By determining the earth moisture content of artificial forestland between 0 and 6 m deep in the Loess Plateau of Shaanxi province, the vertical change of moisture content, distribution and formation causes of a dried...By determining the earth moisture content of artificial forestland between 0 and 6 m deep in the Loess Plateau of Shaanxi province, the vertical change of moisture content, distribution and formation causes of a dried earth layer are researched. The results show that the average moisture content is 9.3%-9.5% between 2 and 4 m under artificial forest of over 10 year＇s growth in Guanzhong Plain, and chronic weak dried earth layers are developed which show that the dried earth layers are distributed extensively on the Loess Plateau. The southern boundary of the dried earth layer has reached the northern foot of the Qinling Mountains. When precipitation reaches 600 mm, there are weak dried earth layers between 2 and 4 m under artificial forest of more than 10 years old. When the precipitation is between 400 and 500 mm, there are moderate dried earth layers. When precipitation is above 800 mm, there are no dried earth layers. There are no dried earth layers under meadow land, corn land and less than 5 years old of artificial forestland in central and southern parts of the Loess Plateau. The development of dried earth layers under cypress forest is weaker than broad-leaved forest. Under the same climatic conditions, the development of dried earth layers under the loess tableland is nearly at the same level as the 2nd and 3rd river terrace. Dried earth layers developed in membrane water zone, and the buried depth is small and motion velocity is slow in the Loess Plateau, which is the direct water factor of the formation of the dried earth layer, while differences of tree age and tree species are the plant factors that consumed much moisture. From the depth of the gravity water and the membrane water in Guanzhong Plain, it is clear that the formation cause of dried earth layers is mainly due to natural factors. The dried layers generally develop in middle-aged artificial forestland that consumed too much moisture, which is the general character of earth moisture in subhumid and semiarid zones. The appearance of dried l展开更多
Ⅰ. NEW GUAIANOLIDES FROM CENTIPEDA MINIMA The Chinese medical herb Centipeda minima (L.) A. Br. et Ascher (Compositae) has been used for treatment of rhinitis, sinusitis and nasopharynger tumor. Previous chemical inv...Ⅰ. NEW GUAIANOLIDES FROM CENTIPEDA MINIMA The Chinese medical herb Centipeda minima (L.) A. Br. et Ascher (Compositae) has been used for treatment of rhinitis, sinusitis and nasopharynger tumor. Previous chemical investigations only gave steroids and triterpenes and cis-chrysanthenyl acetate. A reinvestigation of the dried drug (whole plant) afforded in addition to the triterpenes and steroids 10-isobutyryloxy-8, 9-epoxithymol-isobutyrate 6, the derivatives 1 and 2, three pseudoguaianolides, arnicolide 7, brevilin8 and helenalin 9, as well as three guaianolides, the 2-O-esters of florilenalin 3—5.展开更多
Isatis indigotica(2n=14)is an important medicinal plant in China.Its dried leaves and roots(called Isatidis Folium and Isatidis Radix,respectively)are broadly used in traditional Chinese medicine for curing diseases c...Isatis indigotica(2n=14)is an important medicinal plant in China.Its dried leaves and roots(called Isatidis Folium and Isatidis Radix,respectively)are broadly used in traditional Chinese medicine for curing diseases caused by bacteria and viruses such as influenza and viral pneumonia.Various classes of compounds isolated from this species have been identified as effective ingredients.Previous studies based on transcriptomes revealed only a few candidate genes for the biosynthesis of these active compounds in this medicinal plant.Here,we report a high-quality chromosome-scale genome assembly of I.indigotica with a total size of 293.88 Mb and scaffold N50=36.16 Mb using single-molecule real-time long reads and high-throughput chromosome conformation capture techniques.We annotated 30,323 highconfidence protein-coding genes.Based on homolog searching and functional annotations,we identified many candidate genes involved in the biosynthesis of main active components such as indoles,terpenoids,and phenylpropanoids.In addition,we found that some key enzyme-coding gene families related to the biosynthesis of these components were expanded due to tandem duplications,which likely drove the production of these major active compounds and explained why I.indigotica has excellent antibacterial and antiviral activities.Our results highlighted the importance of genome sequencing in identifying candidate genes for metabolite synthesis in medicinal plants.展开更多
