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Find video protocols related to scientific articles indexed in Pubmed.
Involvement of superoxide and nitric oxide in BRAF(V600E) inhibitor PLX4032-induced growth inhibition of melanoma cells.
Integr Biol (Camb)
PUBLISHED: 11-04-2014
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The BRAF(V600E) inhibitor PLX4032 (Vemurafenib) is an FDA-approved new drug for the treatment of metastatic melanomas, which specifically inhibits the RAS/MEK/ERK signaling pathway to control cell proliferation and adhesion. However, no study has been carried out to investigate the role of intracellular oxidative balance in PLX4032-induced tumor growth inhibition. Herein, for the first time, superoxide (O2?(-)) and nitric oxide (NO) generated from PLX4032-challenged melanoma cells were monitored using electrochemical sensors and conventional fluorescein staining techniques. Impacts of superoxide dismutase (SOD) and NG-monomethyl-l-arginine monoacetate (l-NMMA), a nitric oxide synthase inhibitor, were also examined to demonstrate the specificity of ROS/NO generation and its biological consequences. PLX4032 specifically triggers production of O2?(-) and NO from BRAF(V600E) mutant A375 cells. SOD and l-NMMA could abolish the PLX4032-induced increase in intracellular O2?(-) and NO production, thereby rescuing cell growth in BRAF mutant A375 cells (A375(BRAFV600E)). In addition, PLX4032 treatment could decrease the mitochondrial membrane potential in A375(BRAFV600E) cells. The results suggest that PLX4032 can selectively cause ROS production and depolarization of mitochondrial membranes, potentially initiating apoptosis and growth inhibition of PLX4032-sensitive cells. This work not only proposes a new mechanism for PLX4032-induced melanoma cell inhibition, but also highlights potential applications of electrochemical biosensors in cell biology and drug screening.
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From bistate molecular switches to self-directed track-walking nanomotors.
ACS Nano
PUBLISHED: 10-02-2014
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Track-walking nanomotors and larger systems integrating these motors are important for wide real-world applications of nanotechnology. However, inventing these nanomotors remains difficult, a sharp contrast to the widespread success of simpler switch-like nanodevices, even though the latter already encompasses basic elements of the former such as engine-like bistate contraction/extension or leg-like controllable binding. This conspicuous gap reflects an impeding bottleneck for the nanomotor development, namely, lack of a modularized construction by which spatially and functionally separable "engines" and "legs" are flexibly assembled into a self-directed motor. Indeed, all track-walking nanomotors reported to date combine the engine and leg functions in the same molecular part, which largely underpins the device-motor gap. Here we propose a general design principle allowing the modularized nanomotor construction from disentangled engine-like and leg-like motifs, and provide an experimental proof of concept by implementing a bipedal DNA nanomotor up to a best working regime of this versatile design principle. The motor uses a light-powered contraction-extension switch to drive a coordinated hand-over-hand directional walking on a DNA track. Systematic fluorescence experiments confirm the motor's directional motion and suggest that the motor possesses two directional biases, one for rear leg dissociation and one for forward leg binding. This study opens a viable route to develop track-walking nanomotors from numerous molecular switches and binding motifs available from nanodevice research and biology.
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Architecting the Finite Element Method Pipeline for the GPU.
J Comput Appl Math
PUBLISHED: 09-10-2014
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The finite element method (FEM) is a widely employed numerical technique for approximating the solution of partial differential equations (PDEs) in various science and engineering applications. Many of these applications benefit from fast execution of the FEM pipeline. One way to accelerate the FEM pipeline is by exploiting advances in modern computational hardware, such as the many-core streaming processors like the graphical processing unit (GPU). In this paper, we present the algorithms and data-structures necessary to move the entire FEM pipeline to the GPU. First we propose an efficient GPU-based algorithm to generate local element information and to assemble the global linear system associated with the FEM discretization of an elliptic PDE. To solve the corresponding linear system efficiently on the GPU, we implement a conjugate gradient method preconditioned with a geometry-informed algebraic multi-grid (AMG) method preconditioner. We propose a new fine-grained parallelism strategy, a corresponding multigrid cycling stage and efficient data mapping to the many-core architecture of GPU. Comparison of our on-GPU assembly versus a traditional serial implementation on the CPU achieves up to an 87 × speedup. Focusing on the linear system solver alone, we achieve a speedup of up to 51 × versus use of a comparable state-of-the-art serial CPU linear system solver. Furthermore, the method compares favorably with other GPU-based, sparse, linear solvers.
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Asymmetric information hiding and noise-free recovery based on rotating analyzer ellipsometry and quick-response code.
J Opt Soc Am A Opt Image Sci Vis
PUBLISHED: 08-15-2014
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We report an asymmetric optical information hiding method based on a rotating analyzer ellipsometry technique. This asymmetric hiding architecture not only avoids the interception of keys during transmission or distribution but also makes the cyphertext more inconspicuous for attackers. A new kind of one-way optical trapdoor function is constructed based on the fact that the state of polarization (SOP) of elliptical polarized light cannot be recovered with only the knowledge of intensity captured after passing through a linear polarizer. Meanwhile, the SOP of a polarization ellipse could be calculated by rotating the polarizer to record two scenes of intensity after it. Introduction of a quick response code as a container leads to noise-free recovery for original information and enhances practicality of the proposed cryptosystem with versatile key sensitivity and fault tolerance capability. Numerical simulation results that support theoretical analysis are presented. Analysis on the relationship between hiding effect or quality of decryption and parameters of the algorithm also is provided.
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Nomogram predicting renal insufficiency after nephroureterectomy for upper tract urothelial carcinoma in the Chinese population: exclusion of ineligible candidates for adjuvant chemotherapy.
Biomed Res Int
PUBLISHED: 08-10-2014
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To report the decline of renal function after radical nephroureterectomy (RNU) in upper tract urothelial carcinoma (UTUC) patients and to develop a nomogram to predict ineligibility for cisplatin-based adjuvant chemotherapy (AC).
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The deformation of B4C particle in the B4C/2024Al composites after high velocity impact.
Micron
PUBLISHED: 08-01-2014
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In the present work, B4C/2024Al composites with volume fraction of 45% were prepared by a pressure infiltration method. The microstructure of the crater bottom of B4C/2024Al composite after impact was characterized by transmission electron microscope (TEM), which indicated that recovery and dynamic recrystallization generated in Al matrix, and the grain size distribution was about from dozens of nanometer to 200 nm. Furthermore, the plastic deformation was observed in B4C ceramic, which led to the transformation from monocrystal to polycrystal ceramic grains. The boundary observed in this work was high-angle grain boundary and the two grains at the boundary had an orientation difference of 30°.
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[Efficacy and safety of a combined oral contraceptive containing drospirenone 3 mg and ethinylestradiol 20 µg in a 24+4-day regimen in China].
Zhonghua Fu Chan Ke Za Zhi
PUBLISHED: 07-18-2014
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To assess the efficacy, bleeding pattern, cycle control and safety of a combined oral contraceptive (YAZ) containing drospirenone 3 mg and ethinylestradiol 20 µg in a 24+4-day regimen in China.
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Optical asymmetric cryptography based on elliptical polarized light linear truncation and a numerical reconstruction technique.
Appl Opt
PUBLISHED: 07-01-2014
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We demonstrate a novel optical asymmetric cryptosystem based on the principle of elliptical polarized light linear truncation and a numerical reconstruction technique. The device of an array of linear polarizers is introduced to achieve linear truncation on the spatially resolved elliptical polarization distribution during image encryption. This encoding process can be characterized as confusion-based optical cryptography that involves no Fourier lens and diffusion operation. Based on the Jones matrix formalism, the intensity transmittance for this truncation is deduced to perform elliptical polarized light reconstruction based on two intensity measurements. Use of a quick response code makes the proposed cryptosystem practical, with versatile key sensitivity and fault tolerance. Both simulation and preliminary experimental results that support theoretical analysis are presented. An analysis of the resistance of the proposed method on a known public key attack is also provided.
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Episomal expression of truncated listeriolysin O in LmddA-LLO-E7 vaccine enhances antitumor efficacy by preferentially inducing expansions of CD4+FoxP3- and CD8+ T cells.
