (PO4 )3 . These new batteries are unlike the conventional "rocking-chair" aqueous metal-ion batteries based on the migration of one type of shuttle ion between cathode and anode. They can deliver specific energy of 46 Wh kg(-1) and 53 Wh kg(-1) based on the total mass of active materials; this is superior to current aqueous battery systems based on sodium-ion and/or potassium-ion technologies. These two new batteries together with the previously developed Li(+) /Na(+) mixed-ion battery not only constitute a new battery family for energy storage, but also greatly broaden our horizons for battery research.
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Right ventricular unloading and respiratory support with a wearable artificial pump-lung in an ovine model.
J. Heart Lung Transplant.
PUBLISHED: 02-20-2014
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Device availability of mechanical circulatory or respiratory support to the right heart has been limited. The purpose of this study was to investigate the effect of right heart unloading and respiratory support with a wearable integrated artificial pump-lung (APL).
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Tunable mid-infrared luminescence from Er(3+) -doped germanate glass.
Luminescence
PUBLISHED: 02-13-2014
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Er(3+) -doped germanate glasses with superior thermal stability were prepared. Judd-Ofelt intensity parameters and important spectroscopic properties were discussed in detail. Upon 800 nm and 980 nm LD pumping, 2.7 µm fluorescence characteristics were investigated and it was found that the effective 2.7 µm emission bandwidth can reach to 101.79 nm in prepared glasses. The tunability of the 2.7 µm emission band can be realized by adjusting the Er(3+) content. Moreover, a high-emission cross-section (11.09 ×10(-21) cm(2) ), large gain bandwidth (772.30 ×10(-28) cm(3) ) and gain coefficient (6.72 cm(-1) ) were obtained in the prepared sample. Hence, Er(3+) -doped germanate glass might be a promising mid-infrared material for tunable amplifiers or lasers. Copyright © 2014 John Wiley & Sons, Ltd.
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Thymidylate synthase genetic polymorphisms and colorectal cancer risk: a meta-analysis.
Clin Res Hepatol Gastroenterol
PUBLISHED: 02-13-2014
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The effects of thymidylate synthase (TS) polymorphisms on susceptibility to colorectal cancer (CRC) have been investigated in many studies, but the results remain conflicting rather than conclusive. To resolve these conflicts, we performed a quantitative synthesis of the evidence on the association between these two polymorphisms and CRC risk.
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Improvement of the validity of the simplified modal method for designing a subwavelength dielectric transmission grating.
Appl Opt
PUBLISHED: 02-12-2014
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To accurately and easily design the diffraction characteristics of a rectangular transmission grating under the illumination of Littrow mounting, the validity and limitation of the simplified modal method is evaluated by a comparison of diffraction efficiencies predicted by the modal approach to exact results calculated with rigorous coupled-wave analysis. The influence of the grating normalized period, the normalized groove depth, and the fill factor on the accuracy of the modal method is quantitatively determined. More importantly, the reflection effect of two propagating grating modes with the optical thin-film model and the nonsymmetrical Fabry-Perot model is proposed and applied in the modal method to improve the accuracy of the calculated diffraction efficiencies. Generally, it is found that the thin-film model of reflection loss is valid at the smaller normalized period, but the Fabry-Perot model can exactly calculate the reflection loss of grating modes at the larger normalized period. Based on the fact that the validity of the modal approach is determined independently of the incident wavelength, the exact design and analysis of grating diffraction elements can be implemented at different wavelengths by simply scaling the grating parameters. Moreover, the polarization effect of diffraction properties on the limitation of the modal method without and with the reflection loss of grating modes is clearly demonstrated.
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Microencapsulation of mechano growth factor E peptide for sustained delivery and bioactivity maintenance.