Soil water is strongly affected by land use/cover in the Loess Plateau in China. Water stored in thick loessal soils is one of the most important resources regulating vegetation growth. However, soil water in the deep...Soil water is strongly affected by land use/cover in the Loess Plateau in China. Water stored in thick loessal soils is one of the most important resources regulating vegetation growth. However, soil water in the deep loess proifle, which is critical for maintaining the function of the“soil water pool”is rarely studied because deep proifle soil samples are dififcult to collect. In this study, four experimental plots were established in 2005 to represent different farming systems on the Changwu Tableland：fallow land, fertilized cropland, unfertilized cropland, and continuous alfalfa. The soil water content in the 15-m-deep loess proifles was monitored continuously from 2007 to 2012 with the neutron probe technique. The results showed that temporal variations in soil water proifles differed among the four farming systems. Under fallow land, the soil water content increased gradually over time, ifrst in the surface layers and later in the deep soil layers. In contrast, the soil water content decreased gradually under continuous alfalfa. The distributions of soil water in deep soil layers under both fertilized and unfertilized cropland were relatively stable over time. Thus farming system signiifcantly affected soil water content. Seven years after the start of the experiment, the soil water contents in the 15-m-deep proifles averaged 23.4%under fallow land, 20.3%under fertilized cropland, 21.6%under unfertilized cropland, and 16.0%under continuous alfalfa. Compared to measurements at the start of the experiment, both fallow land and unfertilized cropland increased soil water storage in the 15-m loess proifles. In contrast, continuous alfalfa reduced soil water storage. Fertilized cropland has no signiifcant effect on soil water storage. These results suggest that deep soil water can be replenished under the fallow and unfertilized farming systems. Dry soil layers （i.e., those which have soil water content less than the stable ifeld water capacity） in the subsoil of the Changwu Tableland region can be class展开更多
This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish ...This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine(CAD) and putrescine(PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret(Pampus argenteus)(347.79 mg kg^(-1)). Five of forty three samples exceeded the acceptable content of TYR(100 mg kg^(-1)), and 23.26% of dried-salted fish contained high contents of biogenic amines(above 600 mg kg^(-1)). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count(TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.展开更多
AIM: To study the dibenzocylooctadiene lignans from the stems of Kadsura heteroclita. METHOD: Chromatographic separations of silica gel and semi-preparative HPLC were used. All of the structures were elucidated on the...AIM: To study the dibenzocylooctadiene lignans from the stems of Kadsura heteroclita. METHOD: Chromatographic separations of silica gel and semi-preparative HPLC were used. All of the structures were elucidated on the basis of spectroscopic analysis,including 2D-NMR and HR-MS techniques. RESULTS: Four dibenzocylooctadiene lignans were isolated from K. heteroclita. Their structures were identified as heteroclitin R(1), heteroclitin S(2), gonisin O(3), and schisanlignone A(4). CONCLUSION: Heteroclitin R(1) and heteroclitin S(2) are new natural lignans.展开更多
