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Perspective texture synthesis has great significance in many fields like video editing, scene capturing etc., due to its ability to read and control global feature information. In this paper, we present a novel example-based, specifically energy optimization-based algorithm, to synthesize perspective textures. Energy optimization technique is a pixel-based approach, so it’s time-consuming. We improve it from two aspects with the purpose of achieving faster synthesis and high quality. Firstly, we change this pixel-based technique by replacing the pixel computation with a little patch. Secondly, we present a novel technique to accelerate searching nearest neighborhoods in energy optimization. Using k- means clustering technique to build a search tree to accelerate the search. Hence, we make use of principal component analysis (PCA) technique to reduce dimensions of input vectors. The high quality results prove that our approach is feasible. Besides, our proposed algorithm needs shorter time relative to other similar methods. 相似文献
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2‐photon excitation fluorescence microscopy enables deeper high‐resolution imaging of voltage and Ca2+ in intact mice,rat, and rabbit hearts
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Iffath A. Ghouri Allen Kelly Francis L. Burton Godfrey L. Smith Ole Johan Kemi 《Journal of biophotonics》2015,8(1-2):112-123
We describe a novel two‐photon (2P) laser scanning microscopy (2PLSM) protocol that provides ratiometric transmural measurements of membrane voltage (Vm) via Di‐4‐ANEPPS in intact mouse, rat and rabbit hearts with subcellular resolution. The same cells were then imaged with Fura‐2/AM for intracellular Ca2+ recordings. Action potentials (APs) were accurately characterized by 2PLSM vs. microelectrodes, albeit fast events (<1 ms) were sub‐optimally acquired by 2PLSM due to limited sampling frequencies (2.6 kHz). The slower Ca2+ transient (CaT) time course (>1ms) could be accurately described by 2PLSM. In conclusion, Vm ‐ and Ca2+‐sensitive dyes can be 2P excited within the cardiac muscle wall to provide AP and Ca2+ signals to ~400 µm. (© 2013 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
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Husain SZ Orabi AI Muili KA Luo Y Sarwar S Mahmood SM Wang D Choo-Wing R Singh VP Parness J Ananthanaravanan M Bhandari V Perides G 《American journal of physiology. Gastrointestinal and liver physiology》2012,302(12):G1423-G1433
Biliary pancreatitis is the most common etiology for acute pancreatitis, yet its pathophysiological mechanism remains unclear. Ca(2+) signals generated within the pancreatic acinar cell initiate the early phase of pancreatitis, and bile acids can elicit anomalous acinar cell intracellular Ca(2+) release. We previously demonstrated that Ca(2+) released via the intracellular Ca(2+) channel, the ryanodine receptor (RyR), contributes to the aberrant Ca(2+) signal. In this study, we examined whether RyR inhibition protects against pathological Ca(2+) signals, acinar cell injury, and pancreatitis from bile acid exposure. The bile acid tauro-lithocholic acid-3-sulfate (TLCS) induced intracellular Ca(2+) oscillations at 50 μM and a peak-plateau signal at 500 μM, and only the latter induced acinar cell injury, as determined by lactate dehydrogenase (LDH) leakage. Pretreatment with the RyR inhibitors dantrolene or ryanodine converted the peak-plateau signal to a mostly oscillatory pattern (P < 0.05). They also reduced acinar cell LDH leakage, basolateral blebbing, and propidium iodide uptake (P < 0.05). In vivo, a single dose of dantrolene (5 mg/kg), given either 1 h before or 2 h after intraductal TLCS infusion, reduced the severity of pancreatitis down to the level of the control (P < 0.05). These results suggest that the severity of biliary pancreatitis may be ameliorated by the clinical use of RyR inhibitors. 相似文献
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Xiaowen He Michael Knepper Cheng Ding Jun Li Suita Castro Maham Siddiqui Melitta Schachner 《PloS one》2012,7(9)
