Mediating Role of Perceived Stress in the Relationship between Facing Existential Issues and Symptoms of Depression and Anxiety.

Objective: This study aimed at investigating the mediating role of perceived stress in anticipation of anxiety and depression on facing the ultimate concerns (death, loneliness, freedom, and meaningfulness). Method : A total of 389 students from Ferdowsi University of Mashhad participated in this study in 2017-18. The participants were selected using random sampling. The data were collected using the subscales of anxiety and depression in depression, anxiety, stress scale (DASS), Death Anxiety Scale (DAS), the third edition of Loneliness Scale UCLA (UCLA-LS), the subscale of meaning in life in Meaningfulness of Life Questionnaire (MLQ), responsibility scale of California Psychological Inventory (CPI), and the Perceived Stress Scale (PSS). Then, they were evaluated using Pearson correlation and path analysis. Results: The correlation between the symptoms of anxiety and depression, and death anxiety and loneliness was direct and significant with the perceived stress. The relationship between the perceived stress with meaningfulness of life and responsibility was significantly inverse. The analysis of the data path showed that the component dealing with existence (loneliness and death anxiety) predicted 20% of anxiety symptoms through perceived stress in the model that was fitted well with research data. Conclusion: According to the findings, it can be concluded that the relationship between dealing with ultimate concerns and anxiety symptoms was not linear. Dealing with ultimate concerns affects the anxiety symptoms through the perceived stress. Therefore, attention to the perceived stress management to promote health and prevent anxiety disorders is important.

Use of single chain antibody derivatives for targeted drug delivery.

Single chain antibodies (scFvs), which contain only the variable domains of full-length antibodies, are relatively small molecules that can be used for selective drug delivery. In this review, we display how scFv antibodies help improve the specificity and efficiency of drugs. Small interfering RNA (siRNA) delivery using scFv-drug fusion peptides, siRNA delivery using scFv-conjugated nanoparticles, targeted delivery using scFv-viral peptide- fusion proteins, use of scFv in fusion with cell penetrating peptides for effective targeted drug delivery, scFv-mediated targeted delivery of inorganic nanoparticles, scFv-mediated increase of tumor killing activity of granulocytes, use of scFv for tumor imaging, site-directed conjugation of scFv molecules to drug carrier systems, use of scFv to relieve pain, use of scFv for increasing drug loading efficiency are among the topics that are discussed here.