Cancer Immunol Res
PUBLISHED: 05-28-2014
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Studies have shown that Listeria monocytogenes (Lm)-based vaccine expressing a fusion protein comprising truncated listeriolysin O (LLO) and human papilloma virus (HPV) E7 protein (Lm-LLO-E7) induces a decrease in regulatory T cells (Treg) and complete regression of established, transplanted HPV-TC-1 tumors in mice. However, how the Lm-based vaccine causes a decrease in Tregs remains unclear. Using a highly attenuated Lm dal dat ?actA strain (LmddA)-based vaccine, we report here that the vector LmddA was sufficient to induce a decrease in the proportion of Tregs by preferentially expanding CD4(+)FoxP3(-) T cells and CD8(+) T cells by a mechanism dependent on and directly mediated by LLO. Episomal expression of a nonhemolytic truncated LLO in Lm (LmddA-LLO) significantly augmented the expansion, thus further decreasing Treg frequency. Although adoptive transfer of Tregs compromised the antitumor efficacy of the LmddA-LLO-E7 vaccine, a combination of LmddA-LLO and an Lm-based vaccine expressing E7 protein (Lm-E7) induced complete regression against established TC-1 tumors. An engineered LLO-minus Lm expressing perfringolysin O (PFO) that enables the recombinant bacteria to exit from the phagolysosome without LLO confirmed that the adjuvant effect was dependent on LLO. These results suggest that LLO may serve as a promising adjuvant by preferentially inducing the expansions of CD4(+)FoxP3(-) T cells and CD8(+) T cells, thus reducing the ratio of Tregs to CD4(+)FoxP3(-) T cells and to CD8(+) T cells favoring immune responses to eradicate tumor.
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Conserved expression of lincRNA during human and macaque prefrontal cortex development and maturation.
RNA
PUBLISHED: 05-20-2014
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The current annotation of the human genome includes more than 12,000 long intergenic noncoding RNAs (lincRNA). While a handful of lincRNA have been shown to play important regulatory roles, the functionality of most remains unclear. Here, we examined the expression conservation and putative functionality of lincRNA in human and macaque prefrontal cortex (PFC) development and maturation. We analyzed transcriptome sequence (RNA-seq) data from 38 human and 40 macaque individuals covering the entire postnatal development interval. Using the human data set, we detected the expression of 5835 lincRNA annotated in GENCODE and further identified 1888 novel lincRNA. Most of these lincRNA show low DNA sequence conservation, as well as low expression levels. Remarkably, developmental expression patterns of these lincRNA were as conserved between humans and macaques as those of protein-coding genes. Transfection of development-associated lincRNA into human SH-SY5Y cells affected gene expression, indicating their regulatory potential. In brain, expression of these putative target genes correlated with the expression of the corresponding lincRNA during human and macaque PFC development. These results support the potential functionality of lincRNA in primate PFC development.
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[Preliminary application of injectable calcium phosphate cement/poly (lactic-co-glycolic acid) microspheres for extraction site preservation].
Zhonghua Kou Qiang Yi Xue Za Zhi
PUBLISHED: 05-14-2014
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To investigate the feasibility of extraction site preservation using injectable calcium phosphate cement (CPC) combine with poly (lactic-co-glycolic acid) (PLGA) microspheres.
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Fabrication of CeO2 nanoparticle-modified silk for UV protection and antibacterial applications.
J Colloid Interface Sci
PUBLISHED: 05-13-2014
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To endow silk with UV-shielding ability and antibacterial activity, CeO2 nanoparticles were immobilized on silk surface via a dip-coating approach without changing silk structure. Surface density of the nanoparticles could be easily adjusted by controlling the number of dip-coating cycle. Enhanced thermal stability of the modified silk is exhibited in thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (DTG). The excellent UV-protection ability and antibacterial property of the CeO2 nanoparticle-coated silk are demonstrated in UV-vis diffuse reflectance spectroscopy and colony-forming capability test, respectively. Based on the data, it can be concluded that CeO2 nanoparticles could be used as a very promising coating material to modify silk for UV-protection and antibacterial applications.
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ZnO nanomulberry and its significant nonenzymatic signal enhancement for protein microarray.
ACS Appl Mater Interfaces
PUBLISHED: 05-06-2014
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It is very challenging to make a highly sensitive protein microarray because of its lack of a universal signal amplification method like PCR used in DNA microarray. The current strategies to improve the sensitivity mainly rely on a unique nanostructured substrate or enzymatically catalyzed signal amplification, of which the former requires a complicated and time-consuming fabrication process while the latter suffers from high cost and poor stability of enzymes as well as downstream biochemical reactions. In this work, an inexpensive ZnO nanomulberry (NMB) decorated glass slide is investigated as a superior substrate to nonenzymatically amplify the signal of protein microarray for sensitive detection, accomplishing a limit of detection (LOD) of 1 pg mL(-1) and a broad dynamic range of 1 pg mL(-1) to 1 ?g mL(-1) to detect an important cancer biomarker, carcinoembryonic antigen (CEA) in 10% human serum. The excellent performance is attributed to ZnO NMB possessing high-density loading of capture antibody and intrinsic enhancement of fluorescence emission. The substrate preparation is simple without using any expensive equipment and complicated technique while offering advantages of low autofluorescence, versatility for various fluorophores, and excellent compatibility with existing microarray fabrication techniques. Thus, a ZnO NMB based protein microarray holds great promise for developing a low cost, sensitive, and high throughput protein assay platform for broad applications in both fundamental research and clinical diagnosis.
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ZnO nanorod-templated well-aligned ZrO2 nanotube arrays for fibroblast adhesion and proliferation.
Nanotechnology
PUBLISHED: 05-02-2014
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Cellular responses to porous tubular structures have recently been investigated in highly ordered ZrO2 nanotube arrays fabricated with anodization. However, the potential applications of the nanotube arrays are hindered by instrument requirements and substrate limitations, as well as by the complicated processes needed for synthesis. In this work, ZrO2 nanotube arrays were synthesized by in situ hydrolysis of zirconium propoxide with a zinc oxide nanorod array-based template. Fibroblast cells were able to grow on the nanotube array surface with produced elongated filopodia. Studies of the capability of cell growth and the expression of adhesion- and proliferation-related genes reveal that ZrO2 nanotube arrays may provide a better environment for cell adhesion and growth than a flat titanium surface. These findings not only provide fundamental insight into cell response to nanostructures but also provide an opportunity to use a unique approach to fabricate ZrO2 nanotube array structures for potential implant applications.
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Efficacy of sunitinib in patients with metastatic renal cell carcinoma: initial experience in two Chinese centers.
Chin. Med. J.
PUBLISHED: 04-26-2014
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The advent of targeted therapy has proved a milestone in the history of metastatic renal cell carcinoma treatment, and several guidelines now recommend sunitinib as first- or second-line treatment. But little is known about its efficacy in Asian patients. The aim of this article was to evaluate the efficacy of sunitinib monotherapy in patients with metastatic renal cell carcinoma treated at two Chinese centers.
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Polydopamine-functionalization of graphene oxide to enable dual signal amplification for sensitive surface plasmon resonance imaging detection of biomarker.
Anal. Chem.
PUBLISHED: 04-21-2014
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Surface plasmon resonance imaging (SPRi) is one of the powerful tools for immunoassays with advantages of label-free, real-time, and high-throughput; however, it often suffers from limited sensitivity. Herein we report a dual signal amplification strategy utilizing polydopamine (PDA) functionalization of reduced graphene oxide (PDA-rGO) nanosheets for sensitive SPRi immunoassay in serum. The PDA-rGO nanosheet is synthesized by oxidative polymerization of dopamine in a gentle alkaline solution in the presence of graphene oxide (GO) sheets and then is antibody-conjugated via a spontaneous reaction between the protein and the PDA component. In the dual amplification mode, the first signal comes from capture of the antibody-conjugated PDA-rGO to form sandwiched immunocomplexes on the SPRi chip, followed by a PDA-induced spontaneous gold reductive deposition on PDA-rGO to further enhance the SPRi signal. The detection limit as low as 500 pg mL(-1) is achieved on a nonfouling SPRi chip with high specificity and a wide dynamic range for a model biomarker, carcinoembryonic antigen (CEA) in 10% human serum.
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Novel loss-of-function PRRT2 mutation causes paroxysmal kinesigenic dyskinesia in a Han Chinese family.
BMC Neurol
PUBLISHED: 03-31-2014
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Mutations in proline-rich transmembrane protein 2 (PRRT2) are a cause of paroxysmal kinesigenic dyskinesia (PKD). In this study, we investigated the PRRT2 gene mutation in a Chinese Han family with PKD and study the pathogenesis of the mutation with PRRT2 gene.
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Tracheal rupture related to endotracheal intubation after thyroid surgery: a case report and systematic review.
