Onboard spectral calibration and validation of the satellite calibration spectrometer on HY-1C.

To monitor the spectral position drift, expansion and contraction of the full width at half maximum (FWHM) of the satellite calibration spectrometer (SCS) of the HY-1C satellite during on-orbit operation, an onboard spectral calibration method based on a wavelength diffuser is proposed in this paper. This method uses the wavelength diffuser reflectance measured prelaunch as the standard spectrum, convolves it with the spectral response function of the SCS to obtain a reference spectrum, uses the measured data of the onboard SCS as the measured spectrum, and obtains the spectral drift and variation of the FWHM through spectral line matching. Generally, the spectral response function of a hyperspectral remote sensor follows a Gaussian model, and so does that of the SCS. The spectral calibration results obtained based on the onboard wavelength diffuser are validated and evaluated in comparison to calibration based on an oxygen absorption line. Preliminary results show that (1) the SCS spectral drift is negative, indicating a shift in the shortwave direction, and its absolute value is gradually decreasing with increasing on-orbit operation time; (2) the mean values of the central wavelength and FWHM errors between the two calibration methods are 0.08 nm and 0.20 nm, respectively, indicating that the spectral calibration method based on the wavelength diffuser has high accuracy and reliability; and (3) the SCS spaceborne spectral calibration error has the greatest impact on radiometric calibration in Band 18, with an uncertainty of 0.99%, while the uncertainty in the other bands is less than 0.33%, indicating that the spectral calibration uncertainty meets radiometric calibration accuracy requirements.

The Glucagon-Like Peptide-1 Analogue Liraglutide Inhibits Oxidative Stress and Inflammatory Response in the Liver of Rats with Diet-Induced Non-alcoholic Fatty Liver Disease.

Liraglutide, a glucagon-like peptide-1 (GLP-1) analogue, has been demonstrated to reduce hepatic steatosis. However, the mechanism of the lipid-lowering effect of liraglutide in the liver remains unclear. The aim of the present study was to investigate the beneficial effect of liraglutide on diet-induced non-alcoholic fatty liver disease (NAFLD) and the underlying mechanism in rats. NAFLD was induced in Sprague-Dawley rats by feeding a high fat and high cholesterol (HFHC) diet. Liraglutide (0.6 mg/kg body weight/d) was injected intraperitoneally to the rats subjected to HFHC diet four weeks before sacrificing the animals. Body and liver weight, fasting blood glucose (FBG), fasting insulin, serum aminotransferase (ALT) and lipid accumulation in the liver were determined. Markers of oxidative stress, such as malondialdehyde (MDA), free fatty acid (FFAs), superoxide dismutase (SOD), and pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) were detected by colorimetric detection or enzyme-linked immunosorbent assay (ELISA). Serum and hepatic adiponectin were measured by ELISA. The expression of c-Jun N-terminal kinase-1 (JNK-1) and phosphorylated JNK-1 were examined by Western blotting. Liraglutide improved insulin resistance, decreased hepatic steatosis and reversed liver dysfunction. The hepatic levels of MDA, FFAs, and TNF-α were significantly decreased versus controls. Meanwhile, administration of liraglutide significantly increased SOD and adiponectin levels in the liver and inhibited the expression of JNK-1 and phosphorylated JNK-1 versus control rats. Liraglutide exerted anti-oxidative and anti-inflammatory effects in the liver and consequently reversed hepatic steatosis and insulin resistance. Such effects might be mediated by the elevation of adiponectin levels and the inactivation of JNK-1.

Mediation Effects of Coping Styles on Fear of Progression and Reproductive Concerns in Breast Cancer Patients of Reproductive Age.

PURPOSE: This study aimed to investigate reproductive concerns among breast cancer patients of reproductive age, analyze the influencing factors, explore the relationship between coping styles, fear of progression (FOP), and reproductive concerns, and identify the multiple effects of coping styles on the relationship between FOP and reproductive concerns among Chinese breast cancer patients. METHODS: A cross-sectional, descriptive study was conducted among breast cancer patients in four tertiary grade A hospitals in Fujian, China, from January 2022 to September 2022. A total of 210 patients were recruited to complete paper-based questionnaires, which included the general data questionnaires, the Reproductive Concerns After Cancer Scale (RCACS), the Fear of Progression Questionnaire-Short Form (FOP-Q-SF), and the Medical Coping Modes Questionnaire (MCMQ). Structural equation models were utilized to evaluate the multiple effects of coping styles on FOP and reproductive concerns. RESULTS: Reproductive concerns in breast cancer patients had a mean score of 53.02 (SD, 10.69), out of a total score of 90, and coping styles for cancer (confrontation, avoidance) were closely associated with FOP and reproductive concerns. FOP showed a significant positive correlation with reproductive concerns (r = .52, p < .01). At the same time, confrontation was significantly negatively correlated with both FOP (r = -.28, p < .01) and reproductive concerns (r = -.39, p < .01). Avoidance was positively correlated to both FOP (r = .25, p < .01) and reproductive concerns (r = .34, p < .01). The impact of FOP on reproductive concerns is partially mediated by confrontation and avoidance, with effect sizes of .07 and .04, respectively. These mediating factors account for 22.0% of the total effect. CONCLUSIONS: The FOP directly impacted reproductive concerns, while coping styles could partially mediate the association between FOP and reproductive concerns. This study illustrates the role of confrontation and avoidance in alleviating reproductive concerns, suggesting that it is necessary to focus on the changes in reproductive concerns among reproductive-age breast cancer patients. Healthcare professionals can improve disease awareness and reduce patients' FOP, thereby promoting positive psychological and coping behaviors and ultimately alleviating reproductive concerns.

[Effects of glucagon-like peptide-1 on liver oxidative stress, TNF-α and TGF-ß1 in rats with non-alcoholic fatty liver disease].

OBJECTIVE: To investigate the effects of glucagon-like peptide-1 (GLP-1) on liver oxidative stress, TNF-α and TGF-ß1 in rats with diet-induced non-alcoholic fatty liver disease (NAFLD). METHODS: Thirty male rats were randomly divided into 3 equal groups and fed for 16 weeks with normal diet (ND), high-fat diet (HFD), or high-fat diet with intraperitoneal injection of liraglutide (GLP-1, administered in the later 4 weeks). The rats were then sacrificed to obtain blood samples and liver tissues for analyzing the levels of blood aminotransferase (ALT), triglyceride (TG), and total-cholesterol (TC) using an automatic biochemical analyzer and the levels of superoxide dismutase (SOD), malondial-dehyde (MAD), free fatty acid (FFAs), TNF-α in the liver homogenates and TGF-ß1 in serum by radioimmunoassay or ELISA. RESULTS: Compared with ND group, HFD group showed significantly increased body weight, liver index, serum levels of ALT, TG, TC, and TGF-ß1, and TG, TC, MAD, FFAs, and TNF-α in the liver homogenates, with also significantly increased degree of hepatic steatosis and inflammation activity (P<0.05) and lowered level of SOD. All these changes were markedly ameliorated in GLP-1 group (P<0.05). CONCLUSION: Liraglutide can reduce high-fat diet-induced hepatic steatosis, improve oxidative stress and lipid peroxidation, and decrease TGF-ß1 and TNF-α levels in serum and liver homogenates, suggesting its potential as a therapeutic agent for NAFLD.