The L1 cell adhesion molecule promotes neurite outgrowth and neuronal survival in homophilic and heterophilic interactions and enhances neurite outgrowth and neuronal survival homophilically, i.e. by self binding. We investigated whether exploitation of homophilic and possibly also heterophilic mechanisms of neural stem cells overexpressing the full-length transmembrane L1 and a secreted trimer engineered to express its extracellular domain would be more beneficial for functional recovery of the compression injured spinal cord of adult mice than stem cells overexpressing only full-length L1 or the parental, non-engineered cells. Here we report that stem cells expressing trimeric and full-length L1 are indeed more efficient in promoting locomotor recovery when compared to stem cells overexpressing only full-length L1 or the parental stem cells. The trimer expressing stem cells were also more efficient in reducing glial scar volume and expression of chondroitin sulfates and the chondroitin sulfate proteoglycan NG2. They were also more efficient in enhancing regrowth/sprouting and/or preservation of serotonergic axons, and remyelination and/or myelin sparing. Moreover, degeneration/dying back of corticospinal cord axons was prevented more by the trimer expressing stem cells. These results encourage the view that stem cells engineered to drive the beneficial functions of L1 via homophilic and heterophilic interactions are functionally optimized and may thus be of therapeutic value. 相似文献
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Mike J.L. Peters Nazim Ghouri Paul McKeigue Nita G. Forouhi Naveed Sattar 《Cytokine》2013,61(1):29-32
ObjectiveTo determine any ethnic differences in circulating interleukin (IL)-6 concentrations among SAs and Europeans, and to assess their relationship with body composition and insulin resistance measures.MethodsBody composition was assessed among 80 SA and European men and women using anthropometry, dual-energy X-ray absorptiometry and abdominal CT scan. Oral glucose tolerance tests with insulin response were performed to assess insulin resistance measures. IL-6 levels were measured by high sensitivity ELISA.ResultsMedian IL-6 values were higher in SA compared with European women: 1.94 mg/l versus 1.51 mg/l, p = 0.041, but not so in men (1.56 mg/l versus 1.57 mg/l). Only measures of obesity, in particular percentage fat area (r = 0.6, p = 0.003), were positively correlated with IL-6 in SAs. Differences in body fat percentage (visceral and total) could explain up to 30% of the IL-6 difference between Asian and European women.ConclusionSA women have elevated circulating IL-6 levels, in part due to greater visceral and percent fat levels compared with European women. This observation may in part explain why Asians are at elevated cardiovascular disease risk. Future studies should address the effects of lifestyle factors (physical activity, diet) on plasma IL-6 concentrations in SA women. 相似文献
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Orabi AI Shah AU Muili K Luo Y Mahmood SM Ahmad A Reed A Husain SZ 《The Journal of biological chemistry》2011,286(16):14090-14097
Alcohol abuse is a leading cause of pancreatitis, accounting for 30% of acute cases and 70-90% of chronic cases, yet the mechanisms leading to alcohol-associated pancreatic injury are unclear. An early and critical feature of pancreatitis is the aberrant signaling of Ca(2+) within the pancreatic acinar cell. An important conductor of this Ca(2+) is the basolaterally localized, intracellular Ca(2+) channel ryanodine receptor (RYR). In this study, we examined the effect of ethanol on mediating both pathologic intra-acinar protease activation, a precursor to pancreatitis, as well as RYR Ca(2+) signals. We hypothesized that ethanol sensitizes the acinar cell to protease activation by modulating RYR Ca(2+). Acinar cells were freshly isolated from rat, pretreated with ethanol, and stimulated with the muscarinic agonist carbachol (1 μM). Ethanol caused a doubling in the carbachol-induced activation of the proteases trypsin and chymotrypsin (p < 0.02). The RYR inhibitor dantrolene abrogated the enhancement of trypsin and chymotrypsin activity by ethanol (p < 0.005 for both proteases). Further, ethanol accelerated the speed of the apical to basolateral Ca(2+) wave from 9 to 18 μm/s (p < 0.0005; n = 18-22 cells/group); an increase in Ca(2+) wave speed was also observed with a change from physiologic concentrations of carbachol (1 μM) to a supraphysiologic concentration (1 mM) that leads to protease activation. Dantrolene abrogated the ethanol-induced acceleration of wave speed (p < 0.05; n = 10-16 cells/group). Our results suggest that the enhancement of pathologic protease activation by ethanol is dependent on the RYR and that a novel mechanism for this enhancement may involve RYR-mediated acceleration of Ca(2+) waves. 相似文献
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Nazim Ghouri David Purves Kevin A. Deans Greig Logan Alex McConnachie John Wilson Jason M. R. Gill Naveed Sattar 《PloS one》2015,10(4)