Int J Pharm
PUBLISHED: 02-06-2014
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Mechano growth factor (MGF) and its C-terminal E-peptide with 24 amino acids, MGF-Ct24E, have superiority in resolving the delayed or failed bone repair derived from shortness of suitable biomechanical stimulation. The chitosan/tripolyphosphate microspheres encapsulated with MGF-Ct24E (CS/TPP/MGF-Ct24E) are prepared using emulsion-ionic cross-linking method in order to achieve the sustained release and preserve the bioactivity of MGF-Ct24E. The microspheres are micron-sized and spherical in shape with smooth surface morphology. The TPP component disintegrates in advance of CS matrix and the MGF-Ct24E maintains sustained delivery during in vitro hydrolytic degradation. With the disappearance of TPP, the total weight loss of CS/TPP/MGF-Ct24E is 32% and the release amount of MGF-Ct24E reaches 84.6% after degrading for 2 weeks. In vitro bioactivity assays reveal that the MGF-Ct24E can accelerate MC3T3-E1 cells proliferation and delay their differentiation as well. The encapsulated MGF-Ct24E shows long-term effects after being loaded in the CS/TPP microspheres and the cells exhibit excellent morphology on the surface of microspheres. The continuous delivery of MGF-Ct24E provides a new perspective on resolving the unsatisfactory bone reconstruction associated with microgravity and stress shielding.
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miR-451: potential role as tumor suppressor of human hepatoma cell growth and invasion.
Int. J. Oncol.
PUBLISHED: 02-04-2014
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Malignant hepatoma is the leading cause of morbidity and mortality in primary liver cancer. MicroRNAs are widely accepted to act as tumor regulators to mediate tumorigenesis. Recently, miRNA-451 (miR-451) has attracted increasing attention due to its critical roles in the development of several types of cancers. Unfortunately, its function and underlying mechanism(s) of action in hepatoma remain unclear. In this study, a significant downregulation of miR-451 was observed in hepatoma cell lines. Its overexpression by administration of miR-451 mimics decreased cell viability and promoted cell apoptosis, indicating a critical role of miR-451 in cell growth. Further mechanistic analysis suggested that miR-451 overexpression accelerated cell death in a caspase-3-dependent manner, as pretreatment with its inhibitor z-VAD-fmk notably attenuated miR-451-induced cell apoptotic rates. Moreover, miR-451 upregulation abrogated cell invasive ability, accompanied with the decrease of matrix metalloproteinase-9 (MMP-9) expression levels, which may contribute to miR-451-triggered cell apoptosis. Taken together, these results reveal a prominent role of miR-451 as a tumor suppressor regulating hepatoma cell growth and invasion in a caspase-3- and MMP-9-dependent manner. Thus, our research supports this promising therapeutic agent against hepatoma.
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The types of Anthomyiidae (Diptera) in the Shanghai Entomological Museum, Chinese Academy of Science, China.
Zootaxa
PUBLISHED: 01-28-2014
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An annotated list of the type-specimens of Anthomyiidae deposited in the Shanghai Entomological Museum, China, is presented. A total of 196 holotypes and 479 paratypes representing 212 nominal species (207 valid, 5 synonyms) were recognized and are listed alphabetically. Bibliographical data of the original description, labels and condition of the type-specimens and the current name of the species are provided. At the end, a nomenclatural summary and a geographic summary are provided.
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Intramyocardial transplantation of cardiac telocytes decreases myocardial infarction and improves post-infarcted cardiac function in rats.
J. Cell. Mol. Med.
PUBLISHED: 01-22-2014
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The midterm effects of cardiac telocytes (CTs) transplantation on myocardial infarction (MI) and the cellular mechanisms involved in the beneficial effects of CTs transplantation are not understood. In the present study, we have revealed that transplantation of CTs was able to significantly decrease the infarct size and improved cardiac function 14 weeks after MI. It has established that CT transplantation exerted a protective effect on the myocardium and this was maintained for at least 14 weeks. The cellular mechanism behind this beneficial effect on MI was partially attributed to increased cardiac angiogenesis, improved reconstruction of the CT network and decreased myocardial fibrosis. These combined effects decreased the infarct size, improved the reconstruction of the LV and enhanced myocardial function in MI. Our findings suggest that CTs could be considered as a potential cell source for therapeutic use to improve cardiac repair and function following MI, used either alone or in tandem with stem cells.
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Melanosome transfer: it is best to give and receive.
Curr. Opin. Cell Biol.
