Frazil ice changes winter biogeochemical processes in the Lena River.

The ice-covered period of large Arctic rivers is shortening. To what extent will this affect biogeochemical processing of nutrients? Here we reveal, with silicon isotopes (δSi), a key winter pathway for nutrients under river ice. During colder winter phases in the Lena River catchment, conditions are met for frazil ice accumulation, which creates microzones.

Microbial methane cycling in sediments of Arctic thermokarst lagoons.

Thermokarst lagoons represent the transition state from a freshwater lacustrine to a marine environment, and receive little attention regarding their role for greenhouse gas production and release in Arctic permafrost landscapes. We studied the fate of methane (CH ) in sediments of a thermokarst lagoon in comparison to two thermokarst lakes on the Bykovsky Peninsula in northeastern Siberia through the analysis of sediment CH concentrations and isotopic signature, methane-cycling microbial taxa, sediment geochemistry, lipid biomarkers, and network analysis. We assessed how differences in geochemistry between thermokarst lakes and thermokarst lagoons, caused by the infiltration of sulfate-rich marine water, altered the microbial methane-cycling community.

Subtle signs of breast cancer as an important pitfall in mammographic interpretation: Establishing an accurate diagnosis in an equivocal case.

Mammogram is the standard imaging modality for the early detection of breast cancer, and it has been shown to reduce disease-related mortality by up to 30%. Mammogram, however, has its limitations. It is reported that 10-30% of breast cancers may be missed on a mammogram.

Ongoing clinical trials on axillary management.

Introduction: Within the last 50 years the management of patients with breast cancer has changed dramatically with a significant de-escalation of the role and magnitude of surgery, both for the management of the primary tumor and for the management of the axilla. In the management of the axilla of patients with early stage breast cancer (EBC) and clinically uninvolved axilla (cN0), axillary lymph node dissection (ALND) was gradually replaced by sentinel lymph node biopsy (SLNB) saving more than 60-70% of patients from an unnecessary dissection. Further studies confirmed that isolated tumor cells or micrometastases found on the SLN had no further benefit from ALND sparing even more patients from an unnecessary ALND.

Heat and Salt Flow in Subsea Permafrost Modeled with CryoGRID2.

Thawing of subsea permafrost can impact offshore infrastructure, affect coastal erosion, and release permafrost organic matter. Thawing is usually modeled as the result of heat transfer, although salt diffusion may play an important role in marine settings. To better quantify nearshore subsea permafrost thawing, we applied the CryoGRID2 heat diffusion model and coupled it to a salt diffusion model.