Phase 0

phase

[fāz] 1. one of the aspects or stages through which a varying entity may pass.2. In physical chemistry, any physically or chemically distinct, homogeneous, and mechanically separable part of a system.phase 0 in cardiac physiology, the phase representing the upstroke of the action potential, in which rapid depolarization occurs after the cell reaches or is driven to potential" >threshold potential. It is the result of the opening of fast channels" >sodium channels and channels" >calcium channels.phase 1 in cardiac physiology, the initial rapid repolarization phase of the action potential, caused by the closure of the fast channels" >sodium channels and an exodus of potassium from the cell.phase 2 in cardiac physiology, the phase representing the plateau of the action potential, which contributes to the period" >refractory period of the heart; there is a slow entry of calcium into the cell. It is the result of a balance between inward and outward currents and is particularly long in Purkinje and ventricular cells.phase 3 in cardiac physiology, the terminal rapid repolarization phase of the action potential; it begins with the closing of the slow channels, resulting in an exodus of potassium from the cell and the activation of the pump" >sodium-potassium pump. The result is reestablishment of the normal potential" >resting potential.phase 4 in cardiac physiology, the phase representing electrical diastole, i.e. the time between action potentials. It is the resting phase of the electrical cardiac cycle and is steadily maintained in nonpacemaker cells. In pacemaker cells, the potential" >membrane potential is normally reduced slowly until potential" >threshold potential is reached; if there is an outside stimulus, it may be driven down more rapidly.continuous phase in a heterogeneous system, the component in which the disperse phase is distributed, corresponding to the solvent in a true solution. See also colloid.disperse phase the discontinuous portion of a heterogeneous system, corresponding to the solute in a true solution.G₁ phase a part of the cycle" >cell cycle during interphase, lasting from the end of cell division (the M phase) until the start of DNA synthesis (the S phase).G₂ phase a relatively quiescent part of the cycle" >cell cycle during interphase, lasting from the end of DNA synthesis (the S phase) until the start of cell division (the M phase).M phase the part of the cycle" >cell cycle during which mitosis occurs; subdivided into prophase, metaphase, anaphase, and telophase.S phase a part of the cycle" >cell cycle near the end of interphase, during which DNA is synthesized; it comes between the G₁ and G₂ phases.

Phase 0

A trial that evaluates a small number of healthy volunteer subjects, which is conducted before Phase-1 trials and is intended to assess new candidate therapeutic and imaging agents. The study agent is administered at a low dose for a limited time, or not at all, if exploration of human material for the study (e.g., tissue samples or biomarker determinations) is of interest to the investigators. In Phase 0, there is no therapeutic or diagnostic intent.

单词	phase 0
释义	DictionarySeephase Phase 0 phase [fāz] 1. one of the aspects or stages through which a varying entity may pass.2. In physical chemistry, any physically or chemically distinct, homogeneous, and mechanically separable part of a system.phase 0 in cardiac physiology, the phase representing the upstroke of the action potential, in which rapid depolarization occurs after the cell reaches or is driven to potential" >threshold potential. It is the result of the opening of fast channels" >sodium channels and channels" >calcium channels.phase 1 in cardiac physiology, the initial rapid repolarization phase of the action potential, caused by the closure of the fast channels" >sodium channels and an exodus of potassium from the cell.phase 2 in cardiac physiology, the phase representing the plateau of the action potential, which contributes to the period" >refractory period of the heart; there is a slow entry of calcium into the cell. It is the result of a balance between inward and outward currents and is particularly long in Purkinje and ventricular cells.phase 3 in cardiac physiology, the terminal rapid repolarization phase of the action potential; it begins with the closing of the slow channels, resulting in an exodus of potassium from the cell and the activation of the pump" >sodium-potassium pump. The result is reestablishment of the normal potential" >resting potential.phase 4 in cardiac physiology, the phase representing electrical diastole, i.e. the time between action potentials. It is the resting phase of the electrical cardiac cycle and is steadily maintained in nonpacemaker cells. In pacemaker cells, the potential" >membrane potential is normally reduced slowly until potential" >threshold potential is reached; if there is an outside stimulus, it may be driven down more rapidly.continuous phase in a heterogeneous system, the component in which the disperse phase is distributed, corresponding to the solvent in a true solution. See also colloid.disperse phase the discontinuous portion of a heterogeneous system, corresponding to the solute in a true solution.G₁ phase a part of the cycle" >cell cycle during interphase, lasting from the end of cell division (the M phase) until the start of DNA synthesis (the S phase).G₂ phase a relatively quiescent part of the cycle" >cell cycle during interphase, lasting from the end of DNA synthesis (the S phase) until the start of cell division (the M phase).M phase the part of the cycle" >cell cycle during which mitosis occurs; subdivided into prophase, metaphase, anaphase, and telophase.S phase a part of the cycle" >cell cycle near the end of interphase, during which DNA is synthesized; it comes between the G₁ and G₂ phases. Phase 0 A trial that evaluates a small number of healthy volunteer subjects, which is conducted before Phase-1 trials and is intended to assess new candidate therapeutic and imaging agents. The study agent is administered at a low dose for a limited time, or not at all, if exploration of human material for the study (e.g., tissue samples or biomarker determinations) is of interest to the investigators. In Phase 0, there is no therapeutic or diagnostic intent.
随便看	adjacency adjacency, broadcast adjacency, broadcast advertising adjacency graph adjacency information base adjacency matrix adjacency-matrix representation adjacency structure adjacent adjacent angle adjacent angles adjacent beam interference adjacent cell hit ratio adjacent cell separation adjacent channel adjacent channel attenuation adjacent-channel attenuation adjacent channel constraint adjacent channel coupled power ratio adjacent channel error power ratio adjacent channel interference adjacent-channel interference adjacent channel interference ratio adjacent channel leakage adjacent channel leakage power ratio