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HIV Infection: Viral life cycle

By: HWC, Views: 8704

The series of steps that HIV follows to multiply in the body. The process begins when HIV encounters a CD4 cell. The seven steps in the HIV life cycle are: 1) binding; 2) fusion; 3) reverse transcription; 4) integration; 5) replication; 6) assembly; and 7) budding. Many viruses f...

Cognitive development by Piaget (Preoperational stage or intelligence)

By: HWC, Views: 8504

The next stage of cognitive development proposed by Piaget, is the preoperational stage, roughly between the ages of 2 and 7. At this stage Piaget asserted that a child has what he called preoperational intelligence. hey can mentally representing objects, but do not have a system for organising...

Introduction to Photolithography - WC, BLF, PA, Hard and Soft baking

By: HWC, Views: 8863

Prior to use, wafers are chemically cleaned to remove particulate matter on the surface as well as any traces of organic, ionic, and metallic impurities. Barrier Layer Formation After cleaning, the silicon wafer is covered with the material which will serve as a barrier layer. The most commo...

Double Vacuum Process (Illustration No Audio)

By: HWC, Views: 8479

In this so-called low-pressure process, the wood is first subjected to a short and relatively weak initial vacuum, after which the treatment vessel is flooded with preservative solution and reduced to normal pressure The double vacuum container is loaded with timber. A partial vacuum is draw...

Cellular Defects - Osteoblasts, Osteoclasts and Osteocytes

By: HWC, Views: 8970

■ Metabolically active bone-building cells that secrete astroid. ■ Cover surfaces of newly formed bone and respond to growth stimuli ■ Less responsive to growth factors as the body ages. ■ Contribute to hone loss once their reproductive and biosynthetic potential lessens....

A timeline of the teeth (Explained - No Audio)

By: HWC, Views: 8261

Although most babies don't appear to have any teeth when they are born, they are in fact already well developed out of sight beneath the gum. The first molars erupt at about 12-14 months. The canines follow at about 16-18 months . By 3 years old, the second molars have usually erupted, c...

Oral Hygiene & Braces Animation

By: HWC, Views: 8814

Caring for Your Retainer Retainers, just like your teeth collect plaque, bacteria and food particles. You should clean your retainer everyday! Keep your retainer soaking when it is not in your mouth. Use a mouthwash rinse to freshen it up and keep it free of bacteria. Keep your retainer away fr...

Stages of Mitosis - Prophase, Prometaphase, Metaphase, Anaphase & Telophase

By: HWC, Views: 9097

In mitosis, the nucleus divides to produce two nuclei that are genetically identical to each other and to the parent nucleus. To prepare for division, the DNA replicates in the preceding interphase. Although the chromosomes are not yet compacted and visible as discrete bodies, we illustrate them ...

DNA Sequences - Dideoxy Sequencing

By: HWC, Views: 8661

A short, radiolabeled primer is annealed to the single-stranded DNA to be sequenced. The DNA serves as a template for in vitro DNA synthesis. The DNA-primer mixture is split into four separate tubes. DNA polymerase and a solution of dNTPs are added to each tube. One of the four 2',3' dideoxy-N...