329 research outputs found
Applications on fault tree analysis in railway power supply systems
Fault tree analysis (FTA) is presented to model the reliability of a railway traction power system in this paper. First, the construction of fault tree is introduced to integrate components in traction power systems into a fault tree; then the binary decision diagram (BDD) method is used to evaluate fault trees qualitatively and quantitatively. The components contributing to the reliability of overall system are identified with their relative importance through sensitivity analysis. Finally, an AC traction power system is evaluated by the proposed methods
Less Invasive Mitral Valve Surgery via Right Minithoracotomy
Background/PurposeCurrent trends in cardiac surgical intervention are moving toward less invasiveness, with smaller wound or sternum-sparing, less pump time or off-pump, and beating rather than arrested heart. Data on the efficacy and safety of these newer less invasive techniques, as well as their cosmetic results, are limited. This study analyzed the results of a sternum-sparing mitral valve operation.MethodsThirty patients with mitral valve diseases, including 20 who underwent mitral valve repair and 10 mitral valve replacement, were enrolled. Cardiopulmonary bypass was established via femoral cannu-lation, and blood cardioplegic arrest was induced by using a percutaneous, transthoracic cross-clamp. The main surgical wound was made over the lateral border of the right breast. Two additional small wounds were required for the transthoracic aortic clamp and the mitral retractor.ResultsThere was no operative mortality, and all patients had an uneventful recovery. Two patients underwent redo mitral surgery. Nine associated procedures were performed including tricuspid valve annulo-plasty in six patients, tricuspid valve replacement in two patients and atrial septal defect repair in one patient. The length of the main wound was between 5.8 and 7.8 cm (mean, 7.1 cm). The mean cardiopul-monary bypass time and cross-clamp time were 91.1 and 43.7 minutes, respectively. Although the length of stay was not significantly reduced compared with traditional median sternotomy, all patients had satisfactory results with good cosmesis.ConclusionSternum-sparing mitral valve surgery appears to be a safe and effective alternative to conventional mitral valve surgery; it is less invasive and provides superior cosmetic results for patients
Optimal Locations of Bus Stops Connecting Subways near Urban Intersections
Unsuitable locations of bus stops which provide feeder transportation connecting subways near urban intersections usually lead to the low efficiency of public transport and level of passenger service. A multiobjective optimization model to distribute such stop locations is proposed to attain the shortest total walk distance of passengers and minimum delay time of cars through intersections and travel time of buses. The Pareto frontier and optimal solutions for the proposed model are given by the distance-based and enumerative methods. The Xizhimen bus stop is selected to implement case studies for verifying the validity of the proposed model. The analysis of sensitivity on possible solutions is also carried out in the case studies. The results show that the proposed model is capable of optimizing the locations of bus stops connecting subways near intersections and helpful to improve the level of passengers service and operational efficiency of public transportation
D2ADA: Dynamic Density-aware Active Domain Adaptation for Semantic Segmentation
In the field of domain adaptation, a trade-off exists between the model
performance and the number of target domain annotations. Active learning,
maximizing model performance with few informative labeled data, comes in handy
for such a scenario. In this work, we present D2ADA, a general active domain
adaptation framework for semantic segmentation. To adapt the model to the
target domain with minimum queried labels, we propose acquiring labels of the
samples with high probability density in the target domain yet with low
probability density in the source domain, complementary to the existing source
domain labeled data. To further facilitate labeling efficiency, we design a
dynamic scheduling policy to adjust the labeling budgets between domain
exploration and model uncertainty over time. Extensive experiments show that
our method outperforms existing active learning and domain adaptation baselines
on two benchmarks, GTA5 -> Cityscapes and SYNTHIA -> Cityscapes. With less than
5% target domain annotations, our method reaches comparable results with that
of full supervision.Comment: 14 pages, 5 figure
Catechin prevents ultraviolet B-induced human keratinocyte death via inhibition of JNK phosphorylation
