This study aimed to microencapsulate silver carp oil by spray drying with different combinations of wall materials (gum Arabic, modified starch Hi-cap, maltodextrin, and inulin) and evaluate the effects of these combinations on the physiochemical and oxidative stability of the microcapsules. Feed emulsions were also investigated prior to spray drying. Modified starch-based microcapsules had higher encapsulation efficiency (91.22-92.78%) and yield (87.41-92.15%), excellent solubility (91.85-93.67%), good particle size (301.20-407.73 d.nm), color, and powder morphology. The presence of inulin reduced agglomeration in powders. All the powders exhibited good protection against lipid oxidation during 2 months of storage, whereas the modified starch and inulin combination provided the best stability. 相似文献
This study was conducted to investigate the effects of dietary red seaweed, Gracilaria pygmaea level on growth, antioxidant‐related parameters, digestive enzyme activity and intestinal morphology of rainbow trout (Oncorhynchus mykiss) fry. Five isocaloric and isonitrogenous diets were formulated to contain four G. pygmaea levels (30 (GL‐30), 60 (GL‐60), 90 (GL‐90) and 120 g/kg (GL‐120)), and a control diet was used, without inclusion of seaweed. Results of the feeding trial indicated that final body (FBW: 2.8–3.5 g) and specific growth rate (SGR: 4.8–5.2) were significantly improved when 60 g/kg G. pygmaea was supplemented in the diets. However, there was a significant reduction (p <.05) of final body weight (FBW) and specific growth rate (SGR) in fish fed 120 g/kg G. pygmaea. Protease activity was significantly lower in fish fed GL‐120 diet when compared to GL‐30 or control (p <.05). Lipase was significantly affected by dietary seaweed regardless its level of supplementation (p <.05). The inclusion of the Gracilaria in the diet led to evident changes in the fish antioxidant status with significant reduction of superoxide dismutase, glutathione peroxidase activity and lipid peroxidation products. The histological study demonstrated that all groups of fish displayed normal morphology of anterior intestine and pyloric caeca. Villi absorptive area in the anterior intestine of treatment groups GL‐90 and GL‐120 significantly decreased (p <.05). Overall, the results obtained in this study indicate that dietary G. pygmaea supplementation up to 90 g/kg improves growth performance in rainbow trout fry without compromising antioxidant responses and digestive function. 相似文献
The present work described the development of multifunctional, electrically conductive and durable fabrics by coating of silver and copper particles using a dipping-drying method. The particles were directly grown on fabric structure to form electrically conductive fibers. Particles were found to fill the spaces between the microfibers, and were stacked together to form networks with high electrical conductivity. The electrically conductive fabrics showed low resistance with high stretch ability. The utility of conductive fabrics was analyzed for electromagnetic shielding ability over frequency range of 30 MHz to 1.5 GHz. The EMI shielding was found to increase with increase in concentration of copper and silver particles. Furthermore, the heating performance of the copper and silver coated fabric was studied through measuring the change in temperature at the surface of the fabric while applying a voltage difference across the fabric. The maximum temperature (119°C for silver and 112°C for copper) were obtained when the applied voltage was 10 V. Moreover, the role of deposited particles on antibacterial properties was examined against pathogenic bacteria such as Staphylococcus aureus and Escherichia coli. At the end, the durability of coated fabrics was examined against several washing cycles. The fabrics showed good retention of the particles, proved by small loss in the conductivity of the material after washing. 相似文献
Soybean, as a major oilseed crop, is cultivated in many parts of the world including saline-affected regions. A four-replicated factorial experiment based on a completely randomized design with five salinity levels (control, 50, 100, 150, and 200 mM NaCl) and five wild-type and new mutant cultivars of soybean (Williams, Clark, M-4, M-7, and M-9) was done at two vegetative and reproductive phases to study leaf oxidants, antioxidants and osmolytes under salinity stress. The vegetative phase demonstrated higher K+:Na+ ratio, cell membrane stability, relative water content (RWC) and stomatal conductance to H2O (gs) accompanied with lower oxidative stress, antioxidants and osmolytes contrasting to reproductive phase. At both phenological phases, saline stress stimulated antioxidative defense owing to the enhancement of oxidative stress. The results indicated that mutants possessed a better antioxidative system than their wild-types. 相似文献
