Impact of warming and drought on carbon balance related to wood formation in black spruce.

BACKGROUND AND AIMS: Wood formation in trees represents a carbon sink that can be modified in the case of stress. The way carbon metabolism constrains growth during stress periods (high temperature and water deficit) is now under debate. In this study, the amounts of non-structural carbohydrates (NSCs) for xylogenesis in black spruce, Picea mariana, saplings were assessed under high temperature and drought in order to determine the role of sugar mobilization for osmotic purposes and its consequences for secondary growth. METHODS: Four-year-old saplings of black spruce in a greenhouse were subjected to different thermal conditions with respect to the outside air temperature (T0) in 2010 (2 and 5 °C higher than T0) and 2011 (6 °C warmer than T0 during the day or night) with a dry period of about 1 month in June of each year. Wood formation together with starch, NSCs and leaf parameters (water potential and photosynthesis) were monitored from May to September. KEY RESULTS: With the exception of raffinose, the amounts of soluble sugars were not modified in the cambium even if gas exchange and photosynthesis were greatly reduced during drought. Raffinose increased more than pinitol under a pre-dawn water potential of less than -1 Mpa, presumably because this compound is better suited than polyol for replacing water and capturing free radicals, and its degradation into simple sugar is easier. Warming decreased the starch storage in the xylem as well the available hexose pool in the cambium and the xylem, probably because of an increase in respiration. CONCLUSIONS: Radial stem growth was reduced during drought due to the mobilization of NSCs for osmotic purposes and due to the lack of cell turgor. Thus plant water status during wood formation can influence the NSCs available for growth in the cambium and xylem.

Severe radiation pneumonitis after lung stereotactic ablative radiation therapy in patients with interstitial lung disease.

PURPOSE: To investigate the incidence and predictive factors of severe radiation pneumonitis (RP) after stereotactic ablative radiation therapy (SABR) in early-stage lung cancer patients with preexisting radiological interstitial lung disease (ILD). METHODS AND MATERIALS: A retrospective analysis of patients with stage I lung cancer treated with SABR from 2009 to 2014 was conducted. Interstitial lung disease diagnosis and grading was based on pretreatment high-resolution computed tomography imaging. A central review of pretreatment computed tomography by a single experienced thoracic radiologist was conducted. Univariate and multivariate analyses were conducted to determine potential predictors of severe RP in patients with ILD. RESULTS: Among 504 patients treated with SABR in this period, 6% were identified as having preexisting ILD. There was a 4% rate of ≥ grade 3 RP in the entire cohort. Interstitial lung disease was associated with increased risk of ≥ grade 3 RP (32% in ILD+ vs 2% in ILD-, P < .001). Five patients (21%) with ILD developed grade 5 RP. Lower forced expiratory volume in 1 second and forced vital capacity, higher V5Gy and mean lung dose, presence of severe radiological ILD, and combined emphysema were significant predictors of ≥ grade 3 RP on univariate analysis; only forced expiratory volume in 1 second remained on multivariate analysis. CONCLUSION: Interstitial lung disease is associated with an increased risk of severe RP after SABR. Chest imaging should be reviewed for ILD before SABR, and the risk of fatal RP should be carefully weighed against the benefits of SABR in this subgroup.

Chemical composition and biological activity of the essential oil of Amomum biflorum.

The aim of this study was to investigate the chemical composition and bioactivity of Amomum biflorum Jack harvested in the region of Petchaboon, Thailand. The essential oil of the fresh whole plant obtained by hydrodistillation was analyzed by gas chromatography (GC) (Kovats index) and gas chromatography coupled with mass spectrometry (GC/MS). The average yield of essential oil of A. biflorum was 0.21 +/- 0.05 % (w/w). The major chemical constituents were camphor (17.6 %), alpha-bisabolol (16.0 %), camphene (8.2 %) and alpha-humulene (5.1%). The essential oil was active against Staphylococcus aureus (MIC: 30 microg/mL) and had an antioxidant activity with an ORAC index of 23 +/- 5 micromol Trolox/mg.