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41.
Brassica vegetables are an important dietary source of glucosinolates (GLs), whose breakdown products exhibit anticancer activity. The protective properties of Brassicaceae are believed to be due to the inhibition of Phase-I or induction of Phase-II xenobiotic metabolizing enzymes (XMEs), thus enhancing carcinogen clearance. To study whether GLs affect XMEs and the role of their chemical structure, we focused on two alkylthio GLs differing in the oxidation degree of the side chain sulfur. Male Sprague-Dawley rats were supplemented (per oral somministration by gavage) with either glucoraphasatin (4-methylthio-3-butenyl GL; GRH) or glucoraphenin (4-methylsulfinyl-3-butenyl GL; GRE), at 24 or 120 mg/kg body weight in a single or repeated fashion (daily for four consecutive days), and hepatic microsomes were prepared for XME analyses. Both GLs were able to induce XMEs, showing different induction profiles. While the inductive effect was stronger after multiple administration of the higher GRH dosage, the single lower GRE dose was the most effective in boosting cytochrome P-450 (CYP)-associated monooxygenases and the postoxidative metabolism. CYP3A1/2 were the most affected isoforms by GRH treatment, whereas GRE induced mainly CYP1A2 supported oxidase. Glutathione S-transferase increased up to approximately 3.2-fold after a single (lower) GRE dose and UDP-glucuronosyl transferase up to approximately 2-fold after four consecutive (higher) GRH doses. In conclusion, the induction profile of these GLs we found is not in line with the chemopreventive hypothesis. Furthermore, the oxidation degree of the side chain sulfur of GLs seems to exert a crucial role on XME modulation.  相似文献   
42.
Renal dysplasia is defined as a condition of disorganised development of renal parenchyma due to abnormal differentiation. The case of a 5-month-old intact male Norwegian Forest Cat with a history of polyuria and polydipsia is reported. Ultrasonographic examination showed a slight enlargement of kidneys. Biochemical parameters, haematological examinations and clinical signs were compatible with chronic renal failure (CRF). Histological examination was correlated with a primary tubular disorganisation and modification of glomerular compartment. The clinical history together with the histological lesions is consistent with bilateral juvenile renal dysplasia in this cat. To our knowledge, feline renal dysplasia has been reported in fetal infections with panleukopenia virus; no reports indicate the idiopathic origin in feline dysplastic lesions.  相似文献   
43.
Ochratoxin A (OTA), is a nephrotoxic mycotoxin present in wine, which is nephrotoxic in humans. Our working hypothesis is that natural substances in wine may counteract OTA toxicity. Thirty-six rats were randomized to OTA dissolved in saline, red wine, or 13.5% ethanol or to OTA-free wine, ethanol, or saline. OTA (289 microg/kg of body weight/48 h) was administered by gastric gavage for 2 weeks. Serum creatinine, tubular enzymuria, renal lipohydroperoxides (LOOH), reduced (GSH) and oxidized (GSSG) glutathione, and renal superoxide dismutase activity (SOD) were determined in renal tissue. OTA alone produced significant increases in renal lipoperoxides and significant decreases in SOD and GSH/GSSG ratio. In red wine or ethanol, OTA was less nephrotoxic, reducing oxidative damage as revealed by LOOH. In OTA-wine and OTA-ethanol groups, SOD activity was higher than in the OTA-treated one, suggesting that both ethanol and nonalcoholic fractions may preserve antioxidant reserve. GSH/GSSG ratio was significantly preserved only in the OTA-wine group and not in OTA-ethanol. Red wine may exert a protective effect against OTA nephrotoxicity by limiting oxidative damage. The ostensible protection afforded by ethanol deserves further investigation.  相似文献   
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The clinical and pathologic findings related to an infiltrative facial lipoma in a 5-month-old female Holstein Friesian calf are reported. The tumor was congenital, increased in size with time, and deformed the left side of the face and cranial bones. The clinical condition of the calf was good; the only detectable abnormalities were poor weight gain and decreased motility of the left upper lip. Clinical and radiologic data indicated the mass was not removable. Muscle and lymph node invasion by tumor tissue were detected histologically. Infiltrative lipoma is a rare variety of lipoma that has been reported in dogs, cats, horses, and humans. Although its cytologic characteristics are those of a benign tumor, in this patient the invasiveness of the neoplasm was associated with poor prognosis.  相似文献   
46.
