Ultrasound effect on physical properties of corn starch

High power ultrasound (HPU) represents a non-thermal processing method that has been rapidly researched and used in the last 10 years. The application of power ultrasound offers the opportunity to modify and improve some technologically important compounds which are often used in food products. One of them is starch. The aim of this research was to examine the effect of the high power ultrasound of 24 kHz frequency on rheological and some physical properties of corn starch. Various ultrasound treatments were used; an ultrasound probe set with different intensities (34, 55, 73 W cm⁻²) and treatment times (15 and 30 min) and ultrasound bath of 2 W cm⁻² intensity and treatment times (15 and 30 min). Rheological parameters, turbidity and swelling power of corn starch suspensions were determined for native and ultrasonically treated corn starch suspensions. Differential scanning calorimetry was used in order to examine the pasting properties of corn starch. The results have shown that the ultrasound treatment of corn starch distorts the crystalline region in starch granules. The results of differential scanning calorimetry measurements have shown a decrease in enthalpy of gelatinization. A significant decrease in consistency coefficient (k) has also been observed. The consistency coefficient decreases stepwise jointly with the increasing ultrasound power. The increase in the swelling power is associated with water absorption capacity and corn starch granules solubility, respectively.     

Changes in Protein Profiles of Poplar Tissues during the Induction of Bud Dormancy by Short-Day Photoperiods

Vegetative bud dormancy in woody perennial plants of the temperateregions is an important adaptive strategy for withstanding lowwinter temperatures. We used shortday (SD) photoperiods to inducebud dormancy in poplar (Populus deltoides Bartr. ex Marsh.),and characterized changes in protein profiles during dormancydevelopment. Short days alone, under warm temperatures (25°C)induced a high level of dormancy comparable to that developednaturally. Under SD conditions the amounts of acetone/trichloroaceticacid (TCA)-insoluble dry powder (DP) increased in terminal andlateral buds, leaves and bark tissues. The total protein contentin DP from buds and leaves steadily decreased while total proteinfrom bark increased. The 2-dimensional (2-D) PAGE analyses showedthat terminal and lateral buds responded similarly to SD. Fourpolypeptides that newly appeared or increased in abundance andfive that disappeared or diminished in terminal buds during10 weeks of treatment were also detected in lateral buds. Twoof these newly apparent polypeptides were also found in bark.Similar polypeptides were not found in leaves. Changes in proteinmetabolism and possibly altered gene expression might be importantpart in the overall response of poplar to SD during dormancydevelopment. This is Oregon Agricultural Experimental Station Technical PaperNumber 1122.     

Evaluation of genotoxic effects of fumagillin by cytogenetic tests in vivo

Fumagillin is a naturally secreted antibiotic of the fungus Aspergillus fumigatus. It is used in veterinary medicine against microsporidiosis of bees and fish. In this study, the genotoxicity of fumagillin (in the form of fumagillin dicyclohexylamine) was evaluated in mouse bone-marrow cells using the mitotic index (MI), the chromosome aberration (CA) assay, and the micronucleus (MN) test. Fumagillin was administered to BALB/c mice by gavage, at doses of 25, 50, 75 mg/kg body weight (bw), repeated for 7 days at 24-h intervals, with water-sugar syrup as a negative control and cyclophosphamide (40 mg/kg bw) as a positive control. All experimental doses of fumagillin induced a significant decrease (p<0.001) in MI (3.47+/-0.04%, 3.17+/-0.01%, and 2.27+/-0.02%, respectively) in comparison with the negative control (6.00+/-0.01%). Fumagillin significantly (p<0.001) increased the frequency of MN (4.98+/-0.35, 8.45+/-0.57, and 12.02+/-0.37, respectively) over negative control (1.04+/-0.28). Significantly increased frequencies (p<0.01 or p<0.001) of numerical chromosomal aberrations (aneuploidies and polyploidies) and structural chromosomal aberrations such as gaps, breaks, and centric rings were observed at the highest experimental dose of fumagillin (75 mg/kg bw) compared with the negative control. However, with respect to the induction of Robertsonian translocations, both the intermediate (50 mg/kg bw) and highest (75 mg/kg bw) experimental dose caused a significant (p<0.001) increase (7.12+/-0.26 and 9.00+/-0.10, respectively) in comparison with the negative control (0.00+/-0.00). Chromosomes 4 and 19 participated in these Robertsonian translocations. Regarding total cytogenetic changes, a significant increase (p<0.001) was observed in both the intermediate dose group (17.36+/-1.83) and the highest dose group (59.49+/-1.92) compared with the negative control (7.00+/-1.35). These results suggest that fumagillin has genotoxic (clastogenic) potential in mammals in vivo.     

