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硫酸氨基葡萄糖临床应用的研究进展 被引量:15
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作者 陈怡 《中国药业》 CAS 2012年第9期96-96,I0002,I0003,共3页
骨关节炎是一种退行性疾病,主要表现为关节肿痛和不同程度的功能障碍,严重时导致功能丧失。硫酸氨基葡萄糖作为骨关节炎疾病改善药物,近几年来很受关注。该文主要综述近年来硫酸氨基葡萄糖临床应用的研究进展。
关键词 骨关节炎 硫酸氨基葡萄糖 白介素-β活性
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Gross β activity level of fallout in the environment around Qinshan Nuclear Power Plant
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作者 YEJi-Da CHENBin WUZong-Mei 《Nuclear Science and Techniques》 SCIE CAS CSCD 2005年第1期43-45,共3页
This paper presents the measurement results of gross β activities in fallout samples collected from the en- vironment around Qinshan Nuclear Power Plant (NPP) during 1993-2002. The gross β activity of 191 samples co... This paper presents the measurement results of gross β activities in fallout samples collected from the en- vironment around Qinshan Nuclear Power Plant (NPP) during 1993-2002. The gross β activity of 191 samples col- lected at five monitoring spots were (0.11~3.64) Bq·m-2·d-1, with an average of (0.91±0.49) Bq·m-2·d-1. This value was lower than (1.02±0.35) Bq?m-2?d-1 , the average of the samples collected at the reference spot in Hangzhou. It indicated that no obvious rise in the gross β activity level of fallout was observed in ambience of Qinshan NPP. 展开更多
关键词 秦山核电站 放射性监测 辐射微尘 β活性
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Receptor tyrosine kinases positively regulate BACE activity and Amyloid-β production through enhancing BACE internalization 被引量:5
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作者 Lin Zou Zhu Wang +4 位作者 Li Shen Guo Bin Bao Tian Wang Jiu Hong Kang Gang Pei 《Cell Research》 SCIE CAS CSCD 2007年第5期389-401,共13页
Amyloid-β (Aβ) peptide, the primary constituent of senile plaques in Alzheimer's disease (AD), is generated by β-secretase- and y-secretase-mediated sequential proteolysis of the amyloid precursor protein (AP... Amyloid-β (Aβ) peptide, the primary constituent of senile plaques in Alzheimer's disease (AD), is generated by β-secretase- and y-secretase-mediated sequential proteolysis of the amyloid precursor protein (APP). The aspartic protease, β -site APP cleavage enzyme (BACE), has been identified as the main β-secretase in brain but the regulation of its activity is largely unclear. Here, we demonstrate that both BACE activity and subsequent Aβ production are enhanced after stimulation of receptor tyrosine kinases (RTKs), such as the receptors for epidermal growth factor (EGF) and nerve growth factor (NGF), in cultured cells as well as in mouse hippocampus. Furthermore, stimulation of RTKs also induces BACE internalization into endosomes and Golgi apparatus. This enhancement of BACE activity and A β production upon RTK activation could be specifically inhibited by Src family kinase inhibitors and by depletion of endogenous c-Src with RNAi, and could be mimicked by over-expressed c-Src. Moreover, blockage of BACE internalization by a dominant negative form of Rab5 also abolished the enhancement of BACE activity and Aβ production, indicating the requirement of BACE internalization for the enhanced activity. Taken together, our study presents evidence that BACE activity and Aβ production are under the regulation of RTKs and this is achieved via RTK-stimulated BACE internalization, and suggests that an aberration of such regulation might contribute to pathogenic Aβ production. 展开更多
关键词 β-site APP cleavage enzyme RTK Amyloid-β SRC
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Comparison in effect of different metal ions, pH and reducing agent on the protease activity in human hyper mature and mature cataract 被引量:1
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作者 SAMI Amtul Jamil SAMI Amtul Naseer KANWAL Noreen 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第8期599-603,共5页
This study was undertaken to isolate and characterize the protease activity of human eye lens sample of mature and hyper mature cataract. Samples were collected just after surgery of the cataract lens and were stored ... This study was undertaken to isolate and characterize the protease activity of human eye lens sample of mature and hyper mature cataract. Samples were collected just after surgery of the cataract lens and were stored at -20 ℃. The total protein extract was isolated from 5 samples in each case (mature and hyper mature cataract) and clear supernatant obtained after centrifugation was used as an enzyme source. The optimum pH for the proteases of mature cataract was 7.5 while the proteases of hyper mature cataract were recorded for maximum activity at pH 5.5 and 7.5. The optimum temperature for both enzyme sources was 50 ℃. Effect of different metal ions such as potassium, lead, silver, zinc and borate was studied. In each case protease activity was increased. Reducing agent e.g. β mercaptoethanol also caused an increase in activity indicating the involvement of sulfhydryl groups. Protease activity was also located on agar plates. 展开更多