The most economically important disease of cultivated grapevines worldwide is powdery mildew(PM)caused by the ascomycete fungus Erysiphe necator.The majority of grapevine cultivars used for wine,table grape,and dried ...The most economically important disease of cultivated grapevines worldwide is powdery mildew(PM)caused by the ascomycete fungus Erysiphe necator.The majority of grapevine cultivars used for wine,table grape,and dried fruit production are derived from the Eurasian grape species Vitis vinifera because of its superior aroma and flavor characteristics.However,this species has little genetic resistance against E.necator meaning that grape production is highly dependent on the frequent use of fungicides.The integration of effective genetic resistance into cultivated grapevines would lead to significant financial and environmental benefits and represents a major challenge for viticultural industries and researchers worldwide.This review will outline the strategies being used to increase our understanding of the molecular basis of V.vinifera susceptibility to this fungal pathogen.It will summarize our current knowledge of different resistance loci/genes that have evolved in wild grapevine species to restrict PM infection and assess the potential application of these defense genes in the generation of PM-resistant grapevine germplasm.Finally,it addresses future research priorities which will be important in the rapid identification,evaluation,and deployment of new PM resistance genes which are capable of conferring effective and durable resistance in the vineyard.展开更多
It is difficult to obtain in vivo digestion kinetics data of high protein ingredients using chickens. Collecting kinetics data requires repeated sampling of digesta from the small intestine during the digestion proces...It is difficult to obtain in vivo digestion kinetics data of high protein ingredients using chickens. Collecting kinetics data requires repeated sampling of digesta from the small intestine during the digestion process,which is not easily accomplished due to the anatomical structure of chicken digestive tract. An in vitro technique is proposed for measuring the digestion kinetics of protein sources fed to chickens. The method has a 30 min gastric and 3 h intestinal phase. Five hundred milligram crude protein(CP)equivalent of each meal sample(CP = % N × 6.25) was digested with pepsin(28,260 units) in 50 m L polyethylene centrifuge tubes for 30 min in a shaking water bath(150 strokes/min; 30 mm stroke length)at 41C. The 6.5 mL pancreatin was selected as the enzyme concentration for the intestinal phase, during which time 500 m L aliquots were collected at 0, 15, 30, 45, 60, 90, 120, 150, 180 and 240 min. Samples were diluted 1:820 with HCl and sodium acetate buffer, and then mixed with ninhydrin reagent(2:1) at100 ± 2C for 15 min and spectrometric readings taken at 568 nm. To validate the assay, 5 replications of soybean meal(SBM), corn gluten meal(CGM), corn distillers dried grains with solubles(CDDGS), porcine meal(PCM), fish meal(FM) and casein(CA) were digested. The digestion data were modeled with PROC NLIN procedure, and the intra coefficient of variation(CV) assessed using PROC MEANS of SAS 9.4. The digestion values at 180 min were SBM 95 ± 4, FM 93 ± 3, PCM 68 ± 4, CGM 82 ± 3 and CDDGS 70 ± 2.Intra CV for SBM, CGM, CDDGS, PCM and FM were 5%, 5%, 12%, 10% and 2%, respectively. The estimated fractional digestion rates for SBM, CGM, CDDGS, FM and PCM were 0.023, 0.013, 0.009, 0.024 and 0.013,respectively. In conclusion, the proposed in vitro technique estimated the rate and extent of the digestion of CP for the meals with low intra CV.展开更多
The greatest environmental disaster in Central Asiathe drying up of the Aral Seahas led to the formation of a new terrain, extending over 2.7 million hectares in Uzbekistan. This newly formed terrain is dynamically de...The greatest environmental disaster in Central Asiathe drying up of the Aral Seahas led to the formation of a new terrain, extending over 2.7 million hectares in Uzbekistan. This newly formed terrain is dynamically developing, with emerging soil formations replacing bottom sediments. This paper analyzes the results of a study on soil formation in the eastern part of the dried-up seabed, focusing on the influence of natural processes occurring there.展开更多
基金Foundation： National Natural Science Foundation of China, No.40672108 Project of State Key Laboratory of Loess and Quaternary Geology, CAS, No.SKLLQG0606
