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81.
Thermodynamic solubility is a decisive physicochemical property in drug development. The Chasing Equilibrium method offers an alternative to the classical procedures to measure the solubility of compounds with acid–base properties. The method is fast and yields accurate results. In this work, the solubility of several compounds including acids and bases was determined through the Chasing Equilibrium approach. A study of experimental conditions in terms of sample weight was performed to measure solubilities. The study shows that only a limited range of weights, depending on the nature and solubility of the compounds, is adequate to obtain reliable results. 相似文献
82.
83.
Mojtaba Tabatabaei Yazdi Gholamreza Zarrini Elham Mohit Mohammad Ali Faramarzi Neda Setayesh Navid Sedighi Farzaneh Aziz Mohseni 《World journal of microbiology & biotechnology》2006,22(4):325-330
Summary One hundred and sixty-five strains of microorganisms with the ability to grow in a medium containing uric acid as a major
source of nitrogen were isolated from soil samples during a screening program. Among them, a zygomycete fungus with well-developed
columellae was recognized to produce high levels of the enzyme in a short time. Classification of the isolated fungus was
carried out according to the morphological and culture characteristics of the organism, and it was identified as Mucor hiemalis. The fungus was able to produce an intracellular urate oxidase in a fermentation medium mainly containing uric acid. Optimized
composition of the medium consisted of (l−1 of distilled water) uric acid, 7.0 g; maltose, 6.0 g; Vogel stock solution, 20 and 1 ml of 0.5 M copper sulphate. The optimum
pH and temperature for uricase production in the optimized medium were pH 6 and 30 °C, respectively. 相似文献
84.
The biological evaluation of a new synthesized Pt(II)-complex, 2,2'-bipyridin Butylglycinato Pt(II) nitrate, an anti-tumor component, was studied at different temperatures by fluorescence and far UV circular dichroism (CD) spectroscopic methods. Human serum albumin (HSA) and human tumor cell line K562 were as targets. The Pt(II)-complex has a strong ability to quench the intrinsic fluorescence of HSA. Binding and thermodynamic parameters of the interaction were calculated by fluorescence quenching method. Far-UV-CD results showed that Pt(II)-complex induced increasing in content of α helical structure of the protein and stabilized it. The 50% cytotoxic concentration (Cc(50)) of complex was determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay at different incubation times. Also, fluorescence staining with DAPI (4,6-diamidino-2-phenylindole) revealed some typical nuclear changes, which are characteristic of apoptosis. Above results suggest that Pt (II) complex is a promising anti-proliferative agent and should execute its biological effects by inducing apoptosis. 相似文献
85.
Elham Safaei Masoume Mohseni Kabir Zvonko Jagli?i? Yong-Ill Lee 《Inorganica chimica acta》2011,366(1):275-282
A series of novel copper(II) complexes, L2Cu with newly synthesized 3,5--salicylaldimine (or 5--salicylaldimine) ligands derived from 2,4-di-tert-butyl phenol (or 4-tert-butyl phenol) and alkyl (aryl) amines have been prepared and their spectroscopic (IR, UV-Vis, ESI-MS), X-ray, magnetic and redox properties have been investigated. The X-ray crystallography analysis shows that all complexes are monomeric and their copper(II) centers are surrounded by phenolate oxygens and imine nitrogen atoms. Therefore, the coordination sphere around the copper atoms is N2O2 as seen in galactose oxidase active site. In addition, the geometric configurations of all complexes are square planar or slightly distorted square planar. The crystal system for all complexes is monoclinic, except for which is orthorhombic. The temperature dependence of magnetic susceptibility of complexes confirms the mononuclear structure of complexes. Oxidation of the Cu(II) complexes yielded the corresponding Cu(II)-phenoxyl radical species during the cyclic voltammetry experiments. 相似文献
86.
Olfactory learning may allow insects to forage optimally by more efficiently finding and using favourable food sources. Although
olfactory learning has been shown in bees, insect herbivores and parasitoids, there are fewer examples from polyphagous predators.
In this study, olfactory learning by a predatory coccinellid beetle is reported for the first time. In laboratory trials,
adults of the aphidophagous ladybird Coccinella septempunctata did not prefer the odour of one aphid-infested barley cultivar over another. However, after feeding on aphids for 24 h on
a cultivar, they preferred the odour of that particular cultivar. The mechanism appeared to be associative learning rather
than sensitisation. Although inexperienced ladybirds preferred the odour of an aphid-infested barley cultivar over uninfested
plants of the same cultivar, after feeding experience on a different cultivar this preference disappeared. This may indicate
the acquisition and replacement of olfactory templates. The odour blends of the different aphid-infested barley cultivars
varied qualitatively and quantitatively, providing a potential basis for olfactory discrimination by the ladybird. The results
show that predatory coccinellids can learn to associate the odour of aphid-infested plants with the presence of prey, and
that this olfactory learning ability is sensitive enough to discriminate variability between different genotypes of the same
plant. 相似文献
87.