关键词 Mature cataract Hyper mature cataract Eye lens Protease activity β mercaptoehanol
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Adsorption Kinetics of β-Carotene and Chlorophyll onto Acid-activated Bentonite in Model Oil 被引量:9
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作者 童军茂 武占省 +2 位作者 孙喜房 徐小琳 李春 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第2期270-276,共7页
The textural properties of acid-activated bentonite (AAB), which were prepared using four different concentrations of sulfuric acid, were analyzed by adsorption-desorption isotherm of nitrogen using an automated spe... The textural properties of acid-activated bentonite (AAB), which were prepared using four different concentrations of sulfuric acid, were analyzed by adsorption-desorption isotherm of nitrogen using an automated specific surface area and porosity analyzer. The total pore volume, specific surface area and average pore diameter of these four kinds of AAB show a regular changing trend, increasing first and then decreasing, the optimum of which can be achieved at a sulfuric acid concentration of 25% (sample A25). The kinetic analysis of the adsorption of β-carotene and chlorophyll in model oil solutions, namely, xylene and edible oil solution, has been investigated by using AAB. Experimental results indicated that the adsorption data fit the pseudo-second-order model well. The whole adsorption process of the two pigments on AAB was divided basically into two parts: the initial adsorption of pigments was rapid in the first l0 rain, followed by a slower adsorption process till equilibrium was attained at 60 rain. In addition, the amount and rate of adsorption on A25 increase synchronously with the initial pigment concentration and temperature. The results showed that the adsorption kinetics behavior of AAB with respect to the pigments is not influence by the xylene and edible oil solution. 展开更多
关键词 acid-activated bentonite pigment model oil solution adsorption kinetics
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Syntheses and Crystal Structures of Bis-[oxo-bis(p-ferrocenylbenzoxy di-n-propyltin)](I) and Bis[oxo-bis(β-ferrocenoylpropionyloxy di-n-propyltin )](II) 被引量:2
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作者 PENG Bin SUN Li-Juan CHANG Wei-Xing XIE Qing-Lan② (National Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China) 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2003年第6期647-652,共6页
Bis-[oxo-bis(p-ferrocenylbenzoxy di-n-propyltin)] I and bis-[oxo-bis(-ferrocenoyl- propionyloxy di-n-propyltin)] II were synthesized and their crystal structures have been determined by X-ray diffraction analysis. The... Bis-[oxo-bis(p-ferrocenylbenzoxy di-n-propyltin)] I and bis-[oxo-bis(-ferrocenoyl- propionyloxy di-n-propyltin)] II were synthesized and their crystal structures have been determined by X-ray diffraction analysis. The compound I2C6H6 ([(FcC6H4COOSnPr2)2O]22C6H6 or C92H108Fe4O10Sn42C6H6, Mr = 2384.16) is of triclinic, space group P?with a = 12.826(4), b = 13.099(5), c = 17.539(5) ? = 78.229(5), ?= 71.852(5), = 62.746(5)? V = 2483(1) ?, Z = 1, Dc = 1.490 g/cm3, = 0.71073 ? (MoK? =1.611 mm-1 and F(000) = 1128. The structure was refined to R = 0.0491 and wR = 0.1053 for 4690 unique reflections with I > 2(I). The compound IIC6H6 ([(FcCOCH2CH2COOSnPr2)2O]2C6H6 or C80H108Fe4O14Sn4C6H6, Mr = 2115.93) is of triclinic, space group P?with a = 11.260(4), b = 14.126(5), c = 15.961(6) ? = 91.400(6), = 110.654(6), = 104.931(6), V = 2277(1) 3, Z = 1, Dc = 1.510 g/cm3, = 0.71073 ? (MoK? = 1.750 mm-1 and F(000) = 1046. The structure was refined to R = 0.0466 and wR = 0.1138 for 5061 unique reflections with I > 2(I). The two compounds have the similar structures: both are dimers containing centrosymmetric Sn2O2 cores. But there are some differences in the ligating modes between the carboxylate groups and the Sn atoms. 展开更多
关键词 ferrocenecarboxylate diorganotin dimers X-ray diffraction
