The lamina cribrosa is affected by intraocular pressure, which is the major risk of glaucoma. However, the capability to evaluate the lamina cribrosa in vivo has been limited until recently due to ...poor image quality and the posterior laminar displacement of glaucomatous eyes. In this study, we propose an automatic method to measure the anterior lamina cribrosa surface depth (ALCSD), including a method for detecting Bruch's membrane opening (BMO) based on k-means and region-based active contour. An anterior lamina cribrosa surface segmentation method based on energy constraint is also proposed. In BMO detection, we initialize the Chan-Vese active contour model by using the segmentation map of the k-means cluster. In the segmentation of anterior lamina cribrosa surface, we utilize the energy function in each A-scan to establish a set of candidates. The points in the set that fail to meet the constraints are removed. Finally, we use the B-spline fitting method to obtain the results. The proposed automatic method can model the posterior laminar displacement by measuring the ALCSD. This method achieves a mean error of 45.34 μm in BMO detection. The mean errors of the anterior lamina cribrosa surface are 94.1% within five pixels and 76.1% within three pixels.
Background Curcumin, an active ingredient of turmeric with antioxidant and anti-inflammatory properties has recently been reported to have anticonvulsant effects in several animal models of epilepsy. ...This study aimed to investigate the effects of curcumin on the pilocarpine rat model of status epilepticus. Methods The effect of intraperitoneal administration of curcumin （30, 100, and 300 mg/kg） on pilocarpine-induced seizures in rats was tested. The correlation between seizure activity and hippocampal levels of nitric oxide synthase and free radicals was quantified. Whether curcumin treatment modulated these parameters was also investigated. Results Curcumin significantly increased seizure threshold at doses of 100 and 300 mg/kg. Rats with pilocarpine- induced seizures showed significantly elevated levels of malonaldehyde, nitric oxide synthase, and lactate dehydrogenase, but decreased levels of superoxide dismutase and glutathione compared with normal control rats. At doses of 100 and 300 mg/kg, curcumin reversed the effects of pilocarpine-induced seizures on nitric oxide synthase, lactate dehydrogenase, glutathione, and superoxide dismutase. However, curcumin did not restore the elevated malonaldehyde levels. Conclusion Curcumin has anticonvulsant activity in the pilocarpine rat model of seizures, and that modulation of free radicals and nitric oxide synthase may be involved in this effect.
This article presents a brain switch for patients with amyotrophic lateral sclerosis (ALS). The firststage extract sample entropy (SampEn) features are from 30-channel electroencephalography (EEG) ...signals. Fisher's separability criterion is then performed in the second stage to select the top two EEG channels for each patient. Features of the top two channels are sent into the last stage for classification, where a motor imagery detector based on an adaptive support vector machine (ASVM) is used to keep the false positive rate (FPR) below a near-zero threshold and gain a high true positive rate (TPR). The results on five patients with ALS demonstrated the superior performance of the brain switch in both validation and follow-up sessions.
