首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Antioxidant activities of both cells and extracellular substances were evaluated in 12 soil-isolated strains of microalgae according to FRAP and DPPH-HPLC assays. Their total phenolic contents were also determined by Folin–Ciocalteu method. Extractions were performed with hexane, ethyl acetate, and water. The results of FRAP assay showed that algal cells contained considerable amounts of antioxidants from 0.56 ± 0.06 to 31.06 ± 4.00 μmol Trolox g−1 for Microchaete tenera hexane extract and Chlorella vulgaris water extract, respectively. In water fractions of extracellular substances, the antioxidants were from 1.30 ± 0.15 μmol Trolox g−1 for Fischerella musicola to 73.20 ± 0.16 μmol Trolox g−1 for Fischerella ambigua. Also, DPPH-HPLC assay represented high antioxidant potential of water fractions. The measured radical-scavenging activities of the studied microalgae were at least 0.15 ± 0.02 in Nostoc ellipsosporum cell mass to a maximum of 109.02 ± 8.25 in C. vulgaris extracellular substance. The amount of total phenolic contents varied in different strains of microalgae and ranged from zero in hexane extract to 19.15 ± 0.04 mg GAE g−1 in C. vulgaris extracellular water fraction. Significant correlation coefficients between two measured parameters indicated that phenolic compounds were a major contributor to the microalgal antioxidant capacities.  相似文献   

2.
The taxonomy of Saimiri is controversial because morphological characteristics, traditionally used for identification, are insufficient to distinguish species and subspecies. Genetic studies of specimens become relevant for captive management, especially considering their frequently unknown geographical origin. We analyzed phenotypic and genetic parameters in Saimiri spp. in Argentinean zoological gardens and biological stations to provide a more accurate taxonomic identification. We studied 27 males and 19 females of Saimiri spp. The cytogenetic analysis in mitotic metaphases corroborated a modal number of 2N = 44, XX/XY, and FN = 75 for males and FN = 76 for females. G- and C-bands, fluorescence in situ hybridization (FISH) and the pelage coloration pattern of all the specimens corresponded to Saimiri boliviensis boliviensis. We characterized for the first time the sperm cell morphology and morphometry (mean ± SE): total length: 71.39 ± 5.40 μm; head length: 5.71 ± 0.81 μm; head width: 3.76 ± 0.70 μm; acrosome length: 3.70 ± 0.82 μm; midpiece length: 12.20 ± 2.22 μm. Researchers can use the characterization of the sperm morphology as another parameter for taxonomic identification that, together with cytogenetic and molecular ones, would allow a more precise identification of individual Saimiri boliviensis boliviensis.  相似文献   

3.
Candida-associated denture stomatitis has a high rate of recurrence. Candida biofilms formed on denture acrylic are more resistant to antifungals than planktonic yeasts. Histatins, a family of basic peptides secreted by the major salivary glands in humans, especially histatin 5, possess significant antifungal properties. We examined antifungal activities of histatin 5 against planktonic or biofilm Candida albicans and Candida glabrata. Candida biofilms were developed on poly(methyl methacrylate) discs and treated with histatin 5 (0.01–100 μM) or fluconazole (1–200 μM). The metabolic activity of the biofilms was measured by the XTT reduction assay. The fungicidal activity of histatin 5 against planktonic Candida was tested by microdilution plate assay. Biofilm and planktonic C. albicans GDH18, UTR-14 and 6122/06 were highly susceptible to histatin 5, with 50% RMA (concentration of the agent causing 50% reduction in the metabolic activity; biofilm) of 4.6 ± 2.2, 6.9 ± 3.7 and 1.7 ± 1.5 μM, and IC50 (planktonic cells) of 3.0 ± 0.5, 2.6 ± 0.1 and 4.8 ± 0.5, respectively. Biofilms of C. glabrata GDH1407 and 6115/06 were less susceptible to histatin 5, with 50% RMA of 31.2 ± 4.8 and 62.5 ± 0.7 μM, respectively. Planktonic C. glabrata was insensitive to histatin 5 (IC50 > 100 μM). Biofilm-associated Candida was highly resistant to fluconazole in the range 1–200 μM; e.g. at 100 μM only ~20% inhibition was observed for C. albicans, and ~30% inhibition for C. glabrata. These results indicate that histatin 5 exhibits antifungal activity against biofilms of C. albicans and C. glabrata developed on denture acrylic. C. glabrata is significantly less sensitive to histatin 5 than C. albicans.  相似文献   

