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AIM: To evaluate the global trends in and explore hotspots of high myopia (HM) research. METHODS: This bibliometric analysis was used to reveal the publication trends in HM research field based on the Web of Science Core Collection (WoSCC). VOSviewer version 1.6.13 software was used to analyze the data and construct a knowledge map including the yearly publication number, journals, countries, international collaborations, authors, research hotspots, and intellectual base in HM. RESULTS: The search engine found 3544 peer-reviewed publications on HM between 2010 and 2019, and the yearly research output substantially elevated over the past decade. China is the top publishing country, and Sun Yat-sen University was the most active academic institution. Jonas JB is the top publishing scientist, and Investigative Ophthalmology and Visual Science (IOVS) was the most productive journal. The highest cited references mainly focused on epidemiology and management. The keywords formed 6 clusters: 1) refractive surgery; 2) etiology and clinical characteristics; 3) the mechanism of eye growth; 4) management for myopic maculopathy; 5) vitrectomy surgical treatment; 6) myopia-associated glaucoma-like optic neuropathy. CONCLUSION: The evaluation of development trends based on the data extracted from WoSCC can provide valuable information and guidance for ophthalmologists and public health researchers to improve management procedures in HM field.

Background: Both hospital-acquired infection (HAI) and cancer represents major health concerns worldwide, but there is a paucity of data describing HAI in Chinese cancer patients. The objective of this study is to demonstrate the prevalence, causative agents, antimicrobial use and risk factors for HAI in a cancer hospital in Southwestern China. Methods: We use the criteria of the Ministry of Health of the People's Republic of China to define hospital-acquired infections. One-day cross-sectional surveys were annually conducted from 2014 to 2018. Trained staff collected hospital-acquired infections, antimicrobial use and clinical characteristics data of inpatients. Multivariate logistic regression was used to determine the potential risk factors associated with HAIs. Results: Of the 6717 patients surveyed, there were 140 patients (2.1%, 95% confidence interval, 1.7–2.4%) with 144 distinct HAIs. Lower respiratory tract infections (47, 32.6%) and surgical-site infections (29, 20.1%) were the most common HAIs. Escherichia coli was the most common pathogen (29.6%). Risk factors for HAI included younger age (65 years), hospitalization in the intensive care unit, presence of central catheter and undergoing surgery in the previous 30 days. The overall prevalence of patients receiving antimicrobial agents was 15.2%. Conclusion: To control hospital-acquired infections in cancer patients, surveillance and prevention strategies to infections associated with central catheters or related to surgery should be augmented.

The images obtained by the camera sensors are stored in the format of CFA, Color Filter Array, which only contains limited information about the R, G, and B signals of images. The images in CFA are upsampled into RGB 444 format by demosaicking algorithms, converted into YCbCr 444, then chroma-downsampled into YCrCb 420 format for image/video compression. In this paper, a novel chroma-downsampling method is developed to improve a state-of-the-art method. The optimization problem for the proposed method considers more factors and provides a better closed-form solution for the optimally sampled chroma values. Reversely in the decoder, a chroma-upsampling method is required for the image reconstruction. In the proposed chroma-upsampling method, the neighboring chroma pixels and their distances to the recovered pixel are considered; the procedure is to produce weightings to redistribute the total pixel values in the original estimates. Combining the proposed chroma-downsampling and the proposed chroma-upsampling works, the proposed method outperforms the state-of-the-art method by BDPSNR (Bjontegaard Delta peak signal-to-noise ratio) 0.3161 for H.264/AVC, 0.3845 for HEVC (High Efficiency Video Compression) and 0.3739 for VVC (Versatile Video Coding), averaged over all tested videos and all 7 different considered CFA formats.

Background and purpose Anxiety disorder is a common mental health disorder. However, there are few safe and fast-acting anxiolytic drugs available that can treat anxiety disorder. We previously demonstrated that the interaction of neuronal NOS (nNOS) with its carboxy-terminal PDZ ligand (CAPON) is involved in regulating anxiety-related behaviours. Here, we further investigated the anxiolytic effects of nNOS-CAPON disruptors in chronic stress-induced anxiety in animals. Experimental approach Mice were intravenously treated with nNOS-CAPON disruptors, ZLc-002 or Tat-CAPON12C, at the last week of chronic mild stress (CMS) exposure. We also infused corticosterone (CORT) into the hippocampus of mice to model anxiety behaviours and also delivered ZLc-002 or Tat-CAPON12C on the last week of chronic CORT treatment via pre-implanted cannula. Anxiety-related behaviours were examined using elevated plus maze, open field, novelty-suppressed feeding and light-dark (LD) tests. The level of nNOS-CAPON interaction was determined by co-immunoprecipitation (CO-IP) and proximity ligation assay (PLA). The neural mechanisms underlying the behavioural effects of nNOS-CAPON uncoupling in anxiety animal models were assessed by western blot, immunofluorescence and Golgi-Cox staining. Key results ZLc-002 and Tat-CAPON12C reversed CMS- or CORT-induced anxiety-related behaviours. ZLc-002 and Tat-CAPON12C increased synaptogenesis along with improved dendritic remodelling in CMS mice or CORT-treated cultured neurons. Meanwhile, blocking nNOS-CAPON interaction significantly activated the cAMP response element-binding protein (CREB)-brain-derived neurotrophic factor (BDNF) pathway, which is associated with synaptic plasticity. Conclusion and implications Collectively, these results provide evidence for the anxiolytic effects of nNOS-CAPON uncouplers and their underlying mechanisms in anxiety disorders.