PUBLISHED: 01-21-2014
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The pigmentation of skin and hair in mammals is driven by the creation within melanocytes of melanosomes, a specialized pigment-producing organelle, and the subsequent intercellular transfer of this organelle to keratinocytes. This latter process is absolutely required for visible pigmentation and effective photo-protection because it serves to disperse the pigment in skin and hair. Therefore, the transfer of melanosomes from the melanocyte to the keratinocyte is as important for the biological endpoint of mammalian pigmentation as the biogenesis of this fascinating organelle. Here we review new findings that shed light on, and raise additional questions about, the mechanism of this enigmatic process.
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Analysis of structure origin and luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glass.
Spectrochim Acta A Mol Biomol Spectrosc
PUBLISHED: 01-17-2014
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The near infrared luminescence properties of Yb(3+)-Er(3+) co-doped fluorophosphate glasses have been investigated. The various effects on structure and 1.53 ?m emission were analyzed as a function of Yb(3+) concentration. The energy transfer mechanism was proposed. High measured lifetime (10.75 ms), large effective full widths at half maximum (73.71 nm) and large gain per unit length (62.8 × 10(-)(24)cm(2)s) have been achieved in prepared glass. The present glass co-doped with 6mol% YbF3 and 2 mol% ErF3 showed magnificent luminescence properties for telecommunication application.
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MDR1 C3435T polymorphism and inflammatory bowel disease risk: a meta-analysis.
Mol. Biol. Rep.
PUBLISHED: 01-11-2014
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The C3435T polymorphism of the multidrug resistance gene (MDR1) has been implicated in inflammatory bowel disease (IBD) risk, but the reported results are inconsistent. Here we performed a meta-analysis to evaluate the association between C3435T polymorphism and the risk of IBD using all case-control studies published before February 2013 according to PubMed and Web of Science. A total of 13 case-control studies, including 6,757 cases and 4,295 controls, were included. Pooled odds ratio (OR) with 95 % confidence interval (CI) was calculated using fixed- or random-effects model. Overall, no evidence has indicated that the C3435T polymorphism was associated with the susceptibility to IBD (dominant model: OR = 1.05, 95 % CI: 0.96-1.16; CT vs. CC: OR = 1.06, 95 % CI: 0.95-1.17; TT vs. CC: OR = 1.04, 95 % CI: 0.92-1.17; recessive model: OR = 0.99, 95 % CI: 0.90-1.09). Besides, stratified analysis by clinical type also indicated that no significant association between MDR1 C3435T and the risk of Crohn's disease and ulcerative colitis was observed. This meta-analysis indicated that the C3435T polymorphism of MDR1 may not confer susceptibility to IBD.
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Association between CD14 gene polymorphisms and cancer risk: a meta-analysis.
PLoS ONE
PUBLISHED: 01-01-2014
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Two polymorphisms, -260C/T and -651C/T, in the CD14 gene have been implicated in susceptibility to cancer. However, the results remain inconclusive. This meta-analysis aimed to investigate the association between the two polymorphisms and risk of cancer.
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Glo1 genetic amplification as a potential therapeutic target in hepatocellular carcinoma.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Glyoxalase 1 (Glo1) gene aberrations is associated with tumorigenesis and progression in numerous cancers. In this study, we explored the role of Glo1 genetic amplification and expression in Chinese patients with hepatocellular carcinoma (HCC), and Glo1 genetic amplification as potential therapeutic target for HCC. We used fluorescence in situ hybridization (FISH) analysis and qRT-PCR to examine Glo1 genetic aberrations and Glo1 mRNA expression in paired tumor samples obtained from HCC patients. Glo1 genetic amplification was identified in a subset of HCC patient (6%, 3/50), and up-regulation of Glo1 expression was found in 48% (24/50) of tumor tissues compared with adjacent non-tumorous tissues. Statistic analysis showed that Glo1-upregulation significantly correlated with high serum level of alpha-fetoprotein (AFP). Interfering Glo1 expression with shRNA knocking-down led to significant inhibition of cell growth and induced apoptosis in primarily cultured HCC cells carrying genetic amplified Glo1 gene, while no inhibitory effects on cell proliferation were observed in HCC cells with normal copies of Glo1 gene. Glo1 knockdown also inhibited tumor growth and induced apoptosis in xenograft tumors established from primarily cultured HCC cells with Glo1 gene amplification. In addition, Glo1 knocking-down with shRNA interfering caused cellular accumulation of methylglyoxal, a Glo1 cytotoxic substrate. Our data suggested Glo1 pathway activation is required for cell proliferation and cell survival of HCC cells carrying Glo1 genetic amplification. Intervention of Glo1 activation could be a potential therapeutic option for patients with HCC carrying Glo1 gene amplification.
