Front Cover; The Resolution Revolution: Recent Advances In cryoEM; Copyright; Contents; Contributors; Preface; References; Chapter One: Direct Electron Detectors; 1. Introduction; 2. Past; 3. Present; 3.1. Practical Advice for the User; 4. Future; References; Chapter Two: Specimen Behavior in the Electron Beam; 1. Introduction; 2. High-Energy Electrons Are a Form of Ionizing Radiation as Well as Being a Form of Short-Wavelength Radiation That Can B ... ; 2.1. Electron-Scattering Events Can Be Either Elastic or Inelastic.

2.2. Energy Is Deposited in the Specimen as a Result of Inelastic Scattering2.3. Values of the Linear Energy Transfer (LET) Can Be Used to Estimate the Energy Deposited; 3. Biological Molecules Become Structurally Damaged When Irradiated; 3.1. There Is a Large Literature of Radiation Chemistry and Radiation Biology; 3.2. Fading of Diffraction Patterns Is a Convenient Indicator of Structural Damage; 3.3. Some Residues in Proteins Are Especially Sensitive to Radiation Damage; 3.4. Caging of Fragments and ``Trapping ́́of Radicals Results in Cryo-Protection: This Helps Only to a Limited Extent.

3.5. Radiation Sensitivity of Enzyme Activity: Implications for Dynamic Studies in Liquid Samples4. Vitreous Ice Also Becomes Structurally Damaged by Ionizing Radiation; 4.1. Water Molecules Are Easily Damaged by Ionizing Radiation; 4.2. Weak Thon Rings at High Resolution Show That Vitreous Ice Is Very Sensitive to Radiation Damage; 4.3. Electron-Stimulated Desorption Progressively Thins Ice Specimens; 5. Bubbling of Hydrated Biological Specimens Becomes Apparent at High Electron Exposure; 5.1. Bubbles Consist of Molecular Hydrogen; 5.2. Bubbling Can Be Used to Evaluate the Specimen Thickness.

5.3. Bubbling Can Be Used to Distinguish Regions with Different Chemical Composition (Bubblegrams)6. Cryo-Specimens Exhibit Collective Beam-Induced Movement When Irradiated; 6.1. Radiation-Sensitive Specimens Show Beam-Induced Motion at Quite Low Electron Exposures; 6.2. Thin Cryo-Specimens Undergo Drum-Head-Like Flexing and Doming When Irradiated; 6.3. Images Can Be Corrupted Significantly by There Being Changes in Z-Height; 6.4. The Pattern of Beam-Induced Movement Can Be Quite Unpredictable; 7. More Than One Mechanism May Contribute to Beam-Induced Motion.

7.1. Cryo-EM Specimens, as Made, Are Expected to Be Under Considerable Stress7.2. Irradiation Can Relieve Mechanical Stress; 7.3. Irradiation Can Generate (New) Mechanical Stress; 7.4. Which Comes First, Relaxation or Creation of Stress?; 8. Irradiation Can Produce Electrostatic Charging of the Specimen; 8.1. A Buildup of Net Charge on the Specimen Can Be Easy to Detect; 8.2. Evidence of Net-Charge Buildup Can Be Reduced in Several Ways; 8.3. Other Forms of Specimen Charging Are More Subtle to Detect; 9. Summary and Future Directions; Acknowledgments; References.