Synthesis of biocompatible polymer nanofibers is valuable, due to their use as a cover for burns and as a replacement for bandage because of their antimicrobial properties. In this study, electrospinning of chitosan(Ch) and nanofibers synthesis with antibacterial properties was investigated. Nanofibers with antibacterial properties were synthesized by electrospun of Ch/poly(L-lactide)(PLA)/Imipenem(Imi) polymer solution. The results showed that the optimized ratio of Ch/PLA polymer solution was ratio of 50:50 and Ch 2 wt% and PLA 10 wt% polymer solution was the best weight percentage for nanofiber preparation. Also, the average diameter of Ch/PLA/Imi nanofibers was 143 nm and measured with ImageJ software. Afterwards, the antibacterial properties of Imi as additives (with different percentages) was studied in the polymer solution. The scanning electron microscopy (SEM) images and antibacterial tests were showed that the electrospun of Ch/PLA/Imi polymeric nanofibers were effective against Gram negative bacteria Escherichia coli (E. coli) and inhibited growth of E. coli. The growth and viability percentage of fibroblast cells with nanofibers in αMEM culture are at desirable levels after 6 days. 相似文献
Zinc (Zn) deficiency is a major nutritional problem for rice under sodic conditions. Seedlings (35-d old) of 30 rice genotypes were transplanted in pots at pH2 9.8 [diethylene triamine penta acetic acid (DTPA) Zn 1.8 ppm] to identify genotypes tolerant to both sodicity and Zn deficiency. Ten genotypes (group A) showed potential to tolerate both the stresses. Sixteen genotypes (group B) were sensitive to Zn deficiency. However, some of the seedlings of group B genotypes were normal (without Zn deficiency symptoms). Four genotypes (group C) were sensitive to sodicity. Leaves and their leaf sheaths were analyzed at 33 d after transplanting for Ca, Mg, K, and Na. Group A genotypes (CSR-88IR15, CSR-89IR14, IR4630-22-2-5-1-2, and Trichi) had significantly less Na concentrations in their leaves and the leaf sheaths compared to group B genotypes (CSR10, CSR23, CSR-88IR1, 89H1-931098, and IR47538-3B-9-3B-1). The concentration of Na was invariably higher in the leaf sheath than its leaf in both the groups, but reverse was true for Ca, Mg, and K. Zinc deficient plants had relatively higher concentrations of Ca and Mg in their leaves and the leaf sheaths than group A. Concentration of K was somewhat better in group A than group B genotypes. Higher Na/K ratio in group B genotypes compared to group A may be attributed to increased concentrations of Na rather than decreases in K concentrations. Further studies are needed to understand the processes associated with differential uptake of Na and K by Zn deficient plants of group B genotypes resulting in higher Na/K ratio compared to group A genotypes. 相似文献
Seed viability monitoring is very important in ex situ germplasm preservation to detect germplasm deterioration. This requires seed-, time- and labor- saving methods with high precision to assess seed germination as viability. Although the current non-invasive, rapid, sensing methods (NRSs) are time- and labor-saving, they lack the precision and simplicity which are the virtues of traditional germination. Moreover, they consume a considerable amount of seeds to adjust sensed signals to germination percentage, which disregards the seed-saving objective. This becomes particularly severe for rare or endangered species whose seeds are already scarce. Here we propose a new method that is precise, low-invasive, simple, and quick, which involves analyzing the pattern of dehiscence (seed coat rupture), followed by embryonic protrusion.
Results
Dehiscence proved simple to identify. After the trial of 20 treatments from 3 rice varieties, we recognized that dehiscence percentage at the 48th hour of germination (D(48)) correlates significantly with germination rate for tested seed lots. In addition, we found that the final germination percentage corresponded to D(48) plus 5. More than 70% of the seeds survived post-dehiscence desiccation for storage. Hydrogen peroxide (1 mM) as the solution for imbibition could further improve the survival. The method also worked quicker than tetrazolium which is honored as a fast, traditional method, in detecting less vigorous but viable seeds.
Conclusion
We demonstrated the comprehensive virtues of dehiscence method in assessing rice seed: it is more precise and easier to use than NRSs and is faster and more seed-saving than traditional methods. We anticipate modifications including artificial intelligence to extend our method to increasingly diverse circumstances and species.