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A visual ERP study of impulse inhibition following a zaleplon-induced nap after sleep deprivation.
PLoS ONE
PUBLISHED: 01-01-2014
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The side effects of a zaleplon-induced nap as a countermeasure in the reduction of impulse inhibition function decline following 30 h of sleep deprivation (SD) were examined by event-related brain potentials. Sixteen adult participants performed a Go/NoGo task at five time points: (1) baseline; (2) after 30 h of SD; (3) upon sudden awakening, also called 2 h post-drug; (4) 4 h post-drug; and (5) 6 h post-drug. Behavior results show an increase in both reaction time and false alarm rates after SD and sudden awakening, and a marked decrease at 4 h and 6 h post-drug in zaleplon and placebo conditions. However, no difference was observed between the zaleplon condition and the placebo condition. In event-related potential (ERP) reults compared with results obtained under control conditions, NoGo-P3 latencies significantly increased, whereas the Nogo-P3 amplitude decreased after 30 h of SD and sudden awakening in both the zaleplon condition and the placebo condition. These results indicate that SD attenuates resource allocation and error monitoring for NoGo stimuli. In addition, NoGo-P3 latencies were longer in the zaleplon condition compared with the placebo condition at sudden awakening. Additionally, the NoGo-P3 latencies were shorter in the zaleplon condition than in the placebo condition at 4 h and 6 h post-drug. These results indicate that zaleplon at a dose of 10 mg/day may help subjects achieve a better recovery or maintain better impulse inhibition function, although the side effects of zaleplon last at least 2 h post-drug.
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Meta-analysis: narrow band imaging for diagnosis of gastric intestinal metaplasia.
PLoS ONE
PUBLISHED: 01-01-2014
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Distinguishing early gastric cancer is challenging with current imaging techniques. Narrow band imaging (NBI) is effective for characterizing gastric lesions.
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Association between polymorphisms in XRCC1 gene and treatment outcomes of patients with advanced gastric cancer: a systematic review and meta-analysis.
PLoS ONE
PUBLISHED: 01-01-2014
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Many reports have shown inconsistent results on the relationship between single nucleotide polymorphisms (SNPs) of X-ray repair cross complementing protein (XRCC1) gene and platinum-based chemotherapeutic efficacy. This meta-analysis aimed to summarize published data about the association between two SNPs of XRCC1 (Arg194Trp and Arg399Gln) and treatment outcomes of patients with advanced gastric cancer.
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A combined experimental and computational study of the catalytic dehydration of glycerol on microporous zeolites: an investigation of the reaction mechanism and acrolein selectivity.
Phys Chem Chem Phys
PUBLISHED: 10-26-2013
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The catalytic activity and the acrolein selectivity for liquid phase glycerol dehydration on ? zeolites (HNa-?-k) were found to be dependent on the reaction temperature as well as on the amount of acid sites on the zeolites. An increase in the reaction temperature favors the acrolein selectivity. The acrolein selectivity increases with the Na(+)/H(+) ratio and the glycerol conversion decreases with it so that a maximum acrolein yield is obtained when a certain amount of acidic sites are replaced by non-active Na(+) sites. The computational results indicate that 3-hydoxylpropanal (HPA) is an important intermediate that determines the final product selectivity. The relative rates of the different reaction pathways for HAP can be affected by the amount of water molecules involved in its homogeneous reaction. Based on the reaction mechanism proposed, it was hypothesized that smaller pores reduce activity but increase selectivity to acrolein, and results of the H-MFI zeolite were consistent with this hypothesis. Our work provides important insight into the overall landscape of the reaction mechanism and can be used to help design reaction systems that have good acrolein selectivity for the liquid phase glycerol dehydration reactions.
