Station-based observed precipitation data are available in a limited way and only at low spatial resolution. High-resolution satellite rainfall products can help to monitor precipitation changes over large areas. The Tropical Rainfall Measuring Mission 3B43 (TRMM 3B43) precipitation data with coarse spatial resolution and low data accuracy are capable of depicting the spatial variability of precipitation, but fail to estimate the accurate magnitude. These data available in Xinjiang, China, need to be evaluated, especially because Xinjiang has a complex terrain and application of such data becomes a challenging task. Based on the relation between precipitation and normalized difference vegetation index (NDVI), a proxy for vegetation, a new statistical downscaling algorithm is proposed in this study. The calibration was based on geographical difference analysis (GDA) and the monthly fractions derived from the un-calibrated TRMM data can be used to disaggregate high-resolution annual precipitation to high-resolution monthly precipitation. The accuracy of downscaled TRMM precipitation was evaluated based on station-based observed precipitation for a period of 1998-2010. Results indicated that: (1) optimal relations shown by R 2 between TRMM precipitation and NDVI at different temporal and spatial scales were different: the largest R 2 value was 0.69 for the period of 1998-2010 at a spatial resolution of 1.00 ∘ × 1.00 ∘ , was 0.70 for the dry year (2001 in this study) at a spatial resolution of 0.75 ∘ × 0.75 ∘ , and was 0.67 for the wet year (2010 in this study) at a spatial resolution of 1.25 ∘ × 1.25 ∘ ; (2) the downscaled TRMM precipitation data obtained using NDVI described spatial patterns of precipitation reasonably well at a spatial resolution of 8 km × 8 km with more detailed information when compared to the raw TRMM precipitation at a spatial resolution of 0.25 ∘ × 0.25 ∘ ; (3) the downscaled TRMM precipitation with GDA calibration, P DSGDA , can exclude the regions with irrigation-and/or ground water-induced vegetation coverage. Therefore, P DSGDA obtained in this study can be regarded as estimated alternative precipitation data across Xinjiang for management of water resources and agricultural irrigation activities.
Natural production of anti-cancer drug taxol from Taxus has proved to be environmentally unsustainable and economically unfeasible. Currently, bioengineering the biosynthetic pathway of taxol is an attractive alternative production approach. 10-deacetylbaccatin III-10-O-acetyl transferase (DBAT) was previously characterized as an acyltransferase, using 10-deacetylbaccatin III (10-DAB) and acetyl CoA as natural substrates, to form baccatin III in the taxol biosynthesis. Here, we report that other than the natural acetyl CoA (Ac-CoA) substrate, DBAT can also utilize vinyl acetate (VA), which is commercially available at very low cost, acylate quickly and irreversibly, as acetyl donor in the acyl transfer reaction to produce baccatin III. Furthermore, mutants were prepared via a semi-rational design in this work. A double mutant, I43S/D390R was constructed to combine the positive effects of the different single mutations on catalytic activity, and its catalytic efficiency towards 10-DAB and VA was successfully improved by 3.30-fold, compared to that of wild-type DBAT, while 2.99-fold higher than the catalytic efficiency of WT DBAT towards 10-DAB and Ac-CoA. These findings can provide a promising economically and environmentally friendly method for exploring novel acyl donors to engineer natural product pathways.
ObjectiveWe conducted a systematic review to evaluate questionnaires about patient’s values and preferences to provide information on the most appropriate questionnaires to be used when developing clinical practice guidelines.MethodsA systematic literature search of the Cochrane Library, MEDLINE, Embase, Web of Science, Chinese Biomedical Database, China National Knowledge Infrastructure, and the Wanfang Database was performed to identify studies on questionnaires evaluating patient’s values and preferences. The articles that used fully structured questionnaires or scales with standardized questions and answer options were included. We assessed the questionnaires’ construction and content with a psychometric methodology and summarized the domains and items about patient’s preferences and values.ResultsA total of 7,008 records were retrieved by the search strategy and scanned, and 20 articles were finally included. Of these, 10 (50%) articles described the process of item generation and only four questionnaires (20%, 4/20) mentioned the pilot testing. Regarding “validity”, seven questionnaires (35%, 7/20) assessed validity and only one (5%, 1/20) questionnaire assessed internal consistency, with Cornbrash’s α values of 0.74–0.87. For “acceptability”, the time to complete the questionnaires ranged from 10 to 30 minutes and only nine studies (45%, 9/20) reported the response rates. In addition, the results of domains and items about patient’s preferences and values showed that the “effectiveness” domain was the most considered item in the patient’s value questionnaire followed by “safety”, “prognosis”, and others, whereas the least considered domain was “physician’s experience”.ConclusionOnly a few studies have developed questionnaires with rigorous psychometric methods to measure patient’s preferences and values. Currently, still there is no valid or reliable questionnaire for patient’s preferences and values for use when developing clinical practice guidelines. Further study should be conducted to develop standardized instruments to measure patient’s preferences and values. This study provides the domains and items that may be used in formulating questionnaires about patient’s preferences and values.
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