文摘By determining the earth moisture content of artificial forestland between 0 and 6 m deep in the Loess Plateau of Shaanxi province, the vertical change of moisture content, distribution and formation causes of a dried earth layer are researched. The results show that the average moisture content is 9.3%-9.5% between 2 and 4 m under artificial forest of over 10 year＇s growth in Guanzhong Plain, and chronic weak dried earth layers are developed which show that the dried earth layers are distributed extensively on the Loess Plateau. The southern boundary of the dried earth layer has reached the northern foot of the Qinling Mountains. When precipitation reaches 600 mm, there are weak dried earth layers between 2 and 4 m under artificial forest of more than 10 years old. When the precipitation is between 400 and 500 mm, there are moderate dried earth layers. When precipitation is above 800 mm, there are no dried earth layers. There are no dried earth layers under meadow land, corn land and less than 5 years old of artificial forestland in central and southern parts of the Loess Plateau. The development of dried earth layers under cypress forest is weaker than broad-leaved forest. Under the same climatic conditions, the development of dried earth layers under the loess tableland is nearly at the same level as the 2nd and 3rd river terrace. Dried earth layers developed in membrane water zone, and the buried depth is small and motion velocity is slow in the Loess Plateau, which is the direct water factor of the formation of the dried earth layer, while differences of tree age and tree species are the plant factors that consumed much moisture. From the depth of the gravity water and the membrane water in Guanzhong Plain, it is clear that the formation cause of dried earth layers is mainly due to natural factors. The dried layers generally develop in middle-aged artificial forestland that consumed too much moisture, which is the general character of earth moisture in subhumid and semiarid zones. The appearance of dried l
文摘Ⅰ. NEW GUAIANOLIDES FROM CENTIPEDA MINIMA The Chinese medical herb Centipeda minima (L.) A. Br. et Ascher (Compositae) has been used for treatment of rhinitis, sinusitis and nasopharynger tumor. Previous chemical investigations only gave steroids and triterpenes and cis-chrysanthenyl acetate. A reinvestigation of the dried drug (whole plant) afforded in addition to the triterpenes and steroids 10-isobutyryloxy-8, 9-epoxithymol-isobutyrate 6, the derivatives 1 and 2, three pseudoguaianolides, arnicolide 7, brevilin8 and helenalin 9, as well as three guaianolides, the 2-O-esters of florilenalin 3—5.
基金supported by the National Key Research and Development Program of China(2017YFC0505203)National Natural Science Foundation of China(31590821 and 31561123001)+2 种基金Fundamental Research Funds for the Central Universities(2018CDDY-S02-SCU and SCU2019D013)National High-Level Talents Special Support Plan(10 Thousand of People Plan)985 and 211 Projects of Sichuan University.
文摘Isatis indigotica(2n=14)is an important medicinal plant in China.Its dried leaves and roots(called Isatidis Folium and Isatidis Radix,respectively)are broadly used in traditional Chinese medicine for curing diseases caused by bacteria and viruses such as influenza and viral pneumonia.Various classes of compounds isolated from this species have been identified as effective ingredients.Previous studies based on transcriptomes revealed only a few candidate genes for the biosynthesis of these active compounds in this medicinal plant.Here,we report a high-quality chromosome-scale genome assembly of I.indigotica with a total size of 293.88 Mb and scaffold N50=36.16 Mb using single-molecule real-time long reads and high-throughput chromosome conformation capture techniques.We annotated 30,323 highconfidence protein-coding genes.Based on homolog searching and functional annotations,we identified many candidate genes involved in the biosynthesis of main active components such as indoles,terpenoids,and phenylpropanoids.In addition,we found that some key enzyme-coding gene families related to the biosynthesis of these components were expanded due to tandem duplications,which likely drove the production of these major active compounds and explained why I.indigotica has excellent antibacterial and antiviral activities.Our results highlighted the importance of genome sequencing in identifying candidate genes for metabolite synthesis in medicinal plants.