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Cyclooxygenase-2 polymorphisms and susceptibility to colorectal cancer: a meta-analysis.
Yonsei Med. J.
PUBLISHED: 10-22-2013
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Four polymorphisms, -765G>C, -1195G>A, 8473T>C, and Val511Ala, in the cyclooxygenase-2 (COX-2) gene were identified to be associated with colorectal cancer (CRC) risk. However, the results are inconsistent. The objective of this meta-analysis was to evaluate the association between these four polymorphisms and the risk of CRC.
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Interplay between different magnetisms in Cr-doped topological insulators.
ACS Nano
PUBLISHED: 09-30-2013
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Breaking the time-reversal-symmetry of topological insulators through magnetic doping has led to exotic physical discoveries. Here, we report the gate-dependent magneto-transport measurements on the Cr-doped (BixSb1-x)2Te3 thin films. With effective top-gate modulations, we demonstrate the presence of both the hole-mediated RKKY coupling and carrier-independent van Vleck magnetism in the magnetic TI systems. Most importantly, by varying the Cr doping concentrations from 2% to 20%, we unveil the interplay between the two magnetic orders and establish the valid approach to either enhance or suppress each individual contribution. The electric-field-controlled ferromagnetisms identified in the Cr-doped TI materials will serve as the fundamental step to further explore the TRS-breaking TI systems, and it may also help to expand the functionality of TI-based device for spintronics applications.
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Evidence of the two surface states of (Bi0.53Sb0.47)2Te3 films grown by van der Waals epitaxy.
Sci Rep
PUBLISHED: 09-19-2013
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The discovery of topological insulators (TIs) has led to numerous exciting opportunities for studying topological states of quantum physics and for exploring spintronic applications due to the new physics arising from their robust metallic surface states. Here, we report the high-quality topological insulator (BixSb1-x)2Te3 thin films using a single van der Waals GaSe buffer layer. As a result, ultra-low surface carrier density of 1.3 × 10(12)?cm(-2) and a high Hall mobility of 3100?cm(2)/Vs have been achieved for (Bi0.53Sb0.47)2Te3. The high-quality films enable us to observe quantum oscillations associated with the top and bottom surface states and to manipulate the Dirac electrons and bulk holes conduction properties. The observation of the two surface states may lead to a path towards the implementation of TIs in spintronics.
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Manipulating surface-related ferromagnetism in modulation-doped topological insulators.
Nano Lett.
PUBLISHED: 09-12-2013
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A new class of devices based on topological insulators (TI) can be achieved by the direct engineering of the time-reversal-symmetry (TRS) protected surface states. In the meantime, a variety of interesting phenomena are also expected when additional ferromagnetism is introduced to the original topological order. In this Letter, we report the magnetic responses from the magnetically modulation-doped (Bi(z)Sb(1-z))2Te3/Cr(x)(Bi(y)Sb(1-y))2Te3 bilayer films. By electrically tuning the Fermi level across the Dirac point, we show that the top TI surface carriers can effectively mediate the magnetic impurities and generate robust ferromagnetic order. More importantly, such surface magneto-electric effects can be either enhanced or suppressed, depending on the magnetic interaction range inside the TI heterostructures. The manipulation of surface-related ferromagnetism realized in our modulation-doped TI device is important for the realization of TRS-breaking topological physics, and it may also lead to new applications of TI-based multifunctional heterostructures.
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Increased proliferation and differentiation of pre-osteoblasts MC3T3-E1 cells on nanostructured polypyrrole membrane under combined electrical and mechanical stimulation.
