239 research outputs found
A Study on the Practical Carrying Capacity of Large High-Speed Railway Stations considering Train Set Utilization
Methods for solving the carrying capacity problem for High-Speed Railways (HSRs) have received increasing attention in the literature in the last few years. As important nodes in the High-Speed Railway (HSR) network, large stations are usually the carrying capacity bottlenecks of the entire network due to the presence of multiple connections in different directions and the complexity of train operations at these stations. This paper focuses on solving the station carrying capacity problem and considers train set utilization constraints, which are important influencing factors that have rarely been studied by previous researchers. An integer linear programming model is built, and the CPLEX v12.2 software is used to solve the model. The proposed approach is tested on a real-world case study of the Beijing South Railway Station (BS), which is one of the busiest and most complex stations in China. Studies of the impacts of different train set utilization constraints on the practical station carrying capacity are carried out, and some suggestions are then presented for enhancing the practical carrying capacity. Contrast tests indicate that both the efficiency of the solving process and the quality of the solution show huge breakthroughs compared with the heuristic approach
Recommended from our members
Sensitization of epithelial growth factor receptors by nicotine exposure to promote breast cancer cell growth
Introduction: Tobacco smoke is known to be the main cause of lung, head and neck tumors. Recently, evidence for an increasing breast cancer risk associated with tobacco smoke exposure has been emerging. We and other groups have shown that nicotine, as a non-conventional carcinogen, has the potential to facilitate cancer genesis and progression. However, the underlying mechanisms by which the smoke affects the breast, rather than the lung, remain unclear. Here, we examine possible downstream signaling pathways of the nicotinic acetylcholine receptor (nAChR) and their role in breast cancer promotion. Methods: Using human benign MCF10A and malignant MDA-MB-231 breast cells and specific inhibitors of possible downstream kinases, we identified nAChR effectors that were activated by treatment with nicotine. We further tested the effects of these effector pathways on the regulation of E2F1 activation, cell cycle progression and on Bcl-2 expression and long-term cell survival. Results: In this study, we demonstrated a novel signaling mechanism by which nicotine exposure activated Src to sensitize epidermal growth factor receptor (EGFR)-mediated pathways for breast cancer cell growth promotion. After the ligation of nAChR with nicotine, EGFR was shown to be activated and then internalized in both MCF10A and MDA-MB-231 breast cancer cells. Subsequently, Src, Akt and ERK1/2 were phosphorylated at different time points following nicotine treatment. We further demonstrated that through Src, the ligation of nicotine with nAChR stimulated the EGFR/ERK1/2 pathway for the activation of E2F1 and further cell progression. Our data also showed that Akt functioned directly downstream of Src and was responsible for the increase of Bcl-2 expression and long-term cell survival. Conclusions: Our study reveals the existence of a potential, regulatory network governed by the interaction of nicotine and nAChR that integrates the conventional, mitogenic Src and EGFR signals for breast cancer development
A Study on the Practical Carrying Capacity of Large High-Speed Railway Stations considering Train Set Utilization
Methods for solving the carrying capacity problem for High-Speed Railways (HSRs) have received increasing attention in the literature in the last few years. As important nodes in the High-Speed Railway (HSR) network, large stations are usually the carrying capacity bottlenecks of the entire network due to the presence of multiple connections in different directions and the complexity of train operations at these stations. This paper focuses on solving the station carrying capacity problem and considers train set utilization constraints, which are important influencing factors that have rarely been studied by previous researchers. An integer linear programming model is built, and the CPLEX v12.2 software is used to solve the model. The proposed approach is tested on a real-world case study of the Beijing South Railway Station (BS), which is one of the busiest and most complex stations in China. Studies of the impacts of different train set utilization constraints on the practical station carrying capacity are carried out, and some suggestions are then presented for enhancing the practical carrying capacity. Contrast tests indicate that both the efficiency of the solving process and the quality of the solution show huge breakthroughs compared with the heuristic approach
Rheological properties and structural features of coconut milk emulsions stabilized with maize kernels and starch
peer-reviewedIn this study, maize kernels and starch with different amylose contents at the same concentration were added to coconut milk. The nonionic composite surfactants were used to prepare various types of coconut milk beverages with optimal stability, and their fluid properties were studied. The steady and dynamic rheological property tests show that the loss modulus (G″) of coconut milk is larger than the storage modulus (G′), which is suitable for the pseudoplastic fluid model and has a shear thinning effect. As the droplet size of the coconut milk fluid changed by the addition of maize kernels and starch, the color intensity, ζ-potential, interfacial tension and stability of the sample significantly improved. The addition of the maize kernels significantly reduced the size of the droplets (p < 0.05). The potential values of zeta (ζ) and the surface tension of the coconut milk increased. Based on the differential scanning calorimetry (DSC) measurement, the addition of maize kernels leads to an increase in the transition temperature, especially in samples with a high amylose content. The higher transition temperature can be attributed to the formation of some starches and lipids and the partial denaturation of proteins in coconut milk, but phase separation occurs. These results may be helpful for determining the properties of maize kernels in food-containing emulsions (such as sauces, condiments, and beverages) that achieve the goal of physical stability
Elimination of degenerate trajectory of single atom strongly coupled to the tilted cavity TEM10 mode
We demonstrate the trajectory measurement of the single neutral atoms
deterministically using a high-finesse optical micro-cavity. Single atom
strongly couples to the high-order transverse vacuum TEM_{10} mode, instead of
the usual TEM_{00} mode, and the parameter of the system is (g_{10},\kappa
,\gamma )=2\pi \times (20.5,2.6,2.6)MHz. The atoms simply fall down freely from
the magneto-optic trap into the cavity modes and the trajectories of the single
atoms are linear. The transmission spectrums of atoms passing through the TEM10
mode are detected by a single photon counting modules and well fitted. Thanks
to the tilted cavity transverse TEM10 mode, which is inclined to the vertical
direction about 45 degrees and it helps us, for the first time, to eliminate
the degenerate trajectory of the single atom falling through the cavity and get
the unique atom trajectory. Atom position with high precision of 0.1{\mu}m in
the off-axis direction (axis y) is obtained, and the spatial resolution of
5.6{\mu}m is achieved in time of 10{\mu}s along the vertical direction (axis
x). The average velocity of the atoms is also measured from the atom transits,
which determines the temperature of the atoms in magneto-optic trap, 186{\mu}K
{\pm} 19{\mu}K.Comment: 13 pages, 5figure
Physics-data-driven intelligent optimization for large-scale meta-devices
Meta-devices have gained significant attention and have been widely utilized
in optical systems for focusing and imaging, owing to their lightweight,
high-integration, and exceptional-flexibility capabilities. However, based on
the assumption of local phase approximation, traditional design method neglect
the local lattice coupling effect between adjacent meta-atoms, thus harming the
practical performance of meta-devices. Using physics-driven or data-driven
optimization algorithms can effectively solve the aforementioned problems.