Int Wound J
PUBLISHED: 03-25-2014
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Tracheobronchial rupture is an uncommon but potentially serious complication of endotracheal intubation. The most likely cause of tracheal injury is massive overinflation of the endotracheal tube cuff and pre-existing tracheal wall weakness. We review the relevant literature and predisposing factors contributing to this complication. Only articles that reported at least the demographic data (age and sex), the treatment performed and the outcome were included. Papers that did not detail these variables were excluded. We also focus on a case of tracheal laceration after tracheal intubation in a patient with severe thyroid carcinoma. This patient received surgical repair and recovered uneventfully. Two hundred and eight studies that reported cases or case series were selected for analysis. Most of the reported cases (57·2%) showed an uneventful recovery after surgical therapy. The overall mortality was 19·2% (40 patients). Our patient too recovered without any serious complication. Careful prevention, early detection and proper treatment of the problem are necessary when tracheal rupture occurs. The morbidity and mortality associated with tracheal injury mandate a high level of suspicion and expedient management.
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Incidence, characteristics, treatment strategies, and oncologic outcomes of synchronous bilateral upper tract urothelial carcinoma in the Chinese population.
Urol. Oncol.
PUBLISHED: 03-22-2014
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To investigate the incidence and treatment strategies for bilateral upper tract urothelial carcinoma (UTUC) and to compare the characteristic and oncologic outcomes of bilateral UTUC with those of unilateral tumors.
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One-pot synthesis of one-dimensional CdTe-cystine nanocomposite for humidity sensing.
Nanotechnology
PUBLISHED: 02-20-2014
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Quantum dot (QD)-incorporated one-dimensional (1D) nanocomposites offer great application potential. However, a facile one-step synthesis of the nanocomposites and fabrication of their free-standing film for sensing has not been accomplished. Herein a rod-shaped nanocomposite is one-pot synthesized via an L-cysteine-assisted hydrothermal approach, in which synthesis parameters including L-cysteine amount, temperature and reaction duration are tailored to control the composite nanostructures. CdTe nanocrystals are incorporated into the L-cystine matrices to form the nanorods, which tangle each other to network an intact film structure via a simple drying process. The free-standing CdTe-cystine nanorod film is directly utilized as a humidity sensor. This work provides a one-pot synthesis approach to grow 1D CdTe incorporated nanocomposites, demonstrating their great potential in film sensing applications.
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Application of vitamin E to antagonize SWCNTs-induced exacerbation of allergic asthma.
Sci Rep
PUBLISHED: 02-17-2014
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The aggravating effects of zero-dimensional, particle-shaped nanomaterials on allergic asthma have been previously investigated, but similar possible effects of one-dimensional shaped nanomaterials have not been reported. More importantly, there are no available means to counteract the adverse nanomaterial effects to allow for their safe use. In this study, an ovalbumin (OVA)-sensitized rat asthma model was established to investigate whether single walled carbon nanotubes (SWCNTs) aggravate allergic asthma. The results showed that SWCNTs in rats exacerbated OVA-induced allergic asthma and that this exacerbation was counteracted by concurrent administration vitamin E. A mechanism involving the elimination of reactive oxygen species, downregulation of Th2 responses, reduced Ig production, and the relief of allergic asthma symptoms was proposed to explain the antagonistic effects of vitamin E. This work could provide a universal strategy to effectively protect people with allergic asthma from SWCNTs or similar nanomaterial-induced aggravating effects.
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A bioinspired design principle for DNA nanomotors: mechanics-mediated symmetry breaking and experimental demonstration.
Methods
PUBLISHED: 02-10-2014
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DNA nanotechnology is a powerful tool to fabricate nanoscale motors, but the DNA nanomotors to date are largely limited to the simplistic burn-the-bridge design principle that prevents re-use of a fabricated motor-track system and is unseen in biological nanomotors. Here we propose and experimentally demonstrate a scheme to implement a conceptually new design principle by which a symmetric bipedal nanomotor autonomously gains a direction not by damaging the traversed track but by fine-tuning the motor's size.
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Renal cell carcinoma with infrahepatic vena caval tumor thrombus treated with a novel combined retroperitoneal and transperitoneal pure laparoscopic procedure.
Urology
PUBLISHED: 01-24-2014
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A 61-year-old male patient presented with intermittent gross hematuria. A right renal mass with infrahepatic vena caval tumor thrombus was found using magnetic resonance imaging. We undertook a novel combined retroperitoneal and transperitoneal pure laparoscopic nephrectomy with vena caval thrombectomy for this patient. The patient recovered well after surgery and discharged on day 6. A clear cell renal cell carcinoma with venous extension was confirmed by pathologic assay. To our knowledge, this is the first report of such a novel hybrid surgical strategy.
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Autonomous synergic control of nanomotors.
ACS Nano
PUBLISHED: 01-16-2014
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Control is a hallmark of machines; effective control over a nanoscale system is necessary to turn it into a nanomachine. Nanomotors from biology often integrate a ratchet-like passive control and a power-stroke-like active control, and this synergic active-plus-passive control is critical to efficient utilization of energy. It remains a challenge to integrate the two differing types of control in rationally designed nanomotor systems. Recently a light-powered track-walking DNA nanomotor was developed from a bioinspired design principle that has the potential to integrate both controls. However, it is difficult to separate experimental signals for either control due to a tight coupling of both controls. Here we present a systematic study of the motor and new derivatives using different fluorescence labeling schemes and light operations. The experimental data suggest that the motor achieves the two controls autonomously through a mechanics-mediated symmetry breaking. This study presents an experimental validation for the bioinspired design principle of mechanical breaking of symmetry for synergic ratchet-plus-power stroke control. Augmented by mechanical and kinetic modeling, this experimental study provides mechanistic insights that may help advance molecular control in future nanotechnological systems.
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Graphene oxide-enabled tandem signal amplification for sensitive SPRi immunoassay in serum.
Chem. Commun. (Camb.)
PUBLISHED: 01-14-2014
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A tandem signal amplification using bioconjugated graphene oxide and subsequent silver catalytic deposition for surface plasmon resonance imaging (SPRi) to sensitively and specifically immunoassay tumor biomarkers in serum, achieving a limit of detection down to 100 pg mL(-1) with a broad dynamic range for ?-Fetoprotein (AFP) is reported.
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Risk factors and treatment outcomes of new contralateral upper urinary urothelial carcinoma after nephroureterectomy: the experiences of a large Chinese center.
J. Cancer Res. Clin. Oncol.
PUBLISHED: 01-12-2014
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To explore the risk factors and treatment outcomes of contralateral new upper tract urothelial carcinoma (UTUC) after nephroureterectomy in a large single-center cohort of UTUC patients.
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Cognitive deficits and decreased locomotor activity induced by single-walled carbon nanotubes and neuroprotective effects of ascorbic acid.
Int J Nanomedicine
PUBLISHED: 01-01-2014
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Single-walled carbon nanotubes (SWCNTs) have shown increasing promise in the field of biomedicine, especially in applications related to the nervous system. However, there are limited studies available on the neurotoxicity of SWCNTs used in vivo. In this study, neurobehavioral changes caused by SWCNTs in mice and oxidative stress were investigated. The results of ethological analysis (Morris water maze and open-field test), brain histopathological examination, and assessments of oxidative stress (reactive oxygen species [ROS], malondialdehyde [MDA], and glutathione [GSH]), inflammation (nuclear factor ?B, tumor necrosis factor ?, interleukin-1?), and apoptosis (cysteine-aspartic acid protease 3) in brains showed that 6.25 and 12.50 mg/kg/day SWCNTs in mice could induce cognitive deficits and decreased locomotor activity, brain histopathological alterations, and increased levels of oxidative stress, inflammation, and apoptosis in mouse brains; however, 3.125 mg/kg/day SWCNTs had zero or minor adverse effects in mice, and these effects were blocked by concurrent administration of ascorbic acid. Down-regulation of oxidative stress, inflammation, and apoptosis were proposed to explain the neuroprotective effects of ascorbic acid. This work suggests SWCNTs could induce cognitive deficits and decreased locomotor activity, and provides a strategy to avoid the adverse effects.
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Intraspecific lineages of the lizard Phrynocephalus putjatia from the Qinghai-Tibetan Plateau: Impact of physical events on divergence and discordance between morphology and molecular markers.
Mol. Phylogenet. Evol.
