During a public health crisis such as the current COVID-19 pandemic, governments and health authorities need quick and accurate methods of communicating with the public. While social media can serve as a useful tool for effective communication during disease outbreaks, few studies have elucidated how these platforms are used by the Ministry of Health (MOH) during disease outbreaks in Saudi Arabia. Guided by the Crisis and Emergency Risk Communication model, this study aimed to explore the MOH's use of Twitter and the public's engagement during different stages of the COVID-19 pandemic in Saudi Arabia. Tweets and corresponding likes and retweets were extracted from the official Twitter account of the MOH in Saudi Arabia for the period of January 1 through August 31, 2020. Tweets related to COVID-19 were identified; subsequently, content analysis was performed, in which tweets were coded for the following message types risk messages, warnings, preparations, uncertainty reduction, efficacy, reassurance, anfor information. This, in turn, could raise public awareness regarding disease outbreaks.Epigenetics concerns gene regulatory mechanisms beyond DNA sequence，such as DNA methylation，histone modification，chromatin remodeling，and non-coding RNA. Epigenetic mechanisms play a key role in development，cell fate decision and tumorigenesis. Chromatin modifications and its high order structure across our genome are major forms of epigenetic information，and its establishment and maintenance are closely related to cell metabolism. Metabolic changes in cancer cells include aerobic glycolysis，increased glucose uptake，abnormally active glutamine metabolism，and the use of non-conventional energy supply. These changes meet the vigorous energy and matter needs for the development and spread of cancer，and help tumor cells adapt to hypoxia microenvironment for their survival，proliferation，invasion and migration. There is a complex relationship between epigenetic modifications and cell metabolism in tumor. On the one hand，metabolites in tumor cells may act as cofactors，modification donors or antagonists of epigenetic enzymes，thus modulating the epigenetic landscape. On the other hand，epigenetic modifications can directly regulate the expression of metabolic enzymes，transporters，signaling pathway and transcription factors to affect cell metabolism. This article reviews the crosstalk between epigenetics and cancer metabolism，to explore their potential future applications in the treatment of tumors.To explore early prevention and control of coronavirus disease 2019 （COVID-19） outbreak based on system dynamics model analysis. The data of early outbreak of COVID-19 were collected from the World Health Organization，covering countries of the China，United States，United Kingdom，Australia，Serbia and Italy. The susceptible-exposed-infected-recovered （SEIR） model was generalized and then its parameters were optimized. According to the parameters in the basic infection number expression，the sensitivity in the system dynamics model was used to quantitatively analyze the influence of the protection rate，infection rate and average quarantine time on the early spread of the outbreak. Based on the analysis results，targeted prevention and control measures for the early outbreak of COVID-19 were proposed. The generalized SEIR model had a good fit for the early prediction and evaluation of COVID-19 outbreaks in six countries. The spread of COVID-19 was mainly affected by the protection rate，infection rate and average quarantine time. The improvement of the protection rate in the first ays was the most importantthe greater the protection rate，the fewer the number of confirmed cases. The infection rate in the first 5 days was the most criticalthe smaller the infection rate，the fewer the number of confirmed cases. The average quarantine time in the first 5 days was very importantthe shorter the average quarantine time，the fewer the number of confirmed cases. Through the comparison of key parameters of six countries，Australia and China had implemented strict epidemic prevention policies，which had resulted in good epidemic prevention effects. In the early stage of the outbreak，it is necessary to improve the protection rate，shorten the average quarantine time，and implement strict isolation policies to curb the spread of COVID-19.Cholesterol is an important lipid in the body of mammals and an essential component of membrane structures. Cholesterol homeostasis is critical for the maintenance of cellular and body activities, and is mainly regulated by the balance of cholesterol biosynthesis and the exogenous cholesterol uptake. Aberrantly regulated cholesterol metabolism promotes tumor cell proliferation，survival，invasion and metastasis，and their adaptability into the tumor microenvironment. Therefore，targeting cholesterol biosynthesis and reduction of plasma cholesterol levels and cholesterol esterification will provide new strategies for cancer treatment. This review summarizes the current understanding in cholesterol homeostasis regulation and its function in the occurence and development of cancer，as well as current metabolism-targeted cancer treatments.To establish and verify a risk prediction nomogram for ipsilateral axillary lymph node metastasis in breast cancer stage T1 （mass ≤ 2 cm）. find more The clinicopathological data of 907 patients with T1 breast cancer who underwent surgical treatment from January 2010 to June 2015 were collected，including 573 cases from the Second Affiliated Hospital of Zhejiang University School of Medicine （modeling group） and 334 cases from Zhejiang University Lishui Hospital （verification group）. The risk factors of ipsilateral axillary lymph node metastasis were analyzed by univariate and multivariate logistic regression. The influencing factors were used to establish a nomogram for predicting ipsilateral axillary lymph nodes metastasis in T1 breast cancer. The model calibration，predictive ability and clinical benefit in the modeling group and the verification group were analyzed by C index，receiver operating characteristic curve，calibration curve and decision curve analysis （DCA） curve，respectively. Univariate analysis showed that lymph node metastasis was related with primary tumor size，vascular tumor thrombus，Ki-67，histopathological grade，and molecular type （ vascular tumor thrombus，Ki-67 positive，estrogen receptor （ER） positive，and histopathological grade 2-3 were independent risk factors of axillary lymph node metastasis （ less then 0.