4.
 Investigation of the life history of corals is hampered by an inability to identify early recruits. In this study, the pattern of formation and morphology of the juvenile skeletons of three laboratory-reared pocilloporids, Seriatopora hystrix, Stylophora pistillata and Pocillopora damicornis, were compared to determine whether they could be reliably distinguished. The pattern of skeleton formation, including the origin and structure of the septa, columella and corallite wall was similar in all species. Following the completion of the primary corallite wall after 4–5 days, these species could be identified by differences in the diameter of the primary corallite. The mean diameter (±SE) of each species differed markedly: S. hystrix 400 ± 2.7 μm, range 325–450 μm; S. pistillata 505 ± 3.5 μm, range 400–550 μm; P. damicornis 697 ± 7.5 μm, range 492–885 μm. Values for the primary corallite diameter overlapped in only 3% of samples, demonstrating the potential utility of this feature as a tool for classifying recruits obtained from the field. Accepted: 4 January 2000  相似文献   

5.
Previous studies have demonstrated that oxygen environment is an important determinate factor of cell phenotypes and differentiation, although factors which affect pericellular oxygen concentration (POC) in murine chondrogenic cell culture remain unidentified. Oxygen concentrations in vivo were measured in rabbit musculoskeletal tissues, which were by far hypoxic compared to 20% O2 (ranging from 2.29 ± 1.16 to 4.36 ± 0.51%). Oxygen concentrations in murine chondrogenic cell (C3H10T1/2) culture medium were monitored in different oxygen concentrations (20% or 5%) in the incubator and in different medium volumes (3,700 or 7,400 μl) within 25-cm2 flasks. Chondrogenic differentiation was assessed by glycosaminoglycan production with quantitative evaluation of Alcian blue staining in 12-well culture dishes. Expression of chondrogenic genes, aggrecan, and type II collagen α1, was examined by quantitative real-time polymerase chain reaction. Oxygen concentrations in medium decreased accordingly with the depth from medium surface, and POC at Day 6 was 18.99 ± 0.81% in 3,700-μl medium (1,480-μm depth) and 13.26 ± 0.23% in 7,400-μl medium (2,960-μm depth) at 20% O2 in the incubator, which was 4.96 ± 0.08% (1,480-μm depth) and 2.83 ± 0.42% (2,960-μm depth) at 5% O2, respectively. The differences of POC compared by medium volume were statistically significant (p = 0.0003 at 20% and p = 0.001 at 5%). Glycosaminoglycan production and aggrecan gene expression were most promoted when cultured in moderately low POC, 1,000 μl (2,960-μm depth) at 20% O2 and 500 μl (1,480-μm depth) at 5% O2 in 12-well culture dishes. We demonstrate that medium volume and oxygen concentration in the incubator affect not only POC but also chondrogenic differentiation.  相似文献   

6.
7.
The Raman spectra, water content, and biomass density of wild-type (WT) Pseudomonas aeruginosa PAO1, small colony variant (SCV) PAO1, and Pseudoalteromonas sp. NCIMB 2021 biofilms were compared in order to determine their variation with strain and species. Living, fully submerged biofilms were analyzed in situ by confocal Raman microspectroscopy for up to 2 weeks. Water to biomass ratios (W/BRs), which are the ratios of the O–H stretching vibration of water at 3,450 cm−1 to the C–H stretching band characteristic of biomass at 2,950 cm−1, were used to estimate the biomass density and cell density by comparison with W/BRs of protein solutions and bacterial suspensions, respectively, on calibration curves. The hydration within SCV biofilm colonies was extremely heterogeneous whereas W/BRs were generally constant in young WT biofilm colonies. The mean biomass in biofilm colonies of WT or colony cores of SCV was typically equivalent to 16% to 27% protein (w/v), but was 10% or less for NCIMB 2021. The corresponding cell densities were 7.5 to >10 × 1010 cfu mL−1 for SCV, while the maximum cell density for NCIMB biofilms was 2.8 × 1010 cfu mL−1.  相似文献   