PUBLISHED: 09-12-2013
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The Northeastern Qinghai-Tibetan Plateau (NQTP) contains many physical features that may have contributed to its rich biological diversity. We explored the systematics and genetic structures of the sand lizards Phrynocephalus putjatia, distributed across semi-deserts or rocky steppe habitats, and Phrynocephalus guinanensis, found only in sand dune habitats, from the NQTP using mitochondrial (ND2 and tRNAs) and nuclear (RAG-1) markers. Bayesian analyses revealed two main monophyletic mtDNA groups that separate populations of the Qinghai Lake Basin (QLB) from populations to the southeast of this basin (SEQL), but these did not correspond to the two morphological species. The QLB populations are divided into western and eastern groups. Two major groups with similar geographical structuring were also detected for the nuclear RAG-1 marker, but with some geographical discordance. A Bayesian species delimitation analysis did not support division of P. putjatia/P. guinanensis into separate species. Bayesian dating of mtDNA suggests that the earliest divergence within this group occurred less than 2Ma, which seems to be explained by mountain uplift between the QLB and the SEQL regions. Other Pleistocene events may explain further genetic structuring. Overall, we do not detect reciprocal monophyly of markers between morphological species but note that they do appear to represent ecological forms.
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Inter- and intra-chain disulfide bond prediction based on optimal feature selection.
Protein Pept. Lett.
PUBLISHED: 09-05-2013
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Protein disulfide bond is formed during post-translational modifications, and has been implicated in various physiological and pathological processes. Proper localization of disulfide bonds also facilitates the prediction of protein three-dimensional (3D) structure. However, it is both time-consuming and labor-intensive using conventional experimental approaches to determine disulfide bonds, especially for large-scale data sets. Since there are also some limitations for disulfide bond prediction based on 3D structure features, developing sequence-based, convenient and fast-speed computational methods for both inter- and intra-chain disulfide bond prediction is necessary. In this study, we developed a computational method for both types of disulfide bond prediction based on maximum relevance and minimum redundancy (mRMR) method followed by incremental feature selection (IFS), with nearest neighbor algorithm as its prediction model. Features of sequence conservation, residual disorder, and amino acid factor are used for inter-chain disulfide bond prediction. And in addition to these features, sequential distance between a pair of cysteines is also used for intra-chain disulfide bond prediction. Our approach achieves a prediction accuracy of 0.8702 for inter-chain disulfide bond prediction using 128 features and 0.9219 for intra-chain disulfide bond prediction using 261 features. Analysis of optimal feature set indicated key features and key sites for the disulfide bond formation. Interestingly, comparison of top features between interand intra-chain disulfide bonds revealed the similarities and differences of the mechanisms of forming these two types of disulfide bonds, which might help understand more of the mechanisms and provide clues to further experimental studies in this research field.
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Sacrificial polymer thin-film template with tunability to construct high-density Au nanoparticle arrays and their refractive index sensing.
Phys Chem Chem Phys
PUBLISHED: 08-15-2013
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Great challenges still remain to assemble metal nanoparticles on a substrate with tunability, high density, robust stability, good dispersion and well-retained properties for various applications. Herein a new concept using a polymer thin-film as a sacrificial template is investigated to fabricate highly dense and well-dispersed nanoparticle arrays. In contrast to a conventional "hard" template, the polymer template is a porous multilayered film allowing in situ growth of Au nanoparticles with a restricted ripening mode, and tuning the nanoparticle size and density of the arrays is possible by simply adjusting the loading conditions. The prepared substrate-attached nanoparticle arrays demonstrate good thermal and chemical stability, while offering highly sensitive and tunable localized surface plasmon resonance (LSPR) refractive index sensing with a broad linear dynamic range. This method could be extended to controllably fabricate other robust and "clean" nanoparticle arrays on various substrates for various applications including sensing, catalysis and optoelectronics.
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Genome Sequence of the Pyrene- and Fluoranthene-Degrading Bacterium Cycloclasticus sp. Strain PY97M.
Genome Announc
PUBLISHED: 08-03-2013
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Cycloclasticus sp. strain PY97M was isolated from a phenanthrene-degrading consortium, enriched from Yellow Sea sediment of China. Here, we present the draft genome sequence of strain PY97M, which contains 2,359,509 bp with a G+C content of 41.92% and contains 2, 264 protein-coding genes and 40 tRNAs.
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Directional fidelity of nanoscale motors and particles is limited by the 2nd law of thermodynamics--via a universal equality.
J Chem Phys
PUBLISHED: 07-26-2013
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Directional motion of nanoscale motors and driven particles in an isothermal environment costs a finite amount of energy despite zero work as decreed by the 2nd law, but quantifying this general limit remains difficult. Here we derive a universal equality linking directional fidelity of an arbitrary nanoscale object to the least possible energy driving it. The fidelity-energy equality depends on the environmental temperature alone; any lower energy would violate the 2nd law in a thought experiment. Real experimental proof for the equality comes from force-induced motion of biological nanomotors by three independent groups - for translational as well as rotational motion. Interestingly, the natural self-propelled motion of a biological nanomotor (F1-ATPase) known to have nearly 100% energy efficiency evidently pays the 2nd law decreed least energy cost for direction production.
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Recombinant GnRH-p53 protein sensitizes breast cancer cells to 5-fluorouracil-induced apoptosis in vitro and in vivo.
Apoptosis
PUBLISHED: 06-27-2013
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An ideal approach to treat cancers with dysfunctional p53 tumor suppressor gene is to reinstate p53 functionality by directly using p53 protein as a therapeutic agent. However, this has not been possible because the cells cannot readily internalize the protein. We constructed a fusion protein consisting of gonadotropin-releasing hormone (GnRH-p53) and p53 moieties. The recombinant protein was directly used to treat human breast cancer cells and athymic nude mice bearing breast cancer xenografts, with or without DNA synthesis-arresting agent 5-fluorouracil (5-FU). Treatments of cells from breast cancer cell-lines MDA-MB-231, T47D, or SKBR-3 with GnRH-p53 in combination with 5-FU significantly enhanced p53-activated apoptosis signals, including PUMA expression, BAX translocation to mitochondria, and activated caspase-3. Intratumoral injection of the GnRH-p53 protein inhibited MDA-MB-231 xenograft growth and induced p53-mediated apoptosis in the tumors. Systemic treatment of the tumor-bearing mice via tail vein injection of GnRH-p53 markedly augmented the anticancer efficacy of 5-FU. Substitution of GnRH-p53 with wild type p53 protein had no effect. Recombinant GnRH-p53 is able to function as a surrogate of p53 with regard to its apoptosis-inducing activity. Combination of GnRH-p53 with DNA-damaging drugs may be of important therapeutic value for cancer treatment.
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Genome Sequence of the Polycyclic Aromatic Hydrocarbon-Degrading Bacterium Strain Marinobacter nanhaiticus D15-8WT.
Genome Announc
PUBLISHED: 06-01-2013
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Marinobacter nanhaiticus strain D15-8W(T) was isolated from a phenanthrene-degrading consortium, enriched from sediment of the South China Sea. Here, we present the draft genome of strain D15-8W(T), which contains 5,358,309 bp with a G+C content of 58.53% and contains 4,829 protein-coding genes and 47 tRNA genes.
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Enhanced lactone stability of CZ48 in blood correlates to its lack of toxicity in mice.
J Pharm Pharm Sci
PUBLISHED: 05-21-2013
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The aim of this study was to correlate the relationship between the pharmacokinetic behaviors and the toxicity of a new investigational anticancer agent CZ48, a C20-propionate ester of camptothecin (CPT) in mice.
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Role of directional fidelity in multiple aspects of extreme performance of the F(1)-ATPase motor.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 05-20-2013
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Quantitative understanding of the best possible performance of nanomotors allowed by physical laws pertains to the study of nanomotors from biology as well as nanotechnology. The biological nanomotor F(1) ATPase is the best available model system as it is the only nanomotor known for extreme energy conversion near the limit of energy conservation. Using a unified theoretical framework centered on a concept called directional fidelity, we analyze recent experiments in which the F(1) motors performance was measured for controlled chemical potentials and expose from the experiments quantitative evidence for the motors multiple extreme performances in directional fidelity, speed, and catalytic capability close to physical limits. Specifically, the motor nearly exhausts the available energy from the fuel to retain the highest possible directional fidelity for an arbitrary load, encompassing the motors extreme energy conversion and beyond. The theory-experiment comparison implies a tight chemomechanical coupling up to stalemate as futile steps occur, but unlikely involve fuel consumption. The F(1)-motor data also help clarify the relation between directional fidelity and experimentally measured stepping ratio.
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A clinical study of serum lipid disturbance in Chinese patients with sudden deafness.
Lipids Health Dis
PUBLISHED: 05-20-2013
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Pathological levels of blood lipids could be one of the causes of sudden sensorineural hearing loss (SSNHL). The objective of this manuscript is therefore to evaluate the relationship between blood lipid content and sudden sensorineural hearing loss (SSNHL).
