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A smart multitool platform for theranostics would be useful for monitoring the administration of therapies in vivo. However, the integration of multiple functions into a single small-molecule platform remains a challenge. In this study, we developed a multifunctional probe based on a small-molecule platform. The properties of this probe were investigated via hyperpolarized

A new non-encapsulated fluorinated liposome (TSL) was developed, which showed instantaneous temperature-induced 19F MR signal enhancement and excellent stability under reversible signal transition at different conditions.

PurposeThe purpose of this paper is to explore the key factors in generating trust, and the effects of trust on the intention to cooperate in energy performance contracting (EPC), from the perspective of energy saving companies (ESCOs).Design/methodology/approachA questionnaire survey was undertaken to collect the data from the experienced project managers in ESCOs. Structural equation modeling was used to test the hypotheses.FindingsThe results revealed that competence, integrity, communication, reciprocity and contract had positive effects on calculative trust and relational trust. Both calculative trust and relational trust, in turn, were found to have positive effects on the intention to cooperate.Research limitations/implicationsThe conclusions are derived from the Chinese cultural background and may apply to a certain geographical scope. In addition, this study focused on the perspective of ESCOs but did not consider that of facility owners.Practical implicationsThis research would supply guidance for facility owners or users to cultivate trust from ESCOs and achieve cooperation in EPC.Originality/valueMost of the existing studies have focused on the perspective of facility owners while few have attempted to investigate the perspective of ESCOs. This study contributes to the knowledge body relating to EPC by investigating the relationship between trust and the intention to cooperate from the perspective of ESCOs. In addition, most EPC studies recognized trust as a condition for the successful execution of EPC projects but failed to consider the role of trust in setting up the cooperation relationship prior to project execution.

ObjectiveTo evaluate the longitudinal association of nut consumption with cognitive function in Chinese elderly.MethodsWe analyzed the data from Zhejiang Ageing and Health Cohort Study including 9,028 participants. Nut consumption was evaluated in baseline questionnaire beginning at 2014. Cognitive function was assessed repeatedly through the Mini-Mental State Examination (MMSE) at baseline and three waves of follow-up (2015, 2016, and 2019–2020). Cognitive impairment was defined using education-specific cut-off points. Log-binomial regression models with the generalized estimating equations, controlled for an extensive range of potential confounders, were utilized to evaluate the association and estimate relative risk (RR).ResultsAfter 6 years of follow-up, 3,266 (36.18%) participants were indicated as cognitive impairment by MMSE at least once. Compared with non-consumers or less-than-weekly consumers, participants consuming ≥70 g/week of nuts had 17% lower risks of cognitive impairment (RR = 0.83, 95% CI 0.75–0.91), whereas no association was found in those consuming ConclusionHigher nut consumption was prospectively related to a lower risk of cognitive impairment in Chinese elderly.

The noise in position time series of 568 GPS (Global Position System) stations across North America with an observation span of ten years has been investigated using solutions from two processing centers, namely, the Pacific Northwest Geodetic Array (PANGA) and New Mexico Tech (NMT). It is well known that in the frequency domain, the noise exhibits a power-law behavior with a spectral index of around −1. By fitting various noise models to the observations and selecting the most likely one, we demonstrate that the spectral index in some regions flattens to zero at long periods while in other regions it is closer to −2. This has a significant impact on the estimated linear rate since flattening of the power spectral density roughly halves the uncertainty of the estimated tectonic rate while random walk doubles it. Our noise model selection is based on the highest log-likelihood value, and the Akaike and Bayesian Information Criteria to reduce the probability of over selecting noise models with many parameters. Finally, the noise in position time series also depends on the stability of the monument on which the GPS antenna is installed. We corroborate previous results that deep-drilled brace monuments produce smaller uncertainties than concrete piers. However, if at each site the optimal noise model is used, the differences become smaller due to the fact that many concrete piers are located in tectonic/seismic quiet areas. Thus, for the predicted performance of a new GPS network, not only the type of monument but also the noise properties of the region need to be taken into account.

Satellite attitudes that relate to the satellite antenna phase center and wind-up are essential to high-precision Global Navigation Satellite System (GNSS) data processing. However, during eclipse seasons, various attitude strategies are adopted in the different Multi-GNSS Experiment Analysis Centers (MGEX ACs), which may cause inconsistent yaw attitude errors between the network and user ends. Thus, exchanging satellite attitude quaternions are provided by the Centre National d’Etudes Spatiales and Collecte Localisation Satellites (CNES/CLS) to match the corresponding orbit and clock products. In this research, the yaw angle computation method that uses attitude quaternions is given, and the characteristic of the CNES/CLS attitude model is also described in the eclipse seasons. Experiments with CNES/CLS final orbit and clock products are processed to investigate the benefit of attitude quaternions on satellite clock estimation and precise point positioning (PPP). The results demonstrate that the differences between nominal and quaternion yaw angles can reach 360°. Compared with the nominal attitude, the statistic standard deviation (STD) of the clock difference can be reduced by approximately 70% with the attitude quaternions. Regarding kinematic PPP with nominal attitude, a large impact of approximately 20 cm can be found in the position biases. When applying the attitude quaternions, the root mean square (RMS) of the position biases can be significantly reduced and shows an approximately 29% improvement in the up (U) component. Furthermore, if the specific MGEX AC does not provide the attitude quaternions, deleting the eclipsing satellite can obtain a similar position accuracy to that of attitude quaternions strategy when the satellite geometry is strong. However, under the condition of few redundant observations, such as Galileo-only PPP, position performance of attitude quaternions strategy outperforms that of deleting strategy. Therefore, it is hoped that more ACs can provide attitude quaternions to match with corresponding orbit and clock products.

On 21 May 2021, an earthquake struck Maduo county in Qinghai Province, China, which is the largest earthquake to hit China since the 2008 Wenchuan earthquake. In this paper, ascending/descending Se...

