作为新皮层扩张的驱动因素的基底原始体

Laminins are heterotrimeric proteins with high molecular mass found in the extracellular matrix. Each laminin molecule is composed of three chains, viz. alpha, beta, and gamma, coded by five, four, and three paralogous genes, respectively. Laminins are categories based on the compositions of the three chains.
In humans, the five forms of alpha chains are LAMA 1, LAMA 2, LAMA 3, LAMA 4, and LAMA 5. The four forms of beta chains are LAMB 1, LAMB 2, LAMB 3, and LAMB 4. The three forms of gamma...

The work done by a thermodynamic system depends not only on the initial and final states but also on the intermediate states—that is, on the path. Like work, when heat is added to a thermodynamic system, it undergoes a change of state, and the state attained depends on the path from the initial state to the final state. Consider an ideal gas cylinder fitted with a piston. When the cylinder is heated at a constant temperature, the gas molecules absorb energy and expand slowly in a...

The basal lamina is a thin extracellular layer that lies underneath the cells and separates them from other tissues. The three layers of the basal lamina are lamina lucida, lamina densa and lamina reticularis. The basal lamina, a mixture of glycoproteins and collagen, provides an attachment site for the epithelium, separating it from underlying connective tissue. The framework of basal lamina has other essential proteins such as laminins mesh, perlecan, entactin, and type IV collagen.
Proteins...

Type IV collagen is a 400 nm long, network-forming collagen that acts as a barrier between the epithelial and endothelial cells. Type IV collagen  forms the backbone of the basement membrane by scaffolding with laminin, entactin, proteoglycans, and fibronectin. Apart from rendering structural support to the basement membrane, it also helps entail signaling potentials necessary for both pathological and physiological functions.
A type IV collagen molecule has six alpha chains which can...

The expansion of alcohol in a thermometer is one of many commonly encountered examples of thermal expansion, which is the change in size or volume of a given system as its temperature changes. The most visible example is the expansion of hot air. When air is heated, it expands and becomes less dense than the surrounding air, which then exerts an upward force on the hot air to, for example, make steam and smoke rise, and hot air balloons float. The same behavior happens in all liquids and gases,...

Expanding a binomial expression such as (a + b)n results in a predictable sequence of terms that can be systematically derived using Pascal’s Triangle. This triangular array of numbers plays a central role in understanding and computing the coefficients of binomial expansions.Pascal’s Triangle is constructed such that each row corresponds to the coefficients of a binomial raised to a power. The topmost row, known as the zeroth row, corresponds to (a + b)0, and each successive row...