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Enhanced mesenchymal stem cell survival induced by GATA-4 overexpression is partially mediated by regulation of the miR-15 family.
Int. J. Biochem. Cell Biol.
PUBLISHED: 04-30-2013
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We reported previously that pre-programming mesenchymal stem cells with the GATA-4 gene increases significantly cell survival in an ischemic environment. In this study, we tested whether regulation of microRNAs and their target proteins was associated with the cytoprotective effects of GATA-4.
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Plastic protein microarray to investigate the molecular pathways of magnetic nanoparticle-induced nanotoxicity.
Nanotechnology
PUBLISHED: 04-04-2013
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Superparamagnetic iron oxide nanoparticles (SPIONs) (about 15 nm) were synthesized via a hydrothermal method and characterized by field emission scanning electron microscopy, transmission electron microscopy, dynamic light scattering, x-ray diffraction, and vibrating sample magnetometer. The molecular pathways of SPIONs-induced nanotoxicity was further investigated by protein microarrays on a plastic substrate from evaluation of cell viability, reactive oxygen species (ROS) generation and cell apoptosis. The experimental results reveal that 50 ?g ml(-1) or higher levels of SPIONs cause significant loss of cell viability, considerable generation of ROS and cell apoptosis. It is proposed that high level SPIONs could induce cell apoptosis via a mitochondria-mediated intrinsic pathway by activation of caspase 9 and caspase 3, an increase of the Bax/Bcl-2 ratio, and down-regulation of HSP70 and HSP90 survivor factors.
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Prevalence and factors associated with baseline chronic kidney disease in China: A 10-year study of 785 upper urinary tract urothelial carcinoma patients.
J. Formos. Med. Assoc.
PUBLISHED: 03-17-2013
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BACKGROUND/PURPOSE: There is relatively little literature on prevalence of chronic kidney disease (CKD) prior to surgery in patients with upper urinary tract urothelial carcinoma (UTUC). We evaluated the prevalence and clinical associated factors of baseline CKD in patients with UTUC. MATERIALS AND METHODS: There were 785 patients with a pathologic diagnosis of UTUC from January 2002 to December 2011 who were analyzed in this study. Estimated glomerular filtration rate (eGFR) was calculated by re-expressed Modification of Diet in Renal Disease (MDRD) formulas for the Chinese population. A multivariate logistic regression was performed to evaluate the odds ratios (ORs) for CKD stage 3 or higher in UTUCs after data differences were tested. RESULTS: The prevalence of CKD in UTUCs presenting at our hospital was 58.6% and 70.8% in the group age 70 years and older. Older age [per year increased; OR = 1.050; 95% confidence interval (CI): 1.034-1.067], lower tumor stage (T stage; per stage increased; OR = 0.666; 95% CI: 0.544-0.816), higher tumor grade (per grade increased; OR = 1.392; 95% CI: 1.004-1.930) and the main tumor locating in the pelvis (ureter as reference; OR = 0.648; 95% CI: 0.475-0.885) were independently associated with decreased kidney function in the multivariate logistic regression. The use of serum creatinine (Scr) only to evaluate the renal function would ignore a large proportion of patients suffering from CKD stage 3 in UTUCs, especially in those older than 70 years (39.3% vs. 54.1%, p = 0.022). CONCLUSION: We demonstrated a high prevalence (58.6%) of CKD in patients with UTUC, particularly in the group older than 70 years (70.8%). Older age, lower T stage, higher tumor grade, and the main tumor locating in pelvis (ureter as reference) were independently associated with CKD in UTUCs.
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A portable flow-through fluorescent immunoassay lab-on-a-chip device using ZnO nanorod-decorated glass capillaries.
Lab Chip
PUBLISHED: 03-14-2013
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We report a portable flow-through fluorescent immunoassay lab-on-a-chip device using inexpensive disposable glass capillaries for medical diagnostics. The device is made up of a number of serially connected glass capillaries, of which each interior surface is grown using zinc oxide (ZnO) nanorods, which different probe antibodies are attached to. The ZnO nanorods not only provide a large surface area for high density probe attachment, but also enhance the fluorescent signals to significantly improve the detection signal responses. The glass capillary also allows for convenient flow-through detection. Coupled with a homemade handheld analyzer integrated with an automatic pump system and a fluorescence readout module, a portable immunoassay capillary device enables quantitative detection of multiple biomarkers in 30 min with detection limits of 1-5 ng mL(-1) and wide dynamic ranges for prostate specific antigen (PSA), ?-Fetoprotein (AFP) and carcinoembryonic antigen (CEA) in serum. This new conceptual lab-on-a-chip device eliminates the need for expensive micro-fabrication processes, while offering inexpensive and disposable, but replaceable tube-type "microchannels" for multiplexed detection in portable clinical diagnostics.
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Study on power coupling of annular vortex beam propagating through a two-Cassegrain-telescope optical system in turbulent atmosphere.
Opt Express
PUBLISHED: 03-14-2013
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As a new attractive application of the vortex beams, power coupling of annular vortex beam propagating through a two- Cassegrain-telescope optical system in turbulent atmosphere has been investigated. A typical model of annular vortex beam propagating through a two-Cassegrain-telescope optical system is established, the general analytical expression of vortex beams with limited apertures and the analytical formulas for the average intensity distribution at the receiver plane are derived. Under the H-V 5/7 turbulence model, the average intensity distribution at the receiver plane and power coupling efficiency of the optical system are numerically calculated, and the influences of the optical topological charge, the laser wavelength, the propagation path and the receiver apertures on the power coupling efficiency are analyzed. These studies reveal that the average intensity distribution at the receiver plane presents a central dark hollow profile, which is suitable for power coupling by the Cassegrain telescope receiver. In the optical system with optimized parameters, power coupling efficiency can keep in high values with the increase of the propagation distance. Under the atmospheric turbulent conditions, great advantages of vortex beam in power coupling of the two-Cassegrain-telescope optical system are shown in comparison with beam without vortex.
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AhV_aPA-induced vasoconstriction involves the IP?Rs-mediated Ca²? releasing.
Toxicon
PUBLISHED: 03-06-2013
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AhV_aPA, the acidic PLA? purified from Agkistrodon halys pallas venom, was previously reported to possess a strong enzymatic activity and can remarkably induce a further contractile response on the 60 mM K?-induced contraction with an EC?? in 369 nM on mouse thoracic aorta rings. In the present study, we found that the p-bromo-phenacyl-bromide (pBPB), which can completely inhibit the enzymatic activity of AhV_aPA, did not significantly reduce the contractile response on vessel rings induced by AhV_aPA, indicating that the vasoconstrictor effects of AhV_aPA are independent of the enzymatic activity. The inhibitor experiments showed that the contractile response induced by AhV_aPA is mainly attributed to the Ca²? releasing from Ca²? store, especially sarcoplasmic reticulum (SR). Detailed studies showed that the Ca²? release from SR is related to the activation of inositol trisphosphate receptors (IP?Rs) rather than ryanodine receptors (RyRs). Furthermore, the vasoconstrictor effect could be strongly reduced by pre-incubation with heparin, indicating that the basic amino acid residues on the surface of AhV_aPA may be involved in the interaction between AhV_aPA and the molecular receptors. These findings offer new insights into the functions of snake PLA? and provide a novel pathogenesis of A. halys pallas venom.
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Simultaneous detection of lactate and glucose by integrated printed circuit board based array sensing chip.
Anal. Chim. Acta
PUBLISHED: 01-18-2013
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An integrated printed circuit board (PCB) based array sensing chip was developed to simultaneously detect lactate and glucose in mouse serum. The novelty of the chip relies on a concept demonstration of inexpensive high-throughput electronic biochip, a chip design for high signal to noise ratio and high sensitivity by construction of positively charged chitosan/redox polymer Polyvinylimidazole-Os (PVI-Os)/carbon nanotube (CNT) composite sensing platform, in which the positively charged chitosan/PVI-Os is mediator and electrostatically immobilizes the negatively charged enzyme, while CNTs function as an essential cross-linker to network PVI-Os and chitosan due to its negative charged nature. Additional electrodes on the chip with the same sensing layer but without enzymes were prepared to correct the interferences for high specificity. Low detection limits of 0.6 ?M and 5 ?M were achieved for lactate and glucose, respectively. This work could be extended to inexpensive array sensing chips with high sensitivity, good specificity and high reproducibility for various sensor applications.
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ZnO nanowire array-templated LbL self-assembled polyelectrolyte nanotube arrays and application for charged drug delivery.
