AbstractResolving regional carbon budgets is critical for informing land-based mitigation policy. For nine regions covering nearly the globe, we collected inventory estimates of carbon stock changes complemented by satellite estimates of biomass changes where inventory data are missing. The net land-atmospheric carbon exchange (NEE) was calculated by taking the sum of carbon stock change and lateral carbon fluxes from crop and wood trade and riverine carbon export to the ocean. Summing up NEE from all regions, we obtained a global ‘bottom-up’ NEE for net land anthropogenic CO2 uptake of -2.2 ± 0.6 PgC yr−1 consistent with the independent top-down NEE from the global atmospheric carbon budget during 2000–2009. This estimate is so far the most comprehensive global bottom-up carbon budget accounting, which set up an important milestone for global carbon cycle studies. By decomposing NEE into component fluxes, we found that global soil heterotrophic respiration (SHR) amounts to a source of CO2 of 39 PgC yr−1 with an inter-quartile of 33 to 46 PgC yr−1, a much smaller portion of Net Primary Productivity than previously reported.
We report a facile and environmentally friendly method of preparing highly branched silver nanostructures. By reducing AgNO 3 with l-ascorbic acid in an aqueous solution, silver particles having a coral-like morphology were formed in a few minutes. A mechanistic study of the growth process revealed that the silver branches grew from a bulbous seed formed through aggregation, and that by changing the concentrations of the reagents, the degree of particle branching could be altered. With their potentially high surface areas, these branched structures could find use as catalysts or as substrates for surface-enhanced Raman scattering applications.
Medical science has recently advanced to the point where diagnosis and therapeutics can be carried out with high precision, even at the molecular level. A new field of "precision medicine" has consequently emerged with specific clinical implications and challenges that can be well-addressed by newly developed nanomaterials. Here, a nanoscience approach to precision medicine is provided, with a focus on cancer therapy, based on a new concept of "molecularly-defined cancers." "Next-generation sequencing" is introduced to identify the oncogene that is responsible for a class of cancers. This new approach is fundamentally different from all conventional cancer therapies that rely on diagnosis of the anatomic origins where the tumors are found. To treat cancers at molecular level, a recently developed "microRNA replacement therapy" is applied, utilizing nanocarriers, in order to regulate the driver oncogene, which is the core of cancer precision therapeutics. Furthermore, the outcome of the nanomediated oncogenic regulation has to be accurately assessed by the genetically characterized, patient-derived xenograft models. Cancer therapy in this fashion is a quintessential example of precision medicine, presenting many challenges to the materials communities with new issues in structural design, surface functionalization, gene/drug storage and delivery, cell targeting, and medical imaging.
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