Anxiety is recognized as primary clinical phenotype of psychiatric disorders. However, many patients with anxiety have not yet received effective treatment. Our previous study demonstrated that hippocampal nNOS-CAPON interaction is implicated in anxiety-related behaviors, and blocking nNOS-CAPON interaction in the hippocampus produces anxiolytic-like effects. Here, ZLc-002, a small molecule inhibitor of nNOS-CAPON coupling, was evaluated for anxiolytic-like properties after systemic administered using anxiety behavioral tests, including open-field (OF), elevated plus maze (EPM), novelty-suppressed feeding (NSF) and light-dark (LD) tests. We reported that ZLc-002 when administered intraperitoneally at the dose of 40 or 80 mg/kg/d for 14 days produces anxiolytic-like effects. Furthermore, the similar effects of ZLc-002 were observed when administered intravenously at the dose of 10, 20 or 40 mg/kg/d for 7 days. More importantly, the mice dosing with 80 mg/kg/d ZLc-002 intraperitoneally or 40 mg/kg/d ZLc-002 intravenously for 3 days exerted significant behavioral effects. However, intragastric administration with ZLc-002 was devoid of effect on anxiety behaviors, even at high doses. Furthermore, intraperitoneal or intravenous treatment of ZLc-002 significantly disrupted the interaction between nNOS and CAPON in the hippocampus of adult mice, and there was a significant anxiolytic-like effect of ZLc-002 at day 3 after intrahippocampal microinjection. Our results verified that systemic administration of putative small molecule inhibitor of nNOS-CAPON can be used for the treatment of anxiety disorders.

Plasmon-mediated photocatalytic systems often suffer from weak absorption spectra overlap which limits energy transfer between plasmon metals and semiconductors. Herein, Au-Agx@CdS90 nanoparticles (NPs) with adjustable spectral overlap were prepared. Au-Ag hollow nanoparticles (HNPs) with tunable plasmon absorption peaks were used as the template and were coated with CdS to achieve stepwise spectral overlap for enhanced energy transfer. As the spectral overlap increased between Au-Ag HNPs and CdS, the H2 evolution rate increased and then decreased. Under visible-light irradiation, Au-Ag487@CdS90 nanoparticles (NPs) delivered an H2 evolution rate of 18.73 mmol h-1 g-1, which was 2.2 times higher than pure CdS. The plasmon resonance energy transfer from Au-Ag HNPs to the CdS semiconductor increased the generation of charge carriers in the semiconductor and enhanced the photocatalytic performance. By regulating the position of the plasmon absorption peaks of the noble metal nanoparticles, changing the spectral overlap between metal and semiconductor to enhance the PRET effect is beneficial to the design of new plasmon photocatalysts.

The age of the population is shifting toward the elderly range, which may lead to an increased risk of mild cognitive impairment (MCI). The aims of this study are to evaluate the cognitive function in elderly people using the Montreal Cognitive Assessment (MoCA), to identify the relationship between cognitive function and different characteristics, and to evaluate the efficacy of the intervention after six months of cognitive training. In this study, we included 2886 subjects aged ≧60 years in the baseline survey, and 140 subjects with MCI who participated in the baseline survey were randomly divided into an intervention group (N = 70) and a control group (N = 70). The control group was not provided any intervention measures, and the intervention group was administered cognitive training. The education level, monthly income, sleep time, exercise time, reading times, and time spent engaging in community activities and performing housework were positively correlated with MoCA scores, but age was negatively correlated with MoCA scores. The total MoCA score of the intervention group increased from 19.77 ± 2.24 points to 21.09 ± 2.20 points after six months of cognitive training, but the score of the control group decreased from 20.41 ± 2.10 points to 19.17 ± 2.57 points. The two-way repeated-measures ANOVA revealed a very significant effect of the interaction between time and cognitive training on the total MoCA score. Seventeen participants in the intervention group improved to normal levels, and no participants progressed to dementia after six months of cognitive training. Thus, the efficacy of the intervention was statistically significant. Our study concludes that older age is associated with a cognitive decline. Factors that are more likely to protect against cognitive decline included a higher education level and monthly income, sufficient sleep time, regular physical exercise and reading, frequently engaging in community activities, and continuing to perform housework. Moreover, the cognitive training intervention is effective and may help to decrease the deterioration of cognitive function in patients with MCI, and the interaction between intervention time and cognitive training significantly improves cognitive function.

Optical microscopy is believed to be an efficient method for identifying layer number of two-dimensional (2D) materials. However, since illuminants, cameras and their parameters are different from lab to lab, it is impossible to identify layer numbers merely by comparing a given optical image with standard or calculated images under standard conditions. Here we reported an image reconstruction method, converting raw optical images acquired by arbitrary illuminants and cameras into reconstructed images under the condition of specified illuminant and specified camera. After image reconstruction, the color differences of each layer number roughly equaled those calculated under the specified condition. By comparing the color differences in the reconstructed image with those calculated under the specified condition, the layer numbers of 2D materials in our lab and published papers, including MoS2, WS2, and WSe2, were unambiguously identified. This study makes optical microscopy a precise method to identify layer numbers of 2D materials on known substrates.

Harvesting energy directly in oceans by electrochemical devices is essential for driving underwater appliances such as underwater vehicles or detectors. Owing to the extreme undersea environment, it is important but difficult to use the devices with both a high energy density and power density simultaneously. Inspired by marine organisms that have switchable energy extraction modes (aerobic respiration for long-term living or anaerobic respiration to provide instantaneously high output power for fast movement), an auto-switchable dual-mode seawater energy extraction system is presented to provide high energy density and power density both by initiatively choosing different solutes in seawater as electron acceptors. With assistance from metal-organic frameworks, this device had a theoretical energy density of 3960 Wh kg-1 , and a high practical power density of 100±4 mW cm-2 with exceptional stability and low cost, making practical applications in seawater to be possible.