Nanotechnology
PUBLISHED: 01-08-2013
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Vertically oriented and robust polyelectrolyte nanotube arrays with high density, large area and high uniformity were successfully grown on substrates by a ZnO nanowire array-templated layer-by-layer (LbL) self-assembly approach for the first time, and were further used to deliver charged drugs, showing that they not only possess pH-responsive loading property, but also significantly enhance the loading capacity and sustained release time. This work could be extended to fabricate polyelectrolyte nanotube arrays with different polyelectrolyte combinations, including weak polyelectrolyte/weak polyelectrolyte, weak polyelectrolyte/strong polyelectrolyte and strong polyelectrolyte/strong polyelectrolyte. With the great versatility to use various substrates and building blocks, the polyelectrolyte nanotube arrays may have great potential for broad applications such as biosensor arrays, bioreactor arrays and optoelectronics.
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Laparoscopic ureteral reimplantation with extracorporeal tailoring and direct nipple ureteroneocystostomy for adult obstructed megaureter: a novel technique.
Urology
PUBLISHED: 01-06-2013
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To describe a novel technique using extracorporeal tailoring and an inverted ureteral nipple to perform laparoscopic transperitoneal ureteral reimplantation for adult obstructed megaureter and our initial experience with 10 patients.
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Photoluminescence and energy transfer study of Er3+ and Dy3+ codoped tellurite glasses.
J Nanosci Nanotechnol
PUBLISHED: 12-26-2011
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Photoluminescence properties of the Er(3+)-Dy3+ codoped tellurite glasses were studied by absorption and visible emission spectra, which revealed luminescence bands of both Er3+ and Dy3+ when pumping with the wavelength of 325 nm. The concentration quenching occurred as Dy3+ concentration increased beyond 3 mol%. The dependence of Er3+ characteristic emission on Dy3+ concentration indicated energy transfer process between Er3+ and Dy3+. The chromaticity coordinates of these glasses are close to white light, which implies that these glasses might be potential candidates for white lighting through an appropriate combination.
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Improved infrared emissions of Er(3+)-Tm3+ co-doped Al2O3 thin films: the role of cross relaxation among rare earth ions.
J Nanosci Nanotechnol
PUBLISHED: 12-26-2011
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We report the infrared emissions of Er(3+)-Tm3+ co-doped amorphous Al2O3 thin films pumped at 791 nm by a Ti:sapphire laser. The as-deposited films were annealed to improve the photoluminescence performance. Three cross relaxation channels among Er(3+)-Tm3+ and Tm(3+)-Tm3+ ions incorporated in the films were investigated as annealing temperature increases especially from 800 to 850 degrees C. In order to understand the Stark effect and cross relaxations, the photoluminescence spectra were deconvoluted by Gaussian fittings. Our results indicate that the luminescence intensity of 1.62 microm in comparison to 1.5 microm can be enhanced by the cross relaxation process [Er3+ (4I13/2) + Tm3+ (3H6) --> Er3+ (4I15/2) + Tm3+ (3F4)], and the longer-wavelength side of Er3+ emission can be improved by the CR process [Er3+ (4I15/2) + Tm3+ (3H4) --> Er3+ (4I3/2) + Tm3+ (3F4) at expense of the Tm3+ 1.47 microm emission which is also maybe quenched by the CR effect between themselves. These results suggest one possible approach to achieve broadband infrared emissions at the wavelength region of 1.45-1.65 microm from the Er(3+)-Tm3+ co-doped systems.
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I?B kinase alpha and cancer.
J. Interferon Cytokine Res.
PUBLISHED: 12-07-2011
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I?B kinase alpha (Ikk-?) gene mutations and IKK-? downregulation have been detected in various human squamous cell carcinomas (SCCs), which are malignancies derived from squamous epithelial cells. These squamous epithelial cells distribute to many organs in the body; however, the epidermis is the only organ mainly composed of stratified squamous epithelial cells, called keratinocytes. SCC is the second most common type of skin cancer. Reducing IKK-? expression promotes tumor initiation, and its loss greatly enhances tumor progression from benign papillomas to malignant carcinomas during chemical skin carcinogenesis in mice. Thus, IKK-? has emerged as a tumor suppressor for SCCs. Furthermore, inducible deletion of IKK-? in the keratinocytes of adult mice causes spontaneous skin papillomas and carcinomas, indicating that IKK-? deletion functions as a tumor initiator as well as a tumor promoter. This article discusses IKK-? biological activities and associated molecular events in skin tumor development, which may provide insight into the diagnosis, treatment, and prevention of human squamous cell carcinomas (SCCs) in the future.
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A FAST ITERATIVE METHOD FOR SOLVING THE EIKONAL EQUATION ON TRIANGULATED SURFACES.
SIAM J Sci Comput
PUBLISHED: 10-06-2011
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This paper presents an efficient, fine-grained parallel algorithm for solving the Eikonal equation on triangular meshes. The Eikonal equation, and the broader class of Hamilton-Jacobi equations to which it belongs, have a wide range of applications from geometric optics and seismology to biological modeling and analysis of geometry and images. The ability to solve such equations accurately and efficiently provides new capabilities for exploring and visualizing parameter spaces and for solving inverse problems that rely on such equations in the forward model. Efficient solvers on state-of-the-art, parallel architectures require new algorithms that are not, in many cases, optimal, but are better suited to synchronous updates of the solution. In previous work [W. K. Jeong and R. T. Whitaker, SIAM J. Sci. Comput., 30 (2008), pp. 2512-2534], the authors proposed the fast iterative method (FIM) to efficiently solve the Eikonal equation on regular grids. In this paper we extend the fast iterative method to solve Eikonal equations efficiently on triangulated domains on the CPU and on parallel architectures, including graphics processors. We propose a new local update scheme that provides solutions of first-order accuracy for both architectures. We also propose a novel triangle-based update scheme and its corresponding data structure for efficient irregular data mapping to parallel single-instruction multiple-data (SIMD) processors. We provide detailed descriptions of the implementations on a single CPU, a multicore CPU with shared memory, and SIMD architectures with comparative results against state-of-the-art Eikonal solvers.
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Down-modulation of TNFSF15 in ovarian cancer by VEGF and MCP-1 is a pre-requisite for tumor neovascularization.
Angiogenesis
PUBLISHED: 09-28-2011
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Persistent inflammation and neovascularization are critical to cancer development. In addition to upregulation of positive control mechanisms such as overexpression of angiogenic and inflammatory factors in the cancer microenvironment, loss of otherwise normally functioning negative control mechanisms is likely to be an important attribute. Insights into the down-modulation of such negative control mechanisms remain largely unclear, however. We show here that tumor necrosis factor superfamily-15 (TNFSF15), an endogenous inhibitor of neovascularization, is a critical component of the negative control mechanism that operates in normal ovary but is missing in ovarian cancer. We show in clinical settings that TNFSF15 is present prominently in the vasculature of normal ovary but diminishes in ovarian cancer as the disease progresses. Vascular endothelial growth factor (VEGF) produced by cancer cells and monocyte chemotactic protein-1 (MCP-1) produced mainly by tumor-infiltrating macrophages and regulatory T cells effectively inhibits TNFSF15 production by endothelial cells in vitro. Using a mouse syngeneic tumor model, we demonstrate that silencing TNFSF15 by topical shRNA treatments prior to and following mouse ovarian cancer ID8 cell inoculation greatly facilitates angiogenesis and tumor growth, whereas systemic application of recombinant TNFSF15 inhibits angiogenesis and tumor growth. Our findings indicate that downregulation of TNFSF15 by cancer cells and tumor infiltrating macrophages and lymphocytes is a pre-requisite for tumor neovascularization.
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Technique for interaction of optical fields with turbulent medium containing particles.
Opt Lett
PUBLISHED: 08-18-2011
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We develop a method for transmission of stochastic fields through turbulent media (atmosphere, ocean, biotissues) containing randomly distributed particles. The method is based on the angular spectrum representation of stochastic, statistically stationary, scalar fields, the Rytov perturbation series for propagation in weakly fluctuating media, and the first Born approximation for weak scattering from particulate media. The results for transmission of the deterministic (laser) field may be obtained from our general results as a limiting case.
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GATA-4 promotes myocardial transdifferentiation of mesenchymal stromal cells via up-regulating IGFBP-4.
Cytotherapy
PUBLISHED: 08-17-2011
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GATA-4 is a cardiac transcription factor and plays an important role in cell lineage differentiation during development. We investigated whether overexpression of GATA-4 increases adult mesenchymal stromal cell (MSC) transdifferentiation into a cardiac phenotype in vitro.