Precise orbit products of Global Navigation Satellite Systems (GNSS) are an essential precondition for precise positioning. Ambiguity resolution (AR) can enhance the orbit accuracy in precise orbit determination (POD). To improve the quality of orbits, we propose a method of combined POD for GPS and GLONASS with AR. Firstly, GLONASS wide-lane and narrow-lane fractional cycle biases (FCBs) are daily estimated. Then, by applying the estimated FCBs, GLONASS and GPS double-differenced wide-lane and narrow-lane ambiguities are successfully resolved, even for the baselines of up to several thousand kilometers. Finally, the ambiguity-resolved solutions are achieved by introducing the constraints of the resolved ambiguities into the real-valued solutions. To prove the contribution of the AR to GPS and GLONASS POD, a network including 141 sites is processed over 2018. The results show that the receiver types and firmware versions seriously affect the stability of the daily wide-lane FCBs. The fluctuation of the inter-system biases between two adjacent days is obviously larger than a half narrow-lane wavelength, causing an irregular change of the daily narrow-lane FCBs. After FCB calibration, the success rate of GLONASS can reach up to 90% over the whole year, which is at the same level compared with that of GPS. The improvements of GLONASS and GPS orbits after AR are confirmed by the orbit comparison with the International GNSS Service final products, the orbit misclosures at day boundaries and satellite laser ranging residuals. Due to some other issues, such as the GLONASS frequency-division multiple access and the high noise of observations, the improvement of GLONASS orbit is still less obvious than that of GPS orbit.

China’ cities have made great efforts to seek effective measures to encourage and promote energy-saving building practices, for decades. Shenzhen, a fast-growing megacity in Southern China, has been one of the first practitioners to vigorously promote sustainable development in the building sector, for over 15 years. This study was therefore designed to employ the life cycle assessment approach to quantify the efforts of Shenzhen’s public building practices, and evaluate its real ‘achievement’ by quantifying the CO2 emissions (CO2e) reduction over the past decades. The results show that the total CO2e from public buildings sectors in Shenzhen city have increased rapidly, from 15 Mt in 2005 to 22 Mt CO2e in 2016, because of the fast growth of public buildings’ construction activities. However, current ‘low-carbon’ efforts have only reduced CO2e by approximately 0.5 Mt annually over the past decade, and thus could not offset the rapid growth arising from the increase in floor area. This is hardly enough to contribute proportionally to the city’s overall reduction target. In addition, we conducted a scenario analysis to determine the optimal mitigation measures. The results imply that accelerating the energy-saving renovation of existing buildings is a promising approach and could meet the pressing mitigation needs. These findings could not only inform evidence-based policies to promote the adoption of energy-saving building technologies in Shenzhen, but also shed light on sustainable transition in other megacities.

The Global Navigation Satellite System (GNSS) has proved to be a powerful tool for applications in meteorology. In this study, we propose a novel slant tropospheric delay (STD) model to obtain the vertical distribution of atmospheric refractivity based on a single ground‐based GNSS receiver. The new model is used to convert the STD into a function of the vertical gradient of temperature, and it is divided into two layers (above and below the tropopause) for integration. The optical vertical gradient of temperature can be estimated according to the STD obtained from the GNSS observations from a higher satellite elevation angle. The distribution of atmospheric refractivity can then be derived from the vertical gradient of temperature and the surface atmospheric refractivity. Moreover, to further improve the accuracy of the STD model‐derived atmospheric refractivity, we correct it using a “theoretical retrieval” method based on the STDs obtained at a lower elevation angle. The optical ranges of theoretical retrieval are obtained above and below 5 km. Finally, a search is performed for the value of atmospheric refractivity that best fits the model equations, and this value is taken as the final inversion result. Data collected from eight GNSS stations and nearby radiosonde stations in 2016 were used to verify the new method. Using the radiosonde‐derived values as a reference, the accuracy of the STD model‐derived atmospheric refractivity was improved by 13.4% compared with the traditional technique. In addition, again using the radiosonde‐derived values as a reference, the accuracy of the atmospheric refractivity derived with the optically corrected method was improved by 20.4% compared with the uncorrected STD model.

Precise point positioning (PPP) usually takes about 30 min to obtain centimetre-level accuracy, which greatly limits its application. To address the drawbacks of convergence speed and positioning accuracy, we develop a PPP model with integrated GPS and BDS observations. Based on the method, stations with global coverage are selected to estimate the fractional cycle bias (FCB) of GPS and BDS. The short-term and long-term time series of wide-lane (WL) FCB, and the single day change of narrow-lane (NL) FCB are analysed. It is found that the range of GPS and BDS non-GEO (IGSO and MEO) WL FCB is stable at up to a 30-day-time frame. At times frame of up to 60 days, the stability is reduced a lot. Whether for short-term or long-term, the changes in the BDS GEO WL FCB are large. Moreover, BDS FCB sometimes undergoes a sudden jump. Besides, 17 and 10 stations were used respectively to investigate the convergence speed and positioning errors with six strategies: BDS ambiguity-float PPP (Bfloat), GPS ambiguity-float PPP (Gfloat), BDS/GPS ambiguity-float PPP (BGfloat), BDS ambiguity-fixed PPP (Bfix), GPS ambiguity-fixed (Gfix), and BDS/GPS ambiguity-fixed (BGfix). The average convergence speed of the ambiguity-fixed solution is greatly improved compared with the ambiguity-float solution. In terms of the average convergence time, the Bfloat is the longest and the BGfix is the shortest among these six strategies. Whether for ambiguity-float PPP or ambiguity-fixed PPP, the convergence reduction time in three directions for the combined system is the largest compared with the single BDS. The average RMS value of the Bfix in three directions (easting (E), northing (N), and up (U)) are 2.0 cm, 1.5 cm, and 5.9 cm respectively, while those of the Gfix are 0.8 cm, 0.5 cm, and 1.7 cm. Compared with single system, the BDS/GPS combined ambiguity-fixed system (BGfix) has the fastest convergence speed and the highest accuracy, with average RMS as 0.7 cm, 0.5 cm, and 1.9 cm for the E, N, U components, respectively.