Nevertheless, both of the methods either involve considerable time costs or
require a substantial amount of data sets. Here, we propose a
physics-data-driven approach based "intelligent optimizer" that enables us to
adaptively modify the sizes of the studied meta-atom according to the sizes of
its surrounding ones. Such a scheme allows to mitigate the undesired local
lattice coupling effect, and the proposed network model works well on thousands
of datasets with a validation loss of 3*10-3. Experimental results show that
the 1-mm-diameter metalens designed with the "intelligent optimizer" possesses
a relative focusing efficiency of 93.4% (as compared to ideal focusing) and a
Strehl ratio of 0.94. In contrast to the previous inverse design method, our
method significantly boosts designing efficiency with five orders of magnitude
reduction in time. Our design approach may sets a new paradigm for devising
large-scale meta-devices.Comment: manuscripts:19 pages, 4 figures; Supplementary Information: 11 pages,
12 figure
Molecular evolution of the H6 subtype influenza a viruses from poultry in eastern China from 2002 to 2010
<p>Abstract</p> <p>Background</p> <p>Although extensive data demonstrates that the majority of H6 duck isolates belonged to a single H6N2 virus lineage with a single gene constellation in southern China from 2000 to 2005, the prevalence of H6N2 virus in poultry in Eastern China is largely unknown.</p> <p>Results</p> <p>Epidemiology revealed that H6N2 viruses were the most frequently detected influenza subtypes in live bird markets from 2002 to 2008 in Eastern China, but from 2009 onwards, they were replaced with novel H6N6 viruses. We phylogenetically and antigenically analyzed 42 H6 viruses isolated mainly in domestic ducks from 2002 to 2010 in Eastern China. Surprisingly, none of these isolates grouped with the previously described H6N2 viruses which belonged to a single H6N2 virus lineage with a single gene constellation in domestic ducks in southern China from 2000 to 2005. Two distinct hemagglutinin lineages were identified and they all underwent frequent reassortment with multiple virus subtypes from the natural gene pool, but few reassortants were persistent or prevalent.</p> <p>Conclusions</p> <p>Five subtypes of H6 influenza viruses (H6N1, H6N2, H6N5, H6N6 and H6N8) cocirculated in Eastern China, which form a significant part of the natural influenza virus reservoir in domestic ducks, and significant viral reassortment is still ongoing in this species.</p
Association of Lean Body Mass Index and Peritoneal Protein Clearance in Peritoneal Dialysis Patients
Background/Aims: The relationship between peritoneal protein clearance (PPCl) and nutritional status in peritoneal dialysis (PD) population have not been clarified. This study aims to investigate the relationship between PPCl and nutritional status in PD population. Methods: Prevalent PD patients were enrolled in the cross-sectional survey in a single center from April to November 2013. The total amount of protein loss in the dialysate was calculated. PPCl reflects the individual differences of peritoneal protein loss, and is calculated by the formula, that PPCl (ml/day)=24-h dialysate protein loss / (albumin/0.4783). Nutritional status measured by lean body mass index (LBMI) was assessed by multi-frequency bioelectrical impedance analysis (BIA). Results: Totally 351 PD patients (55% male, 17.1% with diabetes, mean age 47.7±14.3 years) were included. The median PPC l was 58 ml/day. Patients were divided into four groups for comparison according to the PPC quartiles. Compared with lower PPCl quartiles, patients with higher PPCl had higher body mass index (BMI) (P< 0.001), body surface area (BSA) (P < 0 .001), LBMI (P<0.001), 4-hour D/P creatinine ratio (P< 0.001), and lower residual renal CCl (P<0.001). Compared with conventional body index (BMI and BSA) in ROC analysis, LBMI (area under curve: 0.71, 95% confidence interval [CI]: 0.66-0.77) had better performance in predicting higher PPCl. After adjustment in logistic regression models, each 1 kg/m2 increase of LBMI (odd ratio[OR] =1.37; 95% CI: 1.17-1.60), each 0.1 increase of 4-hour D/P creatinine ratio (OR =1.47; 95% CI: 1.11-1.93), and every 1 L/week/1.73m2 decrease of residual renal CCl (OR =0.98; 95% CI: 0.96-0.99) were independently associated with higher PPCl (> 58 ml/day). Conclusion: Higher LBMI was independently associated with higher , indicating that better nutritional status dominates peritoneal protein metabolism in PD patients
- …