Continuum simulations of acetylcholine diffusion with reaction-determined boundaries in neuromuscular junction models

The reaction-diffusion system of the neuromuscular junction has been modeled in 3D using the finite element package FEtk. The numerical solution of the dynamics of acetylcholine with the detailed reaction processes of acetylcholinesterases and nicotinic acetylcholine receptors has been discussed with the reaction-determined boundary conditions. The simulation results describe the detailed acetylcholine hydrolysis process, and reveal the time-dependent interconversion of the closed and open states of the acetylcholine receptors as well as the percentages of unliganded/monoliganded/diliganded states during the neuro-transmission. The finite element method has demonstrated its flexibility and robustness in modeling large biological systems.     

Copper(II) complexes with unsymmetrical pentadentate ed3a-type diamino-tricarboxylate ligands. Crystal structures, configurational analysis and DFT study of complexes

The O-O-N-N-O-type pentadentate ligands H₃ed3a, H₃pd3a and H₃pd3p (H₃ed3a stands ethylenediamine-N,N,N′-triacetic acid; H₃pd3a stands 1,3-propanediamine-N,N,N′-triacetic acid and H₃pd3p stands 1,3-propanediamine-N,N,N′-tri-3-propionic acid) and the corresponding novel octahedral or square-planar/trigonal-bipyramidal copper(II) complexes have been prepared and characterized. H₃ed3a, H₃pd3a and H₃pd3p ligands coordinate to copper(II) ion via five donor atoms (three deprotonated carboxylate atoms and two amine nitrogens) affording octahedral in case of ed3a³⁻ and intermediate square-pyramidal/trigonal-bipyramidal structure in case of pd3a³⁻ and pd3p³⁻. A six coordinate, octahedral geometry has been established crystallographically for the [Mg(H₂O)₆][Cu(ed3a)(H₂O)]₂ · 2H₂O complex and five coordinate square-pyramidal for the [Mg(H₂O)₅Cu(pd3a)][Cu(pd3a)] · 2H₂O. Structural data correlating similar chelate Cu(II) complexes have been used for the better understanding the pathway: octahedral → square-pyramidal ↔ trigonal- bipyramid geometry. An extensive configuration analysis is discussed in relation to information obtained for similar complexes. The infra-red and electronic absorption spectra of the complexes are discussed in comparison with related complexes of known geometries. Molecular mechanics and density functional theory (DFT) programs have been used to model the most stable geometric isomer yielding, at the same time, significant structural data. The results from density functional studies have been compared with X-ray data.     

Antropologic factors in prediction of ovary cancer

The aim of the study was to determine a combination of anthropometric variables that would enable better differentiation between benign and malignant ovarian masses. Prospective study has been performed in a two year period in which 208 women with ovarian lesions were analyzed and correlated with histopathologic surgical findings. We examined the relation between self-reported anthropometric and other variables (height, weight, body mass index--BMI, parity, marital status, education, age, rural versus urban residence, menopausal status) and incidence of ovarian cancer. Age, parity, marital status and menopausal status individually showed statistical significance.     

Effects of clonidine preemptive analgesia on acute postoperative pain in abdominal surgery

Preemptive analgesia refers to blockade of afferent nerve fibers before a painful stimulus, which prevents or reduces subsequent pain even beyond the effect of the block. The aim of the study was to compare the effect of clonidine used before and at the end of operation on pain control in abdominal surgery. A total of 77 patients admitted for colorectal surgery were randomly classified into three groups: epidural clonidine before operation, epidural clonidine at the end of operation, and control group. After the operation on patient demand, analgesia with boluses of epidural morphine was instituted. The parameters of postoperative pain level using VAS score (visual analog scale), sedation and analgesics consumption were determined as outcome measures at 1, 2, 6, and 24 h of the operation. Clonidine administered before operation provided lowest pain scores at 6 and 24 h (p < 0.05). Clonidine administered at the end of operation had low pain scores at 1 and 2 h, with a significant pain breakthrough thereafter (6.93 +/- 1.66 at 6 h and 4.04 +/- 2.39 at 24 h) compared with the group administered clonidine before operation (3.60 +/- 2.94 and 3.71 +/- 1.82). Clonidine administered before operation provided less sedation (p < 0.05) and a significantly lower use of analgesics (p < 0.05). Blockade of nociceptive stimulus using the centrally acting alpha2-adrenergic agonist clonidine before the onset of pain stimulus resulted in reduced pain levels, sedation and analgesic requirement.     

