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41.
Daniel MA Elsey GM Capone DL Perkins MV Sefton MA 《Journal of agricultural and food chemistry》2004,52(26):8127-8131
Damascenone has been shown to undergo reaction with common wine components. Following the action of acid and heat alone, two bicyclic compounds, 4,9,9-trimethyl-8-methylenebicyclo[3.3.1]non-6-en-2-one (2) and 4,4,9-trimethyl-8-methylenebicyclo[3.3.1] non-6-en-2-one (3), were isolated. However, this conversion takes place only very slowly, if at all, under milder conditions (45 degrees C). When treated with a variety of nucleophiles at pH 3.0 and 5.5, the concentration of damascenone in buffered aqueous ethanol decreased by minor amounts (10-20%) except for cysteine and 2-mercaptoethanol addition at pH 5.5 (approximately 40 and approximately 30%, respectively) and SO2 (>90% at pH 3.0; 100% at pH 5.5). An adduct from this last combination was prepared and shown to be the C9 sulfonic acid derivative of damascenone. A detailed investigation into the effect of SO2 demonstrated that loss of damascenone in model wine was directly related to the concentration of added SO2 but was essentially unaffected by small changes in pH. 相似文献
42.
Basil N Ziogas Dimitra Nikou Anastasios N Markoglou Anastasios A Malandrakis John Vontas 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(1):97-107
The molecular basis of resistance to benzimidazole fungicides with laboratory and field mutant isolates of Botrytis cinerea was investigated. After chemical mutagenesis with N-methyl-N-nitrosogouanidine (NMNG) two different benzimidazole-resistant phenotypes were isolated on media containing carbendazim or
a mixture of carbendazim and diethofencarb. The mutant isolates from the fungicide-mixture-containing medium were moderately
resistant to carbendazim with wild-type tolerance to diethofencarb while mutant isolates from carbendazim-containing medium
were highly resistant to carbendazim but sensitive to diethofencarb. The studied field isolates were highly resistant to benzimidazoles
and sensitive to diethofencarb. Study of fitness characteristics of benzimidazole highly-resistant isolates showed that the
resistance mutation(s) had no apparent effect on fitness-determining parameters. Contrary to this, the moderately benzimidazole-resistant
strains, with no increased diethofencarb sensitivity, had a significant reduction in certain ecological fitness-determining
characteristics. Analysis of the sequence of the β-tubulin gene revealed two amino acid replacements in the highly benzimidazole-resistant mutants compared to that of the wild-type
parent strain. One was the glutamic acid (GAG) to alanine (GCG) change at position 198 (E198A), identified in both laboratory
and field highly benzimidazole-resistant isolates, a mutation previously implicated in benzimidazole resistance. The second
was a novel benzimidazole resistance mutation of glutamic acid (GAG) to glycine (GGG) substitution at the same position 198
(E198G), identified in a highly benzimidazole-resistant laboratory mutant strain. Molecular analysis of the moderately benzimidazole-resistant
strains revealed no mutations at the β-tubulin gene. A novel diagnostic PCR-RFLP assay utilising a BsaI restriction site present in the benzimidazole-sensitive (E198) but absent in both resistant genotypes (E198G and E198A)
was developed for the detection of both amino acid replacements at the β-tubulin gene. 相似文献
43.
44.
Labrini V. Athanasiou Constantina N. Tsokana Dimitra Pardali Katerina Adamama Moraitou 《Topics in companion animal medicine》2018,33(4):141-146
Histograms, which are an integral part of the automated complete blood count, are now available through most of the automatic hematology analyzers used in veterinary clinical practice. Data concerning the size and number of blood cells are graphically presented in histograms, and their variations are also illustrated. Important information that is not apparent from numerical results are sometimes provided by histograms. Histograms are also referred to as frequency distribution curves and are essentially graphs resulting from the placement of the sizes of cells on the x-axis and the number of cells on the y-axis. Typically, automated analyzers provide histograms for each class of blood cells, that is, for erythrocytes, leukocytes, and platelets. Thus, when the erythrocyte histogram shows asymmetry with a right shift, it means the size of the erythrocytes is greater than normal (macrocytosis); when it presents a left shift, the size of the erythrocytes is less than normal (microcytosis). When two peaks are found in the curve, two populations of erythrocytes coexist, as in the case of a blood transfusion or therapeutic response. In the leukocyte histogram, three peaks are found: the closest to the y-axis (left) corresponds to the lymphocytes, the middle to the monocytes, and the right to the polymorphonuclear cells (neutrophils, eosinophils, and basophils). Finally, in platelet histogram, asymmetry with a right shift suggests the presence of giant platelets or schistocytes. Although the histogram is not recommended as a stand-alone test, it allows the practitioner to observe abnormalities in the distribution curve that correspond to abnormalities in the size or number of cells, and to quickly make diagnostic or therapeutic decisions that are particularly important in emergencies. 相似文献
45.
