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Advanced glycation end products (AGEs) are increasingly recognized as potentially pathogenic components of processed foods, and long-term consumption of dietary AGEs triggers disruption of the intestinal barrier integrity and increases the risk of chronic diseases. Galactooligosaccharides (GOS) as prebiotics can modulate the intestinal microbiota and improve the intestinal barrier integrity. In this study, we aimed to investigate whether GOS could ameliorate the intestinal barrier damage induced by AGEs. The results showed an increased number of goblet cells (AGEs

Non-alcoholic fatty liver disease (NAFLD) has become a public health burden.

This study aims to explore the molecular mechanisms of

Increased intake of Western diets and ultra-processed foods is accompanied by increased intake of advanced glycation end products (AGEs). AGEs can be generated exogenously in the thermal processing of food and endogenously in the human body, which associated with various chronic diseases. In food, AGEs can be divided into free and bound forms, which differ in their bioavailability, digestion, absorption, gut microbial interactions and untargeted metabolites. We summarized the measurements and contents of free and bound AGE in foods. Moreover, the ingestion, digestion, absorption, excretion, gut microbiota interactions, and metabolites and metabolic pathways between free and bound AGEs based on animal and human studies were compared. Bound AGEs were predominant in most of the selected foods, while beer and soy sauce were rich in free AGEs. Only 10%–30% of AGEs were absorbed into the systemic circulation when orally administered. The excretion of ingested free and bound AGEs was approximately 90% and 60%, respectively. Dietary free CML has a detrimental effect on gut microbiota composition, while bound AGEs have both detrimental and beneficial impacts. Free and bound dietary AGEs changed amino acid metabolism, energy metabolism and carbohydrate metabolism. And besides, bound dietary AGEs altered vitamin metabolism, and glycerolipid metabolism.

Nonalcoholic fatty liver disease (NAFLD) is characterized by marked imbalances in lipid storage and metabolism. Because the beneficial health effects of cereal β-glucan (BG) include lowering cholesterol and regulating lipid metabolism, BG may alleviate the imbalances in lipid metabolism observed during NAFLD. The aim of our study was to investigate whether BG from highland barley has an effect on western diet-induced NAFLD in mice. Using lipidomics, we investigated the underlying mechanisms of BG intervention, and identified potential lipid biomarkers. The results reveal that BG (300 mg/kg body weight) significantly alleviated liver steatosis. Lipidomics analysis demonstrated that BG also altered lipid metabolic patterns. We were able to identify 13 differentially regulated lipid species that may be useful as lipid biomarkers. Several genes in the hepatic lipid and cholesterol metabolism pathways were also modulated. These findings provide evidence that BG ameliorates NAFLD by altering liver lipid metabolites and regulating lipid metabolism-related genes.

Background The influence of β-glucan on the human gut microbiota is closely related to the physicochemical structure of β-glucan. We purified a homogeneous water-soluble polysaccharide from Tibetan hull-less barley 25 and studied its structure and the in vitro fermentation profile. Results Analysis by gas chromatography (GC), Fourier-transformed infrared (FT-IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and atomic force micrograph (AFM) helped determine the hull-less barley polysaccharide to be a β-glucan (molecular weight: 3.45 × 104 Da), which was further characterized as mixed-linkage (1 → 3)(1 → 4)-linked β-d-glucans. SEM images demonstrated an intricate web structure of the hull-less barley polysaccharide, while the AFM images revealed the presence of small spherical particles in its structure. In addition, the microbiota composition of the hull-less barley polysaccharide group was found to be altered, wherein the abundance of Pantoea, Megamonas, Bifidobacterium, and Prevotella-9 were increased. On the other hand, in vitro fermentation revealed that hull-less barley polysaccharide significantly decreased the pH value and increased the production of acetate, propionate, and butyrate. Conclusions Hull-less barley polysaccharide is a type of dietary fiber, and its analysis suggested that it may serve as a prebiotic food supplement for the regulation of the gut microbiota.

Additional file 1: Fig. S1. Rarefaction curves and Shannon index.

