Although satellite radar altimetry was developed and optimized for open oceans, it has been used to monitor variations in the level of inland water-bodies such as lakes and rivers. Here, for the first time, we have further used the altimetry-derived variation of water level for estimating the fluctuation of water storage as an addition to the present in situ water storage estimation systems to be used in remote areas and in emergency situation such as in the events flooding monitoring and for studying the effect of climate change. Lake Dongting, the second largest lake in China, influenced frequently by flooding, was, therefore, chosen to demonstrate the potential of the technique. By using the concept of an "assumed reference point", we converted Topex/Poseidon satellite altimetry data on water level variations in Lake Dongting to "water level" data. The "water level" time-series data and in situ water storage were used to establish a rating curve. From the rating curve, we converted data on "water level" derived from seven years (1993-1999) of Topex/Poseidon data to actual water storage in Lake Dongting. The result reveals that the seasonal and annual fluctuations of water storage occurred during the 1990s with a more frequent flooding at the late 1990s' especially the flooding in whole catchment level in 1998 and 1999. The study supports the usefulness of satellite altimetry for dense and continuous monitoring of the temporal variations in water dynamic in moderate to large lakes.
The metabolic profiling of biofluids using untargeted metabolomics provides a promising choice to discover metabolite biomarkers for clinical cancer diagnosis. However, metabolite biomarkers discovered in biofluids may not necessarily reflect the pathological status of tumor tissue, which makes these biomarkers difficult to reproduce. In this study, we developed a new analysis strategy by integrating the univariate and multivariate correlation analysis approach to discover tumor tissue derived (TTD) metabolites in plasma samples. Specifically, untargeted metabolomics was first used to profile a set of paired tissue and plasma samples from 34 colorectal cancer (CRC) patients. Next, univariate correlation analysis was used to select correlative metabolite pairs between tissue and plasma, and a random forest regression model was utilized to define 243 TTD metabolites in plasma samples. The TTD metabolites in CRC plasma were demonstrated to accurately reflect the pathological status of tumor tissue and have great potential for metabolite biomarker discovery. Accordingly, we conducted a clinical study using a set of 146 plasma samples from CRC patients and gender-matched polyp controls to discover metabolite biomarkers from TTD metabolites. As a result, eight metabolites were selected as potential biomarkers for CRC diagnosis with high sensitivity and specificity. For CRC patients after surgery, the survival risk score defined by metabolite biomarkers also performed well in predicting overall survival time (p = 0.022) and progression-free survival time (p = 0.002). In conclusion, we developed a new analysis strategy which effectively discovers tumor tissue related metabolite biomarkers in plasma for cancer diagnosis and prognosis.
The aims of this study were to explore the effect of high-altitude (HA) exposure on the incidence, determinants, and impacts of right ventricular dyssynchrony (RVD). In our study, 108 healthy young men were enrolled, and physiological and echocardiographic variables were recorded at both sea level and 4,100 m. By using two-dimensional speckle-tracking echocardiography, RVD was evaluated by calculating the R-R intervalcorrected standard deviation of the time-to-peak systolic strain for the four mid-basal RV segments (RVSD4) and defined by RVSD4 > 18.7 ms. After HA exposure, RVSD4 was significantly increased, and the incidence of RVD was approximately 32.4%. Subjects with RVD showed lower oxygen saturation (SaO 2) and RV global longitudinal strain and higher systolic pulmonary artery pressure than those without RVD. Moreover, myocardial acceleration during isovolumic contraction was increased in all subjects and those without RVD, but not in those with RVD. Multivariate logistic regression revealed that SaO 2 is an independent determinant of RVD at HA (odds ratio: 0.72, 95% CI: 0.56-0.92; P = 0.009). However, the mean pulmonary artery pressure was linearly correlated with the magnitude of RVD in the presence of Notch. No changes were found in RV fractional area change, tricuspid annular motion, or tricuspid s' velocity between subjects with and without RVD. Collectively, we demonstrated for the first time that HA exposure could induce RVD in healthy subjects, which may be mainly attributed to the decline in SaO 2 as well as RV overload; the incidence of RVD was associated with reduced RV regional function and blunted myocardial acceleration.
Hypertension is proved to be associated with severity and mortality in coronavirus disease 2019 (COVID‐19). However, little is known about the effects of pre‐admission and/or in‐hospital antihypertension treatments on clinical outcomes. Thus, this study aimed to investigate the association between in‐hospital blood pressure (BP) control and COVID‐19–related outcomes and to compare the effects of different antihypertension treatments. This study included 2864 COVID‐19 patients and 1628 were hypertensive. Patients were grouped according to their BP during hospitalization and records of medication application. Patients with higher BP showed worse cardiac and renal functions and clinical outcomes. After adjustment, subjects with pre‐admission usage of renin‐angiotensin‐aldosterone system (RAAS) inhibitors (HR = 0.35, 95%CI 0.14‐0.86, P = .022) had a lower risk of adverse clinical outcomes, including death, acute respiratory distress syndrome, respiratory failure, septic shock, mechanical ventilation, and intensive care unit admission. Particularly, hypertension patients receiving RAAS inhibitor treatment either before (HR = 0.35, 95%CI 0.13‐0.97, P = .043) or after (HR = 0.18, 95%CI 0.04‐0.86, P = .031) admission showed a significantly lower risk of adverse clinical outcomes than those receiving application of other antihypertensive medicines. Furthermore, consecutive application of RAAS inhibitors in COVID‐19 patients with hypertension showed better clinical outcomes (HR = 0.10, 95%CI 0.01‐0.83, P = .033) than non‐RAAS inhibitors users. We revealed that COVID‐19 patients with poor BP control during hospitalization had worse clinical outcomes. Compared with other antihypertension medicines, RAAS inhibitors were beneficial for improving clinical outcomes in COVID‐19 patients with hypertension. Our findings provide direct evidence to support the administration of RAAS inhibitors to COVID‐19 patients with hypertension before and after admission.
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