Check if a file is a directory in Matlab, before 2018a

The new Matlab versions starting in 2018 rolled out a functioo called isfolder(filename), which is quite handy. But if you're using a version of Matlab before 2018a, you can still easily accomplish this task with the following code: exist(filename,'dir')==7 How does it work? Here, we are telling the exist function to look for the specified filename, and… Read More »

Share

How do CD4 T cells activate CD8 T cells?

CD4 T cells activate CD8 T cells through an indirect process involving an antigen presenting cell (APC), normally a conventional dendritic cell (DC). An APC presents a peptide to a naive CD4 T cell via a Class II MHC molecule. The CD4 T cell becomes active and differentiates into a T helper 1 (Th1) cell… Read More »

Share

How are immune cells activated?

The most important immune cells for adaptive immunity are the lymphocytes. T cells An antigen presenting cell (APC), such as a dendritic cell, binds an a peptide from a pathogen on either a pattern recognition receptor (PRR), a complement receptor (CR), or a Fc antibody receptor (FcR). It can also uptake a pathogen through macropinocytosis.… Read More »

Share

How is a virus attenuated?

How is a virus attenuated? An attenuated virus is a form of virus that is genetically altered so that it is no longer pathogenic to humans. However, the immune system can produce defense against it. This defense is then sufficient to ward off the real, live virus if we ever become infected. First techniques of… Read More »

Share

Mature naive vs mature effector lymphocyte

The terminology "mature naive" and "mature effector" lymphocytes refers to the stage in maturation that the lymphocyte is currently undergoing. Lymphocyte maturation can be split into initial and final maturation. Initial maturation occurs in primary lymphatic organs (eg, bone and thymus) and final maturation occurs in secondary lymphatic organs (eg, lymph nodes). Mature naive lymphocytes… Read More »

Share

Red Pulp vs White Pulp in the Spleen

The spleen functions to filter our blood through a unique system of open circulation. It monitors the blood for foreign antigens and is also involved in red blood cell quality control, since phagocytes in the spleen consume red blood cells as they try to escape into open circulation through arterial capillaries. White pulp is lymphatic… Read More »

Share

Getting ahead before starting Med School

If you just got accepted to Med School and you're wondering what you can do in those last few months to get ahead before school starts, you're not alone. There's an overwhelming urge sometimes to panic if you're headed for Med School, but first step: don't! Firstly, ask yourself if you really want to get… Read More »

Share

The fascinating science of Calico cats

Just like humans, all animals have DNA, the information-code of life. Almost all the DNA between any two individuals is identical. However, in the case of male vs. female, there are some larger differences. DNA is organized into chromosomes, and females have two X chromosomes whereas males have one X chromosome and one Y chromosome.… Read More »

Share

How to know if you have Pectus Excavatum

Pectus Excavatum presents as a deformity of the sternum inwards (i.e., funnel chest) and is usually easily noticed by visual inspection. The severity of the Pectus varies widely among patients. Severity is normally defined by the Haller index, which is the ratio of the width of your chest to the distance between the deepest part… Read More »

Share

Drugs and the Brain

Notes adapted from the Coursera course titled "Drugs and the Brain" taught by Dr. Lester from Caltech. 1-4: Drug Entry into the Nervous System Nicotine passes through 3 cell types and 6 cell membranes in under a few seconds. After being puffed in, it passes through alveolar epithelium cells, then it passes through two types… Read More »

Share