High Blast Explosive

High Blast Explosive, or HBX, is an explosive used as a bursting charge in missile warheads, mines, depth bombs, depth charges, and torpedoes.

History

It was developed during WWII as a desensitized modification of Torpex explosives.

Properties

It is an aluminized (powdered aluminum) explosive having the same order of sensitivity as Composition B.

Tests indicate that it will be about 98% to 100% as powerful as Torpex, that it will definitely be less sensitive than Torpex in both Laboratory Impact and Bullet Impact, that it will be slightly more sensitive in these respects than TNT, and that it will be about the same order as Composition B.

A difficulty with HBX is that they produce gas and build up pressure in the case during stowage. It has been discovered that adding calcium chloride to the mixture will absorb all the moisture and eliminate the production of gas.

Composition

There are three types of HBX explosives: HBX-1, HBX-3, and H-6. Below is each type's "Grade A" composition based on weight:

HBx

HBx is a hepatitis B viral protein. It is 154 amino acids long and interferes with transcription, signal transduction, cell cycle progress, protein degradation, apoptosis and chromosomal stability in the host. It forms a heterodimeric complex with its cellular target protein (HBX interacting protein: HBXIP), and this interaction dysregulates centrosome dynamics and mitotic spindle formation. It interacts with DDB1 (Damaged DNA Binding Protein 1) redirecting the ubiquitin ligase activity of the CUL4-DDB1 E3 complexes, which are intimately involved in the intracellular regulation of DNA replication and repair, transcription and signal transduction.

Although Protein X is normally absent in the Avihepadnavirus, a vestigial version has been identified in the duck hepatitis virus genome.

Although it lacks significant sequence identity with any known vertebrate proteins, it seems likely that it evolved from a DNA glycosylase.

Transgenic mice expressing the X protein in liver are more likely than the wild type to develop hepatocellular carcinoma. This is because the X protein promotes cell cycle progression while binding to and inhibiting tumor suppressor protein p53 from performing their role. Experimental observations also suggest that HBx protein increases TERT and telomerase activity, prolonging the lifespan of hepatocytes and contributing to malignant transformation.

HBX (disambiguation)

HBX is an abbreviation for "high blast explosive".

HBX may also refer to: