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11.
BACKGROUND: Congenital Adrenal Hyperplasia (CAH, the inherited inability to synthesize cortisol) is one of the most common (1 in 10000 to 1 in 15000) autosomal recessive disorders. More than 95% of cases of CAH are caused by 21-hydroxylase deficiency (21-OHD). Females with severe, classic 21-OHD are exposed to excess androgens prenatally and are born with virilized external genitalia. Most patients cannot synthesize sufficient aldosterone to maintain sodium balance and may develop potentially fatal salt wasting crisis if not treated. METHODS: We applied allele specific PCR to detect the eight common mutations in the CYP21 gene in patients. Fifty unrelated patients with symptoms of classical CAH were studied. RESULTS AND CONCLUSION: Seventy percent of our subjects had these mutations. The most frequent mutations were found to be I2G and del-8 bp (28% and 13%, respectively). The frequencies of other alleles were as following: I172N, 9%; V281L, 3%; exon 6 cluster (I236N, V237E and M239K), 4%; Q318X, 9%; R356W, 5%; and P30L, 0%. The frequency of mutations did not differ substantially from other ethnics, however, a higher rate of del-8 bp (13%) was found in our population. The aim of this study was to detect common mutations for setting up a molecular method for prenatal diagnosis.  相似文献   
12.
In this study, multiple shoot induction and whole plant regeneration from decapitated embryo axes of three chick peal genotypes including MCC252, MCC283 and MCC505 were evaluated on modified Murashige and Skoog's medium (MMS) which, its vitamins were replaced by vitamins of B5 medium, supplemented with varied concentration of thidiazuron (0.1, 0.2 mg L(-1)) or 6-benzylaminopurin (1,2 mg L(-1)) or zeatin (1, 2 mg L(-1)) treatments. BAP was found to be the most effective cytokinin in normal multiple shoot induction. Shoots were elongated on growth regulator-free medium and then rooted on two media containing 1/4 MMS salts and B5 vitamins + 3% sucrose + 0.8% agar with indol-3-butyric acid (0.4 or 1 mg L(-1)). The highest rooting frequency resulted in a medium including 0.4 mg L(-1) IBA. It was found that different shoot induction media also positively affected rooting, where a medium with 2 mg L(-1) BAP in MCC252/MCC505 and a medium with 2 mg L(-1) zeatin in MCC283 were the best media in shoot induction that produced high frequency, thick spread roots. Plantlets were preliminary acclimatized in liquid medium (1/4 MMS salts and B5 vitamins + 3% sucrose + 0.4 mg L(-1) IBA) for 7 to 14 days, then transferred to pots filled by cocopit: perlite (1:1) and kept in a growth chamber until their shoots and roots were well developed. This resulted in more than 70% survival rate.  相似文献   
13.
Dust emission from wind erosion is a widespread phenomenon in arid and semi-arid areas having considerable implications for ecosystems and human well-being. However, few studies have examined the efficiency of biochar amended to soil on wind erosion control. Aimed at studying the effect of biochar on resistance of soils against wind erosion, a wind tunnel experiment was conducted. We tested (a) soils amended with hard waste walnut wood biochar and soft maize cob biochar, and (b) soils amended with powdery waste wood and powdery maize cob, and compared them with (c) non-treated soil, in their susceptibility to wind erosion and also the additional effect of various patterns of vegetation cover. Amending soil with biochar and powdery material did significantly increase their resilience to wind erosion because of increased soil aggregation. In comparison with the non-treated control, the mass flux of un-vegetated soil reduced from 4.42 to 1.86 g m−2 s−1 for the waste walnut wood biochar, from 4.28 to 1.50 g m−2 s−1 for maize cob biochar, from 4.11 to 1.44 g m−2 s−1 for powdery maize cob and from 3.97 to 1.14 g m−2 s−1 for powdery waste walnut wood. When combining amendments with vegetation, there was still a substantial improvement, though the soil treatments responded differently in terms of soil loss to different vegetation patterns. A single row vegetation pattern had the highest mass flux, while a zigzag vegetation pattern had the lowest. In conclusion, waste wood or maize cobs, whether applied as biochar or as powdery material, are able to fix soil and reduce wind erosion.  相似文献   
14.
