Review Articles, News & Views, Perspectives, Hypotheses, Analyses and Review in 2021

Natural killer cells can destroy cells infected by SARS-CoV-2, but this immune-system defence malfunctions in people with severe COVID-19. Will this finding drive a search for ways to reinvigorate natural killer cells in such cases?

Efforts to generate nanoscale-resolution images of cell interiors have gained ground through the development and refinement of a microscopy method. The data sets are publicly available as resources for further discoveries.

Understanding how diet affects tumour growth could lead to better treatments. Analysis in mice reveals that a low-calorie diet, but not a ketogenic diet, slows the growth of pancreatic cancer. This effect is mediated by lipid changes.

A set of electromagnets has been used to move metal objects without touching them, even though the objects are not magnetic. This method could potentially be used like a ‘tractor beam’ to move hazardous objects in space.

In this Perspective, a group representing a range of stakeholders makes the case for a set of five proposed globally applicable ethical guidelines for ancient human DNA research.

Nature’s pages feature a look at the wonders of chemistry from a human angle and describe a solar explosion.

Genomes from living and extinct rhinos reveal that different species evolved as a result of geographic isolation. A comparison of DNA from different species also shows that rhinos have long displayed low genetic variability.

Superconductivity and magnetism have been observed in layered graphene in which the sheets are twisted with respect to each other. But a simpler, more stable graphene system also exhibits these phases.

A sophisticated climate model suggests that liquid-water oceans never formed on Venus, and that some planets outside the Solar System that were thought to be habitable might not be.

In mice, the ovarian hormone oestradiol sensitizes neurons in a brain region called the hypothalamus to a melanocortin hormone that signals an energy surplus. Their dual activation increases physical activity.

Release of opioid peptide in the brain leads food-deprived mice to eat more sugar than do mice that are well fed. This opioid signalling mechanism fine-tunes the reward value of food according to the animal’s state.

Neurons that express a specific molecular marker are activated by ‘electroacupuncture’ stimulation. They can then mediate the treatment’s anti-inflammatory effects in a mouse model of the inflammatory condition sepsis.

How will global energy usage change as Earth warms? Modelling now suggests that there will be a modest net decrease in energy consumption — but probably at the expense of human well-being in many regions.

Nature’s pages feature a look at British wild flowers, and examine the construction of an aquarium at Crystal Palace.

The distance between the surface atoms of noble metals, such as platinum, affects the catalytic activity of these elements. An experimental approach using nanoparticles enables this effect to be systematically controlled and measured.

Finding a treatment for dengue, the most prevalent mosquito-borne viral disease in humans, has been difficult. A compound called JNJ-A07 displays promising activity against dengue virus in mouse models of infection.

A study in humans indicates that certain bile acids that are produced by bacteria and commonly found in people over 100 boost gut health and protect against infection. These findings shed light on the contributors to healthy ageing.

Key nutrients that are needed by immune cells are scarce in tumours. Engineered cancer-invading bacteria can recycle tumour waste into metabolic fuel to boost anticancer immune responses in mice.

Computing approaches based on mechanical mechanisms are discussed, with a view towards a framework in which adaptable materials and structures act as a distributed information processing network.

Nature’s pages feature a history of aerial photography for archaeology research, and reports of colourful auroras and magnetic storms.