8.
Whereas the transfer of Listeria from surfaces to foods and vice versa has been well documented, little is known about the mechanism of bacterial transfer. The objective of this work is to gain a better understanding of the forces involved in listerial biofilms adhesion using atomic force microscopy (AFM). L. monocytogenes Scott A was grown as biofilms on stainless steel surfaces by inoculating stainless steel coupons with Listeria and incubating the coupons for 48 h at 32 °C with a diluted 1:20 tryptic soy broth. After growth, biofilms were equilibrated over saturated salt solutions at a constant relative humidity (%RH) before measurement of adhesion forces using AFM. The effects of contact time, loading force, and biofilm relative humidity (%RH) suggested that neither contact time, loading force nor biofilm %RH had a significant effect on biofilm adhesiveness at a cellular level (P > 0.05). In a second set of experiments, the influence of material type on biofilm adhesiveness was evaluated using two different colloidal probes (SiO2 and polyethylene). Results showed that the maximum pull-off force and retraction work needed to retract the cantilever for glass (−85.42 nN and 1.610−15 J, respectively) were significantly lower than those of polyethylene (−113.38 nN and 2.7 × 10–15 J, respectively; P < 0.001). The results of this study suggest that Listeria biofilms adhere more strongly to hydrophobic surfaces than hydrophilic surfaces when measured at a cellular level. These results provide important insights that could lead to new ways to remediate and avoid listerial biofilm formation in the food industry.  相似文献   

9.
Deficiencies in Cu, Se, and Zn impair one or more biochemical functions, and excess are associated with toxicity. Baseline studies on the Ghanaian population are scanty. The study was undertaken to determine whether significant rural/urban differences in the serum levels of Cu, Se, and Zn did exist. Forty males/60 females from rural and 50 males/50 females from urban Ghanaian communities were sampled. Serum Cu, Se, and Zn were determined using flame atomic absorption spectrometry. Cu level for rural and urban subjects was 997 ± 333 and 979 ± 290 μg/L, respectively (p = 0.68). However, Cu levels were significantly higher in the rural females (1,063 ± 367 μg/L) than the rural males (898 ± 249 μg/L; p = 0.0085). Se levels for rural/urban subjects were 97 ± 36 and 87 ± 31 μg/L, respectively (p = 0.03). Zn levels in the rural/urban subjects were 312 ± 218 and 150 ± 102 μg/L, respectively (p = 0.002). Additionally, Zn was significantly higher in rural females (428 ± 204 μg/L) than the urban females (166 ± 103 μg/L; p = 0.0002). Finally, Zn was significantly higher in rural females (428 ± 204 μg/L) than males (172 ± 116 μg/L; p = 0.0028). In conclusion, Cu, Se, and Zn were higher in the rural group compared to the urban group, and the generally low Zn levels were confirmed in another cohort follow-up study.  相似文献   

10.
The aim of this study was to investigate the respiratory function disorders that could be related to dust exposure during the production of copper mine in copper mineworkers (CMWs). The study included 75 male CMWs (mean age, 32.0 ± 7.1 years, 58.6% smokers) and 75 male age- and smoking status-matched healthy control subjects. Serum Cu level was significantly higher in the CMW group (0.80 ± 0.62 μg/ml) than the control group (0.60 ± 0.39 μg/ml) (p = 0.017). Significant negative correlations were found between serum Cu level and forced expiratory volume in first second (r = −0.600; p < 0.001) and between serum Cu level and forced vital capacity (r = −0.593; p = <0.001) in CMWs. Serum Cu level was significantly higher in the restrictive type pulmonary function disorders group (1.36 ± 0.62 μg/ml) than obstructive type (0.90 ± 0.55 μg/ml) and normal pulmonary function pattern group (0.53 ± 0.43 μg/ml) (p < 0.001). Patients with radiological parenchymal abnormalities had significantly higher serum copper levels than those without abnormalities (1.53 ± 0.52 vs. 0.71 ± 0.52 μg/ml, respectively; p = 0.002). In conclusion, result of the study has shown a negative association between pulmonary functions disorders and radiological abnormalities and serum Cu levels in CMWs.  相似文献   