As of July 2020, BeiDou Navigation Satellite System (BDS) has been completed. Due to the unique configuration of the BDS Heterogeneous constellations, and the scale of ground stations continues to expand, it has brought severe challenges to the time-effectiveness and accuracy of precise orbit determination (POD). This paper presents a station-selection algorithm based on coverage. Firstly, the boundary equation of the coverage area is derived; Secondly, based on the criterion of minimum GDOP value, two optimal networks are generated for GEO/IGSO and MEO satellites separately using the satellite-coverage-based and the station-coverage-based algorithm. Finally, an optimal global network for BDS is obtained by merging the two networks. According to the experiment results of 5 adjacent days, the orbit determination using the optimal network is roughly equivalent to that using all stations in precision but with a more shorted processing time up to 32%. and the orbit determination precisions of GEO, IGSO and MEO satellites have increased by about 52%, 58%, and 41% separately compared to those of using a randomly-selected stations network of the same scale. This algorithm helps reducing the time of orbit determination processing while retaining the orbit determination precision for BDS.

Scope Gut barrier dysfunction and inflammation originating from a dysbiotic gut microbiota (GM) are strongly associated with a high-fat diet (HFD). Anthocyanins from Lycium ruthenicum (ACs) show antiobesity effects through modulating the GM. However, the mechanism linking the antiobesity effects of ACs and GM modulation remains obscure. Methods and results To investigate the ameliorative effects of ACs on colonic barrier dysfunction and inflammation, mice are fed an HFD with or without ACs at doses of 50, 100, and 200 mg kg-1 for 12 weeks. AC supplementation reduced weight gain, enriched short-chain fatty acid (SCFA)-producing bacteria (e.g., Ruminococcaceae, Muribaculaceae, Akkermansia, Ruminococcaceae_UCG-014, and Bacteroides) and SCFA content, depleted endotoxin-producing bacteria (e.g., Helicobacter and Desulfovibrionaceae), and decreased endotoxin (i.e., lipopolysaccharide) levels. SCFAs substantially activated G protein-coupled receptors (GPRs), inhibited histone deacetylases (HDAC), increased intestinal tight junction mRNA and protein expression levels, reduced intestinal permeability, and protected intestinal barrier integrity in HFD-induced mice. These effects mitigate intestinal inflammation by inhibiting the LPS/NF-κB/TLR4 pathway. Conclusion These data indicates that ACs can mitigate colonic barrier dysfunction and inflammation, induce SCFA production and inhibit endotoxin production by modulating the GM in HFD-fed mice. This finding provides a clue for understanding the antiobesity effects of ACs.

In this paper the performance of a high sensitivity GPS/GLONASS receiver mounted on CE-5T1 Service Module is studied and the data received on the first Earth-lunar transfer orbit is processed and analyzed. At least four GLONASS satellites are visible for 46% of the data span while for 98% of the data span at least four GPS satellites are visible. GLONASS serves as a necessary supplement to GPS in real time positioning whenever less than four GPS satellites are tracked, and helps to optimize the observation geometry by reducing the Position Dilution of Precision (PDOP) values by up to 77%. However, noisier GLONASS pseudorange data should be properly weighted in order not to deteriorate the positioning accuracy. Studies indicate that when the inverse square of the pseudorange measurement error of each satellite is applied as the weight value, single point positioning (SPP) accuracy improves from 57.7 m (RMS) with GPS data alone to 44.6 m (RMS) with the addition of GLONASS data. Transmitter antenna Equivalent Isotropic Radiated Power (EIRP)s of all the four blocks of GPS satellites as well as GLONASS satellites are derived from the received C/N0 data and show significant variance in sidelobe power patterns. In general, the EIRP patterns of GPS Block IIR-M and GLONASS satellite antennas have a comparatively flat power level of around 10 dB W within the off-boresight angle range of 30–80° and roll off at the off-boresight angle of about 80°, offering deep space applications greater benefits than the other three blocks of GPS satellites. In addition, an interesting close encounter happens between CE-5T1 spacecraft and GLONASS satellite R06. Investigations indicate that the PDOP value increases up to 1.4 times and the SPP accuracy deteriorates by more than 142% if satellite R06 is excluded in the positioning computation.

GNSSs such as GPS, GLONASS, Galileo, and Beidou have demonstrated to be a valid and efficient system for various space applications in LEO. Since the 1990s precise GNSS-based positioning of GEO, MEO, HEO, and even deep space exploration satellites has also been considered feasible. This paper analyzes the GNSS satellite visibility and PDOP performances for 6 space users, including two GEO, one MEO, and three HEO satellites. The simulation results show that a single GNSS receiver with the sensitivity of about −180 to −188 dBW is enough for space user below 50,000 km while the receiver of a Lunar explorer must be able to process the received signal low to −202 ~ −208 dBW. As for a multi-GNSS receiver, the sensitivity requirements decrease about 2–4 dBW compared with the single GNSS one. Viewed from the sensitivity standpoint, a GPS-only receiver and a BDS+GPS receiver are the best single GNSS and multi-GNSS choice for most of the six space users while a Beidou-only receiver performs the best for GEO1 satellite which is fixed above the Asia-Pacific area. It can be concluded that for the space users below 50,000 km, it is possible to attain an average PDOP of below 20 with a receiver sensitivity no higher than −184 dBW. An important conclusion drawn from the analysis is that the higher the space user flies, the more important role multi-GNSS application plays.