Background： Oxygen inhalation therapy is essential for the treatment of patients with chronic mountain sickness （CMS）, but the efficacy of oxygen inhalation for populations at high risk of CMS ...remains unknown. This research investigated whether oxygen inhalation therapy benefits populations at high risk of CMS. Methods： A total of 296 local residents living at an altitude of 3658 m were included; of which these were 25 diagnosed cases of CMS, 8 cases dropped out of the study, and 263 cases were included in the analysis. The subjects were divided into high-risk （180 ≤ hemoglobin （Hb） 〈210 g/L, n = 161） and low-risk （Hb 〈180 g/L, n = 102） groups, and the cases in each group were divided into severe symptom （CMS score ≥6） and mild symptom （CMS score 0-5） subgroups. Severe symptomatic population of either high- or low-risk CMS was randomly assigned to no oxygen intake group （A group） or oxygen intake 7 times/week group （D group）; mild symptomatic population of either high- or low-risk CMS was randomly assigned to no oxygen intake group （A group）, oxygen intake 2 times/week group （B group）, and 4 times/week group （C group）. The courses for oxygen intake were all 30 days. The CMS symptoms, sleep quality, physiological biomarkers, biochemical markers, etc., were recorded on the day before oxygen intake, on the 15th and 30th days of oxygen intake, and on the 15th day after terminating oxygen intake therapy. Results： A total of 263 residents were finally included in the analysis. Among these high-altitude residents, CMS symptom scores decreased for oxygen inhalation methods B, C, and D at 15 and 30 days after oxygen intake and 15 days after termination, including dyspnea, palpitation, and headache index, compared to those before oxygen intake （B group： Z = 5.604, 5.092, 5.741; C group： Z = 4.155, 4.068, 4.809; D group： Z = 6.021, 6.196, 5.331, at the 3 time points respectively; all P 〈 0.05/3 vs. before intake）. However, dyspnea/palpitation （A group： Z = 5.003, 5.428, 5.493, both P 〈 0.05/3 vs. before intake） and headache （A group： Z = 4.263, 3.890, 4.040, both P 〈 0.05/3 vs. before intake） index decreased significantly also for oxygen inhalation method A at all the 3 time points. Cyanosis index decreased significantly 30 days after oxygen intake only in the group of participants administered the D method （Z= 2.701, P = 0.007）. Tinnitus index decreased significantly in group A and D at 15 days （A group： Z = 3.377, P = 0.001, D group： Z = 3.150, P - 0.002）, 30 days after oxygen intake （A group： Z = 2.836, P = 0.005, D group： Z = 5.963, P 〈 0.0001） and 15 days after termination （A group： Z- 2.734, P = 0.006, D group： Z - 4.049, P = 0.0001）, and decreased significantly in the group B and C at 15 days after termination （B group： Z = 2.611, P = 0.009; C group： Z = 3.302, P = 0.001）. In the population at high risk of CMS with severe symptoms, oxygen intake 7 times/weeksignificantly improved total symptom scores of severe symptoms at 15 days （4 2, 5 vs. 5.5 4, 7, Z = 2.890, P = 0.005） and 30 days （3 1, 5 vs. 5.5 2, 7, Z= 3.270, P = 0.001） after oxygen intake compared to no oxygen intake. In the population at high risk of CMS with mild symptoms, compared to no oxygen intake, oxygen intake 2 or 4 times/week did not improve the total symptom scores at 15 days （2 1, 3, 3 1, 4 vs. 3 1.5, 5; 2＂2 = 2.490, P= 0.288）, and at 30 days （2 0, 4, 2 1, 4.5 vs. 3 2, 5;2＂2- 3.730, P = 0.155） after oxygen intake. In the population at low risk ofCMS, oxygen intake did not significantly change the white cell count and red cell count compared to no oxygen intake, neither in the severe symptomatic population nor in the mild symptomatic population. Conclusions： Intermittent oxygen inhalation with proper frequency might alleviate symptoms in residents at high altitude by improving their overall health conditions. Administration of oxygen inhalation therapy 2-4 times/week might not benefit populations at high risk of CMS with mild CMS symptoms while administration of therapy 7 times/week might benefit those with severe symptoms. Oxygen inhalation therapy is not recommended for low-risk CMS populations.