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Design and synthesis of 1-substituted-β-carboline derivatives as potential anticancer agents 被引量:1
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作者 郭亮 范文玺 +3 位作者 甘紫云 陈伟 马芹 曹日晖 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2015年第12期801-808,共8页
In the present study, we designed and synthesized a series of 1-substituted-β-carboline derivatives through modification of position-l, 2 and 9 of β-carboline nucleus in order to discover novel leading compounds wit... In the present study, we designed and synthesized a series of 1-substituted-β-carboline derivatives through modification of position-l, 2 and 9 of β-carboline nucleus in order to discover novel leading compounds with better antitumor activities and less toxicity. Their structures were confirmed by 1H NMR, 13C NMR, MS, IR and elemental analyses. All the target compounds were tested for cytotoxic activity against six cancer cell lines, including Bel-7402, HepG2, A549, A375, 786-0 and HT-29 by methyl thiazolyl tetrazolium (MTT) method. Studies of structure-activity relationships indicated that the effects of substituents in position- 1 on cytotoxic activities were in an order as follows: 2-thienyl 〉2-chlorophenyl 〉4-chlorophenyl 〉benzyl group. 展开更多
关键词 β-Carboline SYNTHESIS Anticancer activity Structure-activity relationships
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Variation in β-amylase activity and thermostability in Tibetan annual wild and cultivated barley genotypes 被引量:2
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作者 Hai-tao ZHANG Tian-long CHEN Bing-lin ZHANG De-zhi WU Ye-chang HUANG Fei-bo WU Guo-ping ZHANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2014年第9期801-808,共8页
13-Amylase activity (BAA) and thermostability (BAT) are important traits for malt quality. In this study, 138 Tibetan annual wild barley accessions and 20 cultivated genotypes differing in BAh, were planted and an... 13-Amylase activity (BAA) and thermostability (BAT) are important traits for malt quality. In this study, 138 Tibetan annual wild barley accessions and 20 cultivated genotypes differing in BAh, were planted and analyzed in 2009 and 2012. Significant differences were detected among genotypes in BAA and BAT. The cultivated genotypes had a mean BAA of 1137.6 U/g and a range of from 602.1 to 1407.5 U/g, while the wild accessions had a mean of 1517.9 U/g and a range of from 829.7 to 2310.0 U/g. The cultivated genotypes had a mean relative residual 13-amylase activity (RRBAA) of 61.6% and a range of from 22.2% to 82.3%, while the wild barleys had a mean of 57.8% and a range of from 21.9% to 96.1%. Moreover, there was a significant difference among genotypes in the response of RRBAA to the temperature and duration of heat treatment. The wild barleys had wider variation in BAA and BAT than cultivated genotvDes. 展开更多
关键词 BARLEY D-Amylase activity Thermostability TIBET
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A simplified and miniaturized glucometer-based assay for the detection of β-glucosidase activity 被引量:1
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作者 Min-yi JIN Tong ZHANG +3 位作者 Yi-shun YANG Yue DING Jun-song LI Gao-ren ZHONG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2019年第3期264-274,共11页
β-Glucosidase activity assays constitute an important indicator for the early diagnosis of neonatal necrotizing enterocolitis and qualitative changes in medicinal plants.The drawbacks of the existing methods are high... β-Glucosidase activity assays constitute an important indicator for the early diagnosis of neonatal necrotizing enterocolitis and qualitative changes in medicinal plants.The drawbacks of the existing methods are high consumption of both time and reagents,complexity in operation,and requirement of expensive instruments and highly trained personnel.The present study provides a simplified,highly selective,and miniaturized glucometer-based strategy for the detection ofβ-glucosidase activity.Single-factor experiments showed that optimumβ-glucosidase activity was exhibited at 50°C and pH 5.0 in a citric acid-sodium citrate buffer when reacting with 0.03 g/mL salicin for 30 min.The procedure for detection was simplified without the need of a chromogenic reaction.Validation of the analytical method demonstrated that the accuracy,precision,repeatability,stability,and durability were good.The linear ranges ofβ-glucosidase in a buffer solution and rat serum were 0.0873–1.5498 U/mL and 0.4076–2.9019 