Qinghai-Tibet plateau is one of the increasingly important parts of Chinese Mainland. After military tension at the boundary between China and India appeared a few years ago, China is focusing on such tasks as remote sensing of Qinghai-Tibet plateau. Qinghai-Tibet plateau is too large to collect basic dataset of meteorology, greenery, and hydrology by manual means. Space-based technique can meet such an requirement. Such payloads onboard spacecraft as lidar, radiometer, radar can provide a good solution to effectively collect dataset for a particular area of interest. With the deployment of comprehensive survey of Qinghai-Tibet plateau by China, the feasibilities assessment of implementing space project to monitor the Qinghai-Tibet plateau are impending. How to choose the most proper orbit is one of the tasks of feasibilities assessment. Herein, three sets of orbits are simulated and assessed. In case 1, a circular orbit with 250 kilometers in altitude is analyzed, and the operation orbit is sun-synchronous. According to relative simulations, orbital altitude damping rate is 10.2 kilometers per day. In order to keep the stable orbit altitude or offset the orbit altitude damping, 558 kilograms of fuel should be needed per year; 1117 kilograms of fuel should be needed to keep a stable orbit every two years. In case 2, an elliptic orbit with perigee altitude of 250km and apogee altitude of 500km is considered. Based on relative simulations, orbital altitude damping rate is 2.461 kilometers per day. In order to keep the stable orbit altitude or offset the orbit altitude damping, 130 kilograms of fuel should be needed per year; 261 kilograms of fuel should be needed to keep a stable orbit every two years. In case 3, an elliptic orbit with perigee altitude of 250km and apogee altitude of 600km is considered. Based on relative simulations, orbital altitude damping rate is 1.67 kilometers per day. In order to keep the stable orbit altitude or offset the orbit altitude damping, 87.6 kilograms of fuel should be needed per year; 175.2 kilograms of fuel should be needed to keep a stable orbit every two years. During the simulation and assessment, the ratio of area to mass of the spacecraft in question is assumed to be 0.01 square meters per kilograms; and the mass of the spacecraft is set to be 500 kilograms. As a result of trade-off between economy and payload priority of observation advantages, the case 3 is preferred to work as the operation orbit. In such an orbit, the spacecraft will contribute more efficiently to the comprehensive surveying of Qinghai-Tibet plateau.

The electron content distribution of the north and south polar ionosphere from 2001 to the beginning of 2019 is analyzed by using the UQRG global ionospheric map (GIM) of vertical total electron content (VTEC), computed every 15 min by UPC-IonSAT with a tomographic-kriging combined technique. We first show that the accuracy of UQRG GIM is slightly better than that of the GIMs of other analysis centers on the whole and also over both poles. Second, we show examples of polar VTEC features in UQRG GIM, previously reported by different authors and with higher-resolution techniques. Third, by means of an unsupervised clustering algorithm, learning vector quantization, we characterize the main features of the ionospheric electron content climatology, separately for the north and south polar regions., The UQRG GIMs, baseline of this work, are openly accessible from IGS server (ftp://cddis.gsfc.nasa.gov/gps/products/ionex/YEAR/DOY/uqrgDOY0.YYi.Z) and from UPC server (https://chapman.upc.es/tomion/rapid/YEAR/DOY_YYMMDD.15min/uqrgDOY0.YYi.Z) being YEAR and YY the four‐ and two‐digit year identifiers, MM is month number, DD is day of month, and DOY is the day of year, all of them with leading zeros when needed (see, for instance, ftp://cddis.gsfc.nasa.gov/gps/products/ionex/2002/003/uqrg0030.02i.Z and https://chapman.upc.es/tomion/rapid/2002/003_020103.15min/uqrg0030.02i.Z). Any missing file can be requested from the authors, in particular from Manuel Hernández‐Pajares (manuel.hernandez@upc.edu). This work has been supported by the POLarGIMs project funded by European Commission Joint Research Centre (JRC). We thank the National Space Science Data Center (NSSDC), Space Physics Data Facility (SPDF), and Principal Investigator K. W. Ogilvie at GSFC, A. J. Lazarus at MIT, and A. Aran at Universitat de Barcelona (UB), for the access of IMF data.

For most Earth observation spacecrafts (EOS), repeating sun-synchronous orbit is a preferred working orbit for the Earth observation spacecraft. Repeating ground trace can provide an ideal observation geometry for space-crafts devoted to Earth observation missions. Sun-synchronous orbit can provide an ideal supply of solar power for the space-crafts. Payloads for EOS usually need demanding pointing stability. One of the main factors which may lead to the variation of payload pointing is the solar radio flux. In different year, the solar radio flux varies. This paper focuses on the characteristics of payload pointing stability due to the variation of the solar radio flux. As historic dataset, solar radio flux shows periodic change of 11 years. In 11 years, solar radio flux experiences the maximal and the minimal solar flux units (sfu). In the case of the payload beam boresight, the simulation results indicate that during the year of severe solar activity with 230sfu, 4 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ±2 deg, and that during the year of severe solar activity with 230 sfu, 2 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ±0.5 deg. And the simulations also indicate that during the year of average solar activity with 150sfu, 4 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ±0.5 deg, and that during the year of average solar activity with 150sfu, 2 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ±0.1 deg; In the case of the payload beam edge, the simulation results indicate that during the year of severe solar activity with 230sfu, 4 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ±5 deg, and that during the year of severe solar activity with 230 sfu, 2 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ± deg. And the simulations also indicate that during the year of average solar activity with 150sfu, 4 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ±2 deg, and that during the year of average solar activity with 150sfu, 2 months of orbit drifting without any orbit maneuver will result in payload pointing change less than ±0.5 deg; The simulations provide an effective constraint of orbit maneuver scenario planning, and further boost the feasibility of space-crafts engineering.

