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81.
Gut microbes play an important role in insect morphogenesis, nutrition, development of resistance against parasitoids and detoxification of toxic compounds. A culture-based approach is therefore an useful tool for the characterization of cultivable microbial communities associated with the insect gut. In the present study an attempt was made to decipher the gender specificity of gut bacterial communities of two major fruit fly species of India viz., Bactrocera dorsalis (Hendel) and Bactrocera cucurbitae (Conquillett) (Diptera: Tephritidae). Based on molecular identification, B. dorsalis females were found to predominantly harbor the bacterial species Enterobacter cloacae, Enterobacter asburiae and Citrobacter freundii, while B. dorsalis males were found to harbor Providencia rettgerii, Klebsiella oxytoca, Enterococcus faecalis and Pseudomonas aeruginosa The cultivable diversity from females of B. cucurbitae comprised mainly of Morganella morganii and Bacillus pumilis while B.cucurbitae males were predominantly colonized by aerobic endospore formers viz., Bacillus cereus, B. licheniformis and B. subtilis. The above findings have thrown light on a distinct pattern of gender specific gut bacterial colonization in fruit flies, which have to be factored in for the formulation of fruit fly management strategies.  相似文献   
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83.
Increased seaweed consumption may be linked to the lower incidence of metabolic syndrome in eastern Asia. This study investigated the responses to two tropical green seaweeds, Ulva ohnoi (UO) and Derbesia tenuissima (DT), in a rat model of human metabolic syndrome. Male Wistar rats (330–340 g) were fed either a corn starch-rich diet or a high-carbohydrate, high-fat diet with 25% fructose in drinking water, for 16 weeks. High-carbohydrate, high-fat diet-fed rats showed the signs of metabolic syndrome leading to abdominal obesity, cardiovascular remodelling and non-alcoholic fatty liver disease. Food was supplemented with 5% dried UO or DT for the final 8 weeks only. UO lowered total final body fat mass by 24%, systolic blood pressure by 29 mmHg, and improved glucose utilisation and insulin sensitivity. In contrast, DT did not change total body fat mass but decreased plasma triglycerides by 38% and total cholesterol by 17%. UO contained 18.1% soluble fibre as part of 40.9% total fibre, and increased magnesium, while DT contained 23.4% total fibre, essentially as insoluble fibre. UO was more effective in reducing metabolic syndrome than DT, possibly due to the increased intake of soluble fibre and magnesium.  相似文献   
84.
Aquaculture is faced with the challenges of the use of synthetic compounds as growth enhancers and the presence of several contaminants in water. These factors severely deteriorate the quality and quantity of aquaculture products. Phytochemicals play a major role by working as antioxidant agents of which curcumin has become the gold standard. Curcumin, from Curcuma longa shows a wide spectrum of biological activities which include anticancerous, antioxidant, anti-inflammatory, antibacterial, antiviral, antifungal, antidiabetic, antistress, hepatoprotective and gastroprotective effects. Curcumin in 0.5 and 1 % doses were given as feed additive to Oreochromis mossambicus for 35 days. After feeding trial, activities of digestive enzymes such as α-amylase, protease and lipase were analysed. There was a significant increase in the activities of α-amylase, protease and lipase with 0.5 and 1 % curcumin supplementation in feed. Real-time quantification of GH in brain, and IGF-1 and IGF-2 genes in muscle revealed that curcumin significantly increased the expression of these genes. This is the first study to report that curcumin supplementation at concentrations of 0.5 and 1 % in the feed improved the activities of digestive enzymes and also modulates the expression of GH in brain and growth factors such as IGF-1 and IGF-2 in muscle of O. mossambicus.  相似文献   
85.