U/mL,respectively.The proposed method was free from interference fromβ-dextranase,snailase,β-galactosidase,hemicellulase,and glucuronic acid released by baicalin.This demonstrated that the proposed assay had a higher selectivity than the conventional dinitrosalicylic acid(DNS)assay because of the specificity for salicin and unique recognition of glucose by a personal glucose meter.Miniaturization of the method resulted in a microassay forβ-glucosidase activity.The easy-to-operate method was successfully used to detect a series ofβ-glucosidases extracted from bitter almonds and cultured by Aspergillus niger.In addition,the simplified and miniaturized glucometer-based assay has potential application in the point-of-care testing ofβ-glucosidase in many fields,including medical diagnostics,food safety,and environmental monitoring. 展开更多
关键词 Glucometer-based assay Β-GLUCOSIDASE Activity detection
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Use of a Bioaugmented Organic Soil Amendment in Combination with Gypsum for Withania somnifera Growth on Sodic Soil 被引量:7
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作者 Manjul GUPTA Pankaj Kumar SRIVASTAVA +2 位作者 SHIKHA Abhishek NIRANJAN Shri Krishna TEWARI 《Pedosphere》 SCIE CAS CSCD 2016年第3期299-309,共11页
Limited availability of organic matter is a problem to sustain crop growth on sodic soil. Organic soil amendments are a costeffective source of nutrients to enhance crop growth. A field study was conducted to evaluate... Limited availability of organic matter is a problem to sustain crop growth on sodic soil. Organic soil amendments are a costeffective source of nutrients to enhance crop growth. A field study was conducted to evaluate the effect of an organic soil amendment bioaugmented with plant growth-promoting fungi(SF_(OA) ) in combination with gypsum on soil properties and growth and yield attributes of Withania somnifera, one of the most valuable crops of the traditional medicinal system in the world, on a sodic soil at the Aurawan Research Farm of CSIR-National Botanical Research Institute, Lucknow, India. The SF_(OA) used was prepared by pre-enriching farm waste vermicompost with plant growth-promoting fungi before mixing with pressmud and Azadirachta indica seed cake. The application of SF_(OA) at 10 Mg ha^(-1)after gypsum(25.0 Mg ha^(-1)) treatment significantly(P < 0.05) increased root length(by 96%) and biomass(by 125%) of Withania plants compared to the control without SF_(OA) and gypsum. Similarly, the highest withanolide contents were observed in leaves and roots of Withania plants under 10 Mg ha^(-1)SF_(OA) and gypsum. Combined application of SF_(OA) and gypsum also improved physical, chemical and enzymatic properties of the soil, with the soil bulk density decreasing by 25%, water-holding capacity increasing by 121%, total organic C increasing by 90%, p H decreasing by 17% and alkaline phosphatase, β-glucosidase, dehydrogenase and cellulase activities increasing by 54%, 128%, 81% and 96%, respectively, compared to those of the control. These showed that application of the SF_(OA) tested in this study might reclaim sodic soil and further support Withania cultivation and results were better when the SF_(OA) was applied after gypsum treatment. 展开更多
关键词 medicinal crop plant growth-promoting fungi soil property soil reclamation vermicompost
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Phenotypic and functional characteristic of a newly dentified CDS+Foxp3-CDI03+ regulatory T cells 被引量:2
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作者 Ya Liu Qin Lan +13 位作者 Ling Lu Maogen Chen Zanxian Xia Jilin Ma Julie Wang Huimin Fan Yi Shen Bernhard Ryffel David Brand Francisco Quismorio Zhongmin Liu David A. Horwitz Anping Xu Song Guo Zheng 《Journal of Molecular Cell Biology》 SCIE CAS CSCD 2014年第1期81-92,共12页
TGF-β and Foxp3 expressions are crucial for the induction and functional activity of CD4+Foxp3+ regulatory T (iTreg) cells. Here, we demonstrate that although TGF-β-primed CD8+ cells display much lower Foxp3 ex... TGF-β and Foxp3 expressions are crucial for the induction and functional activity of CD4+Foxp3+ regulatory T (iTreg) cells. Here, we demonstrate that although TGF-β-primed CD8+ cells display much lower Foxp3 expression, their suppressive capacity is equivalent to that of CD4+ iTreg cells, and both Foxp3- and Foxp3+ CD8+ subsets have suppressive activities in vitro and in vivo. CD8+Foxp3- iTreg cells produce little IFN-γ but almost no IL-2, and display a typical anergic phenotype. Among phenotypic markers expressed in CD8+Foxp3- cells, we identify CD103 expression particularly crucial for the generation and function of this subset. Moreover, IL-IO and TGF-β signals rather than cytotoxicity mediate the suppressive effect of this novel Treg population. Therefore, TGF-β can induce both CD8+Foxp3- and CD8+Foxp3+ iTreg subsets, which may represent the unique immunoregulatory means to treat autoimmune and inflammatory diseases. 展开更多