BACKGROUND The aim of this study was to determine the association between the incidence of road traffic accidents, psychological characteristics, and genotype in bus drivers in a Chinese population. MATERIAL AND METHODS Bus drivers who had been involved in road traffic accidents (n=106) (the study group), and bus drivers with no history of road traffic accidents (n=106) (the control group) completed demographic questionnaires, the Eysenck Personality Questionnaire (EPQ) and the Type-A behavior pattern (TABP) evaluation. Serum 5-hydroxytryptamine (5-HT) (serotonin), and 5-hydroxytryptophan (5-HTP) levels were measured by high-performance liquid chromatography-fluorescent detection (HPLC-FLD). Serotonin transporter promoter-linked polymorphism region (5-HTTLPR) and the 521 C/T single nucleotide polymorphism (SNP) in the regulatory region of the dopamine D4 receptor gene (DRD4-521 C/T) were measured using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS After accounting for potential confounders, extroversion, psychopathy, neuroticism and time hurrying (impatience) were significant factors associated with road traffic accidents in bus drivers (adjusted OR: 1.268, 95% CI: 1.133-1.419; adjusted OR: 1.177, 95% CI: 1.028-1.347; adjusted OR: 1.092, 95% CI: 1.005-1.187; adjusted OR: 1.123, 95% CI: 1.025-1.230, respectively). Reduced serum levels of 5-HT and 5-HTP were significantly associated with the incidence of road traffic accidents (adjusted OR: 0.985, 95% CI: 0.973-0.997; adjusted OR: 0.982, 95% CI: 0.969-0.994, respectively). CONCLUSIONS Psychological characteristics associated with the 5-HTTLPR and DRD4-521 C/T genotypes, including extroversion, psychopathy, neuroticism, and time hurrying (impatience), and low serum levels of 5-HT and 5-HTP in bus drivers were associated with an increased risk of road traffic accidents.

A comprehensive evaluation of Global Positioning System (GPS) Klobuchar, Galileo broadcast NeQuick2, international reference ionosphere (IRI) and global ionospheric map (GIM) models in estimating ionospheric total electron content (TEC) is performed using GPS-derived, constellation observing system for meteorology, ionosphere, and climate and JASON-2 TECs under various solar conditions in the Arctic and Antarctic. The performances of the four ionospheric models are first analysed for the overall polar regions. In addition, according to the temporal and spatial characteristics of the polar regions, the accuracies of the four models are evaluated for the polar days and nights, the Antarctic ice sheet (AIS) and the Arctic Ocean (AO), the Weddell Sea Anomaly (WSA) as well as for ionospheric storm. The results show that Klobuchar, NeQuick2, IRI2016 and GIM can mitigate the ionospheric delay by 28.69–29.41%, 44.57–56.09%, 43.38–55.99% and 67.17–77.56%, respectively. The performances of the four models during the polar days are obviously worse than those during the polar nights. In the AIS and AO, the Galileo broadcast NeQuick outperforms the GPS broadcast Klobuchar, and the root-mean-square error of IRI2016 performs almost the same as NeQuick2, but IRI2016 has a greater deviation. In addition, the GIM model can only mitigate the ionospheric delay by 46.81–56.72%, which is lower than other regions due to the lack of GPS ground station observations. Under the WSA conditions, the four models underestimate the real TEC to varying degrees, and the night-time deviations of the Klobuchar, NeQuick2 and IRI2016 models are significantly greater than the daytime deviations. The relative accuracy of four ionospheric models is lower during the ionospheric storm period than that in the ionospheric quiet period, especially the NeQuick2 and IRI2016 over the Antarctic.

Data transmission between spacecraft and Earth-based data receiving stations is one of the vitally important subsystem for any space mission. The time interval of visibility between spacecraft and ground stations is most valuable to accomplish scheduled data transmission volume. An algorithm to enable the more effective space-based antenna during data transmission process is put forward and analyzed in detail in this paper. A series of detailed phases are formulated, which helps space mission software engineers to easily code the smart algorithm and carry out code-testing conveniently. Once this algorithm is realized in a space mission, it could help to enhance the smartness of onboard computer software and minimize the manned intervention on the ground, which meets the current demands of artificial intelligence in space.

Aortic stenosis (AS) leads to chronic pressure overload, cardiac remodeling and eventually heart failure. Chemokines and their receptors have been implicated in pressure overload‑induced cardiac remodeling and dysfunction. In the present study, the role of C‑C chemokine receptor 5 (CCR5) in pressure overload‑induced cardiac remodeling and dysfunction was investigated in mice subjected to transverse aortic constriction (TAC). Cardiac levels of CCR5 and C‑C motif chemokine ligands (CCLs)3, 4 and 5 were determined by western blotting and reverse transcription‑quantitative PCR, respectively. Cardiac functional parameters were evaluated by echocardiographic and hemodynamic measurements. Myocardial fibrosis was assessed by Masson's trichrome staining and α‑smooth muscle actin immunostaining. Myocardial hypertrophy and inflammatory cell infiltration were evaluated by hematoxylin and eosin staining. Angiotensin II (Ang II)‑induced hypertrophy of H9c2 cardiomyocytes was assessed by F‑actin immunostaining. ERK1/2 and P38 phosphorylation was examined by western blotting. TAC mice exhibited higher myocardial CCL3, CCL4, CCL5 and CCR5 levels compared with sham mice. Compared with sham mice, TAC mice also exhibited impaired cardiac function along with myocardial hypertrophy, fibrosis and inflammatory cell infiltration. TAC‑induced cardiac remodeling and dysfunction were effectively ameliorated by administration of anti‑CCR5 but not by IgG control antibody. Mechanistically, increased ERK1/2 and P38 phosphorylation was detected in TAC hearts and Ang II‑stimulated H9c2 cardiomyocytes. Treatment with anti‑CCR5 antibody decreased ERK1/2 and P38 phosphorylation and attenuated Ang II‑induced H9c2 cell hypertrophy. CCR5 inhibition protected against pressure overload‑induced cardiac abnormality. The findings of the present study indicate that ERK1/2 and P38 signaling pathways may be involved in the cardioprotective effects of CCR5 inhibition.