An adult male bullmastiff dog was treated for paraparesis and ataxia due to discospondylitis and disc herniation. At this time, the dog had a nonhealing ulcer between the pads of the left hindfoot. At re-evaluation, the dog had developed a large exophitic mass in the previously ulcerated area. Cytological examination revealed occasional spindle cells with mild atypia, and a soft tissue tumour was suspected. The mass was excised and submitted for histology. The lesion was characterized by superficial ulceration, an intermediate layer of granulation tissue and a deep portion containing vertically orientated capillaries and perpendicularly arranged fibroblasts and collagen. The histological features led to a diagnosis of hypertrophic scar. Eight weeks after surgery, the lesion recurred and was treated with an intralesional injection of methylprednisolone acetate. The lesion regressed in 10 days, but recurred after 3 months following severe self-trauma. Hypertrophic scars and keloids are two types of exuberant scarring reported in human beings, the pathogenesis of which is still unclear but seems to involve several cytokines, growth factors and inflammatory cells. The histological features identified in this case paralleled those reported in hypertrophic scars in humans. In this case, intralesional corticosteroid therapy was useful in the management of the lesion, but the severe self-trauma could have influenced the recurrence. Even if uncommon, hypertrophic scar should be included among the differential diagnoses of spindle cell tumours in dogs.  相似文献   
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Sponge harvesting was a significant part of the Bahamian economy until the late 1930s when disease, hurricanes, and unsustainable harvesting practices reduced the viability of the sponge industry. Current international demands for natural products, increasing regional needs for economic diversification, and the historical foundation of sponging in The Bahamas makes sponge aquaculture a desirable candidate as a sustainable industry. To determine the feasibility of sponge aquaculture in The Bahamas, we deployed growout arrays between February 2006 and September 2009 at two sites off South Eleuthera to examine the survival and growth rates of grass sponge (Spongia tubulifera) and hardhead sponge (Spongia pertusa) cuttings. Complete skin regeneration occurred for both species by the second week following deployment. Following 43 months of growout, both grass and hardhead sponges showed significant positive growth, with cuttings of both species exhibiting faster growth trajectories at the more protected site (Site A) when compared with the site further from shore (Site B). The proportion of sponge cuttings lost during the course of the study was also considerably less for both species at Site A, as was the amount of required maintenance for the arrays. The initial deployment of larger sponge cuttings could help reduce the overall growout period, as would the selection of sites that offered more protection for growout. Based on these results, sponge aquaculture could prove to be a sustainable low-cost industry in The Bahamas; however, further research on site selection, regulations, and market acceptability remains to be done.  相似文献   
49.
ABSTRACT: BACKGROUND: Starch is the most important source of calories for human nutrition and the majority of it is produced by cereal farming. Starch is also used as a renewable raw material in a range of industrial sectors. It can be chemically modified to introduce new physicochemical properties. In this way starch is adapted to a variety of specific end-uses. Recombinant DNA technologies offers an alternative to starch industrial processing. The plant biosynthetic pathway can be manipulated to design starches with novel structure and improved technological properties. In the future this may reduce or eliminate the economical and environmental costs of industrial modification. Recently, many advances have been achieved to clarify the genetic mechanism that controls starch biosynthesis. Several genes involved in the synthesis and modification of complex carbohydrates in many organisms have been identified and cloned. This knowledge suggests a number of strategies and a series of candidate genes for genetic transformation of crops to generate new types of starch-based polymers. However transformation of cereals is a slow process and there is no easy model system available to test the efficiency of candidate genes in planta. RESULTS: We explored the possibility to use transgenic barley callus generated from immature embryo for a fast test of transgenic modification strategies of starch biosynthesis. We found that this callus contains 4 % (w/w dw) starch granules, which we could modify by generating fully transgenic calli by Agrobacterium-transformation. A Green Fluorescent Protein reporter protein tag was used to identify and propagate only fully transgenic callus explants. Around 1 -- 1.5 g dry weight of fully transgenic callus could be produced in 9 weeks. Callus starch granules were smaller than endosperm starch granules and contained less amylose. Similarly the expression profile of starch biosynthesis genes were slightly different in callus compared with developing endosperm. CONCLUSIONS: In this study we have developed an easy and rapid in planta model system for starch bioengineering in cereals. We suggest that this method can be used as a time-efficient model system for fast screening of candidate genes for the generation of modified starch or new types of carbohydrate polymers.  相似文献   
50.

Background  

Carotenoids are the most widespread group of pigments found in nature. In addition to their role in the physiology of the plant, carotenoids also have nutritional relevance as their incorporation in the human diet provides health benefits. In non-photosynthetic tissues, carotenoids are synthesized and stored in specialized plastids called chromoplasts. At present very little is known about the origin of the metabolic precursors and cofactors required to sustain the high rate of carotenoid biosynthesis in these plastids. Recent proteomic data have revealed a number of biochemical and metabolic processes potentially operating in fruit chromoplasts. However, considering that chloroplast to chromoplast differentiation is a very rapid process during fruit ripening, there is the possibility that some of the proteins identified in the proteomic analysis could represent remnants no longer having a functional role in chromoplasts. Therefore, experimental validation is necessary to prove whether these predicted processes are actually operative in chromoplasts.  相似文献   
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