15.
Nanofertilizers have received considerable attention due to their increased uptake by plants. Therefore, this study aimed to investigate the effect of zinc oxide (ZnO) nanoparticles and also different zinc (Zn) fertilizers (Zn sulfate, Zn chelate) on vegetative and yield traits of two pinto bean cultivars “KS21191” and “KS21193”. This experiment was a factorial based on completely randomized design with 24 treatments (three fertilizer applications and eight levels of Zn fertilizer). The results showed that twice foliar application compared to seed application and once foliar application improved growth and yield characteristics of both pinto bean cultivars. Also, compared to control treatment, zinc nanofertilizers improved vegetative characteristics (such as plant height, internode length, root and shoot dry, and fresh weight), yield (pods number and seed weight) and quality (zinc content in seed) of both pinto bean cultivars. Among the zinc fertilizer treatments, 0.10% and 0.15% of ZnO nanoparticles were as a superior treatment.  相似文献   
16.
Background: L1 retrotransposons are the most active mobile DNA elements in human genome. Unregulated L1 retrotransposition may have deleterious effect by disrupting vital genes and inducing genomic instabilities. Therefore, human cells control L1 elements by silencing their activities through epigenetic mechanisms. It has been shown that cell division and heavy metals stimulate the frequency of L1 activities. Removal of silencing by L1 motivators may restart L1 element functions. Here, we have proposed that weather neurotoxic environmental heavy metals (as L1 stimulating factors) have a role in removing L1 silencing and restating its activities in nondividing neuronal cells. Methods: L1-RP green fluorescent protein (GFP)-tagged knock-in human neuroblastoma clones were prepared. Single-cell clone was treated with mitomycin-c combined with nontoxic and toxic concentrations of iron (Fe), copper (Cu), and mercury (Hg). Silencing status of engineered L1 elements in dividing and nondividing cells was determined through measuring the amount of GFP expressing cells with flow cytometry. The cytotoxic effect of mitomycin-c combined with metals was measured by MTT assay. Results: Hg in nondividing cells and Fe, Cu, and Hg in dividing neuroblastoma cells could significantly remove L1 silencing. Also, mitomycin-c treatment did not have any effect on metal toxicity status in neuroblastoma cells. Conclusion: Totally, our findings have shown that cell division has a role in removing L1 silencing as well as L1 retrotransposition induced by environmental heavy metals. It has been also indicated that Hg at all concentrations could remove silencing of engineered L1 element regardless of cell cycle state. Key Words: Cell division, Heavy metals, L1 retrotransposon  相似文献   
17.
The objective of this research was to assess the hexavalent chromium (Cr(VI)) reducing efficiency of sulfur-based inorganic agents including calcium polysulfide (CPS), iron sulfide (FeS), pyrite (FeS2) and sodium sulfide (Na2S) in three soils. An alkaline soil (soil 1), a neutral soil (soil 2) and a slightly acid soil (soil 3) constituted the investigated soils. The soils were spiked with two levels of Cr(VI) (100 and 500 mg Cr(VI) kg?1 soil) and incubated at field capacity (FC) for one month. Then, CPS, FeS, FeS2 and Na2S were added at 0, 5 and 10 g kg?1 and the concentrations of exchangeable Cr(VI) were measured after 0.5, 4, 48 and 168 h in a batch experiment. The pH and organic carbon content of the soils played predominant role in Cr(VI) self-reduction by the soil itself. Complete self-reduction of Cr(VI) from soils 1, 2 and 3 was achieved at maximum Cr(VI) levels of 1, 50 and 500 mg kg?1, respectively. Therefore, the concentration of Cr(VI) should not exceed the given levels in order to ensure that Cr(VI) is not released into the environment from contaminated sites. Moreover, decreasing pH in the alkaline soil caused significant increase of Cr(VI) reducing efficiency. Na2S, CPS and FeS, in contrast to FeS2, were efficient Cr(VI) reducing agents in all three soils. For all added amendments the following order of Cr(VI) reducing capacity was observed: Na2S > CPS > FeS > FeS2 in soil 1, Na2S ? CPS ~ FeS > FeS2 in soil 2 and Na2S ? FeS > CPS ~ FeS2 in soil 3.  相似文献   
18.