Objective Mutations in polymerase gamma gene (POLG) are believed to be an important cause of early and juvenile onset of non-syndromic intractable epilepsy. The aim of this study is to investigate the incidence/prevalence of POLG pathogenic variants in epilespy patients of Han population through sequencing it.Methods Han Chinese patients with seizures prior valproic acid (VPA) exposure at Shanghai Children's Hospital were collected from 2015 to 2019. The clinical diagnosis was based on the 2014 Consensus Statement of Epilepsy by the International League against Epilepsy (ILAE). Blood sampling were performed before VPA treatment. The POLG gene DNA was sequenced by either the first or the next generation sequencing (NGS). The POLG variant burden was illustrated. Liver functions were tested to describe whether they experienced VPA toxicity.Results Totally 216 Han Chinese patients were included, aged from 1 month to 15 years old, 102 were male and 114 were female. The onset age was 1 month old to 13 years old, and the epilepsy course ranged from 2 weeks to about 3 years. VPA treatment was delivered for the generalized or intractable partial seizures at standard dosage. No patient experienced hepatic toxicity following VPA exposure. DNA sequencing data showed no patient had either a homozygous mutation or compound heterozygous mutation of POLG. Single heterozygous mutations of c.1150G>T and p.D384Y were found in 2 patients, and single heterozygous mutation of c.156_158dupGCA was found in 1 patient. None of these variants showed clinical significance.Conclusions Functional modifying POLG homozygous mutations and compound heterozygous mutations were not detected and VPA toxicity was not seen in the current study. POLG mutation frequency might be rare in Han Chinese, and standard VPA therapeutic dosage might be safe for Han Chinese patients.

BeiDou Navigation Satellite System (BDS) is one of the notably independent Global Navigation Satellite System (GNSS) devised in China. As of the year of 2018,BDS is still operational for regional navigation customers due to its incomplete engineering of global satellites constellation. BDS has a unique function of short message communication. Based on short message communication, low Earth orbiting spacecrafts (LEO S/C) could send imminent information to ground command center and scientific application center as promptly as possible. It is expected that the third phase of BDS will come into being by the end of the year 2020 or so. The third phase of BDS being finished, there will be 19 satellites which have functioning of short message communication; five out of 19 satellites are in geostationary orbits, whose footprints are located in geographic eastern longitude of 58.75deg ,80deg, 110.5deg, 140deg , 160deg; and the other 14 satellites are in middle Earth orbits. With such a modernized GNSS, LEO S/C will find an approach to forward imminent information to ground command center and scientific application center almost in real time, which will greatly improve the observation efficiency of LEO S/C. For LEO in three typical sun-synchronous orbits of 600km,800km,1000km, simulations are presented to demonstrate the advantages of LEO S/C under the co-elaboration with modernized BDS, respectively.

The merged GPS navigation files from the International GNSS Service (IGS) data centers, i.e., the Crustal Dynamics Data Information System (CDDIS), the Bundesamt fur Kartographie und Geodasie (BKG), the Scripps Institution of Oceanography (SIO), and the Institut Geographique National (IGN) are occasionally contaminated by anomalies and inconsistent user range accuracy (URA). This contamination impairs the performance assessment of GPS service, especially the system integrity. We remerged these files starting Day of Year (DOY) 1, 2000 using all available navigation data files from IGS stations. To effectively get the upper bound URA, a frequency-dependent pattern recognition method was developed. In addition, a comprehensive comparison between the navigation data remerged by us and those provided by the four IGS data centers was performed. The compared results revealed that TGD and Issue of Data Clock (IODC) were the dominating anomalies in the merged navigation data from CDDIS and SIO for the first several years after 2000, and M0, Ω0, ω, and af0 were the dominant anomalies in the merged data from IGN. In addition to a number of missing records, many records with incorrect PRN (pseudo-random noise number), identifying a GPS satellite, were found in files from the IGS data centers. Although the number of anomalies in the merged files from CDDIS has continued to decrease in recent years, they have not disappeared and would affect system-level assessment and scientific applications to a certain extent. The results also revealed that our remerged files were more complete, clean, compact and consistent, making them more suitable for GPS system performance assessment and related research studies. Moreover, those data are now openly available.

Elbow as common components in the gas pipeline fails easily to natural gas carrying solid particle erosion in the process of practical work. From the viewpoint of hydromechanics, the paper analyses the flow field distribution of manifold pressure and gas-solid trajectory by using the Gambit model and Fluent software in view of the right-angle elbow and numerical simulation of the adjacent manifold. The result obtains the situation about the manifold inner wall by the solid particle erosion wear. The simulation results show more intuitively the elbow, the most prone to erosion part in the manifold adjacent area and shape in erosion. Meanwhile, the paper analyses the factors affecting the occurrence and development of erosion.

This paper are based on the background of a low-carbon economy, with China's automobile using new energy as the research object, explores the development of new energy automotive industry under collaborative innovation system, as well as the problems it faced. According to it, this paper put forward rational proposals, which has provided great theoretical value and practical significance for the development of new energy automotive industry in China.