J Biomed Nanotechnol
PUBLISHED: 08-29-2013
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Polypyrrole (PPy), as an electrical conductive polymer, has been widely investigated in biomedical fields. In this study, PPy membrane at nanoscale was electrically deposited on indium-tin oxide glass slide with sodium p-toluenesulfonate as supporting electrolyte. Electropolymerization of PPy was performed under a constant 800 mV voltage for 10 seconds. Chemical compositions and morphology were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that the nanoscaled PPy particles distributed uniformly and the average diameter of PPy particles was 62 nm. Since bone cells can respond to both electrical and mechanical stimulation in vivo, pre-osteoblasts MC3T3-E1 cells were cultured ort nanostructured PPy membrane under the combined electrical and mechanical stimulation. The nano-PPy membrane was conducive to transferring uniform electrical stimulation and applying steady mechanical stimulation. It is suggested that the combined stimulation did not affect cells morphologies significantly. However, cell proliferation tested by MTT, alkaline phosphatase activities, and gene expression of Collagen-I indicated that combined stimulation can enhance the proliferation and differentiation of MC3T3-E1 cells more efficiently than single electrical stimulation or single mechanical stimulation. The combined stimulation through a nano-PPy membrane may provide a highly potential stimulated method in bone tissue engineering.
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Centrosome repositioning in T cells is biphasic and driven by microtubule end-on capture-shrinkage.
J. Cell Biol.
PUBLISHED: 08-26-2013
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T cells rapidly reposition their centrosome to the center of the immunological synapse (IS) to drive polarized secretion in the direction of the bound target cell. Using an optical trap for spatial and temporal control over target presentation, we show that centrosome repositioning in Jurkat T cells exhibited kinetically distinct polarization and docking phases and required calcium flux and signaling through both the T cell receptor and integrin to be robust. In "frustrated" conjugates where the centrosome is stuck behind the nucleus, the center of the IS invaginated dramatically to approach the centrosome. Consistently, imaging of microtubules during normal repositioning revealed a microtubule end-on capture-shrinkage mechanism operating at the center of the IS. In agreement with this mechanism, centrosome repositioning was impaired by inhibiting microtubule depolymerization or dynein. We conclude that dynein drives centrosome repositioning in T cells via microtubule end-on capture-shrinkage operating at the center of the IS and not cortical sliding at the IS periphery, as previously thought.
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Optical frequency comb generation from aluminum nitride microring resonator.
Opt Lett
PUBLISHED: 08-02-2013
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Aluminum nitride (AlN) is an appealing nonlinear optical material for on-chip wavelength conversion. Here we report optical frequency comb generation from high-quality-factor AlN microring resonators integrated on silicon substrates. By engineering the waveguide structure to achieve near-zero dispersion at telecommunication wavelengths and optimizing the phase matching for four-wave mixing, frequency combs are generated with a single-wavelength continuous-wave pump laser. Further, the Kerr coefficient (n?) of AlN is extracted from our experimental results.
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Effect of anatase TiO2 nanoparticles on the growth of RSC-364 rat synovial cell.
J Nanosci Nanotechnol
PUBLISHED: 07-19-2013
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Nanoscale materials (such as TiO2, hydroxyapatite nanoparticles) have gained much concern in the coating of implants for cell adhesion and growth to improve the osteoconductivity. However, due to attrition and corrosion, the wear particles would be generated from the joint in living organism, and influence the physiological function of synovial membranes in joint cavity. In this study, the potential cytotoxicity of anatase TiO2 nanoparticles (TiO2 NPs) on rat synovial cell line 364 (RSC-364) was investigated. After treatment with different concentrations of TiO2 NPs (0, 3, 30, 300 microg/ml), the viability of RSC-364 cells were decreased in a dose-dependent manner. TiO2 NPs exposure could disrupt the integrity of cell plasma membrane, leading to the increased leakage of lactate dehydrogenase (LDH) into the culture medium. TiO2 NPs were uptaken by RSC-364 cells. The ultrastructure of RSC-364 cells was changed such as nuclear shrinkage and mitochondrial swelling. The reactive oxygen species (ROS) was over-produced especially in the cells exposed to 30 and 300 microg/ml TiO2 NPs. The activities of endogeneous antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), were significantly decreased. The increased lipid peroxidation product (malondialdehyde, MDA) suggests the oxidative damage in cells. The flow cytometry detected that the cell cycle was blocked in G0/G1 phase, inhibiting the cell proliferation. These preliminary results indicate the oxidative stress injury and cytotoxicity of anatase TiO2 NPs on rat synovial cells. The reasonable and safe application of nanomaterials in artificial implants needs further study.