Routinely, swim‐up method is used to separate high‐quality sperm; however, long processing time and close cell‐to‐cell contact during the centrifugation step are inevitable elements of oxidative stress to sperm. The objective was to evaluate Sephadex? and glass wool filtration to separate motile, intact and viable sperm for in vitro fertilization in buffalo. The cumulus–oocyte complexes (COC s) were collected from ovaries of slaughtered buffaloes by aspiration and matured for 24 hr in CO 2 incubator at 38.5°C and 5% CO 2. Matured COC s were rinsed twice in fertilization TALP and placed in the pre‐warmed fertilization medium without sperm. Cryopreserved buffalo semen was thawed at 37°C for 30 s and processed through Sephadex?, glass wool filtration and swim‐up (control). Total and motile sperm recovery rates were assessed, resuspended in fertilization TALP and incubated for 15–20 min in CO 2 incubator. Samples prepared by each method were divided into two aliquots: one aliquot was studied for sperm quality (progressive motility, membrane integrity, viability, liveability), while the other was subjected to co‐incubation with sets of 10–15 in vitro matured oocytes. Data on sperm quality were analysed by ANOVA , while in vitro fertilizing rates were compared by chi‐squared test using SPSS ‐20. Least significant difference (LSD ) test was used to compare treatment means. Glass wool filtration yielded higher total and motile sperm recovery rate, while Sephadex? filtration improved (p <.05) sperm quality (progressive motility, membrane integrity, viability, liveability). Sperm preparation through Sephadex filtration yielded higher in vitro fertilization rate in terms of cleavage rate compared to glass wool filtration and swim‐up (control). In conclusion, cryopreserved Nili‐Ravi buffalo sperm selected through Sephadex filtration showed improved quality and yielded better fertilization rates (cleavage rate) of in vitro matured/fertilized oocytes. Sephadex filtration could be a promising technique for use in in vitro fertilization in buffalo. 相似文献
High temperature has deleterious impacts on tomato growth and development and limits its production. Acetyl salicylic acid (ASA) and 24-epibrassinolide (EBL) have been widely reported as stress-ameliorating agents. The effect of exogenous application of varying levels of EBL (0.75, 1.5, and 3 µM) and ASA (0.25, 0.75, and 1.25 mM) on root activity (RA) in terms of 2,3,5 triphenyl tetrazolium chloride (TTC) reduction and root morphological features was evaluated in four-week-old tomato seedlings (cultivar: Mei Jie Lo) grown under high-temperature stress (46°C/4 h per day) for 21 days. The daily heat stress treatment almost ceased the root growth of chemically untreated seedlings. However, both EBL and ASA significantly attenuated the deleterious impacts of heat stress to different extents regarding root activity, total root length, surface area, volume, and number of nodes and connections. Different concentrations demonstrated signature effects. EBL (3 µM) was over all the best treatment to improve root activity whereas ASA (0.25 mM) best enhanced root architecture (net length, volume, and area) as compared to the untreated heat-stressed controls. However, EBL (3 µM) and ASA (1.25 mM) slightly inhibited mean root diameter. It is concluded that under high-temperature conditions, the exogenous EBL and ASA in studied doses improve root morphological features and root activity, hence enhance heat stress tolerance. Both chemical agents can be potential candidates in practical agriculture for extension of tomato growth period in summer by virtue of their heat stress amelioration ability. 相似文献
In a 2-year field study, denitrification loss was measured from an irrigated sandy-clay loam under cotton receiving urea-N
at 158–173 kg ha–1. An acetylene inhibition-soil core method was employed for the direct measurement of denitrification, considering also the
N2O entrapped in the soil. Taking into account the N2O evolved from soil cores and that entrapped in the soil, a total of 65.7 kg N ha–1 and 64.4 kg N ha–1 was lost due to denitrification during the 1995 and 1996 cotton-growing seasons, respectively. Most (>70%) of the denitrification
loss occurred during June–August, a period characterized by high soil temperatures and heavy monsoon rains. On average, 35%
of the denitrification-N2O was found entrapped in the soil and the amount of entrapped N2O was significantly correlated with head space N2O concentration and with water-filled pore space. 15N-balance during the 1996 growing season revealed a loss of 71.8 kg N ha–1. It was concluded that a substantial proportion of the fertilizer-N applied to irrigated cotton is lost under the semiarid
subtropical climatic conditions prevailing in the Central Punjab region of Pakistan and that denitrification is the major
N loss process under irrigated cotton in this region.
Received: 8 March 1999 相似文献