基金funded by the National Natural Science Foundation of China (41171033,51179161 and 41101025)
文摘Soil water is strongly affected by land use/cover in the Loess Plateau in China. Water stored in thick loessal soils is one of the most important resources regulating vegetation growth. However, soil water in the deep loess proifle, which is critical for maintaining the function of the“soil water pool”is rarely studied because deep proifle soil samples are dififcult to collect. In this study, four experimental plots were established in 2005 to represent different farming systems on the Changwu Tableland：fallow land, fertilized cropland, unfertilized cropland, and continuous alfalfa. The soil water content in the 15-m-deep loess proifles was monitored continuously from 2007 to 2012 with the neutron probe technique. The results showed that temporal variations in soil water proifles differed among the four farming systems. Under fallow land, the soil water content increased gradually over time, ifrst in the surface layers and later in the deep soil layers. In contrast, the soil water content decreased gradually under continuous alfalfa. The distributions of soil water in deep soil layers under both fertilized and unfertilized cropland were relatively stable over time. Thus farming system signiifcantly affected soil water content. Seven years after the start of the experiment, the soil water contents in the 15-m-deep proifles averaged 23.4%under fallow land, 20.3%under fertilized cropland, 21.6%under unfertilized cropland, and 16.0%under continuous alfalfa. Compared to measurements at the start of the experiment, both fallow land and unfertilized cropland increased soil water storage in the 15-m loess proifles. In contrast, continuous alfalfa reduced soil water storage. Fertilized cropland has no signiifcant effect on soil water storage. These results suggest that deep soil water can be replenished under the fallow and unfertilized farming systems. Dry soil layers （i.e., those which have soil water content less than the stable ifeld water capacity） in the subsoil of the Changwu Tableland region can be class
基金financially supported by the National Natural Science Foundation of China (No.31371800)the National Science-Technology Support Plan Project (2012BAD28B05)
文摘This study was carried out to investigate the biogenic amines(BAs), physicochemical property and microorganisms in dry salted fish, a traditional aquatic food consumed in China. Forty three samples of dry salted fish were gathered from retail and wholesale markets and manufacturers, which had been produced in various regions in China. Cadaverine(CAD) and putrescine(PUT) were quantitatively the most common biogenic amines. About 14% of the samples exceeded the histamine content standards established by the FDA and/or EU. The highest histamine content was found in Silver pomfret(Pampus argenteus)(347.79 mg kg^(-1)). Five of forty three samples exceeded the acceptable content of TYR(100 mg kg^(-1)), and 23.26% of dried-salted fish contained high contents of biogenic amines(above 600 mg kg^(-1)). In addition, species, regions, pickling processes and drying methods made the physicochemical property, microorganisms and biogenic amines in dry salted fish to be different to some extents. The total plate count(TPC) was much higher than that of total halophilic bacteria in all samples. The biogenic amines, physicochemical property and microbiological counts exhibited large variations among samples. Furthermore, no significant correlation between biogenic amines and physicochemical property and TPC was observed. This study indicated that dry salted fish may still present healthy risk for BAs, depending on the processing methods, storage conditions among others.
基金supported by the National High Technology Research and Development Program of China(863 Program)(No.2011AA100607)the National Natural Science Foundation of China(No.81102894)the Key Technologies Research and Development Program of China(No.2011BAI 13B06)
文摘AIM: To study the dibenzocylooctadiene lignans from the stems of Kadsura heteroclita. METHOD: Chromatographic separations of silica gel and semi-preparative HPLC were used. All of the structures were elucidated on the basis of spectroscopic analysis,including 2D-NMR and HR-MS techniques. RESULTS: Four dibenzocylooctadiene lignans were isolated from K. heteroclita. Their structures were identified as heteroclitin R(1), heteroclitin S(2), gonisin O(3), and schisanlignone A(4). CONCLUSION: Heteroclitin R(1) and heteroclitin S(2) are new natural lignans.
基金Researchers in IBD’s laboratory were supported by grants from the Australian Grape and Wine AuthorityResearch projects in WQ’s laboratory were sponsored by the USDA-NIFA grantsMissouri State University and the Missouri Wine and Grape Board.