Isosteric probes provide structural requirements essential for detoxification of the phytoalexin brassinin by the fungal pathogen Leptosphaeria maculans

Brassinin is a plant defense metabolite with antimicrobial activity produced de novo by a variety of Brassica species in response to stress, that is, a phytoalexin. The inhibition of brassinin oxidase (BO), a brassinin-detoxifying enzyme produced by the phytopathogenic fungus Leptosphaeria maculans, is a target in our continuing search for novel crop protection agents. To probe the substrate specificity of BO, in particular the mechanism of the detoxification step, several analogues of brassinin, including functional group isosteres ((mono/dithio)carbamate, urea, and thiourea) and homologue methyl tryptaminedithiocarbamate, were investigated using fungal cultures and purified BO. It was concluded that the essential structural features of substrates of BO were: (i) an -NH at the (mono/dithio)carbamate, urea or thiourea group; (ii) a methylene bridge between indole and the functional group; (iii) a methyl or ethyl group attached to the thiol moiety of the (mono/di)thiocarbamate group. A general stepwise pathway for the oxidation of brassinin was proposed that accounts for the structural requirements of detoxification of brassinin analogues in L. maculans. All compounds that were BO substrates appeared to be oxidized in mycelial cultures to aldehydes, except for the two most polar compounds N'-(3-indolylmethyl)-N'-methylurea and methyl N'-(3-indolylmethyl)carbamate. The substrate specificity of BO suggests that selective inhibitors can be designed for the potential control of L. maculans.     

Functional anthology of intrinsic disorder. 3. Ligands, post-translational modifications, and diseases associated with intrinsically disordered proteins

Currently, the understanding of the relationships between function, amino acid sequence, and protein structure continues to represent one of the major challenges of the modern protein science. As many as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bionformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200 000 proteins from the Swiss-Prot database, each annotated with at least one of the 875 functional keywords, was described in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V.N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Using this tool, we have found that out of the 710 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (see above). The second paper of the series was devoted to the presentation of 87 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions (Vucetic, S.; Xie, H.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions. J. Proteome Res. 2007, 5, 1899-1916). Protein structure and functionality can be modulated by various post-translational modifications or/and as a result of binding of specific ligands. Numerous human diseases are associated with protein misfolding/misassembly/misfunctioning. This work concludes the series of papers dedicated to the functional anthology of intrinsic disorder and describes approximately 80 Swiss-Prot functional keywords that are related to ligands, post-translational modifications, and diseases possessing strong positive or negative correlation with the predicted long disordered regions in proteins.     

Genetic Determinants of the Network of Primary Metabolism and Their Relationships to Plant Performance in a Maize Recombinant Inbred Line Population

Deciphering the influence of genetics on primary metabolism in plants will provide insights useful for genetic improvement and enhance our fundamental understanding of plant growth and development. Although maize (Zea mays) is a major crop for food and feed worldwide, the genetic architecture of its primary metabolism is largely unknown. Here, we use high-density linkage mapping to dissect large-scale metabolic traits measured in three different tissues (leaf at seedling stage, leaf at reproductive stage, and kernel at 15 d after pollination [DAP]) of a maize recombinant inbred line population. We identify 297 quantitative trait loci (QTLs) with moderate (86.2% of the mapped QTL, R² = 2.4 to 15%) to major effects (13.8% of the mapped QTL, R² >15%) for 79 primary metabolites across three tissues. Pairwise epistatic interactions between these identified loci are detected for more than 25.9% metabolites explaining 6.6% of the phenotypic variance on average (ranging between 1.7 and 16.6%), which implies that epistasis may play an important role for some metabolites. Key candidate genes are highlighted and mapped to carbohydrate metabolism, the tricarboxylic acid cycle, and several important amino acid biosynthetic and catabolic pathways, with two of them being further validated using candidate gene association and expression profiling analysis. Our results reveal a metabolite-metabolite-agronomic trait network that, together with the genetic determinants of maize primary metabolism identified herein, promotes efficient utilization of metabolites in maize improvement.