A series of shape memory polyurethanes (SPU) with different component ratio of PEG, MDI, BDO, and crosslinker DEA were synthesized by stepwise polymerization in DMF. WAXD, SAXS, DMTA, and DTA were used to study the microphase structure of SPU. No obvious phase-separation and crystalline evidence of the PEG soft segment and hard segment were obtained in this work. The water-swollen ratio increases with both the increasing molecular weight of PEG soft segment and the decreasing density of the chemical crossbonding. All the samples show good thermally stimulated shape memory properties. When the molar ratio of soft segment to hard segment is close, the shape recovery time reduces along with the increasing density of the chemical crossbonding. When the densities of the chemical crossbonding are similar, the shape recovery time reduces with the increasing molecular weight of the PEG soft segment.
A series of polyacrylate-polyurethane networks (PUA) were synthesized and their pH-sensitive behaviors were studied. An unexpected swelling-deswelling behavior was observed as the composition changed. Dynamic mechanical thermal analysis and differential scanning calorimetry were used to initially explain this phenomenon. By applying small-angle X-ray scattering and wide-angle X-ray diffraction simultaneously, a specific multiphase-transition process could be clearly detected, which made the mechanism of the observed abnormal pH sensitivity more explicit.
Objective. To investigate the prevalence of anxiety and depression in hospitalized patients in the Department of Gastroenterology and to explore the risk factors affecting psychosomatic conditions in patients with digestive disorders. Methods. Patients hospitalized with gastrointestinal diseases were enrolled by the Department of Gastroenterology of Xiangya Hospital of Central South University from November 2017 to June 2018 and completed a cross-sectional questionnaire survey. According to anxiety/nonanxiety, depression/nondepression, the subjects were divided into two groups, respectively, and the risk factors of anxiety/depression were analyzed. Results. A total of 1186 patients were included in this study. The overall detection rate was 20.74% for anxiety symptoms alone, 31.78% for depressive symptoms alone, 13.99% for both anxiety and depressive symptoms, and 38.53% for either depression or anxiety symptoms. The prevalence of anxiety symptoms was higher in female than in male patients and inversely correlated with levels of education. There was no significant difference in the detection rate of anxiety and depression between patients with functional and organic digestive diseases. Sleep quality and quality of life were inversely correlated with the severity of anxiety and depression. Notably, among the patients with abnormal psychological conditions, only 7.6% of them were willing to receive psychological treatment. Gender, sleep quality, and life quality are independent risk factors for anxiety and depression symptoms for inpatients with gastrointestinal diseases. Conclusion. Paying more attention to the education level, sleep quality, and quality of life in patients with gastrointestinal diseases will help doctors to identify the risk of psychological abnormalities and improve medical care.
Cardiovascular disease (CVD), a leading cause of morbidity and mortality, is among the most prevalent health problems worldwide and effective strategies for its prevention and treatment are urgently required. In this regard, increasing research has demonstrated that natural drugs offer antihypertensive, antiatherosclerotic, and cardioprotective activities, and many are applied widely for the treatment of CVD and its manifestations such as myocardial infarction, peripheral vascular diseases, and coronary heart disease. Natural drugs have significant advantages in the treatment of CVD due to their efficacy and safety profiles. Saponins are an important class of active components of plant natural products and play an important role in the treatment of CVD. This review covers the most up-to-date information on saponins concerning their cardioprotective effects and mechanisms of action.
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