Vardar-Unlü G Candan F Sökmen A Daferera D Polissiou M Sökmen M Dönmez E Tepe B 《Journal of agricultural and food chemistry》2003,51(1):63-67
The essential oil, obtained by using a Clevenger distillation apparatus, and water-soluble (polar) and water-insoluble (nonpolar) subfractions of the methanol extract of Thymus pectinatus Fisch. et Mey. var. pectinatus were assayed for their antimicrobial and antioxidant properties. No (or slight) antimicrobial activity was observed when the subfractions were tested, whereas the essential oil showed strong antimicrobial activity against all microorganisms tested. Antioxidant activities of the polar subfraction and the essential oil were evaluated using 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide radical scavenging, and lipid peroxidation assays. The essential oil, in particular, and the polar subfraction of the methanol extract showed antioxidant activity. The essential oil was analyzed by GC/MS, and 24 compounds, representing 99.6% of the essential oil, were identified: thymol, gamma-terpinene, p-cymene, carvacrol, and borneol were the main components. An antimicrobial activity test carried out with fractions of the essential oil showed that the activity was mainly observed in those fractions containing thymol, in particular, and carvacrol. The activity was, therefore, attributed to the presence of these compounds. Other constituents of the essential oil, such as borneol, gamma-terpinene, and p-cymene, could be also taken into account for their possible synergistic or antagonistic effects. On the other hand, thymol and carvacrol were individually found to possess weaker antioxidant activity than the crude oil itself, indicating that other constituents of the essential oil may contribute to the antioxidant activity observed. In conclusion, the results presented here show that T. pectinatus essential oil could be considered as a natural antimicrobial and antioxidant source. 相似文献
46.
Vassiliki Tsioli Lysimachos G. Papazoglou Nikolaos Papaioannou Dimitra Psalla Ioannis Savvas Leonidas Pavlidis Maria Karayannopoulpou 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(1):99-106
Our objective was to evaluate the effectiveness of skin-stretching devices for closing defects on the extremities of dogs. Antebrachial skin defects were created on the limbs of 24 dogs randomly divided into three groups. Skin stretchers included staples and sutures passing through them (group A), sutures and hypodermic needles (group B), and Pavletic device (group C). Wounds on the left were further undermined in all groups. Tension and blood perfusion were assessed. After removing the stretchers on day 3, the defects were sutured and wound healing was clinically scored. Histological variables evaluated were cellular infiltration, edema, collagen orientation, and thickness of epidermis. Significant differences in tension were found among groups (p < 0.0005) and between measurement times for undermined (p = 0.001) or non-undermined (p < 0.0005) wounds. In contrast, blood perfusion values did not differ significantly. Clinical scores for group B seemed to be better than those for groups A and C, but differences were not significant. Primary wound closure using the Pavletic device was not feasible. No significant differences in histological variables were found between groups. Skin stretching with staples or hypodermic needles resulted in successful wound management with minor side effects on skin histology and circulation. 相似文献
47.
The effect of the stage of the ovarian cycle (anoestrus or dioestrus) and of pregnancy on the incidence of gastro‐oesophageal reflux in dogs undergoing ovariohysterectomy 
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下载免费PDF全文 Tilemahos L Anagnostou Ioannis Savvas George M Kazakos Haralabos N Ververidis Dimitra Psalla Charalampos Kostakis Petros Skepastianos Dimitris Raptopoulos 《Veterinary anaesthesia and analgesia》2015,42(5):502-511
ObjectiveTo investigate the potential association of increased blood progesterone (P4) concentrations and/or late pregnancy with the incidence of gastro-oesophageal reflux (GOR), in healthy bitches undergoing ovariohysterectomy under general anaesthesia during anoestrus or dioestrus or during the second half of pregnancy.Study designProspective observational study.AnimalsNinety-four healthy, female, dogs, aged 1–8 years presented for elective ovariohysterectomy.MethodsNon-pregnant animals were classified into group A (anoestrus) (n = 35) if blood P4 concentration was sufficiently low or group D (dioestrus) (n = 26) if blood P4 concentration was sufficiently high. All animals in the second half of pregnancy were classified into group P (n = 33). Acepromazine (0.05 mg kg−1) was administered intramuscularly as preanaesthetic medication, and sodium thiopental (10 mg kg−1, with additional doses if needed) was administered intravenously (IV) for induction of anaesthesia. After endotracheal intubation, halothane (1.1–1.3% end-tidal concentration) in oxygen was used for maintenance of anaesthesia. Lower oesophageal pH was monitored continuously throughout surgery using a pH-measuring probe. Reflux was considered to have occurred whenever pH values of >7.5 (alkaline reflux) or <4 (acid reflux) were recorded. On completion of surgery, carprofen (4 mg kg−1) was administered IV. Further administration of analgesics post-operatively was dictated by visual analogue scale pain scoring.ResultAcid GOR was observed in five of 26 dogs in group D, six of 35 group A, and 12 of 33 group P (p = 0.152). The incidence of GOR in group P approached statistical significance and was higher than the incidence in the combined group A + D (one sided p = 0.044, two sided p = 0.077).ConclusionsIn dogs undergoing ovariohysterectomy, GOR during anaesthesia occurs with a high incidence in dogs in the second half of pregnancy compared to non-pregnant animals during anoestrus or dioestrus.Clinical relevanceMeasures could be taken in such cases to avoid the consequences of potential reflux. 相似文献
48.