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Association between the Pro12Ala polymorphism of PPAR-? gene and the non-alcoholic fatty liver disease: a meta-analysis.
Gene
PUBLISHED: 07-02-2013
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Several studies have been conducted to examine the association between PPAR-?2 Pro12Ala polymorphism and non-alcoholic fatty liver disease (NAFLD), but the results remain inconsistent. In this study, a meta-analysis was performed to assess the association of PPAR-? Pro12Ala polymorphism with NAFLD risk. A total of 8 case-control studies, including 1697 cases and 2427 controls, were selected. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects model. Overall, no evidence has indicated that the Pro12Ala polymorphism was associated with the susceptibility to NAFLD. Besides, stratified analysis with ethnicity also indicated that no significant association between PPAR-? Pro12Ala and the risk of NAFLD under all for genetic model in both Asian and Caucasian populations was observed. This meta-analysis indicated that the Pro12Ala polymorphism is not associated with NAFLD risk. Large and well-designed studies are warranted to validate our findings.
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Three-dimensional morphometric comparison of normal and apoptotic endothelial cells based on laser scanning confocal microscopy observation.
Microsc. Res. Tech.
PUBLISHED: 06-18-2013
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Three-dimensional (3D) morphometric analysis of cellular and subcellular structures provides an effective method for spatial cell biology. Here, 3D cellular and nuclear morphologies are reconstructed to quantify and compare morphometric differences between normal and apoptotic endothelial cells. Human umbilical vein endothelial cells (HUVECs) are treated with 60 ?M H2 O2 to get apoptotic cell model and then a series of sectional images are acquired from laser scanning confocal microscopy. The 3D cell model containing plasma membrane and cell nucleus is reconstructed and fused utilizing three sequential softwares or packages (Mimics, Geomagic, and VTK). The results reveal that H2 O2 can induce apoptosis effectively by regulating the activity of apoptosis-related biomolecules, including pro-apoptotic factors p53 and Bax, and anti-apoptotic factor Bcl-2. Compared with the normal HUVECs, the apoptotic cells exhibit significant 3D morphometric parameters (height, volume and nucleus-to-cytoplasm ratio) variation. The present research provides a new perspective on comparative quantitative analysis associated with cell apoptosis and points to the value of LSCM as an objective tool for 3D cell reconstruction.
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Initial experience with a juvenile sheep model for evaluation of the pediatric intracorporeal ventricular assist devices [corrected].
ASAIO J.
PUBLISHED: 06-07-2013
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There is a scarcity of source material available in animal models appropriate to test pediatric-size blood pump design for assisting the left ventricle. A juvenile ovine animal model was developed to evaluate two pediatric ventricular assist devices (VADs). The child-size Jarvik 2000 and CircuLite VADs were tested with this model. The 33 in vivo experiments were retrospectively studied to evaluate the reliability of the animal model. Dorset hybrid juvenile sheep (20~36 kg) were used to evaluate the small pediatric VADs. Under general anesthesia, a left lateral thoracotomy was performed through the fifth intercostal space. The devices were implanted between the left ventricle apex and the descending aorta without cardiopulmonary bypass. Heparin was infused continuously for anticoagulation therapy. Support duration averaged 26.7 ± 19.6 days. Completion of 75.7% (25/33) experiments was done as intended. The animals were docile and did not require sitters beyond the immediate operative period. Complication includes leg injury, graft infection, gastrointestinal bleeding, intravenous line disconnection, weight loss, renal failure, red urine, (one for each) and pulmonary failure in two. Activated clotting time was adjusted via continuous intravenous heparin to 150-200 seconds. Reliable hemodynamics and biocompatibility data were collected for evaluate pediatric intracorporeal VADs in the animal model. The juvenile sheep model is reliable, reproducible, and translatable for testing pediatric VADs. These experiments provided vital information for improvement of the devices and for clinical application in the future.
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Pre-clinical evaluation of the infant Jarvik 2000 heart in a neonate piglet model.