A study was conducted to investigate the effects of paclobutrazol (PBZ) on ion leakage (IL), proline content and activities of antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) of 1-year-old ‘Olour’ mango plants subjected to NaCl stress. Plants were treated with two levels of salt, i.e., 0.0 g NaCl (control) and 25 g NaCl/25 kg soil and three levels of paclobutrazol (PBZ) solution (0.0 (control), 750 and 1500 mg/l). Ion leakage, proline content and activities of antioxidant enzymes were significantly altered by both salinity and PBZ treatments. Results indicated that PBZ (1500 mg/l) mitigated the salinity stress and reduced ion leakage of mango seedlings by 64% over non-PBZ-treated salinised plants. PBZ upregulated the endogenous proline content and salinised plants treated with PBZ (1500 mg/l) had 17% higher proline content than salinised plants without PBZ treatment. Higher antioxidant enzyme activity was also observed in salinised plants treated by PBZ than salinised plants without PBZ treatments. Moreover, higher dose of PBZ (1500 mg/l) resulted in higher activity of these enzymes in mango leaves. In comparison to salinised plants without PBZ treatment, salinised plants treated with PBZ (1500 mg/l) had higher SOD (24%), CAT (46%) and POD (163%) activities. Our results suggest that PBZ application under salt stress conditions alters the equilibrium between free radical production and enzymatic defense reactions in mango by enhancing the proline content and free radical scavenging capacity.  相似文献   
86.
Benefits from the application of plant growth-promoting bacteria in agriculture largely depend on the complex interactions between several factors including the nature of fertilizers selected. This study was designed to determine the fine tuning between the inoculated bacteria and different fertilizers and their effect on the growth of lettuce plants (Lactuca sativa L.). Plant growth promotion by a novel species of the genus Azospirillum, namely A. rugosum IMMIB AFH-6, was tested by biochemical, bioassay, and greenhouse studies. The treatments used in the greenhouse study were; unfertilized control (Blank), half recommended dose of chemical fertilizer (1/2CF), full recommended dose of chemical fertilizer (1CF), pig manure fertilizer (PMF), pig manure fertilizer + half recommended dose of chemical fertilizer (PMF + 1/2CF), and pig manure fertilizer + full recommended dose of chemical fertilizer (PMF + 1CF). All these treatments when inoculated with A. rugosum IMMIB AFH-6 inoculation were, respectively, In-Blank, In-1/2CF, In-1CF, In-PMF, In-PMF + 1/2CF, and In-PMF + 1CF. Significant increase in plant biomass and shoot N, P, Ca, and Fe was shown in the In-Blank treatment. Plant growth in soil amended with PMF and A. rugosum IMMIB AFH-6 was significantly lower than in soil treated with the chemical fertilizer, but inoculation combined with chemical fertilizer significantly elevated the plant biomass. The In-PMF + 1/2CF treatment showed the highest yield. A. rugosum IMMIB AFH-6 facilitated the accumulation of trace minerals in higher concentrations when PMF was combined with 1CF. To examine the benefits of inoculation by A. rugosum IMMIB AFH-6, we have proposed a new type of data analysis which considers both biomass and nutrient content of plants. This new type of analysis has shown the importance of the mineral content of plant.  相似文献   
87.
The activity of cellulase was determined in the intestine of rohu, Labeo rohita, fingerlings fed on separate dietary formulations incorporating Leucaena leaf meal and synthetic cellulose at 20% level in proportional replacement of the ingredients from the fish-meal-based reference diet. Three more replicate experimental diets were prepared by incorporating 1% tetra-cycline, a broad-spectrum antibiotic, into the former three dietary formulations so as to circumvent the action of microflora in digestive function. Cellulase activity was found to be highest in fish fed on the cellulose incorporated diet, followed by those maintained on the plant-protein-based and reference diets, respectively. A diet-dependent variation in cellulase activity was apparent. However, a sharp decline in the level of cellulase activity was observed in the fish fed diets containing tetracycline, which is supposed to have destroyed all the gut microflora. The microbial culture of intestinal and hepatopancreatic extracts also confirmed the absence of microflora in the fish fed tetracycline-compounded diets. The study indicates that cellulase activity in rohu is largely contributed by the intestinal microflora, while the reduced activity recorded in the fish reared on antibiotic-compounded diets may be due to the presence of some other source of cellulase secretion apart from cellulolytic microbial action. The information generated from the present investigation might contribute towards better feed formulation for carp at low cost, incorporating plant-based feed ingredients. © Rapid Science Ltd. 1998  相似文献   
88.