11.
Fourteen indigenous microalgal samples from Malaysia were isolated, purified and cultured from fresh, brackish and marine waters. The ability of the microalgae to be natural sources of antioxidants was studied by a screening test using three antioxidant chemical assays [ferric thiocyanate (FTC), thiobarbituric acid (TBA) and 1, 1’-diphenyl-2-picrylhydrazyl (DPPH)]. The results showed that six microalgal methanolic crude extracts (Isochrysis galbana, Chaetoceros calcitrans, Scenedesmus quadricauda, Chlorella vulgaris, Nannochloropsis oculata and Tetraselmis tetrathele) were active in inhibiting the lipid peroxidation of linoleic acid. Among all the microalgae, I. galbana and C. calcitrans showed the highest antioxidant activity (>90%) in FTC and TBA assays, indicating that these microalgae might contain active compounds for protection from lipid peroxidation. Nutritional analyses were performed on microalgae with high antioxidant activities (I. galbana and C. calcitrans) in order to investigate their nutritive value. Both microalgae were found to be rich in nutrients. For examples, I. galbana had average percentage composition of protein, carbohydrate, and lipid, as 47.9 ± 2.5; 26.8 ± 0.2; 14.5 ± 1.4%, respectively, while the corresponding values for C. calcitrans were 36.4 ± 1.7; 27.4 ± 3.0; 15.5 ± 0.9%. In addition, they contained high levels of omega-3 polyunsatrated fatty acids (PUFA) (28.0% ± 0.7 in I. galbana and 28.5% ± 1.4 in C. calcitrans), omega-6 PUFA (6.5% ± 1.8 in I. galbana and 23.0% ± 2.5 in C. calcitrans) and a high composition of essential amino acids. This study illustrates that some microalgae such as I. galbana and C. calcitrans have the potential to be used as natural sources of antioxidants with high nutritional value. Presented at the 6th Meeting of the Asian Pacific Society of Applied Phycology, Manila, Philippines.  相似文献   

12.
The purpose of the study was to determine the concentration of trace elements present in scalp hair sample of schizophrenic patients and to find out the relationship between trace elements level and nutritional status or socioeconomic factors. The study was conducted among 30 schizophrenic male patients and 30 healthy male volunteers. Patients were recruited from Bangabandhu Sheikh Mujib Medical University by random sampling. Hair trace element concentrations were determined by flame atomic absorption spectroscopy and analyzed by independent t test, Pearson’s correlation analysis, regression analysis, and analysis of variance (ANOVA). Mn, Zn, Ca, Cu, and Cd concentrations of schizophrenic patients were 3.8 ± 2.31 μg/gm, 171.6 ± 59.04 μg/gm, 396.23 ± 157.83 μg/gm, 15.40 ± 5.68 μg/gm, and 1.14 ± 0.89 μg/gm of hair sample, while those of control subjects were 4.4 ± 2.32 μg/gm, 199.16 ± 27.85 μg/gm, 620.9 ± 181.55 μg/gm, 12.23 ± 4.56 μg/gm, and 0.47 ± 0.32 μg/gm of hair sample, respectively. The hair concentration of Zn and Ca decreased significantly (p = 0.024; p = 0.000, respectively) and the concentration of Cu and Cd increased significantly (p = 0.021; p = 0.000, respectively) in schizophrenic patients while the concentration of Mn (p = 0.321) remain unchanged. Socioeconomic data reveals that most of the patients were poor, middle-aged and divorced. Mean body mass indices (BMIs) of the control group (22.26 ± 1.91 kg/m2) and the patient group (20.42 ± 3.16 kg/m2) were within the normal range (18.5−25.0 kg/m2). Pearson’s correlation analysis suggested that only Ca concentration of patients had a significant positive correlation with the BMI (r = 0.597; p = 0.000) which was further justified from the regression analysis (R 2 = 44%; t = 3.59; p = 0.002) and one-way ANOVA test (F = 3.62; p = 0.015). A significant decrease in the hair concentration of Zn and Ca as well as a significant increase in the hair concentration of Cu and Cd in schizophrenic patients than that of its control group was observed which may provide prognostic tool for the diagnosis and treatment of this disease. However, further work with larger population is suggested to examine the exact correlation between trace element level and the degree of disorder.  相似文献   