Low-carbon economy is the driving force for sustainable regional economic development. The logistics industry is the fastest growing industry in recent years. In this paper, for example Beijing, Tianjin and Hebei, analyzes the development of the metropolitan area's logistics industry. In the context of low-carbon economy, the use of wisdom logistics to build a new logistics industry, the integration of resources, to reduce waste, improve efficiency, and protect the environment.

The flow field of gas-liquid-solid three-phase hydrocyclone was analyzed by using the software FLUNET. We have researched different structural parameters on the effect of degassing and degritting. The result shows that the change of inverted cone length ratio, inverted cone diameter, the form of liquid outlet hole structure and the angle of vent structure have some influence on degassing and degritting. Simulation results provides a good technical support for the optimization design of three-phase hydrocyclone structure.

Ship ballast water has been identified as one of four major environmental threats by the international maritime organization. This paper presents a portable on-site rapid detection system of microalgae in ship ballast water. The system consists of a microfluidic chip platform, LED light source and drive systems, optical detection system, ARM software and hardware system, power supply system and so on. Microalgae particles can go through the detection area inside the micro channels one by one by using a sheath fluid focus. The resulting chlorophyll fluorescence is converted to the electrical pulse signal by photodiode. The experimental results show that the system can quickly and accurately detect the ballast water living microalgae concentration. The minimum detectable microalgae size is about 3μm (mean diameter). This system has some advantages such as miniaturized, portable, fast, accurate and label free, and has great potential for on-site rapid detection of ship ballast water.

Compared with the traditional drilling string, the components of the new string downhole oil-water separation process is increased. To prevent the vibration fault and structure damage of the new downhole oil-water separation process string, the analysis of the finite element, modal and harmonic response on the structure system made. By solving the dynamics equation, the finite element model is determined, the inherent frequency and vibration model are calculated, and the vibration characteristics of system structure are analyzed. By analyzing the harmonic response and determining the reasonable speed of the string, the dynamic characteristics of the structure is optimized.

Sufficient icing data are very important for the design and operation of power grid in the places with potential accreted ice, meaning that it is necessary to pay due attention to the ice measurement devices. In this paper, the current ice measurement devices are classified into different types according to corresponding classification criteria with the aim of understanding the characteristics of each type of devices. Moreover, the research progress of the manual ice measurement devices are introduced in detail, including the diameter of conductors, the angle between conductor and wind direction. Finally, the existing problems are proposed for the further development of manual ice measurement devices for overhead transmission lines.

The aim of this study was to investigate the modified Ross criteria score and the diagnostic cut-off level for plasmatic amino-terminal pro-brain natriuretic peptide (NT-proBNP) in the diagnosis of pediatric heart failure, by analyzing the receiver operating characteristic (ROC) curve. The plasma NT-proBNP level was measured in 80 children diagnosed with heart failure according to the modified Ross criteria, 80 children with non-cardiogenic dyspnea and 80 healthy children. The NT-proBNP levels were then compared using an F-test. The cut-off score for heart failure in the modified Ross criteria and the diagnostic cut-off level for plasmatic NT-proBNP in pediatric heart failure were determined by ROC curve analysis. The results demonstrated that the NT-proBNP level was markedly increased in 76 of the 80 children with heart failure, and the correlation with the modified Ross criteria was 95%. Based on ROC curve analysis, the diagnosis of pediatric heart failure was most accurate when the modified Ross criteria score was ≥4 and the plasmatic NT-proBNP level was ≥598 ng/l. The NT-proBNP level was normal (0–300 ng/l) in the children with non-cardiogenic dyspnea and the healthy children. Significant differences were observed in the comparison of the three groups (P

According to the unsafety exist in the steel cord conveyor belt running, introduces the design of a new steel cord conveyor belt online testing system which based on ARM and sensors array, describes the system hardware, software, and testing results in detail.

Inner flow field, pressure field and gas phase concentration of the gas-liquid cylindrical cyclone (GLCC) was studied and simulated with a Fluent soft pack by means of Computational Fluid Dynamics (CFD). Distribution characteristics of pressure drop and velocity field of the GLCC reveal that the inlet position and the outlet diameter of overflow can affect its separation performance. Low pressure drop and high separation efficiency can be obtained by designing the inlet position and the overflow tube diameter.

In this paper, an open-loop frequency domain analysis based on system identification is introduced. Using model identification tools in Matlab, the open-loop frequency domain characteristic could be derived accurately with the open-loop step response. Then, the closed-loop regulator could be designed with the open-loop frequency domain characteristic to fulfill the steady and dynamic requirements. This method is suitable for most of the systems. An example of Buck converter is proposed to represent the analysis process. Simulation model is built in Matlab software, and some factors which affect the precision of model identification and frequency domain analysis are taken into consideration. Finally, both open- and closed-loop experimental results verify the feasibility of the proposed scheme.

This paper presents the realization of two second-order quasi-elliptic ferroelectric tunable bandpass filters for millimeter-wave applications in Ka- and U-band, respectively. These filters include a coplanar-waveguide topology implemented on epitaxial barium-strontium-titanate-on-sapphire technology. The Ka-band filter has a frequency tuning of 2.4 GHz (33.6-36 GHz) at low biasing levels (

A MPPT (Maximum Power Point Tracking) control method of PV (Photovoltaic) generation system is proposed based on the shortcoming of the existing MPPT algorithms. The method applies CVT (Constant Voltage Tracking) algorithm to adjust the working point of PV array near the MPP (Maximum Power Point) for fast tracking when working point is far from MPP, and uses adapting duty cycle perturb method to optimize the steady state characteristic of MPP for effectively eliminate the output power oscillation under the setting precision. Its model is established and simulated with Matlab/Simulink.The CVT, duty cycle method and proposed methods are simulated respectively and simulation results show that, the proposed method tracks the MPP exactly and quickly and improves the energy conversion efficiency of PV generation system by eliminate the output power oscillation around MPP. Its fast response speed improves the static and dynamic performance of photovoltaic power system.

