The value of contrast-enhanced ultrasound for sentinel lymph node identification and characterisation in pre-operative breast cancer patients: A prospective study.

OBJECTIVE: To explore the feasibility of sentinel lymph node (SLN) identification by contrast-enhanced ultrasound (CEUS) in pre-operative breast cancer patients and the value of enhancement patterns for diagnosing lymph node metastases and characterising axillary nodal burden. METHODS: 110 consecutive breast cancer patients were enrolled. Before the surgery, microbubbles were injected intradermally. The lymphatic drainage pathway was detected to identify the SLNs. Blue dye and indocyanine green (ICG) fluorescence were used to trace SLNs during the operation. The enhancement patterns of SLNs were recorded and compared with the final pathological diagnosis. RESULTS: SLN detection rate was 96.4 % of 110 patients, 134 SLNs were detected in total. The sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of predicting SLNs metastases by CEUS enhancement patterns were 100 %, 52.0 %, 43.4 %, 100 % and 64.9 %, respectively. No metastatic SLNs were presented as homogeneous enhancement. Low nodal burden with 0-2 SLN metastases in 92.5 % nodes presented as heterogeneous enhancement. No enhancement pattern was proved to be SLN metastases in 100 % patients. CONCLUSIONS: CEUS is a feasible approach for SLN identification. CEUS enhancement patterns can be helpful in recognising metastatic SLNs and nodal burden. KEY POINTS: • CEUS is a feasible approach for SLN identification and characterisation. • The enhancement patterns on CEUS can be helpful in recognising metastasised SLNs. • Homogeneous enhancement pattern has the highest negative-predictive value.

[Carbon Sequestration Characteristics Under Natural Vegetation Restoration in Ziwuling Area of the Loess Plateau].

The aim of this study was to analyze the carbon sink effect under natural vegetation restoration and the influence of changes in vegetation community characteristics on ecosystem carbon density in ecologically fragile areas of the Loess Plateau. In this study, the changes in carbon sequestration of a vegetation-soil system under eight successional stages[slope cropland, abandoned cropland for 10 years, abandoned cropland for 20 years, Sophora davidii (Franch.) Skeels., Betula platyphylla Suk., Pinus tabulaeformis Carr., Quercus wutaishanic Mary+P. tabulaeformis Carr mixed forests, and Q. wutaishanic Mary] in Ziwuling area over 150 restoration periods were investigated using the common method of spatial and temporal substitution. This study also discussed the relationship between changes in vegetation community characteristics and vegetation-soil system carbon density. The results showed that the community coverage of the investigated vegetation fluctuated from 85% in the slope cropland stage to 100% in the arbor stage. The number of species, Margalef index, Shannon-Wiener index, Pielou index, and Simpson index initially increased rapidly, then declined slowly until becoming stable, and reached a peak in the middle of the succession (B. platyphylla Suk.). The biomass and carbon density of vegetation components (above-ground biomass, below-ground roots, and litter) increased exponentially during the succession, i.e., increased slowly before B. platyphylla Suk. but increased significantly in B. platyphylla Suk. and P. tabulaeformis Carr.(P<0.05). The biomass and carbon density reached the maximum values of 27858.08 g·m-2 and 13232.51 g·m-2, respectively, in Q. wutaishanic Mary+P. tabulaeformis Carr mixed forests and tended to be stable in the late succession stage. Soil organic carbon density showed a power function relationship with vegetation restoration, with the greatest increase in the stages of abandoned cropland for 10 years and B. platyphylla, but no significant changes in the subsequent stages (P>0.05). In the early succession stage, the carbon density of the farmland ecosystem was the lowest (4395.70 g·m-2), whereas the other seven stages increased by 55.54%, 40.37%, 69.96%, 202.48%, 326.35%, 357.43%, and 351.07%, respectively, compared with the farmland ecosystem. Community coverage, Margalef index, Shannon-Wiener index, above-ground biomass, root biomass, and litter biomass were significantly positively correlated with vegetation-soil system carbon density (P<0.05). The carbon sink effect of long-term natural restoration in Ziwuling Region was significant, and the carbon density of the vegetation-soil system under interspecific competition tended to be stable in the late succession stage. Dynamic changes in the vegetation community structure and plant diversity during the succession process increased vegetation carbon density and soil carbon density. This study helps to clarify the carbon sink effect of natural vegetation restoration in ecologically fragile areas of the Loess Plateau and provides a theoretical basis for promoting natural forest conservation and achieving carbon neutrality.