Due to the disturbances along the signal path, it’s inevitable that the loss of lock or data interruption interval of a few satellites reach to decades of seconds or even minutes. It will be difficult to recover data and evaluate cycle slips after a long gap in real time kinematic (RTK) positioning. A double-differenced (DD) velocity estimation method is proposed for the repair of cycle slip in RTK positioning, assuming available of fixed coordinate solutions for the previous epoch. We achieve the precise coordinate solution of the current epoch by using triple-differenced (TD) combinations. The dual-frequency observed minus computed (OMC) combinations are then calculated by using the observations and coordinate solutions. The differenced OMC values between two epochs are used to repair cycle slips. Two kinematic experiments carried out to evaluate the performance of the proposed method are for velocities less than 2 m s−1 for a boat and about 10 m s−1 for a vehicle. The averaged distance of boat and vehicle relative to the reference are about 11 km and 24.5 km, respectively. The experimental results of the boat case indicate that all cycle slips are corrected within 0.25 cycles even though sampling interval reaches to 120 s. The cycle slips fixing uncertainty is close to 0.3 cycles for a sampling interval of 30 s and 60 s vehicle experiments. As the sampling interval increases to 90 s and 120 s, the uncertainty rises to 0.35 cycles for the vehicle-dynamic vehicle experiment.

The rapid development of multi-GNSS (Global Navigation Satellite System) constellations has provided numerous benefits for common PNT (Positioning, Navigation and Timing) services. Generally, DD (Double Difference) observations are used in GNSS baseline processing. However, in traditional DD data processing methods, DD observations are normally not formed between different GNSS systems or the inter-system DD ambiguities are rather difficult to be resolved due to the different wavelength. As a result, DD observations are normally formed in each system or their inter-system ambiguities are left unresolved, which could not be regarded as the optimal baseline processing methods for multi-GNSS. This paper presents an improved algorithm for multi-GNSS short baseline processing where SD (Single Difference) rather than DD observations are formed between two receivers and this method is found to be equivalent to the ideal DD method with inter-system DD observations and resolved inter-system DD ambiguities. Furthermore, an average approach and linear model are proposed to isolate the receiver-dependent Uncalibrated Phase Delays (UPDs) from the SD ambiguities for CDMA (Code Division Multiple Access) and FDMA (Frequency Division Multiple Access) GNSS systems, respectively, to address ambiguity resolution. Experiments show that after removing the UPDs derived by the proposed methods, the fractional parts of the residuals for almost all ambiguities are less than 0.1 cycles for the GPS, BDS, GLONASS and Galileo systems, which confirms the validity of our UPD calibration methods. Experiments also show that the mean differences between the daily solutions derived by GAMIT and the 4-h solutions derived by the proposed SD method are approximately −0.12, −0.33, 1.04 and 0.31 cm in the north, east, up and length components, respectively. We also find that the baseline repeatability of the new SD method outperforms that of the DD method with only DD observations formed in each GNSS system by 36% and 26% in the north and up directions, respectively. These improvements are more significant in environments with poor observation conditions. An improvement of 40% and 30% in the north and up directions are, respectively, found when only 5 GPS and 4 BDS satellites are available. Therefore, more reliable and precise baselines can be derived with our new baseline processing method in multi-GNSS cases.

The purpose of this research is to explore the mediating role of project leadership between Confucian principles and project performance from the perspectives of contractors. Using a set of questio...

A precise Global Navigation Satellite System (GNSS) satellite orbit is an essential prerequisite for precise point positioning (PPP). Due to the daily orbit discontinuities (DODs) between adjacent daily orbit products provided by the International GNSS Service, the interpolation accuracy at the epochs near the day boundaries cannot be as high as expected and can significantly degrade the positioning accuracy. This is especially for the emerging Beidou and Galileo satellites with larger DODs. In this study, a new interpolation strategy was proposed to mitigate the DOD effect by estimating the zero- to second-order biases between the orbits of two adjacent days. The results show that the proposed interpolation strategy outperforms the traditional interpolation strategies. The 3D orbit interpolation error for the last 10 min on each day is reduced from almost a few centimeters or even meters to millimeters, an improvement of approximately 86–99% for all satellites. PPP validation also provides concrete evidence of this improvement, as the DOD-induced satellite phase residuals are reduced significantly. Thus, the new interpolation strategy mitigates the DOD effect and helps multi-GNSS users obtain the highest interpolation accuracy at the day boundaries, which can be comparable to that at the non-day boundaries.

Reanalysis products have been applied to calculate the tropospheric delay for Global Navigation Satellite System (GNSS) positioning purposes widely. It is necessary to obtain high-precision tropospheric delay information from GNSS users with a high-precision tropospheric vertical stratification model because the height of the grids of the atmospheric reanalysis data is inconsistent with that of GNSS users, especially in regions with high terrains. In addition, the variation of the tropospheric delay in the vertical direction is much higher than that in the horizontal direction. The zenith total delay (ZTD) vertical stratification model is also key to the development of real-time and high-precision ZTD models. A new approach, the sliding window algorithm, is proposed to develop a ZTD vertical stratification model. In this work, a ZTD vertical stratification model considering spatiotemporal factors is developed based on the second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) data, which is named the GZTD-H model. Radiosonde and International GNSS Service (IGS) data are treated as reference values to evaluate the performance of the GZTD-H model, which is compared to the model GPT2w. The results show that the GZTD-H model realizes the highest performance in ZTD layered vertical interpolation against ZTD layered profiles obtained at radiosonde sites, which achieves an improvement of 10% over the model GPT2w. Compared to model GPT2w, the GZTD-H model attains a spatial interpolation improvement of 8% for the Global Geodetic Observing System (GGOS) Atmosphere gridded ZTD over the surface ZTD calculated from radiosonde profiles. Furthermore, compared to model GPT2w, the model GZTD-H also attains improvements of 11% over the precise ZTD products acquired at IGS sites. In terms of model parameters, the GZTD-H model is greatly reduced and optimized over model GPT2w. Hence, the applicability of this model is enhanced in terms of GNSS atmospheric sounding and precise GNSS positioning.