Nylon 6 fabric with self-cleaning properties was prepared by corona discharge pre-treatment and coating with TiO2 nanoparticles (NPs) using pad-dry-cure technique. The self-cleaning property was studied by discoloration of methylene blue (MB), ketchup, tea and coffee stains from the corona+TiO2 treated nylon-6 fabric. Color difference (ΔΕ*), reflectance (R) and K/S of MB stain were investigated by diffuse reflectance spectrophotometry. The MB stain was almost completely removed from the corona+TiO2 treated nylon surface after 24 h under UV light/daylight irradiation. Both of these phenomena (corona and TiO2) led to an increase in the discoloration of stains under UV and daylight irradiations. The EDS analysis showed an increase in the concentration of deposited TiO2 NPs coating after corona treatment. The FE-SEM images revealed that the surface of nylon 6 was coarser after the corona treatment. Also, the FE-SEM micrographs exhibited that a uniform layer of TiO2 NPs was formed on the corona treated nylon fabric. The corona+TiO2 treated nylon illustrated antibacterial activity against E. coli and B. subtillis microorganisms. The EDS and FE-SEM analysis confirmed that after 5 washing cycles, the amount of TiO2 NPs was higher on the surface of corona+TiO2 treated nylon than that of the fabric only treated with TiO2 without corona pretreatment. This result justifies that the corona+TiO2 treated nylon fabric with appropriate self-cleaning property can be applied cost-effectively in the textile industry.  相似文献   
19.
Current literature on restorative environments generally shows the importance of urban natural landscapes in increasing perceived restorativeness of urban environments. However, little is known about the positive role of visual characteristics of urban natural landscapes in increasing Perceived Restorative Potential (PRP) of urban environments. This study aimed to understand the role of four predictors of visual preference as characteristics of urban natural landscape on the restorativeness of environments. In this study, 120 students from Universiti Putra Malaysia rated 12 colored slides of urban natural landscape scenes for four restorative components (Being away, Fascination, Coherence, and Compatibility), four predictors of visual landscape preference (Coherence, Complexity, Legibility, Mystery) and a criterion variable (PRP). Coherence, however, was considered as a predictor of visual landscape preference since it is not a significant predictor in explaining PRP. Results indicate that Coherence, Complexity, and Mystery positively explained PRP while Legibility did not. Further analysis revealed that the effect of Coherence and Complexity on PRP was fully mediated by the restorative components and Mystery was only partially mediated. The findings indicate that some predictors of visual landscape preference of urban natural landscapes contribute to increasing PRP of urban landscapes. Although Coherence as a restorative component was not a significant predictor of PRP, it contributed toward increasing the restorative potential of urban natural landscapes when considered as a predictor of visual landscape preference. The results of this study can aid city planners, landscape architects and developers with regards to the influence of visual landscape characteristics in increasing the restorative potential of urban environments.  相似文献   
20.

Drought stress is the main factor limiting the growth and crop yield in most regions; thus, reducing the effects of drought stress is a research priority worldwide. The aim of this experiment was to evaluate the effect of sodium nitroprusside (SNP) on physiological traits and grain yield of oilseed rape under drought stress. Two field experiments with three irrigation levels (I1: full irrigation (control), I2: irrigation cut-off at the beginning of pod development, and I3: irrigation cut-off at the beginning of grain filling) and SNP foliar applications with four levels (0, 100, 200 and 300?μM) were conducted during the 2015–2017 growing seasons. The results indicated that applying 200 and 300?μM of SNP significantly increased antioxidant enzymes, total chlorophyll, and proline at all levels of drought stress in comparison with applying zero and 100?μM of SNP. Moreover, applying SNP increased grain yield via improving the biochemical traits of the plant under stress and non-stress conditions. Comparison results of the average test of two years showed that the application of 200 and 300?μM SNP increased grain yield to 11.2 and 15.1% in control conditions, 33.6 and 36.7% in I2 and 20.9 and 40.6% in I1 compared to the control. Generally, the results indicated that applying SNP reduced the effects of water-deficit stress on oilseed rape.

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