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1.
K. Ferrazzoli Devienne M.S. Gonalves Raddi R. Gomes Coelho W. Vilegas 《Phytomedicine》2005,12(5):378-381
Three naturally occurring isocoumarins (paepalantine, paepalantine 9-O-beta-D-glucopyranoside and paepalantine 9-O-beta-D-allopyranosyl(1 --> 6) glucopyranoside) and two semi-synthetic analogues, 9,10-acylated compound and 9-OH-10-methylated compound, structurally similar to paepalantine, were evaluated for antimicrobial activity using a spectrophotometric microdilution technique. The paepalantine was active against S. aureus, S. epidermidis, and E. faecalis while the other four compounds proved ineffective against all microorganisms tested at concentrations of 500 microg/ml. Variations in phenolic substitution at OH-9 and/or OH-10 in the paepalantine molecule resulted in compounds without antimicrobial activity. A combination of structural features, two phenolic groups as cathecolic system, forms an oxygenated system arrangement that may reflect the potentially antimicrobial properties of paepalantine. 相似文献
2.
Leandro Neves Faria Marlon Gomes Da Rocha Quirijn De Jong Van Lier Derblai Casaroli 《Plant and Soil》2010,331(1-2):299-311
Correct modeling of root water uptake partitioning over depth is an important issue in hydrological and crop growth models. Recently a physically based model to describe root water uptake was developed at single root scale and upscaled to the root system scale considering a homogeneous distribution of roots per soil layer. Root water uptake partitioning is calculated over soil layers or compartments as a function of respective soil hydraulic conditions, specifically the soil matric flux potential, root characteristics and a root system efficiency factor to compensate for within-layer root system heterogeneities. The performance of this model was tested in an experiment performed in two-compartment split-pot lysimeters with sorghum plants. The compartments were submitted to different irrigation cycles resulting in contrasting water contents over time. The root system efficiency factor was determined to be about 0.05. Release of water from roots to soil was predicted and observed on several occasions during the experiment; however, model predictions suggested root water release to occur more often and at a higher rate than observed. This may be due to not considering internal root system resistances, thus overestimating the ease with which roots can act as conductors of water. Excluding these erroneous predictions from the dataset, statistical indices show model performance to be of good quality. 相似文献
3.
4.
G-11 staining in Turner's syndrome with mos 45,X/46,X,r(?) 总被引:2,自引:0,他引:2
J C de Almeida J C Llerena D Molina Gomes R Rita Martins M Jung D F Reis A G Cunha 《Annales de génétique》1985,28(1):37-41
Mos 45,X/46,X,r(?) in 4 patients with Turner's syndrome and no signs of virilization, and in one pair of monozygotic twins, one of them with clitoral hypertrophy, was studied using combined cytogenetic techniques and specially G-11 staining for the characterization of the X or Y origin of the rings. In all 6 patients the ring was G-11 positive, attesting its Y origin. Both twins were operated and bilateral streak gonads with a bilateral nodule of testicular tissue were found. Similar small rings were also studied in one patient with mos 46,XX/46,X,r(X) and in one nonvirilized Turner's syndrome patient with a larger ring; in these two cases the ring was G-11 negative. It seems that the small rings occasionally found in Turner's syndrome are more frequently from Y origin and therefore prophylactic gonadectomy should be considered. 相似文献
5.
M C Oliveira I Y Hirata J R Chagas P Boschcov R A Gomes A F Figueiredo L Juliano 《Analytical biochemistry》1992,203(1):39-46
Six intramolecularly quenched fluorogenic peptides related to the sequences Phe8 to His13, His6 to His13, and Tyr4 to His13 of the human angiotensinogen, containing o-aminobenzoyl (Abz) and ethylenediamine dinitrophenyl (EDDnp) groups at amino- and carboxyl-terminal amino acids residues, were synthesized by classical solution methods. The Leu-Val is the only bond of all obtained peptides that was hydrolyzed by human renin with different degrees of purity and was resistant to hydrolysis by pig renin and cathepsin D. The hydrolysis of Abz-His-Pro-Phe-His-Leu-Val-Ile-His-EDDnp by human renin was inhibited by a highly specific transition-state analog of angiotensinogen (IC50 = 7.8 x 10(-9) M), described by K. Iizuka et al. (1990, J. Med. Chem. 33, 2707-2714). Therefore, specific and sensitive substrates for the continuous assay of human renin in which as little as 70 microGU of human renin could be detected by Abz-Phe-His-Leu-Val-Ile-His-EDDnp were described. The optimal pHs of hydrolysis of the substrates were in the range 4 to 6. 相似文献
6.
A. Magalhaes B. Maigret J. Hoflack J. N. F. Gomes H. A. Scheraga 《Journal of Protein Chemistry》1994,13(2):195-215
Although the majority of the ion pairs found in proteins consists of two charges of opposite sign, the observation of some unusual arrangements of two arginines led us to a search of such occurrences in the Brookhaven Protein Data Bank. We have found 41 Arginine-Arginine interactions with a C...C distance less than 5 å. Computer graphics analysis of these structures shows that most of the Arg-Arg pairs are found in the vicinity of the surface of the proteins, in an easily hydrated region. In order to determine which factors could stabilize such arrangements of species of similar charge, we have carried out AM1 semi-empirical calculations on a model of two guanidinium ions surrounded by several water molecules. The results show the existence of stable clusters with six or more water molecules, with distances between C atoms around 3 å. The bridging role of the water molecules is an important structural and energetic feature and we find bridges of two and three molecules between the guanidinium ions. These results are in good agreement with the structures found in our search of the experimental data. Enhancement of the electrostatic potential around these clusters, when compared to one of the guanidinium ions alone, is also demonstrated. 相似文献
7.