关键词 CD8+ regulatory T cells TGF-Β FOXP3 CD103
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Effects of Maize Residue Quality and Soil Water Content on Soil Labile Organic Carbon Fractions and Microbial Properties 被引量:4
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作者 LI Zengqiang ZHAO Bingzi ZHANG Jiabao 《Pedosphere》 SCIE CAS CSCD 2016年第6期829-838,共10页
Investigating the effects of residue chemical composition on soil labile organic carbon (LOC) will improve our understanding of soil carbon sequestration. The effects of maize residue chemical composition and soil w... Investigating the effects of residue chemical composition on soil labile organic carbon (LOC) will improve our understanding of soil carbon sequestration. The effects of maize residue chemical composition and soil water content on soil LOC fractions and microbial properties were investigated in a laboratory incubation experiment. Maize shoot and root residues were incorporated into soil at 40% and 70% field capacity. The soils were incubated at 20 ℃ for 150 d and destructive sampling was conducted after 15, 75, and 150 d. Respiration, dissolved organic carbon (DOC), hot-water extractable organic carbon (HEOC), and microbial biomass carbon (MBC) were recorded, along with cellulase and β-glucosidase activities and community-level physiological profiles. The results showed that the cumulative respiration was lower in root-amended soils than in shoot-amended soils, indicating that root amendment may be beneficial to C retention in soil. No significant differences in the contents of DOG, HEOC and MBC, enzyme activities, and microbial functional diversity were observed between shoot- and root-amended soils. The high soil water content treatment significantly increased the cumulative respiration, DOC and HEOC contents, and enzyme activities compared to the low soil water content treatment. However, the soil water content treatments had little influence on the MBC content and microbial functional diversity. There were significantly positive correlations between LOC fractions and soil microbial properties. These results indicated that the chemical composition of maize residues had little influence on the DOC, HEOC, and MBC contents, enzyme activities, and microbial functional diversity, while soil water content could significantly influence DOC and HEOC contents and enzyme activities. 展开更多
关键词 community-level physiological profile dissolved organic carbon enzyme activities hot-water extractable organic carbon maize roots maize shoots
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Biochemical and behavioral characterization of the double transgenic mouse model (APPswe/PS1dE9) of Alzheimer’s disease 被引量:4
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作者 Huaqi XIONG Debbie Callaghan +5 位作者 Jolanta Wodzinska Jiejing XU Maryna Premyslova Qing-Yan LIU John Con- nelly Wandong ZHANG 《Neuroscience Bulletin》 SCIE CAS CSCD 2011年第4期221-232,共12页
Objective The double transgenic mouse model (APPswe/PSldE9) of Alzheimer's disease (AD) has been widely used in experimental studies. β-Amyloid (Aβ) peptide is excessively produced in AD mouse brain, which af... Objective The double transgenic mouse model (APPswe/PSldE9) of Alzheimer's disease (AD) has been widely used in experimental studies. β-Amyloid (Aβ) peptide is excessively produced in AD mouse brain, which affects synaptic function and the development of central nervous system. However, little has been reported on characterization of this model. The present study aimed to characterize this mouse AD model and its wild-type counterparts by biochemical and functional approaches. Methods Blood samples were collected from the transgenic and the wild-type mice, and radial arm water maze behavioral test was conducted at the ages of 6 and 12 months. The mice were sacrificed at 12-month age. One hemisphere of the brain was frozen-sectioned for immunohistochemistry and the other hemisphere was dissected into 7 regions. The levels ofAβ1-40, Aβ1-42 and 