J. Heart Lung Transplant.
PUBLISHED: 06-05-2013
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The infant Jarvik 2000 heart is a very small, hermetically sealed, intracorporeal, axial-flow ventricular assist device (VAD) designed for circulatory support in neonates and infants. The anatomic fit, short-term biocompatibility and hemodynamic performance of the device were evaluated in a neonate piglet model.
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Direct atom-by-atom chemical identification of nanostructures and defects of topological insulators.
Nano Lett.
PUBLISHED: 05-30-2013
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We present a direct atom-by-atom chemical identification of the nanostructures and defects of topological insulators (TIs) with a state-of-the-art atomic mapping technology. Combining this technique and density function theory calculations, we identify and explain the layer chemistry evolution of Bi(2)Te(3–x)Se(x) ternary TIs. We also reveal a long neglected but crucially important extended defect found to be universally present in Bi(2)Te(3) films, the seven-layer Bi(3)Te(4) nanolamella acceptors. Intriguingly, this defect is found to locally pull down the conduction band, leading to local n-type conductivity, despite being an acceptor which pins the Fermi energy near the valence band maximum. This nanolamella may explain inconsistencies in measured conduction type as well as open up a new route to manipulate bulk carrier concentration. Our work may pave the way to more thoroughly understand and tailor the nature of the bulk, as well as secure controllable bulk states for future applications in quantum computing and dissipationless devices.
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Sinomenine sensitizes gastric cancer cells to 5-fluorouracil in vitro and in vivo.
Oncol Lett
PUBLISHED: 05-24-2013
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Sinomenine (SIN) has been reported to exert antitumor effects in various types of human cancer. The present study aimed to investigate the effects of SIN on gastric cancer and to briefly address its mechanism of action. In this study, the single and combined effects of SIN with 5-fluorouracil (5-FU) on human gastric cancer cells were assessed using an MTT assay, a combination index method and an MKN-28 xenograft mice model. Levels of apoptosis were determined using Hoechst 33258 staining and flow cytometry. Expression levels of certain apoptosis-related proteins were examined by western blotting. mRNA levels of the 5-FU-associated gene, thymidylate synthase (TS), were measured by RT-PCR. The results showed that SIN enhances 5-FU-mediated cellular growth inhibition and apoptosis in gastric cancer cells, reduces TS mRNA accumulation and activates the mitochondrial apoptotic pathway. The same chemotherapy sensitizer effect of SIN was confirmed in vivo. SIN is a promising chemotherapy sensitizer for 5-FU. Our results indicate that this may be a potential combination chemotherapeutic strategy for gastric cancer.
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Interest of a new biodegradable stent coated with paclitaxel on anastomotic wound healing after biliary reconstruction.
Eur J Gastroenterol Hepatol
PUBLISHED: 05-15-2013
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Benign biliary stricture of anastomotic stoma is frequent after biliary reconstruction. To prevent such a complication, a new paclitaxel-coated poly-L-lactide acid (PLLA) biodegradable biopolymer stent was designed. This original device was intended both to exert adequate mechanical support properties and to allow controlled drug delivery from the coating, with the goal of favoring wound healing after biliary reconstruction.
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Autophagy regulates endothelial cell processing, maturation and secretion of von Willebrand factor.
Nat. Med.
PUBLISHED: 05-09-2013
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Endothelial secretion of von Willebrand factor (VWF) from intracellular organelles known as Weibel-Palade bodies (WPBs) is required for platelet adhesion to the injured vessel wall. Here we demonstrate that WPBs are often found near or within autophagosomes and that endothelial autophagosomes contain abundant VWF protein. Pharmacological inhibitors of autophagy or knockdown of the essential autophagy genes Atg5 or Atg7 inhibits the in vitro secretion of VWF. Furthermore, although mice with endothelial-specific deletion of Atg7 have normal vessel architecture and capillary density, they exhibit impaired epinephrine-stimulated VWF release, reduced levels of high-molecular weight VWF multimers and a corresponding prolongation of bleeding times. Endothelial-specific deletion of Atg5 or pharmacological inhibition of autophagic flux results in a similar in vivo alteration of hemostasis. Thus, autophagy regulates endothelial VWF secretion, and transient pharmacological inhibition of autophagic flux may be a useful strategy to prevent thrombotic events.
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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.