A series of potassium methyl 1-（substituted phenoxyacetoxy）alkylphosphonates（9a--9o） was designed and synthesized. The results of preliminary bioassays indicate that most of the title compounds ...possess excellent pre-emergence and post-emergence herbicidal activities against Brassica napus, Amaranthus mangostanus, Medicago sativa, Echinochloa crusgalli, and Digitaria sanguinalis at a dosage of 1500 g/ha（1 ha=10000 m2）. Especially, potas- sium methyl 1-（2,4-dichlorophenoxyacetoxy）-l-（4-methylphenyl）methylphosphonate（9g） and potassium methyl 1-（2,4-dichlorophenoxyacetoxy）-l-（furan-2-yl）methylphosphonate（9j） show the best herbicidal activity against five tested weeds with more than 85% inhibitory rate in Dre-emergence.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A bisphenol A based epoxy was incorporated with a quadruply hydrogen bonded supramolecular polymer as a toughening agent to prepare a composite epoxy resin with higher impact resistance. The ...supramolecular polymer comprising poly-（propylene glycol） bis（2-aminopropyl） ether chains and 2-ureido-41H-pyrimidinone moieties（UPy） self-assembled into spherical domains with sizes of 300 nm to 600 nm in diameter by micro phase separation in bulk epoxy matrixes. A significant improvement of 300% in impact resistance of the supramolecular polymer incorporated epoxy resin was obtained when the content of supramolecular polymer was 10 wt%. Tensile tests showed that the mechanical properties of the modified epoxy resin containing the hydrogen-bonded supramolecular polymers are also improved compared with those of the neat epoxy resin.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Fast response control of a boost PFC converter Kuo-Lung Chai; Wei-Hao Peng; Ying-Yu Tzou
The Fifth International Conference on Power Electronics and Drive Systems, 2003. PEDS 2003,
2003, Volume:
2
Conference Proceeding
This paper presents the fast response control of a single-phase boost AC-DC converter using a digital signal processor. Both active current shaping and voltage estimation techniques have been ...employed for the power factor correction and DC voltage regulation of a boost PFC converter. All the control functions are realized by using software control technique which provides flexibility for system modification and applications. An adaptive dead-beat controller has been developed for the current shaping control and a combinational voltage ripple estimation algorithm has been proposed for the instantaneous detection of the average output voltage for a boost PFC converter. The proposed control scheme has been realized by using a single-chip DSP controller. Simulations and experimental results have been given to illustrate the performance of the implemented DSP-controlled PFC converter.
This paper presents a new method based on an immune-tabu hybrid algorithm to solve the thermal unit commitment （TUC） problem in power plant optimization. The mathematical model of the TUC problem is ...established by analyzing the generating units in modem power plants. A novel immune-tabu hybrid algorithm is proposed to solve this complex problem. In the algorithm, the objective function of the TUC problem is considered as an antigen and the solutions are considered as antibodies, which are determined by the affinity computation. The code length of an antibody is shortened by encoding the continuous operating time, and the optimum searching speed is improved. Each feasible individual in the immune algorithm （IA） is used as the initial solution of the tabu search （TS） algorithm after certain generations of IA iteration. As examples, the proposed method has been applied to several thermal unit systems for a period of 24 h. The computation results demonstrate the good global optimum searching performance of the proposed immune-tabu hybrid algorithm. The presented algorithm can also be used to solve other optimization problems in fields such as the chemical industry and the power industry.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Floor grouting in soft rock roadway is one of the effective ways in floor heave control, and this method is being promoted quietly and quickly, but the applying effect is far from satisfied, the ...reasons are that: the depth of floor grouting is not enough and the influence of water hiding in floor hasnt been attached great importance. This paper analyzed the characteristics of floor broken rock zone in soft rock roadway and pointed out the importance of floor grouting in soft rock roadway, then proposed a practical method of floor grouting. The analysis conclusions show that: the depth of floor broken rock zone that can reach more than 4m is much greater than that of roof broken rock zone due to the double influences of surrounding rock stress and water; the important role of floor grouting in soft rock roadway is draining off free water from broken rock zone in order to strengthen roadway floor; floor grouting includes three important steps: plugging water channels, pumping out free water and grouting in deep holes. The article has revealed common blind spots of floor grouting methods existing, the method this article has noted can solve floor heave of soft rock roadway well, and it has very good application prospects.
Key words: soft rock roadway, floor grouting, broken rock zone, free water in floor
Treating surrounding rock as absolutely loose mass helps to determine positions of the four key reinforced points in roadway, in other words, they are juncture locations between 45 degrees angle ...directions of two arch haunches and two footwalls. Surrounding rock deformation can be effectively controlled with the help of reinforcement on key reinforced points, furthermore, it is possible to save lots of supporting materials, in short, it is a very effect way. New technology proposed in this paper what is about stable augmentation has deeply unearthed important effect of anchor in floor of roadway, it argues that anchor in floor has quadruplex efficacies: transferable effect of surrounding rock stress, displacement boundary effect, decreasing equivalent stress of basic angle area and the inverted wedge effect, so it can suppress floor heave effectively, and this lays a solid foundation for roadway stability. Article deeply analyzed basic mechanism about deformation of roadway under loading, exposed essentiality of roadway support, and provided important theoretical basis for floor heave control emerged more and more frequently in deep mine roadway.
Key words: broken rock zone, bolt support, floor heave, equivalent stress
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