Moeini MM Kiani A Mikaeili E Shabankareh HK 《Biological trace element research》2011,144(1-3):529-537
Forty heifers at the late stage of gestation were randomly assigned into five groups. Heifers were balanced for age, weight, and time of calving in each group. Four and 2?weeks before expected time of calving, the heifers were injected with 0?ml (C), 10?ml (T1), 20?ml (T2), 30?ml (T3), and 40?ml (T4) Se and VE supplements, respectively. Each milliliter of the supplement contained of 0.5?mg Se as sodium selenite and 50?IU of dl-alpha-tocopheryl acetate. Blood samples were collected from the heifers 4?weeks before expected calving and at calving day and from the calves at birth and 7?days of age. The serum Se and immunoglobulin G (IgG) concentrations, white blood cell and differential leukocyte counts were measured. The Se concentrations in the sera of the heifers before the injections of Se and VE supplements were the same among the groups (P?>?0.05), but after calving were significantly increased in the treated heifers (P?0.05). Similarly, the serum Se levels of calves of the treated heifers were higher (P?0.05). The Se concentrations in the colostrums of the heifers were affected by treatments (P?0.05). Colostrum and daily milk productions at 8-week lactation were increased in treated heifers compared with the controls (P?0.05). Likewise, the milk somatic cell counts decreased in the treated heifers compared with the controls. The changes of the mean serum IgG levels did not differ among calves (P?>?0.05). The white blood cell counts were higher in calves of heifers in groups T3 and T4 compared with the control group at 7?days of age (P?0.05). 相似文献
88.
El Husseiny NM Said ES El Shahat Mohamed N Othman AI 《Biological trace element research》2011,143(3):1451-1460
The aim of this study was to confirm if there is a link between the alteration in blood levels of trace elements (chromium,
copper, lead, cadmium, and zinc) and dehydroepiandrosterone sulfate (DHEAS) in healthy and diabetic states. This study is
the first study to test these parameters in Egyptians. The study included 150 subjects divided into the following four groups:
healthy middle-aged, healthy elderly, middle-aged diabetics, and elderly diabetics. Our results revealed a statistically significant
decrease in the level of DHEAS in the elderly compared to middle-aged healthy and diabetic groups (p < 0.05). There was a significant difference between the middle-aged groups with respect to zinc, copper, chromium, and cadmium
levels. Zinc and copper were lower in the diabetic subjects while chromium and cadmium were higher in the same group in comparison
to healthy subjects. In the elderly groups, there were significant increases in chromium and cadmium levels in diabetic subjects
rather than healthy ones. There was a significant increase in the thiobarbituric acid reactive substance level in the elderly
healthy and diabetic groups and a significant decrease in the glutathione level in the elderly groups. There was no correlation
between the levels of trace elements and DHEAS or between the levels of DHEAS, oxidants, and antioxidants in all of the tested
groups. In conclusion, only the DHEAS level was correlated with age. There was no difference between the diabetic and healthy
groups with respect to the levels of trace elements, with the exception of chromium and cadmium, which suggests the effect
of pollution on the pathogenesis of diabetes in Egyptians. No correlation existed between the levels of DHEAS and trace elements,
oxidants, and antioxidants. Finally, we believe that there is a large regional variation in the levels of trace elements due
to different environmental exposure and nutritional factors which are responsible for contradictory results regarding the
pathogenesis of diseases related to alterations in the levels of trace elements. 相似文献
89.
Rapid growth in the biotechnological industry and production has put tremendous pressure on the biological methods that may be used according to the guidelines of green chemistry. However, despite continuing dramatic increases in published research on organic biotransformation by microorganisms, more research exists with microalgae. Our efforts in transforming chemicals such as organic compounds for the production of functionalized products help to lessen the environmental effects of organic synthesis. These biotransformations convert organic contaminants to obtain carbon or energy for growth or as cosubstrates. This review aims to focus on the potential of microalgae in transformation, conversion, remediation, accumulation, degradation, and synthesis of various organic compounds. However, these technologies have the ability to provide the most efficient and environmentally safe approach for inexpensive biotransforming of a variety of organic contaminants, which are most industrial residues. In addition, the recent advances in microalgal bioactivity were discussed. 相似文献
90.