Glyoxal (GO) and methylglyoxal (MGO) are important precursors for advanced glycation end products (AGEs) in foods and in vivo, which are also known as reactive carbonyls. Accumulation of AGEs may result in health risk. The effect of frying time and temperature on GO and MGO formation during fried dough twist processing was investigated. The changes in GO and MGO content of fried dough twist were also examined under the different storage condition. Sample extraction, derivatization, and cleanup conditions were evaluated to provide a sample preparation method for GO and MGO analysis by RP-HPLC–DAD. Quantification limits of GO and MGO were 0.01 and 0.02 mg/L for fried dough twist, respectively. The average recovery rate was 89 % with detection relative standard deviation of lower than 5.7 %. During frying and prolonged storage, GO and MGO contents in fried dough twist ranged from 6.5 to 11.8 mg/kg and from 5.1 to 12.0 mg/kg, respectively. The results indicated that content of GO and MGO in fried dough twist depended on the frying time and temperature. For GO, no significant differences (p < 0.05) among the all types of samples were found during the whole process of storage, with the exception of storage temperature after 60-day storage. Changes in MGO occurred during the 60-day storage, indicating storage temperature, oxygen content, lighting, and storage duration, exert a significant effect on the development of the MGO.

Multipath on carrier phase measurements is among the major error sources for short baseline positioning. A new method is proposed to improve the accuracy of the positioning results by mitigating the multipath effects on carrier phase measurements using the variable length Least Mean Square (VLLMS) adaptive filter. The performance of the filter is analyzed as well as compared with that of the standard LMS adaptive filter using a set of carrier phase observation data of two consecutive days collected in a short baseline experiment. Because the two antennas are static, the multipath error is the only dominant component in the carrier phase double-differenced residuals and indicates a repeated pattern. The numerical results show that both filters can significantly mitigate the multipath effects in carrier phase double-differenced residuals, and hence improve the positioning results. Furthermore, the VLLMS filter that reduces up to about 47.4% of the multipath effects on 3D positioning performs better than the LMS filter that only reduces 22.0%. Both filters are suitable for real-time applications.

BeiDou navigation satellite precise orbit determination is one of the key technologies in BeiDou satellite navigation system application. To analyze the no-modeling system error in BeiDou navigation satellite system, this paper proposes Ensemble Empirical Mode Decomposition (EEMD) and Hilbert spectrum method for orbit determination residual feature extraction. Firstly, the feature extraction principle of EEMD and Hilbert spectrum is analyzed, and the method model of feature extraction is established, then Pseudo-range and carrier phase orbit determination residuals in BeiDou satellite navigation system are analyzed, finally, the proposed method is applied to multi-stations GEO receiving multiple BeiDou navigation satellite signals for the orbit residuals analyzing. The results show that the proposed method can accurately extract the 86,400 s period feature which is closely related to the time period items with one day in the BeiDou orbit residuals. It is very important for separating the no-modeling system error in BeiDou navigation satellite orbit determination residuals for improving the orbit determination precision.

Coexistence and development of four kinds of Global Satellite Navigation System, GPS, GLONASS, BDS, and GALILEO have initially established. In order to benefit from multi-GNSS applications, including increase in usable SVs, signals and frequencies, increase in availability and coverage, more robust and reliable services, and so on, firstly we need to obtain the precise multi-GNSS orbit and clock in a unified space and time frame. Based on the knowledge of the EPOS and EPOS-RT (Earth Parameter and Orbit determination System in Real-Time) software package, Beijing Aerospace Control Center (BACC) has been working on his own software package for multi-GNSS data processing. This paper firstly introduces the multi-GNSS processing strategies in detail, and adopts additional inter system biases parameter (ISB) except the normal IGS and GFZ observation model and dynamic model. On the basis of above strategies and the observation data from a network of multi-GNSS capable receivers from the IGS Multi-GNSS EXperiment (MGEX) and a regional BDS station network operated by China, the experiments and simulation are carried out. The results are validated against products from other institutes and by overlap comparison. The impact on orbit and clock precision by combined processing against single system processing is investigated and the improvement on precise point positioning (PPP) is also evaluated.