In this study, we followed the guidelines for systematic review and meta-analysis. We searched the foreign language database by computer: PubMed (, Web of Science (, Embase (, the Cochrane Library ( Chinese database: CNKI (, WanFang Data (, SinoMed ( The system of literature retrieval was carried out, and the search databases were published from the database to October 1, 2020. The randomized controlled study of nicorandil in the treatment of microvascular angina. The search language is limited to Chinese and English. Chinese literature search terms: nicorandil, microvascular angina, cardiac X syndrome, etc. The steps of English literature retrieval are as follows: search subject words (the key words designated by the official database) + free words (referring to the key words formulated by ourselves). Taking PubMed database as an example (Table (Table11).

Retrieval strategy of PubMed database by MeSH terms and keywords.

Note: The content above has been extracted from a research article, so it may not display correctly.

Please log in to submit your questions online.
Your question will be posted on the Bio-101 website. We will send your questions to the authors of this protocol and Bio-protocol community members who are experienced with this method. you will be informed using the email address associated with your Bio-protocol account.

We use cookies on this site to enhance your user experience. By using our website, you are agreeing to allow the storage of cookies on your computer.