Capone DL Pardon KH Cordente AG Jeffery DW 《Journal of agricultural and food chemistry》2011,59(20):11204-11210
Precursors to varietal wine thiols are a key area of grape and wine research. Several such precursors, in the form of odorless conjugates, have been closely studied in recent years. A new conjugate has now been identified as 3-S-cysteinylglycinehexan-1-ol (Cysgly-3-MH), being the dipeptide intermediate between cysteine and glutathione precursors of tropical thiol 3-mercaptohexan-1-ol (3-MH). Authentic Cysgly-3-MH was produced via enzymatic transformation of the glutathione conjugate and used to verify the presence of both diastereomers of Cysgly-3-MH in Sauvignon blanc juice extracts. Cysgly-3-MH was added into our HPLC-MS/MS precursor method, and the validated method was used to quantify this new analyte in a selection of Sauvignon blanc juice extracts. Cysgly-3-MH was found in the highest concentrations (10-28.5 μg/L combined diastereomer total) in extracts from berries that had been machine-harvested and transported for 800 km in 12 h. This dipeptide conjugate was much less abundant than the glutathione and cysteine conjugates in the samples studied. On the basis of the results, the new cysteinylglycine conjugate of 3-MH seemingly has a short existence as an intermediate precursor, which may explain why it has not been identified as a natural juice component until now. 相似文献
49.
Capone DL Van Leeuwen K Taylor DK Jeffery DW Pardon KH Elsey GM Sefton MA 《Journal of agricultural and food chemistry》2011,59(3):953-959
A new method has been developed for the quantitation of 1,8-cineole in red and white wines using headspace solid-phase microextraction (SPME) combined with stable isotope dilution analysis (SIDA) and gas chromatography-mass spectrometry (GC-MS). An extensive survey of Australian wines (44 white and 146 red) highlighted that only red wines contained significant amounts of 1,8-cineole (up to 20 μg/L). Hydrolytic studies with limonene and α-terpineol, putative precursors to 1,8-cineole, showed a very low conversion into 1,8-cineole (< 0.6%) over a 2 year period, which does not account for the difference between white and red wines. 1,8-Cineole was chemically stable in model wine solution over 2 years, and absorption from a Shiraz wine by bottle closures was most evident for a synthetic closure only (14% absorption after 1 year). Two commercial ferments at two different locations were monitored daily to investigate the evolution of 1,8-cineole throughout fermentation. Both ferments showed daily increases in 1,8-cineole concentration while in contact with grape solids, but this accumulation ceased immediately after pressing. This observation is consistent with the extraction of 1,8-cineole into the ferment from the solid portions of the grape berries. 相似文献
50.
Olubukola O. Ajigboye Dasuni P. Jayaweera Dimitra Angelopoulou Alexander V. Ruban Erik H. Murchie Victoria Pastor Richard Summers Rumiana V. Ray 《Plant pathology》2021,70(6):1421-1435
This study provides new insights into the role of photoprotection in preformed and induced defence of two wheat genotypes with contrasting phenotypes to infection by Zymoseptoria tritici. We investigated the mechanisms of the photoprotective response during early infection, including nonphotochemical quenching (NPQ), β-carotene-derived xanthophylls, reactive oxygen species, and the phytohormones abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA). Furthermore, we quantified the effects of pathogenesis on photosynthesis, stomatal control, and expression of plant defence molecular markers. The photoprotective mechanism of successful defence involved the qI component of NPQ leading to rapid down-regulation of photosystem II quantum yield and chlorophyll a:b, increased biosynthesis of the xanthophyll neoxanthin and ABA, and the expression of chloroplast-specific enzymes to engage in scavenging of O2●−. Elevated ABA in the resistant genotype correlated with preformed leaf defence traits including low stomatal density, increased expression of wax biosynthesis, and lignification. Z. tritici exhibited reduced germination and branching on the resistant host genotype and hijacked stomatal control in both genotypes by enhancing stomatal sensitivity to light. Increased biosynthesis of JA and anthocyanins, in contrast to SA, were quantified in the incompatible interaction. Our results indicate that ABA and JA in antagonistic action to SA were associated with defence in the resistant genotype, Cougar, against Z. tritici. 相似文献