The Global Positioning System (GPS) derived bedrock displacements respond to multiple geophysical effects, ranging from surface elastic loads to tectonic sources or viscoelastic uplifts stemming from Earth’s viscous mantle. In this study, the GPS-inferred vertical crustal velocities are rigorously estimated in mainland China. We integrate the GPS vertical velocity field with Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GFO) data, adopting an empirical Spatial Structure Function (SSF), to image tectonic deformation in mainland China with respect to the International Terrestrial Reference Frame (ITRF) 2014. We present four profiles across China, which indicate that our new robust results are superior to kriging. Furthermore, we use the GRACE/GFO products to account for elastic deformation due to surface mass changes to isolate tectonic deformation signals at GPS sites within mainland China from 2002 to 2019. By integrating GPS and GRACE/GFO measurements, our results reveal the long-term spatial patterns of vertical tectonic motion in different blocks in mainland China. We conclude that significant steep velocity gradients occur at tectonic block boundaries that are attributable to locking and elastic strain accumulation on active block boundary faults. Published version We are most grateful to the National Key Scientific Projects “Tectonic and Environmental Observation Network of Mainland China” (CMONOC I and II). The project was funded by the NSFCs (Grant 41904012, 41721003, 41774024, and 41974022), China Postdoctoral Science Foundation (2020T130482, 2018M630879).

Adaptive and accurate trend estimation of the sea level record is critically important for characterizing its nonlinear variations and its study as a consequence of anthropogenic climate change. Sea level change is a nonstationary or nonlinear process. The present modeling methods, such as least squares fitting, are unable to accommodate nonlinear changes, including the choice of a priori information to help constrain the modeling. All these problems affect the accuracy and adaptability of nonlinear trend estimation. Here, we propose a method called EMD‐SSA, that effectively combines adaptive empirical mode decomposition (EMD) and singular spectrum analysis (SSA). First, the sea level change time series is decomposed by EMD to estimate the intrinsic mode functions. Second, the periodic or quasiperiodic signals in the intrinsic mode functions can be determined using Lomb‐Scargle spectral analysis. Third, the numbers of the identified periodicities/quasiperiodicities are used as embedding dimensions of SSA to identify possible nonlinear trends. Then, the optimal nonlinear trend with the largest absolute Mann‐Kendall rank is selected as the final trend for the sea level change. Based on a comprehensive experiment using simulated sea level change time series, we concluded that the EMD‐SSA method can adaptively provide better estimate of the nonlinear trend in a realistic sea level change time series with consistency or high accuracy. We suggest that EMD‐SSA can be used not only to robustly extract nonlinear trends in sea level data, but also for trends in other geodetic or climatic records, including gravity, GNSS observed displacements, and altimetry observations.

Observing subdaily surface deformations is important to the interpretation of rapidly developing transient events. However, it is not known whether GNSS (Global Navigation Satellite System) is able to identify millimeter‐level transient displacements over various subdaily timescales. We studied non‐tidal ocean loading (NTOL) using 18 GNSS stations along the southern North Sea for November–December 2013, and compared 3‐hourly GPS/GLONASS displacements with NTOL predictions. It was found that they overall agreed well with a mean correlation coefficient of 0.6 and their vertical differences had an RMS of 5.7 mm, but a 10‐mm subsidence prediction for December 5th could only be marginally detected. Hence the spatial coherence among the loading signatures at the 18 stations was harnessed to improve subdaily GNSS, and then the predicted displacements of 5–10‐mm over the subdaily timescales could be discriminated successfully. We envision that adding Galileo/BeiDou signals to GPS/GLONASS can further improve the resolution of subdaily GNSS, which can also enhance the spatial coherence of transient signals captured by regional GNSS stations.

Single-difference (SD) ambiguity resolution (AR) and track-to-track (T2T) AR are two typical AR methods in precise orbit determination (POD) for Low Earth Orbit (LEO) satellites, which could improve the accuracy of orbits greatly. In this study, SD AR and T2T AR methods are introduced and analyzed. The performance of these two methods is assessed by three months of GPS observations from the Gravity Recovery and Climate Experiment Follow On (GRACE-FO) twin satellites. Results show that T2T AR is highly dependent on the stability of receiver hardware delays, while SD AR requires Fractional Cycle Bias (FCB) or Integer Recovery Clock (IRC) products. We find that these two methods have comparable performance in Reduced Dynamic Precise Orbit Determination (RDPOD), while SD AR slightly outperforms T2T AR in Kinematic Precise Orbit Determination (KPOD). We also find that SD AR has a higher AR success rate than T2T AR. Therefore, we recommend SD AR as the top choice in LEO orbit determination, and T2T AR can be a good alternative when FCB or IRC products are not available.

Construction of noise model is an important task in the analysis of Global Positioning System (GPS) reference station coordinate time series. Ignoring the relationship between the noise on different components within a GPS station network may affect the accuracy of station's velocity and its uncertainty. In view of this problem, we propose to use the singular value decomposition (SVD) method to establish a new three‐dimensional (3‐D) noise model for GPS station networks. Our simulation tests show that the accuracy of the noise amplitude obtained based on the proposed 3‐D noise model is 30–50% higher than that directly obtained from Create and Analyze Time Series (CATS) software, thereby improving the accuracy of the velocity uncertainty by approximately two times. Taking the coordinate time series of 82 GPS stations from the Crustal Motion Observation Network of China (CMONOC) as an example, we confirm that significant correlation exists among noise amplitude estimates in the different components of the CMONOC stations. In general, the variation of white noise (WN) amplitude is 2–6% smaller than that of flicker noise (FN) amplitude, and the FN amplitude in the vertical component is 1% larger than that in the horizontal component. Compared with the velocity uncertainty obtained from CATS software, the variations of the velocity uncertainty obtained from the new 3‐D noise model in the horizontal components (7% for North, 8% for East) are slightly less than that in the Up component (9%). However, the velocity estimation is hardly affected by the new 3‐D noise model.

