198 research outputs found
Color Image Enhancement Based on Ant Colony Optimization Algorithm
In the collection, transmission, decoding process, the images are likely to produce noise. Noise makes the image color distorted and the articulation dropped, and also affects the image quality. Due to different causes, there are different types of noise, and the impulse noise is most common among them which exert great influence on the image quality. This paper, according to the characteristics of the color image, combines the ant colony algorithm and weighted vector median filter method to put forward an algorithm for the impulse noise removal and the color image enhancement. This method finds the optimal filter bank parameter by ant colony optimization (ACO) and processes image points polluted by the noise to achieve the purpose of image enhancement and protect the image details and edge information. Simulation experiment proves the correctness and validity of this method
Polygonum cuspidatum glycoside mitigated LPS-induced human endometrial stromal cell inflammation by regulating NF-κB/Nrf2 signaling pathway-related proteins
Purpose: To study the influence of polydatin on LPS-provoked human endometrial stromal cell inflammation, and its mechanism of action.Methods: Fifty ICR female mice were selected and assigned to control and three-dose polydatin groups. Before establishment of the model, mice in low-dose group, middle-dose group and high-dose group were given polydatin at doses of 5, 10 and 20 mg/kg, respectively, by oral gavage for 5 days. Protein expression levels of interleukin 1β (IL-1 β), tumor necrosis factor- α (TNF-α) level, nuclear factor E2-related factor 2 (NRF-2) and nuclear transcription factor kappa-B (NF-2 κB) were determined with Western blot assay.Results: Model group mice protein levels of NF- κB and nrf-2 were significantly reduced, relative to the corresponding control values (p < 0.05). The NF-κB and NRF-2 proteins in model group were markedly up-regulated, relative to control group, but they were and dose-dependently lower in the 3 polydatin groups than in control (p < 0.05). Conclusion: Polydatin reduces LPS-induced inflammatory response in mouse endometrial stromal cells, and promotes the repair of endometrium and regeneration of glands via a mechanism related to regulation of NF-κ B/Nrf2 signaling pathway-related proteins
A Novel Helical Superconducting Fault Current Limiter for Electric Propulsion Aircraft
It is crucial to achieve a high safety and reliability standard in future Electric Propulsion Aircraft (EPA). Due to low short-circuit impedance and high rate of fault current rise in EPA systems, the superconducting fault current limiter (SFCL) plays a promising role, with advantages of light weight, high efficiency and compact size, compared to conventional FCL. A novel helical bifilar coil is proposed which is composed of two windings wound in opposite directions on the same bobbin, these are connected in series to achieve equal current sharing and a non-inductive circuit. 12 mm-wide stainless steel reinforced superconducting tape from AMSC was used for the windings. To characterize the proposed helical bifilar coil connected in series (BCS), AC loss tests under three frequencies and quench tests under prospective fault current up to 2223 A were carried out. They were compared with the results measured from a conventional helical bifilar coil connected in parallel (BCP) which had an identical specification to the BCS. It was concluded that AC losses measured in the BCP is dependent on current and frequency. The fault current was suppressed effectively by the BCS at the first half peak from 2223 A to 495 A, corresponding to 22.3% of the prospective fault current. Quench performance of BCP was also tested and discussed
Recommended from our members
Towards universal health coverage: achievements and challenges of 10 years of healthcare reform in China.
Universal health coverage (UHC) has been identified as a priority for the global health agenda. In 2009, the Chinese government launched a new round of healthcare reform towards UHC, aiming to provide universal coverage of basic healthcare by the end of 2020. We conducted a secondary data analysis and combined it with a literature review, analysing the overview of UHC in China with regard to financial protection, coverage of health services and the reported coverage of the WHO and the World Bank UHC indicators. The results include the following: out-of-pocket expenditures as a percentage of current health expenditures in China have dropped dramatically from 60.13% in 2000 to 35.91% in 2016; the health insurance coverage of the total population jumped from 22.1% in 2003 to 95.1% in 2013; the average life expectancy increased from 72.0 to 76.4, maternal mortality dropped from 59 to 29 per 100 000 live births, the under-5 mortality rate dropped from 36.8 to 9.3 per 1000 live births, and neonatal mortality dropped from 21.4 to 4.7 per 1000 live births between 2000 and 2017; and so on. Our findings show that while China appears to be well on the path to UHC, there are identifiable gaps in service quality and a requirement for ongoing strengthening of financial protections. Some of the key challenges remain to be faced, such as the fragmented and inequitable health delivery system, and the increasing demand for high-quality and value-based service delivery. Given that China has committed to achieving UHC and 'Healthy China 2030', the evidence from this study can be suggestive of furthering on in the UHC journey and taking the policy steps necessary to secure change
Recommended from our members
Towards universal health coverage: lessons from 10 years of healthcare reform in China.
