introduction: addiction is a habit or behavior that is often hard to quit. it is estimated that 190 million persons are substance users around the world. substance abuse creates tolerance after a while. shortly after taking the drug, a person will not enjoy as the beginning of its use that is why the amount of substance used is gradually increased. the purpose of this study was to find the reas...

background: since the treatments of long tracheal leisions are associated with some limitations, tissue enginered trachea is considered as an alternative option. this study aimed at preparing a composite scaffold, based on natural and synthetic materials for tracheal tissue engineering. methods: nine chitosan silk-based scaffolds were fabricated using three freezing rates (0.5, 1, and 2°c/min) ...

T he practice of therapeutic drug substitution has become common throughout the United States, often without the awareness of many physicians. It occurs to some extent in more than 52% of the nation’s acute care hospitals and more than 30% of health maintenance organizations (HMOs) (1, 2). Therapeutic substitution entails dispensing a drug different in chemical structure from the one originally...

The “evidence” is evidence-based medicine, which defines therapeutic efficacy and safety for specific pharmacological interventions. The “weight” or power of evidence in support of treatment is maximum when determined by large, placebo-controlled, randomized trials (Level A), less definite when based on smaller randomized trials and/or clinical registries (Level B), and least reliable when depe...