Search results for "CTAB"
showing 10 items of 231 documents
Les vagues de chaleur au Sahel : caractérisation, mécanismes, prévisibilité.
2016
The mechanisms controlling Sahelian heat wave (HW) variability are examined on the period 1979-2014 using the GSOD observational database and ERA-Interim reanalyses. HW events are analyzed through all terms of the atmospheric energy balance, showing a predominant role of incoming shortwave radiation on daily maximum temperature (Tx) and atmospheric water vapor on minimum temperature (Tn). The low-frequency warming trend, not explained by the previous terms, is thought to relate to the increase of greenhouse gases concentrations, due to anthropogenic emissions. The predictability of Sahelian HW events is assessed for lead times reaching up to 15 days. The model's skill, biases and uncertaint…
CCDC 1998895: Experimental Crystal Structure Determination
2020
Related Article: Hui Shen, Zhen Xu, Maryam Sabooni Asre Hazer, Qingyuan Wu, Jiang Peng, Ruixuan Qin, Sam Malola, Boon K. Teo, Hannu Häkkinen, Nanfeng Zheng|2020|Angew.Chem.,Int.Ed.|60|3752|doi:10.1002/anie.202013718
Pigments and their solubility in and extractability by supercritical CO2 - I: the case of curcumin
2000
A specially designed high-pressure cell was used simultaneously as extractor/autoclave and photometric cell in a Perkin Elmer Lambda 5 spectrophotometer. Based on this cell, a simple method was developed to determine the extractability of pigments by pure and by modified supercritical (sc) CO2. The method is demonstrated with curcumin from turmeric. With sc CO2 modified by 10% ethanol, the extraction yield for curcumin from two commercial finely ground dry turmeric samples was about 100%, measured by reference to the (complete) extraction of samples of the same charge with pure ethanol under standard conditions. Extractable curcumin content was from 1.8 to 2.5%, with three samples of turmer…
INJECTABLE HYDROGEL BASED ON A NOVEL AMPHIPHILIC HYALURONIC ACID DERIVATIVE FOR CONTROLLED DRUG RELEASE
2015
Extraction of lapachol from Tabebuia avellanedae wood with supercritical CO2: an alternative to Soxhlet extraction?
2003
The solubility of lapachol in supercritical CO2 was determined at 40°C and pressures between 90 and 210 bar. Supercritical fluid extraction of lapachol and some related compounds by CO2 from Tabebuia avellanedae wood is compared to Soxhlet extraction with different solvents. A standard macroscale (100-200 g wood) and a microscale (~10 mg wood) experimental setup are described and their results are compared. The latter involved direct spectrophotometric quantification in a high-pressure autoclave with an integrated optical path and a magnetic stirrer, fitted directly into a commercial spectrophotometer. The relative amount of lapachol extracted by supercritical CO2 at 40°C and 200 bar was ab…
CHOOSING OF OPTIMAL REFERENCE SAMPLES FOR BOREAL LAKE CHLOROPHYLL A CONCENTRATION MODELING USING AERIAL HYPERSPECTRAL DATA
2018
Abstract. Optical remote sensing has potential to overcome the limitations of point estimations of lake water quality by providing spatial and temporal information. In open ocean waters the optical properties are dominated by phytoplankton density, while the relationship between color and the constituents is more complicated in inland waters varying regionally and seasonally. Concerning the difficulties relating to comprehensive modeling of complex inland and coastal waters, the alternative approach is considered in this paper: the raw digital numbers (DN) recorded using aerial remote hyperspectral sensing are used without corrections and derived by means of regression modeling to predict C…
HCC surveillance improves early detection, curative treatment receipt, and survival in patients with cirrhosis: A meta-analysis
2022
Background & Aims: There is controversy regarding the overall value of hepatocellular carcinoma (HCC) surveillance in patients with cirrhosis given the lack of data from randomized-controlled trials. To address this issue, we conducted a systematic review and meta-analysis of cohort studies evaluating the benefits and harms of HCC surveillance in patients with cirrhosis. Methods: We performed a search of the Medline and EMBASE databases and national meeting abstracts from January 2014 through July 2020 for studies reporting early-stage HCC detection, curative treatment receipt, or overall survival, stratified by HCC surveillance status, among patients with cirrhosis. Pooled risk ratios …
Magnetoencephalography Responses to Unpredictable and Predictable Rare Somatosensory Stimuli in Healthy Adult Humans
2021
Mismatch brain responses to unpredicted rare stimuli are suggested to be a neural indicator of prediction error, but this has rarely been studied in the somatosensory modality. Here, we investigated how the brain responds to unpredictable and predictable rare events. Magnetoencephalography responses were measured in adults frequently presented with somatosensory stimuli (FRE) that were occasionally replaced by two consecutively presented rare stimuli [unpredictable rare stimulus (UR) and predictable rare stimulus (PR); p = 0.1 for each]. The FRE and PR were electrical stimulations administered to either the little finger or the forefinger in a counterbalanced manner between the two conditio…
Data from: Adaptation in response to environmental unpredictability
2017
Understanding how organisms adaptively respond to environmental fluctuations is a fundamental question in evolutionary biology. The Mediterranean region typically exhibits levels of environmental unpredictability that vary greatly in habitats over small geographical scales. In cyclically parthenogenetic rotifers, clonal proliferation occurs along with occasional bouts of sex. These bouts contribute to the production of diapausing eggs, which allows survival between growing seasons. Here, we studied two diapause-related traits in rotifers using clones from nine Brachionus plicatilis natural populations that vary in the degree of environmental unpredictability. We tested the hypothesis that t…