13.
Pharmaceutical aerosols have been targeted to the lungs for the treatment of asthma and pulmonary infectious diseases successfully. Micafungin (Astellas Pharma US, Deerfield, IL, USA) has been shown to be an effective antifungal agent when administrated intravenously. Pulmonary delivery of micafungin has not previously been reported. In the present pilot study, we characterize the performance of two nebulizers and their potential for delivering micafungin to the lungs as well as the use of multivariate data analysis for mass distribution profile comparison. The concentration of micafungin sodium increased by 21% when delivered by the Acorn II nebulizer and by 20% when delivered by the LC Plus nebulizer, respectively, from the first to the second sampling period. The Acorn II nebulizer delivered a fine particle fraction FPF5.8 (%<5.8 μm) of 92.5 ± 0.8 and FPF3.3 (%<3.3 μm) of 82.3 ± 2.1 during the first sampling period. For the LC Plus nebulizer, FPF5.8 was 92.3 ± 0.1 and FPF3.3 was 67.0 ± 0.7 during the first sampling period. The mass median aerodynamic diameter (MMAD) increased from 1.67 ± 0.05 to 1.77 ± 0.04 μm (Acorn II nebulizer) and from 2.09 ± 0.01 to 2.20 ± 0.01 μm (Pari LC Plus nebulizer) from the first to the second sampling periods. These changes in MMAD were statistically significant by paired t test. Multivariate data analysis showed that this could be explained systematically by greater drug deposition on stages with larger cutoff sizes and reduced drug deposition on stages with smaller cutoff sizes rather than multimodal deposition or other anomalies in size distribution.  相似文献   

14.
Codium fragile (Suringar) Hariot is an edible green alga farmed in Korea using seed stock produced from regeneration of isolated utricles and medullary filaments. Experiments were conducted to reveal the optimal conditions for nursery culture and out-growing of C. fragile. Sampling and measurement of underwater irradiance were carried out at farms cultivating C. fragile at Wando, on the southwestern coast of Korea, from October 2004 to August 2005. Growth of erect thalli and underwater irradiance were measured over a range of depths for three culture stages. During the nursery cultivation stage (Stage I), growth rate was greatest at 0.5 m depth (0.055 ± 0.032 mm day−1), where the average midday irradiance over 60 days was 924 ± 32 μmol photons m−2 s−1. During the pre-main cultivation stage (Stage II), the greatest growth rate occurred at a depth of 2 m (0.113 ± 0.003 mm day−1) with an average irradiance of 248 ± 116 μmol photons m−2 s−1. For the main cultivation stage (Stage III) of the alga, thalli achieved the greatest increase in biomass at 1 m depth (7.2 ± 1.0 kg fresh wt m−1). These results suggest that optimal growth at each cultivation stages of C. fragile could be controlled by depth of cultivation rope.  相似文献   