The image search engines have been effective tools to find pictures from the Internet. They provide a list of image items in response to a user’s query, and rank the items according to their relevance to the query. An image item is often accompanied with a short descriptive text, which is brief text summaries extracted from the webpage title, content, image caption, or its metadata, to provide auxiliary information about the image. In this paper, we present a new and effective descriptive text generation method by using the idea of summarizing an image’s surrounding text, using text’s position information, and finding an image’s nearest neighbors.

In this work, we have demonstrated that scanning polarization modulation microscopy (SPMM) provides a fast method for the identification of crystalline orientation of anisotropic two-dimensional (2D) materials. Using home-built 532 nm excited transmission SPMM, we identified the crystalline orientation of 2D orthorhombic black phosphorus, monoclinal 1T′-MoTe2, and triclinic ReS2 by measuring signals in only two incident polarization directions. So, it took just a few seconds to identify the crystalline orientation of anisotropic 2D materials. Our studies revealed that the SPMM method could be applied to arbitrary anisotropic 2D materials when selecting a suitable wavelength.

The function of human macrophage metalloelastase (HME) also known as matrix metalloproteinase 12, in tumorigenesis is contradictory. The current study was designed to investigate the association of HME expression with angiogenesis and prognosis of gastric carcinomas. In situ hybridization and immunohistochemistry were used to detect HME in human gastric carcinomas, chronic gastritis with atypical hyperplasia, and normal gastric epithelium mucosa. The results were further confirmed by RT-PCR or semi-quantitative reverse transcription polymerase chain reaction and Western blotting in gastric carcinomas and paired noncancerous tissues. VEGF and microvessel density count were also detected by immunohistochemical staining in all carcinoma tissues. The prognostic significance of HME was assessed with multiple linear regression analysis and Cox proportional hazards model. High expression of HME protein/mRNA was observed in gastric carcinomas and atypical hyperplasia tissues compared with normal gastric epithelium mucosa, or paired noncancerous tissues. HME protein/mRNA were negatively correlated with MVD (p

To obtain the optimization formulation of pure cultures in Tibetan kefir, the influence of the different mixtures of five strains in the pure cultures in Tibetan kefir on the flavor components in fermented milk was studied using the mixture design. The regression model on microorganism composition and main metabolites was established. The results suggested that the predictable production of lactate reached the maximum of 8.16 g L−1, while the most predictable production of diacetyl, ethanol, and CO2 were 77.23 mg L−1, 4259 mg L−1, and 2.12 g L−1, respectively. Based on these, the response values that satisfied all expectations were optimized, and the most excellent combination was Lactococcus lactis 27%, Leuconostoc mesenteroides 37%, Lactobacillus kefiri 11%, Lactobacillus casei 10%, and Kluyveromyces marxianus 15%. With the aid of analysis software (Design-expert 6.0.5), the formulation of pure cultures in Tibetan kefir can be optimized for several responses and the best formulation can be obtained.

The inherent properties of diamond can, in principle, make it an ideal material for radiation detectors with interesting capabilities. We have fabricated a particle detector using a free-standing CVD diamond film with a thickness of 300 μm and area of 2 cm×2 cm and measured 5.5 MeV α spectra from an 241Am source. The I–V characteristics indicate that a fine Ohmic contact is formed between the CVD diamond and electrode. At the external electric field 10 kV/cm, the collection efficiency reaches an average value of 41%, corresponding to a charge collection distance (CCD) of about 259 μm and the energy resolution achieves 4.3%.

The outstanding properties of diamond, such as radiation hardness, high carrier mobility, high band gap and breakdown field, distinguish it as a good candidate for radiation detectors. The detector's performance is strongly limited by the concentration of defects (grain boundaries and/or impurities) in chemical vapor deposition (CVD) diamond. We report the response of freestanding CVD diamond with a thickness of 300 μm and area of 2 × 2 cm 2 , synthesized by a hot filament chemical vapor deposition (HFCVD) technique, to 5.9 keV X-ray radiation from a 55 Fe source. The linear I-V characteristics indicate that CVD diamond has good ohmic contacts. This detector also shows good results such as dark-current of 10 -8 A, photocurrent of 10 -6 A, energy resolution

Chronic diarrhea is a common bowel disorder; disturbance of intestinal microorganisms may play a role in its pathogenesis. This study assessed the clinical efficacy of lyophilized, heat-killed Lactobacillus acidophilus LB versus living lactobacilli in the treatment of chronic diarrhea. One hundred thirty-seven patients with chronic diarrhea were randomly allocated to receive either a 4-week course of 2 capsules of Lacteol Fort twice a day (Lacteol group, 69 patients) or a 4-week course of 5 chewable tablets of Lacidophilin three times a day (Lacidophilin group, 64 patients). The frequency of stools was recorded quantitatively, and semiquantitative parameters such as stool consistency, abdominal pain, distention, and feeling of incomplete evacuation were evaluated. At the second and fourth week of treatment, mean bowel frequency was significantly lower in the Lacteol group than in the Lacidophilin group (1.88 +/- 1.24 vs 2.64 +/- 1.12, 1.39 +/- 0.92 vs 2.19 +/- 1.05; P

Orbit information of the Low Earth Orbiter carrying a GPS receiver is needed in the conception of atmospheric monitor by GPS occultation. It is unavoidable to analyze the effects of orbit uncertainty of the low Earth Orbiter on the observable in GPS occultation for atmospheric monitor. Based on the present Earth atmospheric model, three dimensional raytracing techniques are employed to simulate five representative complete GPS occultation events. The effect of the orbit error is quantified on the key observable in occultation. It is indicated that orbit error contributes little to the uncertainty of the observable. It is facilitated to deploy a differencing autonomous positioning of the Low Earth orbiter with sufficient accuracy.

