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Quantification of methane emissions from municipal solid waste landfills in China during the past decade
No full textMethane is responsible for 20% of the global warming resulting from greenhouse gas emissions. Municipal solid waste (MSW) landfills are the third largest anthropogenic source of methane and are thus important to estimating the global methane budget and evaluating its contribution to global greenhouse gas emissions. Based on the greenhouse gas inventory guidelines from the Intergovernmental Panel on Climate Change (IPCC) and the first-order decay method used to estimate emissions from MSW landfills - and in line with MSW management in various regions we calculated methane emissions from MSW landfills in various Chinese provinces from 2003 to 2013. During this period, methane emissions from MSW landfills increased from 1141.10 Gg to 1858.98 Gg, representing a mean annual increase of 71.79 Gg. MSW emissions tended to increase more in the northern and western provinces than in the southern and eastern provinces, as methane emissions strongly and positively correlated with population and socioeconomic demographics. MSW decontamination is growing rapidly in China, and landfills predominate in all MSW treatments; moreover, incineration has also dramatically increased in recent years
Youngia jiulongensis (Crepidinae, Cichorieae, Asteraceae), a New Species from Sichuan, China
No full textYoungia jiulongensis Y. L. Peng, X. F. Gao & Li Bing Zhang, a new species of Asteraceae from western Sichuan, China, is described. This new species is similar to Y mairei Lev.) Babe. & Stebbins and Y. pilifera C. Shih in having blackish brown achenes, a white pappus, and fewer capitula, but distinct from the latter two in having a taller stature (28-50 cm vs. 8-30 cm), two or three well developed, undivided caudical leaves, sparsely toothed leaf margins, acute leaf apices, long non winged petioles, reduced pubescence on the whole plant, glabrous phyllaries, and midveins of all inner phyllaries plane
Altered precipitation patterns and simulated nitrogen deposition effects on phenology of common plant species in a Tibetan Plateau alpine meadow
No full textThe interactive effects of five seasonal precipitation distribution patterns and two levels of N deposition (ambient and doubled) on phenological traits of six common plant species were studied in an alpine meadow of the Tibetan Plateau for two consecutive years. Seasonal precipitation patterns included ambient (control), reduced fall/winter/spring - increased summer, increased fall/winter - reduced spring, increased fall/winter - reduced spring/summer, and increased spring - reduced summer. Our results indicate that: 1) phenological trait variation was predominantly due to species differences (P= 2 years); 3) redistributing dormant season and spring precipitation to summer caused earlier flowering and longer flowering duration for perennial graminoids (P. pratensis, K setchwanensis, respectively) and earlier and shorter duration of fruiting for the annual forb G. paludosa; yet N addition diminished and/or reversed these effects. Moreover, augmenting fall and winter precipitation at the expense of spring and summer precipitation decreased all phenological traits of P. anserina except for flowering date, but N addition reversed these effects, and; 4) interannual variation in species phenology was strongly influenced by environmental differences among the two growing seasons rather than different precipitation patterns and N addition. We discuss how seasonal shifts in precipitation and/or greater N deposition in the future may impact plant species fitness, species coexistence, and vegetation composition in alpine meadow ecosystems of the Tibetan Plateau. (C) 2017 Elsevier B.V. All rights reserved
A review on antiviral activity of the Himalayan medicinal plants traditionally used to treat bronchitis and related symptoms
