自然杀伤（NK）细胞毒性

The D-value is the time required at a specific temperature to kill 90% (or one log reduction) of a target microorganism population. It is a critical parameter in thermal sterilization, quantifying a microbe's resistance to heat. For example, if a population of [latex]10^6[/latex] spores has a D-value of 2 minutes, it takes 2 minutes to reduce it to [latex]10^5[/latex].

一种使用环氧乙烷气体的低温化学灭菌方法。该方法可有效灭菌塑料、电子设备和光学仪器等热敏性和湿敏性材料。该过程涉及烷基化，其中环氧乙烷会破坏微生物的DNA和蛋白质，从而阻止其复制。该方法需要严格控制气体浓度、温度、湿度和暴露时间。

细胞毒性是指物质或细胞对其他细胞具有毒性的特性。细胞毒性药物可通过坏死（细胞膜失去完整性，导致细胞溶解和炎症）或凋亡（一种受控的程序性细胞死亡过程）诱导细胞死亡。这与细胞抑制剂不同，细胞抑制剂仅抑制细胞分裂，而不会直接导致细胞死亡。

Biomimicry is an innovation approach that seeks sustainable solutions to human challenges by emulating nature's time-tested patterns and strategies. The core idea is that nature, through 3.8 billion years of evolution, has already solved many of the problems we are grappling with. It involves observing and learning from the designs and processes of organisms and ecosystems to create more sustainable designs.

Overpotential is the potential difference (voltage) between a half-reaction's thermodynamically determined reduction potential and the potential at which the redox event is experimentally observed. It represents the extra energy required to overcome activation barriers for the electrode reaction to proceed at a significant rate. It is a key factor in the energy efficiency of all electrolytic processes.

Cellular respiration is a series of redox reactions where organic molecules, like glucose, are oxidized to release energy. Glucose ([latex]C_6H_{12}O_6[/latex]) is oxidized to [latex]CO_2[/latex], while oxygen ([latex]O_2[/latex]) is reduced to water ([latex]H_2O[/latex]). This process transfers electrons through an electron transport chain, creating a proton gradient that drives the synthesis of ATP, the cell's primary energy currency.

Electrochemical potential is fundamental to life, driving processes across cell membranes. Ion pumps actively create concentration gradients, while the selective permeability of ion channels establishes an electrical potential (membrane potential). The resulting electrochemical gradient dictates the passive flow of ions, which is crucial for nerve signaling (action potentials), muscle contraction, and cellular energy production (ATP synthesis) in mitochondria.

SAL is a quantitative measure representing the probability of a single viable microorganism surviving on an item after sterilization. A commonly required SAL for medical devices is [latex]10^{-6}[/latex], meaning a one-in-a-million chance of a non-sterile unit. This probabilistic approach acknowledges that absolute sterility cannot be proven, only inferred statistically from process validation.

MTT 测定法是一种用于评估细胞代谢活性的比色法，可作为细胞活力、增殖和细胞毒性的指标。具有活性线粒体的活细胞含有还原酶，可将黄色四唑盐 MTT（3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四唑溴化物）转化为不溶性紫色甲臜。甲臜的生成量与活细胞数量成正比。