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Method for tracing the position of an alien object embedded in a random particulate medium.
J Opt Soc Am A Opt Image Sci Vis
PUBLISHED: 08-04-2011
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We have developed a new technique based on light scattering experiments for tracing an alien particle with deterministic potential in a random collection of particles. We have shown that, via a sequence of measurements of light scattered to a far field of a scattering collection, it is possible to locate the center of the alien particle. The analysis of the stability of reconstruction is provided, and it is demonstrated via simulations that the results are stable for sufficiently large wavelength of the incident light and in cases when the size of the alien particle is comparable with the size of the typical particle in the collection.
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[Identification and characterization of a novel hydrocarbon-degrading Marinobacter sp. PY97S].
Wei Sheng Wu Xue Bao
PUBLISHED: 08-02-2011
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To identify and characterize a hydrocarbon-degrading bacterium isolated from the sediment of the Yellow Sea.
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Rewritable multicolor fluorescent patterns for multistate memory devices with high data storage capacity.
Chem. Commun. (Camb.)
PUBLISHED: 07-28-2011
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We report a branched polyethyleneimine (BPEI)-quantum dot (QD) based rewritable fluorescent system with a multicolor recording mode, in which BPEI is both QD-multicolor patterning "writer" and data erasing "remover". This method could write distinct colors from size-tailored QDs to represent large numbers of logic states for high data storage capacity.
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Paracrine effect of Wnt11-overexpressing mesenchymal stem cells on ischemic injury.
Stem Cells Dev.
PUBLISHED: 06-01-2011
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Our previous studies have suggested that transduction of Wnt11 directly increases bone marrow-derived mesenchymal stem cells (MSCs) differentiation into cardiac phenotypes. In this study, we investigated whether Wnt11 enhances MSC-mediated cardioprotection via paracrine fashion after acute ischemia. MSCs were harvested from male rat bone marrow and transduced with Wnt11 (MSC(Wnt11)). An acute myocardial infarction model in rats was developed by ligation of the left anterior descending coronary artery. MSC(Wnt11) were transplanted into the peri-infarct region after acute myocardial infarction. To mimic ischemic injury, cultured cardiomyocytes (CMs) isolated from neonatal ventricles were exposed to hypoxia. ELISA studies indicated that the release of Wnt11 (3.45-fold) as well as transforming growth factor-?2 (TGF?2) (1.5-fold) was significantly increased from MSC(Wnt11) compared with transduced control MSC (MSC(Null)). Hypoxia-induced apoptosis and cell death was significantly reduced when CM were co-cultured with MSC(Wnt11) in a dual chamber system. The cell protection mediated by MSC(Wnt11) was mimicked by treating CM with conditioned medium obtained from MSC(Wnt11) and abrogated by Wnt11- and TGF?2 neutralizing antibodies. Further, animals receiving MSC(Wnt11) showed a significant improvement in cardiac contractile function as assessed by echocardiography. Masson trichrome and TUNEL staining showed a significant reduction in infarct size and apoptosis of CM in MSC(Wnt11)-treated animals. Transplantation of MSC(Wnt11) improved cardiac function. The release of Wnt11 and other factors from transplanted MSC(Wnt11) is more likely responsible for protection of native CM at risk.
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Highly sensitive poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] brush-based flow-through microarray immunoassay device.
Biomed Microdevices
PUBLISHED: 05-07-2011
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Flow-through immunoassay is an attractive method for fast, inexpensive and high-throughput protein analyses. However, its practical application is limited by low sensitivity. In this work, a highly sensitive flow-through microarray immunoassay device is developed, in which a poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] (P(GMA-co-PEGMA)) brush as a flexible matrix is uniformly coated on a glass slide through a purge-free surface-initiated atom transfer radical polymerization (SI-ATRP) to immobilize capture proteins for a larger loading capacity and higher bioactivity while allowing easy target access to the brush-attached probes for efficient antibody-antigen (Ab-Ag) bindings. The integrated device is then constructed by simply laminating the protein-arrayed slide onto a ready-for-bonding double-sided adhesive tape-attached poly(methyl methacrylate) (PMMA) microfluidic structure. As a demonstration, a parallel microarray panel is designed to perform flow-through immunoassays for good detection flexibility and simultaneous analysis of various samples. The limit of detection (LOD) of 1-10 pg/mL for detected target proteins is achieved, which is one to two orders better than those of reported flow-through immunoassays. The device also demonstrates significantly reduced total assay time over the static microarray immunoassay. The rapid and sensitive detection can be mainly ascribed to the P(GMA-co-PEGMA) brushed substrate, of which both the hydrophilicity from its PEG component and the binding capability from its GMA moiety result in higher protein loading capacity, lower nonspecific adsorption, and higher Ab-Ag binding efficiency. The integrated microfluidic device was further used to detect an important cancer biomarker carcinoembryonic antigen (CEA) in serum and achieved a LOD of 10 pg/mL, demonstrating its great potential for clinical applications.
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Squamous cell carcinoma of the enlarged prostatic utricle in an adult.
Urology
PUBLISHED: 04-14-2011
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A 39-year-old man with gross terminal hematuria and urethral discharge for 5 months was found to have a partial cystic and partial solid mass above the normal site of prostate, which was confirmed by magnetic resonance imaging (MRI) and transrectal ultrasonagraphy. A radical resection of the tumor was performed, and classical squamous cell carcinoma was confirmed by pathologic assay.
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Sensitive protein microarray synergistically amplified by polymer brush-enhanced immobilizations of both probe and reporter.
J Colloid Interface Sci
PUBLISHED: 04-11-2011
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Great challenge remains to continuously improve sensitivity of protein microarrays for broad applications. A copolymer brush is in situ synthesized on both substrate and silica nanoparticle (SNP) surface to efficiently immobilize probe and reporter protein respectively for synergistic amplification of protein microarray signals. As a demonstration, sandwich immunoassay for a cancer biomarker carcinoembryonic antigen (CEA) detection is performed on microarray platform, showing a limit of detection (LOD) of 10 pg/ml and dynamic range of 10 pg/ml to 100 ng/ml. Two orders improvement of LOD is achieved in comparison to the small crosslinker-activated substrate. The improved sensitivity is attributed to not only the high immobilization amount of both probe and reporter but also the favorite protein binding orientations offered by the flexible brushes. This work provides a universal approach to inexpensively and significantly improve protein microarray sensitivity.
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Biocompatible fluorescence-enhanced ZrO?-CdTe quantum dot nanocomposite for in vitro cell imaging.
Nanotechnology
PUBLISHED: 03-10-2011
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With advances of quantum dots (QDs) in bioimaging applications, various materials have been used to coat QDs to reduce their nanotoxicity; however, the coating could introduce new toxic sources and quench the fluorescence in bioimaging applications. In this work, ZrO?, an excellent ceramic material with low extinction coefficient and good biocompatibility, is utilized to coat CdTe QDs for the first time. Experimental results show that ZrO?-QD nanocomposites with the size of ~30 nm possess enhanced fluorescence emission, lower nanotoxicity and gradually increased fluorescence under 350 nm light illumination. After functionalization with folic acid, they were applied to label cultured HeLa cells effectively. Therefore, the ZrO?-QD nanocomposites could be promising biocompatible nanomaterials with strong fluorescence emission to replace or complement QDs in biomedical applications.
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Universal optimal working cycles of molecular motors.
Phys Chem Chem Phys
PUBLISHED: 03-01-2011
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Molecular motors capable of directional track-walking or rotation are abundant in living cells, and inspire the emerging field of artificial nanomotors. Some biomotors can convert 90% of free energy from chemical fuels into usable mechanical work, and the same motors still maintain a speed sufficient for cellular functions. This study exposed a new regime of universal optimization that amounts to a thermodynamically best working regime for molecular motors but is unfamiliar in macroscopic engines. For the ideal case of zero energy dissipation, the universally optimized working cycle for molecular motors is infinitely slow like Carnot cycle for heat engines. But when a small amount of energy dissipation reduces energy efficiency linearly from 100%, the speed is recovered exponentially due to Boltzmanns law. Experimental data on a major biomotor (kinesin) suggest that the regime of universal optimization has been largely approached in living cells, underpinning the extreme efficiency-speed trade-off in biomotors. The universal optimization and its practical approachability are unique thermodynamic advantages of molecular systems over macroscopic engines in facilitating motor functions. The findings have important implications for the natural evolution of biomotors as well as the development of artificial counterparts.
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Transduction of Wnt11 promotes mesenchymal stem cell transdifferentiation into cardiac phenotypes.
Stem Cells Dev.