No full textObjectivesBronchitis is a common respiratory tract infection of humans mainly caused by influenza virus, rhinovirus, adenovirus, coronavirus and respiratory syncytial virus. The aim of this review was to gather fragmented literature on ethnomedicinal plants used against bronchitis in the Himalayan region and their in-vitro validation against bronchitis causing viral pathogens. Key findingsPresent review contains ethnomedicines of total 55 plants from different countries of the Himalayas. Most of the literature reported was from India followed by Pakistan, China and Nepal. Familiarly used plant families for bronchitis treatment in the Himalayan region were Leguminosae (six plants) and Lamiaceae (five plants). Leaves and roots were the most common parts used in ethnomedicines against bronchitis. Of these 55 plants, only six plants have been studied in vitro against viral pathogens causing bronchitis. Different compounds like monoterpenoids, flavonoids, triterpenoids, iridoid glycosides, sesquiterpenes, benzoic and phenolic compounds were reportedly isolated from these plant extracts having strong antiviral potential. SummaryThe Himalayan regions possess variety of ethnomedicinal plants used against respiratory diseases, but still there are only few studies related with their in-vitro validation. We invite the attention of researchers for detailed ethnopharmacological and phytochemical studies on unexplored plants used to treat bronchitis for the development of novel antiviral drugs
BIOMASS ALLOCATION AND TRADEOFFS OF PEDICULARIS LONGIFLORA RUDOLPH. AT TWO SLOPE ASPECTS IN AN ALPINE MEADOW OF THE EASTERN TIBETAN PLATEAU
No full textPedicularis longiflora is a typical grassland plant located in the alpine habitat in wet meadows or besides streams. This paper addresses the response and adaptation of P. longiflora under heterogeneous environmental conditions at different slope aspects in an alpine wet meadow, eastern Tibetan Plateau. The results show that P. longiflora at the southeast slope benefited more for its development and population maintenance. It also showed a relatively greater leaf biomass. However, P. longiflora invested more biomass to reproductive organs at the southwest slope aspect, where this species has better population continuation. Isometric scaling existed in coupled organ biomasses of P. longiflora which indicated that genetic regulation plays a key role in biomass allocation. P. longiflora allocated more biomass to aboveground parts, vegetative biomass, and non-photosynthetic organs biomass according to tradeoff values, respectively. In addition, both biotic and abiotic factors influenced biomass production of P. longiflora. Thus, soil temperature and interspecies competition in different habitats needs to be clearly understood and paid more attention to for cultivation and better industrialization of this herbal medicinal plant
氮素富集对青藏高原东缘窄叶鲜卑花灌丛根系分泌物碳输入的影响
No full text为探究高寒灌丛生态系统根系分泌物碳(C)输入通量对大气氮(N)沉降的响应规律,该文以青藏高原东缘窄叶鲜卑花(Sibiraea angustata)灌丛为研究对象,采用根系分泌物野外原位收集法,分析了不同施N水平(对照N0=0 g·m~(–2)·a~(–1);低N处理N5=5 g·m~(–2)·a~(–1);高N处理N10=10 g·m~(–2)·a~(–1))对根系分泌物C输入速率与通量季节动态变化规律的影响。结果表明:(1)窄叶鲜卑花灌丛单位根生物量、单位根长、单位根表面积根系分泌物C输入速率均表现出明显的季节性动态变化,具体表现为8月>6月>10月,并呈现出与5 cm土壤温度相一致的变化趋势。(2)施N降低了窄叶鲜卑花灌丛单位根生物量、单位根长和单位根表面积根系分泌物C输入速率,但仅N10处理与对照(N0处理)间存在显著差异(p<0.05)。(3)N5和N10处理下,窄叶鲜卑花灌丛细根生物量与N0处理相比分别降低了23.36%和33.84%。(4)由于施N导致根系分泌物C输入速率与细根生物量二者均显著降低,使得施N对窄叶鲜卑花灌丛根系分泌物C输入通量(g·m~(–2)·a~(–1))有显著的抑制作用,并随着施N浓度的增加抑制作用增大。推测其可能的原因是N素富集在一定程度上缓和了植物根系对养分的微生物驱动需求,从而降低了植物根系分泌物C输入通量,即N素富集条件下植物采取了低N收益-低C投入的生理策略。该研究结果对于进一步认知不同环境变化下高寒灌丛生态系统根系分泌物C输入及其介导的土壤生物C-养分循环过程具有重要的理论意义
成都至宜宾高速公路沿线植被类型及分布特征研究
No full text本研究对拟建成都至宜宾高速公路沿线植物资源及植被分布情况进行调查,以期为该项目建设的环境影响评价提供现状基础资料,为该项目建设采取合理的环境保护措施提供依据。调查结果表明:调查范围内共有维管植物约125科360属575种,其中有小黑桫椤、金毛狗、油樟等3种国家二级重点保护野生植物;调查区植被类型以人工林、经果林和农作物等栽培植被为主,自然植被相对较少;自然植被类型主要是以柏木和马尾松为主的暖性针叶林,以慈竹、毛竹、斑竹等为主的竹林,以黄荆、构树、盐肤木为主的落叶阔叶灌丛
Biodiesel synthesis from Saussurea heteromalla (D.Don) Hand-Mazz integrating ethanol production using biorefinery approach