Backgrounds: To describe the clinical characteristics of coronavirus disease 2019 hospitalized patients and further analyze the potential risk factors related to the severity of the disease and 28-day mortality of patients.Methods: A total of 122 coronavirus disease 2019 patients hospitalized in Wuhan Third Hospital from 26 January 2020 to 16 March 2020 were included in this retrospective study. Clinical data of patients were retrospectively analyzed, and the risk factors associated with disease severity and 28-day mortality were screened by cox regression analysis.Results: Of all 122 patients, the median age was 64 years old (interquartile range, 57- 71 years old).Compared with non-severe patients, severe patients had higher indices like cardiac troponin T and respiratory rate. In cox regression analysis, cardiac troponin T correlated with 28-day mortality most.Conclusions: Abnormal cardiac troponin T value after admission were in strong correlation with 28-day survival status.

Our exploration of multimodal nanoprobes aims to combine photoacoustic (PA) imaging

Intracerebral hemorrhage (ICH) is a common and severe neurological disorder that can effectively induce oxidative stress responses. NADPH oxidase 4 (NOX4) is a member of the NOX family of oxidases. It is expressed in the brain normally and involved in cell signal transduction and the removal of harmful substances. In some pathological conditions, it mediates inflammation and the aging of cells. However, few studies have focused on whether NOX4 is involved in brain injury caused by ICH. Therefore, this study aimed to clarify the role of NOX4 in the pathological process that occurs after ICH and the potential mechanism underlying its role. A rat model of ICH was established by the injection of collagenase type IV, and the expression of NOX4 was then determined. Further, siRNA-mediated protein expression knockdown technology was used for NOX4 knockdown, and western immunoblotting, immunohistochemistry, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and other molecular biological techniques were performed to assess the effects of NOX4 knockdown. Neurobiological scoring, brain water content determination, and other brain injury detection methods were also performed to assess the role of NOX4 following ICH. We found that the expression of NOX4 increased in the brains of rats after ICH, and that it was mainly expressed in neurons, astrocytes, vascular endothelial cells and microglia. Following NOX4 knockdown, the level of oxidative stress in the brain decreased considerably, the neurobehavioral scores improved, the levels of neuronal apoptosis reduced markedly, and the impairment of blood-brain barrier function was significantly ameliorated in rats with ICH. In conclusion, this study suggests that NOX4 expression is upregulated after ICH, which may cause an imbalance in the oxidative stress of relevant cells in the brain, leading to subsequent apoptosis of neurons and damage to the blood-brain barrier due to secondary brain injury following ICH.

A new non-encapsulated fluorinated liposome (TSL) was developed, which showed instantaneous temperature-induced 19F MR signal enhancement and excellent stability under reversible signal transition at different conditions.

We propose a multiple global navigation satellite system (multi-GNSS) differential phase kinematic post-processing method, expand the current Track ability, and finely tune processing parameters to achieve the best results for research purposes. The double-difference (DD) phase formulas of GLONASS are especially formulated, and the method of arc ambiguity resolution (AR) in post-processing is developed. To verify the feasibility of this AR method, a group of static baselines with ranges from 8 m to 100 km and two kinematic tests were used. The results imply that 100% of ambiguities in short baselines and over 90% in long baselines can be fixed with the proposed ambiguity resolution method. Better than a 10-mm positioning precision was achieved for all the horizonal components of those selected baselines and the vertical components of the short baselines, and the vertical precision for long baselines is around 20 to 40 mm. In the posterior residual analysis, the means of the residual root-mean-squares (RMSs) of different systems are better than 10 mm for short baselines and at the range of 10–20 mm for baselines longer than 80 km. Mostly, the residuals satisfy the standard normal distribution. It proves that the new method could be applied in bridge displacement and vibration monitoring and for UAV photogrammetry.

The BeiDou navigation satellite system (BDS) currently has 41 satellites in orbits and will reach its full constellation following the launch of the last BDS satellite in June 2020 to provide navigation, positioning, and timing (PNT) services for global users. In this contribution, we investigate the characteristics of inter-system bias (ISB) between BDS-2 and BDS-3 and verify whether an additional ISB parameter should be introduced for the BDS-2 and BDS-3 precise point positioning (PPP). The results reveal that because of different clock references applied for BDS-2 and BDS-3 in the International GNSS Service (IGS) precise satellites clock products and the inconsistent code hardware delays of BDS-2 and BDS-3 for some receiver types, an ISB parameter needs to be introduced for BDS-2 and BDS-3 PPP. Further, the results show that the ISB can be regarded as a constant within a day, the value of which is closely related to the receiver type. The ISB values of the stations with the same receiver type are similar to each other, but a great difference may be presented for different receiver types, up to several meters. In addition, the impact of ISB on PPP has also been studied, which demonstrates that the performance of kinematic PPP could be improved when ISB is introduced.

MRI with hyperpolarized 129Xe can achieve low-concentration detection. Herein, nanoparticle-coated perfluorooctyl bromide (PFOB) was developed as a 129Xe MRI contrast agent with a moderate exchange rate, sufficient stability and feasible surface modification. The αvβ3 integrin overexpressed by non-small-cell lung cancer A549 cells was successfully detected by 129Xe MRI with high specificity through adequate surface modifications.

