ABSTRACT
Astragali radix is a traditional medicinal herb with a long history and wide application. It is frequently used in prescriptions with other medicinal materials to replenish Qi. According to the classics of traditional Chinese medicine, Astragali radix is attributed with properties such as Qi replenishing and surface solidifying, sore healing and muscle generating, and inducing diuresis to reduce edema. Modern pharmacological studies have demonstrated that some extracts and active ingredients in Astragali radix function as antioxidants. The polysaccharides, saponins, and flavonoids in Astragali radix offer beneficial effects in preventing and controlling diseases caused by oxidative stress. However, there is still a lack of comprehensive research on the effective components and molecular mechanisms through which Astragali radix exerts antioxidant activity. In this paper, we review the active components with antioxidant effects in Astragali radix; summarize the content, bioavailability, and antioxidant mechanisms; and offer a reference for the clinical application of Astragalus and the future development of novel antioxidants.
Subject(s)
Antioxidants , Astragalus propinquus , Drugs, Chinese Herbal , Antioxidants/pharmacology , Antioxidants/chemistry , Astragalus propinquus/chemistry , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/pharmacology , Humans , Astragalus Plant/chemistry , Oxidative Stress/drug effects , Animals , Flavonoids/chemistry , Flavonoids/pharmacology , Medicine, Chinese Traditional , Saponins/pharmacology , Saponins/chemistryABSTRACT
Vertical tanks are commonly used appliances for liquids, and its capacity is very important for quantitative liquid ratio and liquid trade. In order to measure the capacity of vertical tanks more conveniently, this paper proposes a vertical tank capacity measurement method based on Monte Carlo Method. The method arranges a plurality of sensor points on the inner surface of the tank, and then performs Monte Carlo tests by generating a large number of random sample points, and finally calculates the capacity by counting the sample points that meet the criterion. The criterion for whether a sample point is located in the tank, which is the core issue, is established with the coordinates of sensor points and the distance between different sensor points along the surface of the tank. The results show that the absolute error of the measurement results of the proposed method does not exceed ±0.0003[m3], and the absolute error of capacity per unit volume has a linear relationship with the height of the vertical tank, and has little effect with the radial size of the vertical tank.
Subject(s)
Forecasting/methods , Dimensional Measurement Accuracy , Models, Theoretical , Monte Carlo Method , Weights and MeasuresABSTRACT
OBJECTIVE: This systematic review aims to investigate and synthesize qualitative evidence related to midwifery students' perceptions and experiences of learning in clinical practice. INTRODUCTION: Midwifery students are required to develop strong competencies during pre-registration education for future practice. Clinical placements provide a good opportunity for students to build essential practice capacities. Understanding the perceptions and experiences of midwifery students in clinical practice helps develop effective midwifery clinical educational strategies. A qualitative systematic review is therefore proposed to improve midwifery clinical education. INCLUSION CRITERIA: This proposed review will consider qualitative studies that have explored midwifery students' perceptions and experiences of learning in clinical practice in all degrees. The search will be limited to English-language published and unpublished studies to the present. METHODS: This review will follow the JBI approach for qualitative systematic reviews. A three-stage search will be conducted to include published and unpublished literature. Databases to be searched include PubMed, Science Direct, Web of Science, CINAHL, PsycINFO, American Nurses Association, Google Scholar, ProQuest Dissertation & Theses, and Index to Theses in Great Britain and Ireland. Identified studies will be screened for inclusion in the review by two independent reviewers. Any disagreements will be resolved through discussion. Data will be extracted using a standardized tool. Data synthesis will adhere to the meta-aggregative approach to categorize findings. The categories will be synthesized into a set of findings that can be used to inform midwifery education. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO CRD42020208189.