No full textBiodiesel is a renewable and substitute fuel to diesel engines. The main limit for adoption of biodiesel on industrial scale as an alternative fuel is the high cost of its synthesis process using raw methanol during transesterification reaction. Using bio-refinery approach and inexpensive high-quality oil feedstock is an effective means to produce low-cost biodiesel. In this study Saussurea heteromalla a novel non-edible seed with high oil contents (30 wt%) was subjected first time to integrated synthesis of biodiesel and ethanol. Transesterification and simultaneous saccharification along with fermentation process was applied to produce biodiesel and ethanol respectively. Alkaline pretreatment with sodium hydroxide (8% w/v) at 100 degrees C was used to enhance ethanol yield from 30% to 80%. A highest biodiesel yield of 99% was achieved via optimized parameters of 6:1 alcohol to oil ratio with 0.26 wt% catalyst in 55 min time at 65 degrees C temperature using Response Surface Methodology. It was observed that 112.2 +/- 1.6 g of biodiesel and 42.0 +/- 0.5 g of ethanol were produced using 1 kg of Saussurea heteromalla seed oil. In addition, the fuel properties of prepared biodiesel were in accordance to ASTM D 6751 and EN 14214 standards. (C) 2017 Elsevier Ltd. All rights reserved
Extraction of ochratoxin A in red wine with dopamine-coated magnetic multi-walled carbon nanotubes
No full textA new, rapid, green, and cost-effective magnetic solid-phase extraction of ochratoxin A from red wine samples was developed using polydopamine-coated magnetic multi-walled carbon nanotubes as the absorbent. The polydopamine-coated magnetic multi-walled carbon nanotubes were fabricated with magnetic multi-walled carbon nanotubes and dopamine by an in situ oxidative self-polymerization approach. Transmission electron microscopy, dynamic light scattering, X-ray photoelectron spectroscopy and vibrating sample magnetometry were used to characterize the absorbents. Ochratoxin A was quantified with high-performance liquid chromatography coupled with fluorescence detection, with excitation and emission wavelengths of 338 and 455 nm, respectively. The conditions affecting the magnetic solid-phase extraction procedure, such as pH, extraction solution, extraction time, absorbent amount, desorption solution and desorption time were investigated to obtain the optimal extraction conditions. Under the optimized conditions, the extraction recovery was 91.8-104.5% for ochratoxin A. A linear calibration curve was obtained in the range of 0.1-2.0 ng/mL. The limit of detection was 0.07 ng/mL, and the limit of quantitation was 0.21 ng/mL. The recoveries of ochratoxin A for spiked red wine sample ranged from 95.65 to 100.65% with relative standard deviation less than 8%. The polydopamine-coated magnetic multi-walled carbon nanotubes showed a high affinity toward ochratoxin A, allowing selective extraction and quantification of ochratoxin A from complex sample matrixes
Isolation, identification and characterization of potential impurities of anidulafungin
No full textEight impurities ranging from 0.03 to 0.97% in anidulafungin bulk drug were detected by HPLC. Four impurities (Imp-I, Imp-II, Imp-III and Imp-VIII) among impurities were isolated from the self-prepared or marketed samples of anidulafungin bulk drug by means of preparative HPLC. A thorough study was undertaken to characterize these impurities and based on 1D (H-1, C-13, H-D, DEPT 90 and 135) and 2D (COSY, TOCSY, HSQC, HMBC) NMR and ESI-MS spectral data. Based on the characterization data, Imp-I was found to be known open-chain hydrolysis product formed during the synthesis and degradation. Imp-II and Imp-III was lacked a methyl group at the C-4 and C-8 in anidulafungin, respectively, whereas Imp-VIII contained a methoxy group at the C-23. The latter three new impurities were identified as process-related substances. (C) 2017 Elsevier B.V. All rights reserved