Min Xu

Bio: Min Xu is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Panax notoginseng & Medicine. The author has an hindex of 25, co-authored 122 publications receiving 1832 citations. Previous affiliations of Min Xu include Nanjing Normal University & Griffith University.

Modeling Glacier Mass Balance and Runoff in the Koxkar River Basin on the South Slope of the Tianshan Mts. during 1959 to 2009, China

Abstract: Water resources provided by alpine glaciers are an important pillar for people living in the arid regions in the west of China. In this study, the HBV (Hydrologiska Byrans Vattenavdelning) light model was applied to simulate glacier mass balance and runoff in the Koxkar River Basin (KRB) on the south slope of Mt. Tumur, western Tianshan Mts.. Daily temperature and precipitation were calculated by multiple linear regressions and gradient-inverse distance weighting, respectively, based on in-situ observed data by automatic weather stations (AWSs) in the basin (2007-2009) and at four meteorological stations neighbering the basin (1959-2009). Observed daily air temperature and precipitation were taken as input data for the HBV model, which was calibrated using runoff in 2007/08 and 2009/10, and validated in 2008/09 and 2010/11. Generally, the model could simulate runoff very well. The annual glacier mass balance and runoff were calculated using the HBV model driven by interpolated meteorological data for the period of 1959-2009. The simulated glacier mass balance were reasonable when compared with those observed values at nearby glaciers, indicating a decrease trend of mass balance in the basin with an average value of -370.4 mm a-1 since 1959. The annual runoff showed a slight increase trend (5.51 mm a-1). Futher analysis indicated that the runoff is more sensitive to temperature than precipitation amuont in the Koxkar river basin.

Modeling glacier mass balance and runoff in the Koxkar river basin on the south slope of the Tianshan Mountains, China, from 1959 to 2009

Abstract: Water resources provided by alpine glaciers are an important pillar for people in the arid regions of west China. In this study, the Hydrologiska Byrans Vattenavdelning (HBV) light model was applied to simulate glacier mass balance (GMB) and runoff in the Koxkar River Basin (KRB) on the south slope of Mount Tumur, in the western Tianshan Mountains. Daily temperature and precipitation were calculated by multiple linear regressions and gradient-inverse distance weighting, respectively, based on in-situ observed data by automatic weather stations (AWSs) in the Koxkar River Basin (KRB; 2007–2009) and four meteorological stations neighboring the basin (1959–2009). Observed daily air temperature and precipitation were input into HBV model. The runoff data in 2007/2008 and 2008/2009 were used to calibrate and validate the model in 2009/2010 and 2010/2011. Generally, the model simulated runoff very well. The annual glacier mass balance and runoff were calculated by the HBV model and were driven by interpolated meteorological data between 1959 and 2009. The calculated glacier mass balances were reasonable, and were compared with nearby glaciers. The results indicate the decreasing trend of mass balance in the Koxkar Glacier, with an average value of ablation of −370.4 mm·a−1 between 1959 and 2009. The annual runoff showed an increasing trend (5.51 mm·a−1). Further analysis showed that the runoff is more sensitive to temperature than precipitation in KRB.

Solving the supply of Resveratrol Tetramers from Papua New Guinean rainforest Anisoptera species (Dipterocarpaceae) that inhibit bacterial type III secretion systems

Abstract: The supply of (–)-hopeaphenol was achieved via enzymatic biotransformation in order to provide material for pre-clinical investigation. High-throughput screening of a pre-fractionated natural product library aimed to identify compounds that inhibit the bacterial virulence type III secretion system (T3SS) identified several fractions derived from two Papua New Guinean Anisoptera species, showing activity against Yersinia pseudotuberculosis outer proteins E and H (YopE and YopH). Bioassay-directed isolation from the leaves of A. thurifera, and similarly A. polyandra, resulted in three known resveratrol tetramers, (–)-hopeaphenol (1), vatalbinoside A (2) and vaticanol B (3). Compounds 1–3 displayed IC50 values of 8.8, 12.5 and 9.9 M in the reporter-gene assay, and IC50 values of 2.9, 4.5 and 3.3 M in the YopH assay, respectively, which suggested that they could potentially act against the T3SS in Yersinia. The structures of 1-3 were confirmed through a combination of spectrometric, chemical methods and single crystal X-ray structure determinations of the natural product 1 and the permethyl ether analogue of 3. The enzymatic hydrolysis of the β-glycoside 2 to the aglycone 1 was achieved through biotransformation using the endogenous leaf enzymes, this significantly enhanced the yield of the desired bioactive natural product from 0.08% to 1.3% and facilitates ADMET studies of (–)-hopeaphenol (1).

Eucalmaidials A and B, Phloroglucinol‐Coupled Sesquiterpenoids from the Juvenile Leaves of Eucalyptus maideni.

Abstract: Two new phloroglucinol-coupled sesquiterpenoids, eucalmaidials A and B (1 and 2), were isolated from the juvenile leaves of Eucalyptus maideni, along with eight known macrocarpals (3–10), eucalyptone (11), and three known triterpenoids (12–14). Eucalmaidials A and B represent a new skeleton of phloroglucinol-coupled iphionane. Their structures were elucidated by extensive NMR spectroscopic analysis and theoretical calculation of the 13C NMR chemical shifts. The biosynthetic pathway of 1 and 2 was also postulated. Compounds 1, 3, 5, 7, 8, and 10–14 were evaluated for their antifungal and antibacterial activities. Compound 1 exhibited antifungal activity against Candida glabrata with an IC50 value of 0.75 μg mL−1.

Different glacier status with atmospheric circulations in Tibetan Plateau and surroundings

Abstract: Glacial melting in the Tibetan Plateau affects the water resources of millions of people. This study finds that—partly owing to changes in atmospheric circulations and precipitation patterns—the most intensive glacier shrinkage is in the Himalayan region, whereas glacial retreat in the Pamir Plateau region is less apparent.