Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data (http://www.brainchart.io/). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

A phase-sensitive optical time-domain reflectometry (Φ-OTDR) with 175 km sensing range and 25 m spatial resolution is demonstrated, using the combination of co-pumping second-order Raman amplification based on random fiber lasing, counter-pumping first-order Raman amplification, and counter-pumping Brillouin amplification. With elaborate arrangements, each pumping scheme is responsible for the signal amplification in one particular segment of all three. To the best of our knowledge, this is the first time that distributed vibration sensing is realized over such a long distance without inserting repeaters. The novel hybrid amplification scheme in this work can also be incorporated in other fiber-optic sensing systems for extension of sensing distance.

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This paper proposes a switchable terahertz (THz) metamaterial absorber based on vanadium dioxide (VO2), which can not only realize ultra-wideband (UWB) perfect absorption in the THz range, but also has the ability to adjust the absorption rate by regulating the conductivity of VO2. When VO2 conductivity is 2×105S/m, the designed UWB absorber can achieve over 90% absorption in the frequency range of 2.62–10 THz. Simultaneously, the peak absorption intensity of the absorber can also be regulated dynamically ranging from 100% to 0.8% when the conductivity of VO2 is adjusted to change from 2×105 to 20 S/m. Furthermore, the designed absorber has the advantages of polarization insensitivity and wide-angle absorption. For TE polarization with an incident angle of less than 40° and TM polarization with an incident angle of less than 60°, the absorption rate remains above 90%. The UWB absorber has the advantages of simple structure, wide tuning range, and good absorption performance, and it has potential applications in many fields such as THz filtering, invisibility, sensing, optoelectronic switches, and so on.