An analytic expression for the angle of refraction in GPS radio occultation in the general case is presented. The angle of refraction without assuming a circular orbit is calculated iteratively starting with the value from the circular assumption. The atmospheric parameters are then calculated by inversion with and without the circular assumption. It is shown that the bias caused by the circular assumption is up to about 1 mbar in the pressure and up to about one degree Celsius in the temperature. On one hand, this result supports the practice of using the circular assumption in qualitative error analyses; on the other hand, it shows the necessity of foregoing the circular assumption when the highest accuracy is required of the atmospheric parameters.

Spatial resolution and spectral contrast are two major bottlenecks for non-destructive testing of complex samples with current imaging technologies. We use a three-dimensional terahertz (THz) imaging system to obtain the internal structure of the sample, and exploit the wavelet transform algorithm to improve the spatial resolution and the spectral contrast. With this method, the longitudinal resolution of terahertz imaging system can be improved to the wavelength comparable thickness, while the x-y plane resolution can be as high as 0.2 mm0.2 mm, which benefits from the point-to-point scanning on the x-y plane. In this three-dimensional terahertz imaging system, the Syn View Head 300 with light source/detector frequency of 0.3 THz is used for two-dimensional scanning (x-y direction) of the sample, and the linear frequency modulated continuous wave technique is used to obtain the reflected terahertz light intensity at different depths (z axis) of the sample. When the sample is thin, the upper and lower interface reflection peaks are difficult to distinguish due to broad peak width of the THz source. To solve this problem efficiently, continuous wavelet transform (CWT) is used. In recent years, CWT is applied widely because of its particular mathematical properties in the feature signal recognition. Since the Gaus2 wavelet basis is better to highlight the peak signal, we choose it for CWT. After CWT, one scale of the wavelet coefficients is chosen for three-dimensional data reconstruction, for which the widths of the reflection peaks are narrower and the noise signals are weaker. That means if we reconstruct the three-dimensional wavelet coefficient data on the chosen scale, the three-dimensional image of the tested sample will be enhanced. In order to demonstrate that, the three-dimensional images reconstructed by wavelet coefficients are compared with those by original data. The tested sample has holes inside with different depths. Based on the original three-dimensional THz image, it is hard to locate the top of 4 mm deep hole (1 mm deep photosensitive material plate), while the top of the inner 4 mm deep holes (the bottom of the 1 mm deep photosensitive material plate) can be distinctly located and the noises are greatly reduced based on the three-dimensional images reconstructed by wavelet coefficients. With this method, the longitudinal resolution of terahertz detection systems can be improved to 1 mm that is comparable to the wavelength, which demonstrates advantages of this method.

An asymmetric inductively-coupled lumped tunable bandpass filter using epitaxial BST thin film varactors and SMT inductors is designed, fabricated and tested. To the best of the authors' knowledge, the proposed filter is the smallest reported filter among tunable ferroelectric filters for VHF/UHF applications. The biasing conditions (simultaneously or not) of the frequency responsible varactors (C p ) and the magnitude responsible varactor (C g ) give the ability to choose between different frequency responses, including stable fractional bandwidths and stable insertion loss levels. The largest frequency tuning is about 37% from 1.06 GHz to 1.45 GHz at bias voltages of 30 V, and the best insertion loss is 3.55 dB (V Cp = 30 V, V Cg = 0 V).

This paper designed an automatic tracking solar lights based on microcontroller, mainly by the solar panels, solar auto-tracking controller, batteries, lights and other components. Through the solar sensor circuit, convert solar energy into electrical signals by the single-chip computer to control the sampling signal analysis and processing, output control commands to control the stepper motor rotating solar panels, so that automatic tracking solar panels solar power solar panels to improve efficiency. Use of solar energy during the day by solar panels for battery charging, the battery discharge at night light up the LED lights. Single-chip computer, put the battery charging voltage control, a PWM output of the DC-DC converter control circuit for charging, the battery for three-stage charging, when the battery charging voltage is too high, automatically disconnect the charging circuit, when the battery discharge voltage is too low, automatically disconnect the discharge circuit, the battery overcharge protection, over discharge and short circuit the battery to protect, thereby increasing battery life and extend the use of time. The way the system can automatically track the solar lights solar, solar energy utilization increase, reducing the area of solar panels, low cost, reliable, high sensitivity, their power consumption characteristics.

Shipborne shrapnel is an indispensably suppressive weapon during firing on shore. In order to make proper command decision, it is necessary for commander of warship to evaluate the damage probability of shipborne shrapnel. In the first place, the simulation and calculation process of damage probability based on monte carlo method is set up. Then the way of confirming simulation times and making damage judgement is put forward respectively. Finally, the influence of firing distance on damage probability is analyzed. Because monte carlo method can well resolve the overlapping problem of damage areas among different bomblets, it will be widely used to calculate damage probability of shipborne shrapnel.

In this paper, the frequency-domain physical optics expression is derived from the normal electromagnetic scattering field calculation, and the general time-domain physical optics (TD-PO) expression is derived by inverse Fourier transform, and thus a time-domain physical optics calculation formula of an ideal conductor's scattering in the far field region is given. The metal plate and metal sphere's transient scattering in the far field region is programmed. The calculation results show that the time-domain physical optics has the lower requirements on computer hardware and faster computational speed. It is an efficient method to analyze electromagnetic scattering problem for electrically large objects.