Removal of the common mode error (CME) is very important for the investigation of global navigation satellite systems&rsquo, (GNSS) error and the estimation of an accurate GNSS velocity field for geodynamic applications. The commonly used spatiotemporal filtering methods normally process the evenly spaced time series without missing data. In this article, we present the variational Bayesian principal component analysis (VBPCA) to estimate and extract CME from the incomplete GNSS position time series. The VBPCA method can naturally handle missing data in the Bayesian framework and utilizes the variational expectation-maximization iterative algorithm to search each principal subspace. Moreover, it could automatically select the optimal number of principal components for data reconstruction and avoid the overfitting problem. To evaluate the performance of the VBPCA algorithm for extracting CME, 44 continuous GNSS stations located in Southern California were selected. Compared to previous approaches, VBPCA could achieve better performance with lower CME relative errors when more missing data exists. Since the first principal component (PC) extracted by VBPCA is remarkably larger than the other components, and its corresponding spatial response presents nearly uniform distribution, we only use the first PC and its eigenvector to reconstruct the CME for each station. After filtering out CME, the interstation correlation coefficients are significantly reduced from 0.43, 0.46, and 0.38 to 0.11, 0.10, and 0.08, for the north, east, and up (NEU) components, respectively. The root mean square (RMS) values of the residual time series and the colored noise amplitudes for the NEU components are also greatly suppressed, with average reductions of 27.11%, 28.15%, and 23.28% for the former, and 49.90%, 54.56%, and 49.75% for the latter. Moreover, the velocity estimates are more reliable and precise after removing CME, with average uncertainty reductions of 51.95%, 57.31%, and 49.92% for the NEU components, respectively. All these results indicate that the VBPCA method is an alternative and efficient way to extract CME from regional GNSS position time series in the presence of missing data. Further work is still required to consider the effect of formal errors on the CME extraction during the VBPCA implementation.

Removal of the Common Mode Error (CME) is very important for the investigation of Global Navigation Satellite Systems (GNSS) technique error and the estimation of accurate GNSS velocity field for geodynamic applications. The commonly used spatiotemporal filtering methods cannot accommodate missing data, or they have high computational complexity when dealing with incomplete data. This research presents the Expectation-Maximization Principal Component Analysis (EMPCA) to estimate and extract CME from the incomplete GNSS position time series. The EMPCA method utilizes an Expectation-Maximization iterative algorithm to search each principal subspace, which allows extracting a few eigenvectors and eigenvalues without covariance matrix and eigenvalue decomposition computation. Moreover, it could straightforwardly handle the missing data by Maximum Likelihood Estimation (MLE) at each iteration. To evaluate the performance of the EMPCA algorithm for extracting CME, 44 continuous GNSS stations located in Southern California have been selected here. Compared to previous approaches, EMPCA could achieve better performance using less computational time and exhibit slightly lower CME relative errors when more missing data exists. Since the first Principal Component (PC) extracted by EMPCA is remarkably larger than the other components, and its corresponding spatial response presents nearly uniform distribution, we only use the first PC and its eigenvector to reconstruct the CME for each station. After filtering out CME, the interstation correlation coefficients are significantly reduced from 0.46, 0.49, 0.42 to 0.18, 0.17, 0.13 for the North, East, and Up (NEU) components, respectively. The Root Mean Square (RMS) values of the residual time series and the colored noise amplitudes for the NEU components are also greatly suppressed, with an average reduction of 25.9%, 27.4%, 23.3% for the former, and 49.7%, 53.9%, and 48.9% for the latter. Moreover, the velocity estimates are more reliable and precise after removing CME, with an average uncertainty reduction of 52.3%, 57.5%, and 50.8% for the NEU components, respectively. All these results indicate that the EMPCA method is an alternative and more efficient way to extract CME from regional GNSS position time series in the presence of missing data. Further work is still required to consider the effect of formal errors on the CME extraction during the EMPCA implementation.

The analysis of daily position Global Navigation Satellite System (GNSS) time series provides information about various geophysical processes that are shaping the Earth’s crust. The goodness of fit of a trajectory model to these observations is an indication of our understanding of these phenomena. However, the fit also depends on the noise levels in the time series and in this study we investigate for 568 GNSS stations across North America the noise properties, its relation with the choice of trajectory model and if there exists a relationship with the type of monuments. We use the time series of two processing centers, namely the Central Washington University (CWU) and the New Mexico Tech (NMT), which process the data using two different complete processing strategies.We demonstrate that mismodelling slow slip events within the geodetic time series increases the percentage of selecting the Random-Walk + Flicker + White noise (RW+FN+WN) as the optimal noise model for the horizontal components, especially when the Akaike Information Criterion is used. Furthermore, the analysis of the spatial distribution of the RW component (in the FN+WN+RW) around North America takes place at stations mostly localised around tectonic active areas such as the Cascadia subduction zone (Pacific Northwest) or the San Andreas fault (South California) and coastal areas. It is in these areas that most shallow and drilled-braced monuments are also located. Therefore, the comparison of monument type with observed noise level should also take into account its location which mostly has been neglected in previous studies. In addition, the General Gauss-Markov (GGM) with white noise (GGM+WN) is often selected for the Concrete Pier monument especially on the Up component which indicates that the very long time series are experiencing this flattening of the power spectrum at low frequency. Finally, the amplitude of the white noise is larger for the Roof-Top/Chimney (RTC) type than for the other monument’s types. With a varying seasonal signal computed using a Wiener filter, the results show that RTC monuments have larger values in the East and North components, whereas the deep-drilled brace monuments have larger values on the vertical component.

Precise point positioning (PPP) is famous for its capability of high-precision positioning with just one station as long as the receiver can receive global navigation satellite system (GNSS) signals. With the rapid development of BDS and Galileo, the number of available satellites for positioning has increased significantly. In addition, GPS III, GLONASS-K, BDS, and Galileo satellites can transmit triple-frequency signals. The potentials of multi-constellation GNSS PPP requires further analysis on a global scale. Therefore, we selected 96 multi-GNSS experiment (MGEX) stations with a global distribution and used 1 week’s data to assess the PPP performance. The results show that the PPP based on multi-frequency raw observations with spatial and temporal constraints has better performance than PPP using dual-frequency ionospheric-free observations. The main contribution of multi-constellation GNSS PPP is to shorten the convergence time. The convergence time for GPS PPP is approximately 40 min, which can be shortened to less than 20 min in multi-GNSS PPP. After convergence, the positioning accuracy of multi-GNSS PPP is improved by 0.5 to 1.0 cm compared with GPS or GLONASS PPP. The positioning accuracy of multi-GNSS could be further improved in the future with the BDS and Galileo precise products of orbits, clock and phase center offset/variation.