PUBLISHED: 02-26-2011
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Transplantation of mesenchymal stem cells (MSCs) has emerged as a potential treatment for ischemic heart repair. Previous studies have suggested that Wnt11 plays a critical role in cardiac specification and morphogenesis. In this study, we examined whether transduction of Wnt11 directly increases MSC differentiation into cardiac phenotypes. MSCs harvested from rat bone marrow were transduced with both Wnt11 and green fluorescent protein (GFP) (MSC(Wnt11)) using the murine stem cell virus (pMSCV) retroviral expression system; control cells were only GFP-transfected (MSC(Null)). Compared with control cells, MSC(Wnt11) was shown to have higher expression of Wnt11 by immunofluorescence, real-time polymerase chain reaction, and western blotting. MSC(Wnt11) shows a higher expression of cardiac-specific genes, including GATA-4, brain natriuretic peptide (BNP), islet-1, and ?-actinin, after being cultured with cardiomyocytes (CMs) isolated from ventricles of neonatal (1-3 day) SD rats. Some MSC(Wnt11) were positive for ?-actinin when MSCs were cocultured with native CMs for 7 days. Electron microscopy further confirmed the appearance of sarcomeres in MSC(Wnt11). Connexin 43 was found between GFP-positive MSCs and neonatal rat CMs labeled with red fluorescent probe PKH26. The transdifferentiation rate was significantly higher in MSC(Wnt11) than in MSC(Null), as assessed by flow cytometry. Functional studies indicated that the differentiation of MSC(Wnt11) was diminished by knockdown of GATA-4 with GATA-4-siRNA. Transduction of Wnt11 into MSCs increases their differentiation into CMs by upregulating GATA-4.
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Maximum directionality and systematic classification of molecular motors.
Phys Chem Chem Phys
PUBLISHED: 02-07-2011
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Track-walking molecular motors are widely used in living cells for transport purposes, and artificial mimics are being vigorously pursued in engineered molecular systems. The defining character for a motor is its intrinsic capability to utilize energy input to rectify a sustained directional motion out of stochastic thermal motion. The energy injection can be coupled to a motors mechanical steps in different ways, leading to different motor mechanisms. We derive here a formulation for maximum motor performance in terms of a new quantity called directionality based on a general representation of the track-walking motors. Compared to performance measures like velocity and processivity, directionality is a cleaner and more robust indicator of the rectification mechanism that amounts to a motors inner design/working principles. Meaningful and distinctly different upper limits of directionality were found to exist for a wide variety of experimentally demonstrated and theoretically proposed motors and their biological counterparts. The maximum directionality provides a conceptual framework by which all of these different motors were quantitatively compared and systematically classified according to their mechanistic advancement. The results yield a series of guidelines for artificial motor development, and expose important evolutionary traits of biomotors.
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Bio-inspired track-walking molecular motors (Perspective).
Biointerphases
PUBLISHED: 12-22-2010
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The emerging field of artificial track-walking molecular motors is reviewed. The author attempted to clarify the scientific and technological challenges that face the field. A comprehensive mechanistic diagram for molecular walkers was introduced, thereby the directions and possible routes for future development were suggested.
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Paracrine factors released by GATA-4 overexpressed mesenchymal stem cells increase angiogenesis and cell survival.
Am. J. Physiol. Heart Circ. Physiol.
PUBLISHED: 09-24-2010
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Transplanted mesenchymal stem cells (MSC) release soluble factors that contribute to cardiac repair and vascular regeneration. We hypothesized that overexpression of GATA-4 enhances the MSC secretome, thereby increasing cell survival and promoting postinfarction cardiac angiogenesis. MSCs harvested from male rat bone marrow were transduced with GATA-4 (MSC(GATA-4)) using the murine stem cell virus retroviral expression system; control cells were either nontransduced (MSC(bas)) or transduced with empty vector (MSC(Null)). Compared with these control cells, MSC(GATA-4) were shown by immunofluorescence, real-time PCR, and Western blotting to have higher expression of GATA-4. An increased expression of angiogenic factors in MSC(GATA-4) and higher MSC resistance against hypoxia were observed. Human umbilical vein endothelial cells (HUVEC) treated with MSC(GATA-4) conditioned medium exhibited increased formation of capillary-like structures and promoted migration, compared with HUVECs treated with MSC(Null) conditioned medium. MSC(GATA-4) were injected into the peri-infarct region in an acute myocardial infarction model in Sprague-Dawley rats developed by ligation of the left anterior descending coronary artery. Survival of MSC(GATA-4), determined by Sry expression, was increased at 4 days postengraftment. MSC(GATA-4)-treated animals showed significantly improved cardiac function as assessed by echocardiography. Furthermore, fluorescent microsphere and histological studies revealed increased blood flow and blood vessel density and reduced infarction size in MSC(GATA-4)-treated animals. We conclude that GATA-4 overexpression in MSCs increased both MSC survival and angiogenic potential in ischemic myocardium and may therefore represent a novel and efficient therapeutic approach for postinfarct remodeling.
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A coordinated molecular fishing mechanism in heterodimeric kinesin.
Phys Biol
PUBLISHED: 08-20-2010
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Kar3 is a kinesin motor that facilitates chromosome segregation during cell division. Unlike many members of the kinesin superfamily, Kar3 forms a heterodimer with non-motor protein Vik1 or Cik1 in vivo. The heterodimers show ATP-driven minus-end directed motility along a microtubule (MT) lattice, and also serve as depolymerase at the MT ends. The molecular mechanisms behind this dual functionality remain mysterious. Here, a molecular mechanical model for the Kar3/Vik1 heterodimer based on structural, kinetic and motility data reveals a long-range chemomechanical transmission mechanism that resembles a familiar fishing tactic. By this molecular fishing, ATP-binding to Kar3 dissociates catalytically inactive Vik1 off MT to facilitate minus-end sliding of the dimer on the MT lattice. When the dimer binds the frayed ends of MT, the fishing channels ATP hydrolysis energy into MT depolymerization by a mechanochemical effect. The molecular fishing thus provides a unified mechanistic ground for Kar3s dual functionality. The fishing-promoted depolymerization differs from the depolymerase mechanisms found in homodimeric kinesins. The fishing also enables intermolecular coordination with a chemomechanical coupling feature different from the paradigmatic pattern of homodimeric motors. This study rationalizes some puzzling experimental observation, and suggests new experiments for further elucidation of the fishing mechanism.
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One-step aqueous synthesis of graphene-CdTe quantum dot-composed nanosheet and its enhanced photoresponses.
J Colloid Interface Sci
PUBLISHED: 08-19-2010
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Although CdTe nanocrystal has been applied in quantum dot (QD)-based solar cells, there is no report on a graphene-CdTe QD hybrid system and its photoresponses. In this work, graphene-CdTe QD composed nanosheets were one-step synthesized in aqueous solution using a hydrothermal method and demonstrated enhanced photoresponses, rendering potentials in optoelectronics applications. This work could provide an environmental-friendly and universal approach to fabricate graphene-based hybrid nanomaterials for various applications.
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Prediction of deleterious non-synonymous SNPs based on protein interaction network and hybrid properties.
PLoS ONE
PUBLISHED: 06-01-2010
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Non-synonymous SNPs (nsSNPs), also known as Single Amino acid Polymorphisms (SAPs) account for the majority of human inherited diseases. It is important to distinguish the deleterious SAPs from neutral ones. Most traditional computational methods to classify SAPs are based on sequential or structural features. However, these features cannot fully explain the association between a SAP and the observed pathophysiological phenotype. We believe the better rationale for deleterious SAP prediction should be: If a SAP lies in the protein with important functions and it can change the protein sequence and structure severely, it is more likely related to disease. So we established a method to predict deleterious SAPs based on both protein interaction network and traditional hybrid properties. Each SAP is represented by 472 features that include sequential features, structural features and network features. Maximum Relevance Minimum Redundancy (mRMR) method and Incremental Feature Selection (IFS) were applied to obtain the optimal feature set and the prediction model was Nearest Neighbor Algorithm (NNA). In jackknife cross-validation, 83.27% of SAPs were correctly predicted when the optimized 263 features were used. The optimized predictor with 263 features was also tested in an independent dataset and the accuracy was still 80.00%. In contrast, SIFT, a widely used predictor of deleterious SAPs based on sequential features, has a prediction accuracy of 71.05% on the same dataset. In our study, network features were found to be most important for accurate prediction and can significantly improve the prediction performance. Our results suggest that the protein interaction context could provide important clues to help better illustrate SAPs functional association. This research will facilitate the post genome-wide association studies.
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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.

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

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