15.
Despite the efficacy of antibiotics as well as bacteriophages in treatment of bacterial infections, their role in treatment of biofilm associated infections is still under consideration especially in case of older biofilms. Here, efficacy of bacteriophage alone or in combination with amoxicillin, for eradication of biofilm of Klebsiella pneumoniae B5055 has been assessed. Planktonic cells as well as biofilm of K. pneumoniae B5055 grown in 96-well microtiter plates were exposed to bacteriophage and amoxicillin at various Multiplicity of Infections (MoIs) as well as at three different antibiotic concentrations (512, 256 and 128 μg/ml), respectively. After exposure to 256 μg/ml (MIC) of amoxicillin, bacterial load of planktonic culture as well as 1-day-old biofilm was reduced by a log factor of 4.1 ± 0.31 (P = 0.008) and 1.24 ± 0.27 (P < 0.05), respectively but reduction in the bacterial load of mature biofilm (8-day-old) was insignificant (P = 0.23). When 8-day-old biofilm was exposed to higher antibiotic concentration (512 μg/ml) or phage alone (MoI = 0.01) a log reduction of 2.97 ± 0.11 (P = 0.182) and 3.51 ± 0.19 (P = 0.073), respectively was observed. While on exposing to a combination of both the amoxicillin and phage, a significant reduction (P < 0.01) in bacterial load of the biofilm was seen. Hence, when antibiotic was used in combination with specific bacteriophage a greater destruction of the biofilm structure suggested that the phages could be used successfully along with antibiotic therapy. An added advantage of the combination therapy would be its ability to check formation of resistant mutants that otherwise develop easily upon using phage or antibiotic alone.  相似文献   

16.
Total synaptonemal complex (SC) lengths were estimated from Oreochromis aureus Steindachner (which has a WZ/ZZ sex determination system), O. mossambicus Peters and O. niloticus L. (both of which have XX/XY sex determination systems). The total SC length in oocytes was greater than that in spermatocytes in all three species (194 ± 30 μm and 134 ± 13 μm, 187 ± 22 μm and 127 ± 17 μm, 193 ± 37 μm and 144 ± 19 μm, respectively). These sex-specific differences did not appear to be influenced by the type of sex determination system (the female/male total SC length ratio was 1.45 in O. aureus, 1.47 in O. mossambicus and 1.34 in O. niloticus) and do not correlate with the lack of any overall sex-specific length differences in the current Oreochromis linkage map. Although based on data from relatively few species, there appears to be no consistent relationship between sex-specific SC lengths and linkage map lengths in fish. Neomale (hormonally masculinized genetic female) O. aureus and O. mossambicus had total SC lengths of 138 ± 13 μm and 146 ± 13 μm respectively, more similar to normal males than to normal females. These findings agree with data from other vertebrate species that suggest that phenotypic sex, rather than genotype, determines traits such as total SC length, chiasmata position and recombination pattern, at least for the autosomes.  相似文献   

17.
Although there are many studies on effect of fluoride on trace elements in experimental animals, few studies exist on serum trace elements levels in patients with endemic fluorosis. We aimed to determine the serum levels of trace elements including serum copper (Cu), zinc (Zn), and serum levels of minerals including calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K) in patients with endemic fluorosis. The study group consisted of 30 patients with endemic fluorosis (17 females, 13 males, mean age 33.53 ± 9.85 years). An age, gender, and body mass index matched 30 healthy volunteers comprised control group (21 females, ten males with a mean age 33.93 ± 7.39 years). Urine fluoride levels of chronic fluorosis patients were significantly higher than that of control subjects as expected (1.92 ± 0.10 mg/l vs. 0.41 ± 0.09 mg/l, respectively; P < 0.001). Serum Cu levels (89.14 ± 16.77 μg/dL vs. 102.69 ± 25.04 μg/dL, respectively, P = 0.017), serum Zn levels (77.98 ± 20.58 μg/dL vs. 94.57 ± 35.87μg/dL, respectively, P = 0.032), and serum Mg levels (1.92 ± 0.18 mg/dL vs. 2.07 ± 0.31 mg/dL, respectively, p = 0.022) was significantly lower in chronic fluorosis patients than in controls. There were no statistically significant differences between the fluorosis group and control group with respect to serum levels of Na, K, Ca, and P. We concluded that chronic fluorosis is associated with reduced serum levels of Cu, Zn, and Mg.  相似文献   