Abstract High levels of (+)-catechin are found in the skin and seed of many fruits such as apples and grapes. Dietary supplementation with (+)-catechin has been demonstrated to protect epidermal cells against damage induced by ultraviolet B (UVB) radiation. However, the underlying mechanisms are not well understood yet. To determine whether (+)-catechin protects keratinocytes from UVB-induced damage, the viability of UVB-and H 2 O 2 -treated cells was determined by cell viability assay. Intracellular H 2 O 2 level was measured by flow cytometry. UVB-or H 2 O 2 -induced signaling pathways were detected by Western blotting. The results indicated that (+)-catechin inhibited UVB-and H 2 O 2 -induced keratinocyte death. In parallel, intracellular H 2 O 2 generation in keratinocytes irradiated by UVB was inhibited by (+)-catechin in a concentration-dependent manner. (+)-Catechin also inhibited UVB-and H 2 O 2 -induced JNK activation in keratinocytes. However, it had little inhibitory effect on UVB-and H 2 O 2 -induced ERK and p38 activation even at a higher concentration, suggesting indirectly that JNK activation is required for the induction of apoptosis in keratinocytes exposed to UVB. Finally, we compared the cytotoxicity of (+)-catechin and (−)-epigallocatechin-3-gallate (EGCG) on keratinocytes. Cell viability assay showed that (+)-catechin was relatively nontoxic at higher doses. Taken together, our results demonstrate that (+)-catechin inhibits UVB-and oxidative stress-induced H 2 O 2 production and JNK activation and enhances human keratinocyte survival. However, although it seems that (+)-catechin and EGCG are equally effective in preventing keratinocyte death, (+)-catechin is relatively nontoxic and thus is suitable for developing as an anti-ageing agent for skin care
Mortality associated with the use of non-vitamin K antagonist oral anticoagulants in cancer patients:Dabigatran versus rivaroxaban
Abstract Objective This study assesses the mortality outcomes of non‐vitamin K antagonist oral anticoagulants (NOACs) in cancer patients with venous thromboembolism (VTE) and atrial fibrillation (AF). Methods Medical records of cancer patients receiving NOACs for VTE or AF between January 1, 2011, and December 31, 2016, were retrieved from Taiwan's National Health Institute Research Database. NOACs were compared using the inverse probability of treatment weighting (IPTW) method. The primary outcome was cancer‐related death. Secondary outcomes were all‐cause mortality, major bleeding, and gastrointestinal (GI) bleeding. Results Among 202,754 patients who received anticoagulants, 3591 patients (dabigatran: 907; rivaroxaban: 2684) with active cancers were studied. Patients who received dabigatran were associated with lower risks of cancer‐related death at one year (HR = 0.71, 95% CI = 0.54–0.93) and at the end of follow‐ups (HR = 0.79, 95% CI = 0.64–0.98) compared with rivaroxaban. Patients who received dabigatran were also associated with lower risks of all‐cause mortality (HR = 0.81, 95% CI = 0.67–0.97), major bleeding (HR = 0.64, 95% CI = 0.47–0.88), and GI bleeding (HR = 0.57, 95% CI = 0.39–0.84) at the end of follow‐ups compared with rivaroxaban. Conclusion Compared with rivaroxaban, the use of dabigatran may be associated with a lower risk of cancer‐related death and all‐cause mortality
Coherent narrow-band light source for miniature endoscopes.
In this work, we report the successful implementation of a coherent narrow-band light source for miniature endoscopy applications. An RGB laser module that provides much higher luminosity than traditional incoherent white light sources is used for illumination, taking advantages of the laser light's high spatial coherence for efficient light coupling. Notably, the narrow spectral band of the laser light sources also enables spectrally resolved imaging, to distinguish certain biological tissues or components. A monochrome CMOS camera is employed to synchronize with the time lapsed RGB laser module illumination for color image acquisition and reconstruction, which provides better spatial resolution than a color CMOS camera of comparable pixel number, in addition to spectral resolving
Using Capacitance Sensor to Extract Characteristic Signals of Dozing from Skin Surface
Skin is the largest organ of the human body and a physiological structure that is directly exposed to the environment. From a theoretical perspective, numerous physiological and psychological signals use the skin as a medium for input and output with the outside world. Therefore, the skin is considered an optimal signal interception point when developing noninvasive, direct, and rapid signal exploration devices. To date, skin signal interceptions are predominantly performed by measuring skin impedance. However, this method is prone to interference such as sweat secretion, salt accumulation on the skin, and muscle contractions, which may result in a substantial amount of interference and erroneous results. The present study proposes novel and effective methods for skin signal interception, such as using a nested probe as a sensor to measure capacitance to be further processed as physiological and psychological signals. The experimental results indicate that the capacitance curve for the transition between wakefulness and dozing exhibits significant changes. This change in the curve can be analyzed by computer programs to clearly and rapidly determine whether the subject has entered the initial phases of sleep
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