Identification and characterization of foliar polyphenolic composition in sweetpotato (Ipomoea batatas L.) genotypes   总被引：1，自引：0，他引：1  

Islam MS  Yoshimoto M  Yahara S  Okuno S  Ishiguro K  Yamakawa O 《Journal of agricultural and food chemistry》2002,50(13):3718-3722

Trials over two years were conducted using 1389 sweetpotato (Ipomoea batatas L.) genotypes collected from all over the world to characterize the polyphenolic composition in sweetpotato leaves. Wide variation was observed in relation to their total and individual leaf polyphenolic constituents. In all genotypes studied, the total polyphenol contents of sweetpotato leaf ranged from 1.42 to 17.1 g/100 g dry weight. The six different polyphenolic compounds were identified and quantified by NMR, FABMS, and RPHPLC analysis procedures. This is the first report of polyphenolic compositions in sweetpotato leaves. The relative levels of polyphenolic acids in sweetpotato leaves were as follows: 3,5-di-O-caffeoylquinic acid > 4,5-di-O-caffeoylquinic acid > chlorogenic acid (3-O-caffeoylquinic acid) > 3,4-di-O-caffeoylquinic acid > 3,4,5-tri-O-caffeoylquinic acid > caffeic acid. The highest 3,4,5-tri-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid occurred at 221 and 1183.30 mg/100 g dry weight, respectively.  相似文献   

Genetic variability in cultivated common bean beyond the two major gene pools   总被引：7，自引：0，他引：7  

F.M.A. Islam  K.E. Basford  R.J. Redden  A.V. Gonzalez  P.M. Kroonenberg  S. Beebe 《Genetic Resources and Crop Evolution》2002,49(3):271-283

It is generally accepted that two major gene pools exist in cultivatedcommon bean (Phaseolus vulgaris L.), a MiddleAmerican and an Andean one. Some evidence, based on unique phaseolin morphotypesand AFLP analysis, suggests that at least one more gene pool exists incultivated common bean. To investigate this hypothesis, 1072 accessions from acommon bean core collection from the primary centres of origin, held at CIAT,were investigated. Various agronomic and morphological attributes (14categorical and 11 quantitative) were measured. Multivariate analyses,consisting of homogeneity analysis and clustering for categorical data,clustering and ordination techniques for quantitative data and nonlinearprincipal component analysis for mixed data, were undertaken. The results ofmost analyses supported the existence of the two major gene pools. However, theanalysis of categorical data of protein types showed an additional minor genepool. The minor gene pool is designated North Andean and includes phaseolintypes CH, S and T; lectin types 312, Pr, B and K; and mostly A5, A6 and A4 types-amylase inhibitor. Analysis of the combined categorical data ofprotein types and some plant categorical data also suggested that some othergermplasm with C type phaseolin are distinguished from the major gene pools.  相似文献   

A Chemoautotrophically Based Cave Ecosystem   总被引：1，自引：0，他引：1  

SM Sarbu  TC Kane  BK Kinkle 《Science (New York, N.Y.)》1996,272(5270):1953-1955

Microbial mats discovered in a ground-water ecosystem in southern Romania contain chemoautotrophic bacteria that fix inorganic carbon, using hydrogen sulfide as an energy source. Analysis of stable carbon and nitrogen isotopes showed that this chemoautotrophic production is the food base for 48 species of cave-adapted terrestrial and aquatic invertebrates, 33 of which are endemic to this ecosystem. This is the only cave ecosystem known to be supported by in situ autotrophic production, and it contains the only terrestrial community known to be chemoautotrophically based.  相似文献   

Premelting at defects within bulk colloidal crystals     

Alsayed AM  Islam MF  Zhang J  Collings PJ  Yodh AG 《Science (New York, N.Y.)》2005,309(5738):1207-1210

Premelting is the localized loss of crystalline order at surfaces and defects at temperatures below the bulk melting transition. It can be thought of as the nucleation of the melting process. Premelting has been observed at the surfaces of crystals but not within. We report observations of premelting at grain boundaries and dislocations within bulk colloidal crystals using real-time video microscopy. The crystals are equilibrium close-packed, three-dimensional colloidal structures made from thermally responsive microgel spheres. Particle tracking reveals increased disorder in crystalline regions bordering defects, the amount of which depends on the type of defect, distance from the defect, and particle volume fraction. Our observations suggest that interfacial free energy is the crucial parameter for premelting in colloidal and atomic-scale crystals.  相似文献   