Vicente Gomes Phan Van Ngan Claude de Broyer Maria José deA. C. Rocha Passos 《Hydrobiologia》1993,262(2):109-113
Mitotic and meiotic chromosomes of the Antarctic lysianassoid amphipod Waldeckia obesa are described. The modal chromosome number is n = 25 and 2n = 50. The potential applications of cytogenetical studies in this group are discussed. 相似文献
8.
Amanda dos Santos Marina Tenório Botelho Willian Reina Joviano Vicente Gomes José Roberto Machado Cunha da Silva Gisela de Aragão Umbuzeiro 《Invertebrate Biology》2023,142(1):e12394
Hemocytes are circulating blood cells that play a crucial function in amphipods and other crustacean immune systems. The hemocytes of the marine tropical amphipod Parhyale hawaiensis have been used for the evaluation of DNA damage and micronuclei, but they have not been characterized in the scientific literature. The aim of this study was to describe the hemolymph cells of P. hawaiensis and study their phagocytotic activity. Basic dyes were used to differentiate the cell types and the presence of lipids. The total hemocyte counts (THCs) and the proportion and sizes of the hemocyte types were determined. Hemolymph was exposed to Escherichia coli for verification of the presence of phagocytosis. Three cell types, all containing lipids, were identified in P. hawaiensis: granulocytes (oval shape, 13.4 × 7.6 μm), semi-granulocytes (oval shape, 14.1 × 7.2 μm), and hyalinocytes (round shape, 9.6 × 7.2 μm). Those three cell types were found in different percentages in males (64.8%, 31.1%, and 4.2%) and females (70.1%, 28.2%, and 1.7%). THCs for males were 9007 ± 3800 cells per individual and 4695 ± 1892 cells per individual for females. The cells of E. coli were phagocytized by the hemocytes. Our findings increased the knowledge of hemocytes in P. hawaiensis and is a step forward in using hemocyte-based immune responses as an endpoint in ecotoxicology. 相似文献
9.
Janaine Almeida Neto Daniel Amando Nery Katia Simoni Bezerra Lima Maria Eduarda Gomes da Cruz Silva Tarcísio Cícero de Lima Araújo Nathália Andrezza Carvalho de Souza Rodolfo Hideki Vicente Nishimura Camila de Souza Araújo Ana Paula de Oliveira Jackson Roberto Guedes da Silva Almeida Larissa Araújo Rolim 《化学与生物多样性》2023,20(3):e202201039
This article describes the phytochemical study of Cannabis sativa roots from northeastern Brazil. The dried plant material was pulverized and subjected to exhaustive maceration with ethanol at room temperature, obtaining the crude ethanolic extract (Cs-EEBR). The volatile compounds were analyzed by gas chromatography coupled with mass spectrometry (GC/MS), which allowed to identify 22 compounds by comparing the linear retention index (LRI), the similarity index (SI) and the fragmentation pattern of the constituents with the literature. By this technique the major compounds identified were: friedelan-3-one and β-sitosterol. In addition, two fractions were obtained from Cs-EEBR by classical column chromatography and preparative thin layer chromatography. These fractions were analyzed by NMR and IR and together with the mass spectrometry data allowed to identify the compounds: epifriedelanol, friedelan-3-one, β-sitosterol and stigmasterol. The study contributed to the phytochemical knowledge of Cannabis sativa, specifically the roots, as there are few reports on the chemical constituents of this part of the plant. 相似文献
10.
Computer-aided comparison of protein electrophoretic patterns for grouping and identification of heterotrophic bacteria from mineral water 总被引:2,自引:1,他引:1
A.C. Ferreira P.V. Morais C. Gomes M.S. da Costa 《Journal of applied microbiology》1996,80(5):479-486
The microflora of a natural mineral water was studied immediately after bottling (T0) and after 7 d storage (T7) during 6 months, and isolates were clustered by SDS-PAGE of wholecell protein profiles. Isolates from each cluster were further characterized by API 20NE, fatty acid composition and quinone profiles. The numerical analysis of the electrophoregrams of all bacteria isolated from the mineral water formed 15 clusters and five unclustered strains. Except for five minor clusters, all clusters were composed of strains isolated over several months. The numerical analysis of the electrophoregrams of bacteria isolated immediately after bottling formed 15 clusters while after 7 d storage only four of these populations could be isolated, indicating that populations present in the mineral water were stable and that changes occurring after bottling probably resulted from a selection process. Only one unclustered strain was identified simultaneously by all the systems, as Sphingomonas paucimobilis. The monitoring of the aquifer and the bottling system, and the construction of a large database with bacteria of the autochthonous flora allows the detection of alterations in the aquifer by changes in the microflora. 相似文献