Universal health coverage (UHC) is driving the global health agenda. Many countries have embarked on national policy reforms towards this goal, including China. In 2009, the Chinese government launched a new round of healthcare reform towards UHC, aiming to provide universal coverage of basic healthcare by the end of 2020. The year of 2019 marks the 10th anniversary of China's most recent healthcare reform. Sharing China's experience is especially timely for other countries pursuing reforms to achieve UHC. This study describes the social, economic and health context in China, and then reviews the overall progress of healthcare reform (1949 to present), with a focus on the most recent (2009) round of healthcare reform. The study comprehensively analyses key reform initiatives and major achievements according to four aspects: health insurance system, drug supply and security system, medical service system and public health service system. Lessons learnt from China may have important implications for other nations, including continued political support, increased health financing and a strong primary healthcare system as basis
Experimental Tests of DC SFCL under Low Impedance and High Impedance Fault Conditions
DC system protection is more challenging than that for AC system due to the rapid rate of rise of the fault current and absence of natural current zero-crossing in DC systems. Superconducting fault current limiter (SFCL) in DC systems is a promising technology to reduce the fault current level and the rate of rise of the fault current, and also SFCLs have no resistance during normal operation. In this paper, the behaviors of an SFCL coil are investigated under both low impedance and high impedance fault conditions in DC systems. In the low impedance fault condition system, the SFCL coil performs effective limitation of the fault current level under different prospective fault current levels. The application of SFCLs with limited inductance in the DC system can be a potential solution to effectively suppress the fault current under low impedance short-circuit faults. The SFCL coil under the high impedance fault condition can only limit the prospective fault current when it is much higher than the critical current of the coil
Supply chain quality management: an investigation in the Chinese construction industry
Recently, in China, the issue of poor quality construction has drawn much public attention. This problem is related not only to poor quality control on the part of the construction firm, but also to the use of inadequate materials and inexperienced subcontractors, that is, to poor quality assurance in the construction supply chain. The purpose of this article is to examine supply chain quality management (SCQM) in the construction industry. Using a case-study approach, this research focuses on a Chinese medium-sized private enterprise in order to determine the most efficient way to conduct a high-quality project when collaborating with material suppliers and subcontractors. To this end, we replicate and extend the SCQM practices to help develop a more refined SCQM conceptual model relevant to the construction industry. Based on the different perspectives of managers and engineers, two frameworks are presented to illustrate (1) the correlation between SCQM and purchasing function (PF), and (2) how to work with material suppliers and subcontractors; the proposed models also show how these aspects will influence and control the quality of projects. Although constrained by the limitations inherent in case-study methodology, this article consolidates the work in one particular area of supply chain management. It also succeeds in meeting two core challenges, namely to explicate the interaction between SCQM and PF, and to provide guidance to construction firms on how to deal with SCQM issues with material suppliers and subcontractors
All-trans retinoic acid regulates the expression of the extracellular matrix protein fibulin-1 in the guinea pig sclera and human scleral fibroblasts
Purpose: Fibulin-1 (FBLN1) mRNA is expressed in human sclera and is an important adhesion modulatory protein that can affect cell-matrix interactions and tissue remodeling. Scleral remodeling is influenced by all-trans retinoic acid (RA). Our purpose was to confirm the presence of fibulin-1 protein in guinea pig sclera and investigate the effect of RA on the expression of fibulin-1 in guinea pig sclera in vivo and in cultured human scleral fibroblasts (HSFs). Methods: Confocal fluorescence microscopy was used to study fibulin-1 and aggrecan expression and localization in sclera from control guinea pigs and in animals given RA by daily gavage from 4 to 8 days of age. The effects of RA (from 10⁻⁹ to 10⁻⁵ M) on fibulin-1 expression in HSFs were observed by immunohistochemistry and assayed by real-time PCR and western blot analysis. Results: Fibulin-1 protein expression was detected by confocal fluorescence microscopy in guinea pig sclera and in cultured HSFs. Upregulation of fibulin-1 in scleral tissue was observed after feeding with RA. In vitro, the level of Fbln1 mRNA was increased after treatment of HSFs with RA (at concentrations of 10⁻⁸ to 10⁻⁶ M; p<0.001), with a maximum effect at 10⁻⁷ M. Fibulin-1 protein levels were significantly increased after treatment of HSFs with 10⁻⁷ M of RA for 24 or 48 h (p<0.05). Conclusions: Fibulin-1 protein was expressed in guinea pig sclera and cultured HSFs. Expression was regulated by RA, a molecule known to be involved in the regulation of eye growth. Further studies on the role of fibulin-1 in the regulation of eye growth, including during the development of myopia, are therefore warranted
Influence of floodwater irrigation on vegetation composition and vegetation regeneration in a Taklimakan desert oasis
Naturally occurring floods in the summer months are the main source of surface water application in the foreland of Qira oasis, which is characterized by a hyperarid climate and is located at the southern fringe of the Taklimakan Desert. We investigated the impact of repeated artificial flood irrigation on seedling recruitment and growth of Alhagi sparsifolia and Karelinia caspica plant communities which are part of the dominant vegetation in Qira oasis. Flood irrigation was applied three times during the growing season and we studied the effect of irrigation on species recruitment, vegetation growth, species composition, and changes in soil water and nutrient concentrations in the soil profile. Results show that (1) repeated flood irrigation had a positive effect on seedling recruitment of the two species, with vegetative recruitment via root tillers being more important than seed recruitment for both species. (2) Irrigation promoted the germination and establishment of herbaceous weed species, which increased species diversity as well as ground coverage. (3) Irrigation also increased soil water and soil nutrient concentrations in the upper soil layer and changed the soil nutrients in the vertical profile. Available N, P, K and the total P and K increased in the soil profile. Our study demonstrates that naturally occurring flood irrigation has significant ecological benefits and plays an important role in promoting the renewal of desert vegetation and a short-term increase of soil nutrients. Our study also highlights the potential negative consequences for vegetation composition and rejuvenation if naturally occurring floods in the study area are diminished by either the effects of climate change or human management
- …