18.
This investigation was undertaken to evaluate practical feasibility of site specific pulmonary delivery of liposomal encapsulated Dapsone (DS) dry powder inhaler for prolonged drug retention in lungs as an effective alternative in prevention of Pneumocystis carinii pneumonia (PCP) associated with immunocompromised patients. DS encapsulated liposomes were prepared by thin film evaporation technique and resultant liposomal dispersion was passed through high pressure homogenizer. DS nano-liposomes (NLs) were separated by ultra centrifugation and characterized. NLs were dispersed in phosphate buffer saline (PBS) pH 7.4 containing different carriers like lactose, sucrose, and hydrolyzed gelatin, and 15% l-leucine as antiadherent. The resultant dispersion was spray dried and spray dried formulation were characterized to ascertain its performance. In vitro pulmonary deposition was assessed using Andersen Cascade Impactor as per USP. NLs were found to have average size of 137 ± 15 nm, 95.17 ± 3.43% drug entrapment, and zeta potential of 0.8314 ± 0.0827 mV. Hydrolyzed gelatin based formulation was found to have low density, good flowability, particle size of 7.9 ± 1.1 μm, maximum fine particle fraction (FPF) of 75.6 ± 1.6%, mean mass aerodynamic diameter (MMAD) 2.2 ± 0.1 μm, and geometric standard deviation (GSD) 2.3 ± 0.1. Developed formulations were found to have in vitro prolonged drug release up to 16 h, and obeys Higuchi's Controlled Release model. The investigation provides a practical approach for direct delivery of DS encapsulated in NLs for site specific controlled and prolonged release behavior at the site of action and hence, may play a promising role in prevention of PCP.  相似文献   

19.
Tecoma stans is a tropical plant from the Americas. Antioxidant activity and both phenolic compound and flavonoid total content were determined for callus tissue of T. stans cultured in either a set photoperiod or in darkness. Callus lines from three explant types (hypocotyls, stem, and leaf) were established on B5 culture medium supplemented with 0.5 μM 2,4-D and 5.0 μM kinetin. While leaf-derived callus grew slower under a 16-h photoperiod (specific growth rate, μ = 0.179 d−1, t D = 3.9 d) than in darkness (μ = 0.236 d−1, t D = 2.9 d), it accumulated the highest amount (p < 0.05) of both phenolics (86.6 ± 0.01 mg gallic acid equivalents/g) and flavonoids (339.6 ± 0.06 mg catechin equivalents/g). Similarly, antioxidant activity was significantly higher (p < 0.05) when callus was cultured in period light than when grown in extended darkness. Antioxidant activity measured with a 2,20-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS)-based assay was 350.5 ± 15.8 mmol Trolox/g extract for callus cultured under a defined photoperiod compared to 129.1 ± 7.5 mmol Trolox/g extract from callus cultured in darkness. Content of phenolic compounds and flavonoids was in agreement with a better antioxidant power (EC50 = 450 μg extract/mg 1,1-diphenyl-2-picrylhydrazyl) and antiradical efficiency. Results of the present study show that calli of T. stans are a source of compounds with antioxidant activity that is favored by culture under a set photoperiod.  相似文献   

20.
The purpose of this study was to compare plasma leptin, plasma zinc, and plasma copper levels and their relationship in trained female and male judo athletes (n = 10 women; n = 8 men). Blood samples were obtained 24 h after training to measure plasma zinc, copper, and leptin levels. Subjects presented similar values to age (22 ± 2 years old), body mass index (24 ± 1 kg/m2), plasma zinc (17.2 ± 2 μmol/L), copper (12.5 ± 2 μmol/L), and leptin (5.6 ± 1.3 μg/L). However, height, total body mass, lean mass, fat mass, and sum of ten-skinfold thickness were higher in male than female. Plasma leptin was associated with sum of ten skinfolds in male (r = 0.91; p < 0.001) and female athletes (r = 0.84; p < 0.003). Plasma zinc was associated with leptin in males (r = 0.82; p < 0.05) while copper was associated with plasma leptin in females (r = 0.66; p < 0.05). Our results suggest that young judo athletes lost sex-related differences in leptin levels. Plasma zinc, plasma copper, and energy homeostasis may be involved in regulation of plasma leptin.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号