Site-dependent effects are now the key factors that restrict the high accuracy applications of Global Navigation Satellite System (GNSS) technology, such as deformation monitoring. To reduce the effects of non-line-of-sight (NLOS) signal and multipath, methods and models applied to both of the function model and stochastic model of least-squares (LS) have been proposed. However, the existing methods and models may not be convenient to use and not be appropriate to all GNSS satellites. In this study, the SNR features of GPS and GLONASS are analyzed first, and a refined SNR based stochastic model is proposed, in which the links between carrier phase precision and SNR observation have been reasonably established. Compared with the existing models, the refined model in this paper could be used in real-time and the carrier phase precision could be reasonably shown with the SNR data. More importantly, it is applicable to all GNSS satellite systems. Based on this model, the site observation environment can be assessed in advance to show the obstruction area. With a bridge deformation monitoring platform, the performance of this model was tested in the aspect of integer ambiguity resolution and data processing. The results show that, compared with the existing stochastic models, this model could have the highest integer ambiguity resolution success rate and the lowest noise level in the data processing time series with obvious obstruction beside the site.

Osteocalcin (OCN) is a bone-derived hormone involved in the regulation of glucose metabolism. In serum, OCN exists in carboxylated and uncarboxylated forms (ucOCN), and studies in rodents suggest that ucOCN is the bioactive form of this hormone. Whether this is also the case in humans is unclear, because a reliable assay to measure ucOCN is not available. Here, we established and validated a new immunoassay (ELISA) measuring human ucOCN and used it to determine the level of bioactive OCN in two cohorts of overweight or obese subjects, with or without type 2 diabetes (T2D). The ELISA could specifically detect ucOCN concentrations ranging from 0.037 to 1.8 ng/mL. In a first cohort of overweight or obese postmenopausal women without diabetes ( n = 132), ucOCN correlated negatively with fasting glucose (r = −0.18, P = 0.042) and insulin resistance assessed by the homeostatic model assessment of insulin resistance (r = −0.18, P = 0.038) and positively with insulin sensitivity assessed by a hyperinsulinemic-euglycemic clamp (r = 0.18, P = 0.043) or insulin sensitivity index derived from an oral glucose tolerance test (r = 0.26, P = 0.003). In a second cohort of subjects with severe obesity ( n = 16), ucOCN was found to be lower in subjects with T2D compared with those without T2D (2.76 ± 0.38 versus 4.52 ± 0.06 ng/mL, P = 0.009) and to negatively correlate with fasting glucose (r = −0.50, P = 0.046) and glycated hemoglobin (r = −0.57, P = 0.021). Moreover, the subjects with ucOCN levels below 3 ng/mL had a reduced insulin secretion rate during a hyperglycemic clamp ( P = 0.03). In conclusion, ucOCN measured with this novel and specific assay is inversely associated with insulin resistance and β-cell dysfunction in humans.

The Global Positioning System (GPS) based monitoring technology has been recognised as an essential tool in the long-span bridge health monitoring throughout the world in recent years. However, the high observation noise is still a big problem that limits the high precision displacement extraction and vibration response detection. To solve this problem, GPS double-difference model and many other specific function models have been developed to eliminate systematic errors e.g. unmodeled atmospheric delays, multipath effect and hardware delays. However, relatively less attention has been given to the noise reduction in the deformation monitoring area. In this paper, we first proposed a new carrier phase elevation-dependent precision estimation method with Geometry-Free (GF) and Melbourne-Wubbena (MW) linear combinations, which is appropriate to regardless of Code Division Multiple Access (CDMA) system (GPS) or Frequency Division Multiple Access (FDMA) system (GLONASS). Then, the method is used to estimate the receiver internal noise and the realistic GNSS stochastic model with a group of zero-baselines and short-baselines (served for the GNSS and Earth Observation for Structural Health Monitoring of Bridges (GeoSHM) project), and to demonstrate their impacts on the positioning. At last, the contribution of integration of GPS and GLONASS is introduced to see the performance of noise reduction with multi-GNSS. The results show that the higher level receiver internal noise in cost effective receivers has less influences on the short-baseline data processing. The high noise effects introduced by the low elevation satellite and the geometry variation caused by rising and dropping satellites, can be reduced by 10–20% with the refined carrier phase elevation-dependent stochastic model. Furthermore, based on observations from GPS and GLONASS with the refined stochastic model, the noise can be reduced by 30–40%, and the spurious signals in the real-life bridge displacements tend to be completely eliminated.

BACKGROUND Liposarcoma is the most common type of soft tissue sarcoma, but its molecular mechanism is poorly defined. This study aimed to identify genes crucial to the pathogenesis of liposarcoma and to explore their functions, related pathways, and prognostic value. MATERIAL AND METHODS Differentially expressed genes (DEGs) in the GSE59568 dataset were screened. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to investigate the DEGs at the functional level. Protein-protein interaction (PPI) networks and module analysis were applied to identify hub genes from among the DEGs. The GSE30929 dataset was used to validate the relationship between hub genes and the distant recurrence-free survival (DRFS) of liposarcoma patients using Cox model analysis. RESULTS A total of 1111 DEGs were identified. GO and KEGG pathway analysis indicated that the DEGs were mainly associated with lipopolysaccharides and pathways in cancer. The PPI network and module analysis identified 10 hub genes from the DEG network. The Cox model identified 3 genes (NIP7, RPL10L, and MCM2) significantly associated with DRFS. The risk score calculated by the Cox model of the NIP7-RPL10L-MCM2 signature could largely predict the 1-, 3-, and 5-year DRFS of liposarcoma patients, and the prognostic value was even higher for subtypes of liposarcoma. CONCLUSIONS This study identified genes that might play critical roles in liposarcoma pathogenesis as well as a 3-gene-based signature that could be used as a candidate prognostic biomarker for patients with liposarcoma.

Project participants especially project owners and contractors have important effect in promoting project success. This study investigated the relationship between project participants’ trust netwo...