8-hydroxydeoxyguanosine (8-OHdG) in blood or/and brain samples were analyzed by ELISA. Secretase activities in brain regions were analyzed by in vitro assays. Results The pre-mature death rate of transgenic mice was approximately 35% before 6-month age, and high levels of Aβ1-40 and Aβ1-42 were detected in these dead mice brains with a ratio of 1 : 1 0. The level of blood-borne Aβ at 6-month age was similar with that at 12-month age. Besides, Aβ1-40 level in the blood was significantly higher than Aβ1-42 level at the ages of 6 and 12 months (ratio 2.37:1). In contrast, the level of Aβ1-42 in the brain (160.6 ng/mg protein) was higher than that of Aβ1-40 (74 ng/mg protein) (ratio 2.17:1). In addition, the levels of Aβ1-40 and Aβ1-42 varied markedly among different brain regions. Aβ1-42 level was significantly higher than Aβ1-40 level in cerebellum, frontal and posterior cortex, and hippocampus. Secretase activity assays did not reveal major differences among different brain regions or between wild-type and transgenic mice, suggesting that the transgene PS1 did not lead to higher 7-secretase activity but was more efficient in producing Aβ1-42 peptides. 8-OHdG, the biomarker of DNA oxidative damage, showed a trend of increase in the blood of transgenic mice, but with no significant difference, as compared with the wild-type mice. Behavioral tests showed that transgenic mice had significant memory deficits at 6-month age compared to wild-type controls, and the deficits were exacerbated at 12-month age with more errors. Conclusion These results suggest that this mouse model mimics the early-onset human AD and may represent full-blown disease at as early as 6-month age for experimental studies. 展开更多
关键词 mouse model Alzheimer's disease β-amyloid peptides secretase activities DNA oxidative damage behavioral test
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Cover Crop and Irrigation Effects on Soil Microbial Communities and Enzymes in Semiarid Agroecosystems of the Central Great Plains of North America 被引量:3
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作者 Francisco J. CALDERON David NIELSEN +2 位作者 Veronica ACOSTA-MARTINEZ Merle F. VIGIL Drew LYON 《Pedosphere》 SCIE CAS CSCD 2016年第2期192-205,共14页
Cover crops can have beneficial effects on soil microbiology by increasing carbon (C) supply, but these beneficial effects can be modulated by precipitation conditions. The objective of this study was to compare a f... Cover crops can have beneficial effects on soil microbiology by increasing carbon (C) supply, but these beneficial effects can be modulated by precipitation conditions. The objective of this study was to compare a fallow-winter wheat (Triticum aestivum L.) rotation to several cover crop-winter wheat rotations under rainfed and irrigated conditions in the semiarid US High Plains. Experiments were carried out at two sites, Sidney in Nebraska, and Akron in Colorado, USA, with three times of soil sampling in 2012--2013 at cover crop termination, wheat planting, and wheat maturity. The experiments included four single-species cover crops, a 10-species mixture, and a fallow treatment. The variables measured were soil C and nitrogen (N), soil community structure by fatty acid methyl ester (FAME) profiles, and soil β-glucosidase,β-glucosaminidase, and phosphodiesterase activities. The fallow treatment, devoid of living plants, reduced the concentrations of most FAMEs at cover crop termination. The total FAME concentration was correlated with cover crop biomass (R = 0.62 at Sidney and 0.44 at Akron). By the time of wheat planting, there was a beneficial effect of irrigation, which caused an increase in myeorrhizal and protozoan markers. At wheat maturity, the cover crop and irrigation effects on soil FAMEs had subsided, but irrigation had a positive effect on the β-glucosidase and phosphodiesterase activities at Akron, which was the drier of the two sites. Cover crops and irrigation were slow to impact soil C concentration. Our results show that cover crops had a short-lived effect on soil microbial communities in semiarid wheat-based rotations and irrigation could enhance soil enzyme activity. In the semiarid environment, longer time spans may have been needed to see beneficial effects of cover crops on soil microbial community structure, soil enzyme activities, and soil C sequestration. 展开更多
关键词 crop rotation enzyme activity FAME profile fatty acid methyl ester winter wheat
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