文摘The most economically important disease of cultivated grapevines worldwide is powdery mildew(PM)caused by the ascomycete fungus Erysiphe necator.The majority of grapevine cultivars used for wine,table grape,and dried fruit production are derived from the Eurasian grape species Vitis vinifera because of its superior aroma and flavor characteristics.However,this species has little genetic resistance against E.necator meaning that grape production is highly dependent on the frequent use of fungicides.The integration of effective genetic resistance into cultivated grapevines would lead to significant financial and environmental benefits and represents a major challenge for viticultural industries and researchers worldwide.This review will outline the strategies being used to increase our understanding of the molecular basis of V.vinifera susceptibility to this fungal pathogen.It will summarize our current knowledge of different resistance loci/genes that have evolved in wild grapevine species to restrict PM infection and assess the potential application of these defense genes in the generation of PM-resistant grapevine germplasm.Finally,it addresses future research priorities which will be important in the rapid identification,evaluation,and deployment of new PM resistance genes which are capable of conferring effective and durable resistance in the vineyard.
基金the National Science and Engineering Research Council(NSERC)Industrial Research Chair Program for financial support for this project(Grant No.IRCSA452664-12)+10 种基金Funding for this program was derived from AviagenCanadian Poultry Research CouncilChicken Farmers of SaskatchewanNSERCOntario Poultry Industry CouncilPrairie Pride Natural Foods Ltd.Saskatchewan Egg ProducersSaskatchewan Hatching Egg ProducersSaskatchewan Turkey ProducersSofina Foods Inc.the University of Saskatchewan
文摘It is difficult to obtain in vivo digestion kinetics data of high protein ingredients using chickens. Collecting kinetics data requires repeated sampling of digesta from the small intestine during the digestion process,which is not easily accomplished due to the anatomical structure of chicken digestive tract. An in vitro technique is proposed for measuring the digestion kinetics of protein sources fed to chickens. The method has a 30 min gastric and 3 h intestinal phase. Five hundred milligram crude protein(CP)equivalent of each meal sample(CP = % N × 6.25) was digested with pepsin(28,260 units) in 50 m L polyethylene centrifuge tubes for 30 min in a shaking water bath(150 strokes/min; 30 mm stroke length)at 41C. The 6.5 mL pancreatin was selected as the enzyme concentration for the intestinal phase, during which time 500 m L aliquots were collected at 0, 15, 30, 45, 60, 90, 120, 150, 180 and 240 min. Samples were diluted 1:820 with HCl and sodium acetate buffer, and then mixed with ninhydrin reagent(2:1) at100 ± 2C for 15 min and spectrometric readings taken at 568 nm. To validate the assay, 5 replications of soybean meal(SBM), corn gluten meal(CGM), corn distillers dried grains with solubles(CDDGS), porcine meal(PCM), fish meal(FM) and casein(CA) were digested. The digestion data were modeled with PROC NLIN procedure, and the intra coefficient of variation(CV) assessed using PROC MEANS of SAS 9.4. The digestion values at 180 min were SBM 95 ± 4, FM 93 ± 3, PCM 68 ± 4, CGM 82 ± 3 and CDDGS 70 ± 2.Intra CV for SBM, CGM, CDDGS, PCM and FM were 5%, 5%, 12%, 10% and 2%, respectively. The estimated fractional digestion rates for SBM, CGM, CDDGS, FM and PCM were 0.023, 0.013, 0.009, 0.024 and 0.013,respectively. In conclusion, the proposed in vitro technique estimated the rate and extent of the digestion of CP for the meals with low intra CV.
文摘The greatest environmental disaster in Central Asiathe drying up of the Aral Seahas led to the formation of a new terrain, extending over 2.7 million hectares in Uzbekistan. This newly formed terrain is dynamically developing, with emerging soil formations replacing bottom sediments. This paper analyzes the results of a study on soil formation in the eastern part of the dried-up seabed, focusing on the influence of natural processes occurring there.