Glioma is one of the most treatment-refractory intracranial tumors, and the aberrant expressed Wnt/β-catenin pathway is closely associated with glioma malignancy. In this regard, Wnt/β-catenin signaling has been reported to play an essential role in cellular proliferation, migration, invasion, and angiogenesis, therefore contributing to glioma progression. However, the underlying mechanisms of Wnt/β-catenin signaling involvement in gliomagenesis remain unknown. Here, we present an overview of the Wnt components and then go on to summarize the current knowledge describing the multitude of roles of Wnt/β-catenin in glioma, which are mediated by transcription factors, microRNAs, long noncoding RNAs, and so on. In the latter portion of the review, we elaborate the increasing apparent crosstalk of Wnt/β-catenin pathway with PI3K/AKT signaling involved in these processes. Ultimately, compounds targeting the Wnt/β-catenin are described in glioma. As better understanding of the regulatory mechanisms to glioma malignancies increases, Wnt/β-catenin cascade may represent an area of developmental glioma therapeutics focus.

Rapid initialization with ambiguity fixed resolution plays a key role in real-time Global Navigation Satellite Systems (GNSS) displacement monitoring of bridges. In this study, we propose a rapid initialization method with triple-frequency (TF) BeiDou Navigation Satellite System (BDS) and Global Positioning System (GPS) observations. The key step of this method is to form extra-wide-lane (EWL) ambiguity with TF BDS and GPS carrier-phase to reduce the ambiguity search space. In order to improve the speed of ambiguity resolution (AR) further, the strategies of fixing ambiguities in groups sequentially from long wavelength to the short and partial AR (PAR) with elevation and signal-to-noise ratio (SNR) criterions were proposed. Based on the real monitoring data on the Baishazhou Yangtze River Bridge, the AR efficiency was tested. The results illustrate that over 90% EWL ambiguities can be fixed by only single-epoch with TF BDS + GPS. After EWL ambiguity is fixed, the wide-lane (WL) ambiguity success rate could improve from 20% with dual-frequency (DF) BDS + GPS data to 70% with TF BDS + GPS data, 50–80% and 80–90% for the three stations respectively. Since the area of ambiguity search space is reduced by TF observations, the ambiguity search time decrased significantly compared with the DF BDS + GPS. In the Time-to-first-fix (TTFF) test, over 85% of epochs can complete the initialization process by only one epoch with one hour of 10 Hz TF BDS + GPS data. However, DF BDS + GPS has only 25%. As for the initialization time longer than two epochs, the counts of TTFFs of TF BDS + GPS are significantly less than that of DF BDS + GPS. Meanwhile, the integrated BDS and GPS can further enhance the geometry of satellites, which will be better for the precision improvement than the increase of signal frequencies.

GPS has been widely applied to monitor displacements using direct measurements. Even conventional ways using direct measurement can achieve millimeter level (better than 1 mm in horizontal and 2 mm in vertical component) accuracy displacement, the causative loads such as hydraulic thermal loads always have to be obtained by other sensors or methods. This paper proposes a novel method to derive reservoir level variation data with displacement estimation simultaneously for the mechanism explanation of deformations. This method is based on multipath theory for specular reflections and the use of Signal-to-Noise Ratio (SNR) data, rather than direct measurements in GPS. We took data from an existing GPS monitoring system which has been set up on the Xilongchi Dam in Shanxi Province, China. A whole year of data from the sites located beside the reservoir was used to conduct the experiments. The result indicates that the water level variation daily time series estimated with SNR measurements can be achieved to centimeter level. The correlation between the estimated value and the daily records can even reach up to 0.98. It can be concluded that the GPS-based system designed by this paper can monitor displacements and reservoir level synchronously, and GPS is also confirmed to be a viable tool for both the monitoring of dam displacements and a reservoir water level indicator.

In ground-based global positioning system (GPS) meteorology, atmospheric weighted mean temperature, $$T_\mathrm{m}$$ , plays a very important role in the progress of retrieving precipitable water vapor (PWV) from the zenith wet delay of the GPS. Generally, most of the existing $$T_\mathrm{m} $$ models only take either latitude or altitude into account in modeling. However, a great number of studies have shown that $$T_\mathrm{m} $$ is highly correlated with both latitude and altitude. In this study, a new global grid empirical $$T_\mathrm{m} $$ model, named as GGTm, was established by a sliding window algorithm using global gridded $$T_\mathrm{m} $$ data over an 8-year period from 2007 to 2014 provided by TU Vienna, where both latitude and altitude variations are considered in modeling. And the performance of GGTm was assessed by comparing with the Bevis formula and the GPT2w model, where the high-precision global gridded $$T_\mathrm{m} $$ data as provided by TU Vienna and the radiosonde data from 2015 are used as reference values. The results show the significant performance of the new GGTm model against other models when compared with gridded $$T_\mathrm{m} $$ data and radiosonde data, especially in the areas with great undulating terrain. Additionally, GGTm has the global mean $$\hbox {RMS}_{\mathrm{PWV}} $$ and $$\hbox {RMS}_{\mathrm{PWV}} /\hbox {PWV}$$ values of 0.26 mm and 1.28%, respectively. The GGTm model, fed only by the day of the year and the station coordinates, could provide a reliable and accurate $$T_\mathrm{m} $$ value, which shows the possible potential application in real-time GPS meteorology, especially for the application of low-latitude areas and western China.

Cycle slip detection for single frequency Global Navigation Satellite System (GNSS) data is currently mainly based on measurement modelling or prediction, which cannot be effectively performed for kinematic applications and it is difficult to detect or repair small cycle slips such as half-cycle slips. In this paper, a new method that is based on the total differential of ambiguity and Least-Squares Adjustment (LSA) for cycle slip detection and repair is introduced and validated. This method utilises only carrier-phase observations to build an ambiguity function. LSA is then conducted for detecting and repairing cycle slips, where the coordinate and cycle slips are obtained successively. The performance of this method is assessed through processing short and long baselines in static and kinematic modes and the impact of linearization and atmospheric errors are analysed at the same time under a controlled variable method. The results indicate this method is very effective and reliable in detecting and repairing multiple cycle slips, especially small cycle slips.