Growth of SiO2 at room temperature with the use of catalyzed sequential half-reactions     

JW Klaus  O Sneh  SM George 《Science (New York, N.Y.)》1997,278(5345):1934-1936

Films of silicon dioxide (SiO2) were deposited at room temperature by means of catalyzed binary reaction sequence chemistry. The binary reaction SiCl4 + 2H2O --> SiO2 + 4HCl was separated into SiCl4 and H2O half-reactions, and the half-reactions were then performed in an ABAB ellipsis sequence and catalyzed with pyridine. The pyridine catalyst lowered the deposition temperature from >600 to 300 kelvin and reduced the reactant flux required for complete reactions from approximately 10(9) to approximately 10(4) Langmuirs. Growth rates of approximately 2.1 angstroms per AB reaction cycle were obtained at room temperature for reactant pressures of 15 millitorr and 60-second exposure times with 200 millitorr of pyridine. This catalytic technique may be general and should facilitate the chemical vapor deposition of other oxide and nitride materials.  相似文献   

Aeromonas hydrophila-associated septicemia in captive crocodiles (Crocodylus johnstoni and Crocodylus porosus)     

Roh YS  Park H  Cho HU  Cho A  Islam MR  Cho HS  Lim CW  Kim B 《Journal of zoo and wildlife medicine》2011,42(4):738-742

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Canning and pH stability of epichlorohydrin-treated parboiled rice     

J E Rutledge  M N Islam 《Journal of agricultural and food chemistry》1973,21(3):458-460

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Sequence Analysis of the Full‐Length Cloned DNA of a Chicken Anaemia Virus (CAV) Strain from Bangladesh: Evidence for Genetic Grouping of CAV Strains Based on the Deduced VP1 Amino Acid Sequences     

M. R. Islam  R. Johne  R. Raue  D. Todd  H. Müller 《Zoonoses and public health》2002,49(7):332-337

Chicken anaemia virus (CAV) was detected in the bursa of Fabricius of a 4‐week‐old chicken obtained from an outbreak of acute infectious bursal disease in Bangladesh. Repeated attempts to grow this virus in MDCC‐MSB1 cells were not successful. A full‐length PCR amplicon of the genome of this strain, designated as BD‐3 CAV, was cloned and sequenced. The complete nucleotide sequence and the deduced amino acid sequence were compared with those of 12 other CAV strains. The genetic analysis of the amino acid sequences of VP1 indicated the possible existence of genetic groups among CAV strains, as BD‐3 CAV along with four other strains (CIA‐1, L‐028, Isolate 704 and TR‐20) formed a distinct lineage. These strains have four signatory amino acids in VP1, such as ⁷⁵I/T, ⁹⁷L, ¹³⁹Q and ¹⁴⁴Q, out of which the latter two are located in a small hydrophilic peak.  相似文献   

BIOMECHANICAL COMPARISON OF THREE INTERNAL FIXATIONS FOR TREATMENT OF SLIPPED CAPITAL FEMORAL EPIPHYSIS IN IMMATURE DOGS     

Belkoff SM  Millis DL  Probst CW 《Veterinary surgery : VS》1993,22(3):183-183

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Seedbed Characteristics and Seeding Depth Effects on Emergence and Seedling Vigour of Upland Rice     

A. F. M. Ekramul Haque  A. Hamid    M. T. Islam  M. Mohiuddin 《Journal of Agronomy and Crop Science》1992,168(1):61-64

Effects of seedbed condition and seeding depth on the emergence and seedling vigour of upland rice was studied. Regardless of aggregate size distribution, seeds sown at 2 cm depth gave the maximum emergence rate (80-90 %) which was reduced to 47 % for sowing at 5 cm depth. Seeding at 10 cm depth caused total failure in emergence. When planted at 2 cm depth, aggregate size produced considerable variation in the speed of emergence but caused no significant differences in final emergence count. For seeds sown at 5 cm depth, seedbed with aggregate size < 2 mm resulted in poor emergence (12 %) while with aggregates > 8 mm reduced emergence by 34 % compared with balanced proportion of larger, moderate and smaller aggregates. Neither the seedbed condition nor seeding depth caused significant variation in seedling height or seedling dry weight.  相似文献