An experiment was designed to evaluate the requirement of dietary protein for Reba carp, Cirrhinus reba fingerlings using semi‐purified diet. Five isocaloric diets were prepared containing 20%, 25%, 30%, 35% and 40% level of protein using casein, gelatin as a major protein source. The experiment was conducted for 105 days in triplicates to evaluate the growth, survival, feed utilization, carcass composition of C. reba. Mean weight gain was highest (p < .05) in T3. Specific growth rate was highest in T3 and lowest in T1. Similarly, significantly (p < .05) highest net fish yield were recorded in T3. No significant difference was recorded in survivability. Feed conversion ratio, protein efficiency ratio, feed conversion efficiency and protein conversion efficiency were significantly (p < .05) higher for T3 compared with other treatments. Highest carcass protein and lipid values were recorded in T3. So, conclusion can be drawn that 30% crude protein is optimum for overall performance. Furthermore, broken‐line analysis for specific growth rate, final biomass and net fish yield indicated that dietary protein level of 28.148 to 28.253% is optimum for the best growth performance of fingerling C. reba.  相似文献   
89.
Consistent and effective methods for early discrimination of pathogen resistance, and selection of times for tissue sampling, are important for experiments using global gene expression and metabolomics. Assays for resistance to the vascular pathogen Verticillium dahliae (Vd), the causal agent of Verticillium wilt (VW), are particularly difficult because escapes are common in field assays. Seedling dip assays offer a potential solution, but homogeneous populations are not typically available. As an alternative strategy, we have developed a protocol for studying spatiotemporal infection dynamics of Vd using potato stem cuttings. The protocol was validated using genotypes varying in resistance/susceptibility to Vd. Although there were no visual symptoms in the plants, stem sections were infested with Vd as early as 7 dpi. Symptoms were first observed in the most susceptible genotype at 10 dpi and became apparent on all test subjects at 14 dpi. The protocol has potential applications in resistance breeding and ‘omics’ studies where populations derived from true seeds are not available.  相似文献   
90.
Commiphora wightii (Arn.) Bhandari syn. C. mukul Engl. (Burseraceae) is an economically and pharmacologically important slow growing, dioecious, balsamiferous woody, multipurpose shrub heading towards extinction. Commonly known as “Guggul” due to the presence of steroidal compound guggulsterone in the oleo-gum resin, it has been used in treating various ailments and disorders since ancient times (2000 B.C.). Evaluation and confirmation of hypolipidemic effects of guggul based on Ayurvedic text in 1960s provided a new insight into its pharmacological applications. Two bioactive isomers of guggulsterone, E and Z, are responsible for lipid- and cholesterol-lowering activities. Recently, it has been shown to have anti-cancerous activity also. It is found in the dry regions of Indian subcontinent, namely India, Pakistan and Bangladesh. Ruthless and unscientific harvesting of oleo-gum resin from the wild, by local populations, for economic benefits with negligible conservation efforts has made this species endangered and has led to its inclusion in Red Data Book of IUCN. Although this plant has many excellent traits, adequate attention has not been focused on its conservation and improvement. Conventional propagation methods i.e., seeds, cuttings and air layering are in place but have many limitations. Therefore, application of modern biotechnological tools needs to be standardized for harnessing maximum benefits from this pharmaceutically important plant. An efficient regeneration system needs to be in place for improvement of this genus through genetic transformation and production of useful metabolites in cell cultures. Studies are in progress for micropropagation through shoot multiplication and somatic embryogenesis, as well as for secondary metabolite (guggulsterone) production in callus cultures and bioreactors. No selected germplasm is available for C. wightii since it is a wild plant. Breeding programs have not yet been started due to lack of systematic cultivation and conservation programs. Moreover, little information has been gathered regarding the genetic variability in this species using RAPD and ISSR markers. No details are available about genetic makeup and QTL linkage maps. Investigations are in progress to search sex linked markers in this dioecious species. Research is also in progress to decipher the molecular mechanisms underlying various pharmacological actions of guggul. Since the approval of use of guggul as a food supplement by United States Food and Drug Administration in 1994, an exponential increase in research publications on various aspects of research on guggul have been published. Present communication summarizes the problems, progress made and suggests some future directions of research for this important endangered medicinal plant.  相似文献   
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