Chapter 2 · MCQ Read Mode

Biomaterials

Biocompatibility is best defined as the ability of a material to:

A material that forms a direct chemical bond with bone tissue is described as:

The direct structural and functional connection between living bone and the surface of a load-bearing implant is called:

Which surface analysis technique provides elemental composition together with the chemical bonding state of the outermost few nanometres?

A low water contact angle on a biomaterial surface indicates that the surface is:

The technique that gives three-dimensional surface topography at nanometre resolution and can operate in liquid is:

Which of the following is the principal disadvantage of ceramics as load-bearing biomaterials?

The mismatch in elastic modulus between a metallic implant and bone leads to:

Which class of biomaterial carries the specific risk of disease transmission and batch-to-batch variability?

Surface analysis is emphasised over bulk analysis in biomaterials because:

The series of international standards governing the biological evaluation of medical devices is:

A limitation common to most electron- and ion-based surface techniques when applied to biomaterials is that they:

Which property would be considered the single most important requirement for a material used in a blood-contacting catheter?

The letter L in 316L stainless steel indicates:

Which implant alloy has an elastic modulus closest to that of cortical bone?

The corrosion resistance of titanium implants is due to:

Placing a stainless steel bone plate with titanium screws risks:

Corrosion occurring in the oxygen-depleted, acidified space beneath a screw head is called:

Nitinol is used in self-expanding stents because of its:

In the collagen triple helix, which amino acid must occupy every third position?

A deficiency of vitamin C weakens collagen because vitamin C is required for:

The collagen type found predominantly in hyaline cartilage is:

Glutaraldehyde crosslinking of a bioprosthetic heart valve improves durability but has the drawback of:

Which glycosaminoglycan is non-sulphated and is not covalently attached to a protein core?

The ability of articular cartilage to resist compressive load derives principally from:

Heparin is used to coat blood-contacting devices because it:

The polymer used as the bearing surface in total hip and knee replacements is:

Polymethyl methacrylate bone cement presents which particular hazard during implantation?

Which polymer degrades in vivo by hydrolysis and is therefore used for resorbable sutures and fixation pins?

The glass transition temperature is important in selecting a medical polymer because it determines:

Expanded PTFE is preferred to solid PTFE for vascular grafts because it:

Ceramics are described by Weibull statistics rather than a single strength value because:

The Ca/P molar ratio of stoichiometric hydroxyapatite is:

Bioglass 45S5 bonds to bone because in body fluid it:

Which material is used for the leaflets and components of mechanical heart valves because of its thromboresistance and wear resistance?

Zirconia is tougher than alumina principally because of:

For a unidirectional fibre composite loaded along the fibre direction, the modulus is given by:

Increasing the filler content of a dental restorative composite principally serves to:

A carbon-fibre-reinforced PEEK bone plate is attractive compared with a stainless steel plate because it is:

The principal purpose of surface modification of a biomaterial is to:

A plasma is best described as:

In a cold (non-thermal) plasma:

Treating a polymer surface with an oxygen plasma generally:

A plasma using a fluorine-containing gas such as CF4 is used to make a surface:

The loss of hydrophilicity of a plasma-treated polymer surface over the following days is called:

Hydroxyapatite is most commonly applied to a titanium hip stem by:

Ion implantation is attractive as a surface treatment because it:

Which surface property would be deliberately maximised for the porous region of a cementless hip stem?

Grafting polyethylene glycol chains onto a device surface is done principally to:

Plasma-enhanced chemical vapour deposition is preferred to conventional CVD for polymer substrates because it:

A practical limitation shared by most plasma surface treatments is that they:

A silane coupling agent is used to:

The tripeptide sequence most widely grafted onto biomaterial surfaces to promote cell adhesion is:

Which immobilization method is the simplest and mildest but suffers from leaching of the biomolecule?

Covalent immobilization of an enzyme has the principal disadvantage that:

Entrapping cells in calcium alginate beads has which main limitation?

Microencapsulation of pancreatic islet cells in a semipermeable membrane is designed to:

The binding pair most commonly exploited for orientated affinity immobilization is:

A polyethylene glycol spacer arm is introduced between a support and an immobilized enzyme in order to:

In a classic glucose biosensor, the immobilized biological recognition element is:

Which support material is essential when the transducer of a biosensor is electrochemical?

Crosslinking enzymes to one another with glutaraldehyde without a support has the drawback of:

The main reason for immobilizing heparin on the surface of a dialysis membrane is to:

Correct orientation is particularly critical when immobilizing an antibody because:

Compared with releasing a growth factor into the tissue, immobilizing it on a scaffold offers the advantage of:

The very first event to occur when a biomaterial is implanted in tissue is:

The Vroman effect describes the:

Which adsorbed plasma protein most strongly promotes platelet adhesion to a device surface?

The histological hallmark of the foreign body reaction is the presence of:

A thick fibrous capsule around an implanted glucose sensor is a problem chiefly because it:

Late aseptic loosening of a total hip replacement is most often caused by:

Healthy vascular endothelium resists thrombosis partly by secreting:

Cells attach to the extracellular matrix and to RGD-modified surfaces through receptors called:

Regenerated cellulose haemodialysis membranes were largely abandoned because they:

Phosphorylcholine coatings improve blood compatibility because they:

The concept that host tissue cells and bacteria compete to colonise an implant surface is known as:

Bacteria within a mature biofilm are difficult to eradicate mainly because:

The organism most classically associated with biofilm infection of catheters and prosthetic devices is:

How many NOT gates are required to build a 2:1 Multiplexer?

How many 2-input NAND gates are contained in a standard 7400 TTL IC?

In TTL logic, what is the input voltage range for a logic LOW (active LOW level)?

When an invalid BCD code (1010–1111) is detected and auto-corrected, what value is added?

What is the terminal (reset) state of a MOD-10 (decade) counter?

What is the minimum number of flip-flops (memory blocks) required to build a MOD-6 ripple counter?

An SR flip-flop is also called a:

A JK flip-flop with J = 1 and K = 1 is clocked at 20 kHz. What is the output waveform and its frequency?

What is the duty cycle of an ideal astable multivibrator?

Which of the following is NOT a valid operation of flip-flops?

The TRAP interrupt in 8085 microprocessor is:

Small-Scale Integration (SSI) refers to ICs with how many transistors?

In VHDL, a signal that represents a bus (multi-bit connection) is declared as:

In VHDL, the primary design unit that represents a hardware block's interface (ports and generics) is called:

The shadow mask technique is used in:

Left-shifting an unsigned binary number by 1 bit is equivalent to:

The expression x << 3 is equivalent to:

Which logic gate is commonly used for parity checking and overflow detection?