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At least 1,297 records · Page 72Linked to original sources
PubMed2000

[Effect of mixing seed with fulvic acid on spring wheat yield and its water use efficiency].

Four treatments were installed to study the effect of seed mixed with fulvic acid on sring wheat yield and water use efficiency: CK(without any treatment of fulvic acid); FA(seeds were mixed with fulvic acid before sowing), WM(pre-sowing irrigation of 30 mm plus clear plastic film mulch), and WMFA(pre-sowing irrigation of 30 mm plus plastic film mulch, and seeds were mixed with fulvic acid before sowing). The plastic film mulches in WM and WMFA treatments were removed after sowing for 62 days. Compared to treatment CK, the spring wheat in FA treatment grew more roots and absorbed more water from soil, and increased the spike weight and grain weight per spike and harvest index, which resulted in a higher yield and higher water use efficiency. There was no differenece in water consumption between treatments WM and WMFA, but in treatment WMFA, more dry matter was distributed in shoots, and hence yield and water use efficiency were improved significantly. The yields for the four treatments CK, FA, WM, WMFA were 917.7, 1275.1, 1269.4, 1737.1 kg.hm-2, respectively; and the water use efficiencies were 6.58, 7.85, 6.20, 9.05 kg.hm-2.mm-1, respectively.

Benzopyrans↗
PubMed1999

[Effects of cultivating measures on rhizome yield and some main active constituents of Curcuma longa L].

OBJECTIVE: To substantiate the effects of cultivating measures on the rhizome yield and main active constituents of Curcuma longa. METHOD: Randomized block design was applied to the study of the sowing time and plant density, and orthogonal experiment L9 (3(4)) was conducted to determine the quantity of fertilizer. RESULT: The effects of cultivating measures on the rhizome yield and some main active constituents of Curcuma longa were noticeable. The rhizome yield went up, and the contents of curcuminoids and essential oils went down with the increase of fertilizer application. CONCLUSION: The main cultivating measures for high-yield and good-quality of rhizome: rational sowing time-late March, plant population-12 checkrows per m2, 1 mother rhizome per checkrow. The suitable fertilizer requirements have also been formulated.

Curcuma↗
PubMed2002

An HPLC method for the measurement of 5-fluorouracil in human plasma with a low detection limit and a high extraction yield.

High performance liquid chromatographic (HPLC) techniques for the quantification of 5-fluorouracil (5-FU) in human plasma have been reported in the literature, however, a low limit of detection was generally found to result in a comparatively low extraction yield. We have developed a simple, rapid and sensitive HPLC method for the measurement of 5-FU in plasma which provides both a low limit of quantification and a high extraction yield. This method involves the solid phase extraction of 5-FU from a 500 microl plasma sample. The extract is then injected into an HPLC system equipped with a C18 (mu)Bondapak column, and a UV detector set at 260 nm. Ethyl acetate and potassium dihydrogen phosphate are used for the solid phase extraction and the HPLC mobile phase, respectively. This method provides in a good baseline, a sharp and symmetrical peak for 5-FU, and a high resolution between 5-FU and the internal standard. The retention time of 5-FU using this method is 4.7 min with a limit of detection of 5 ng/ml, and an extraction yield of 96.2+/-0.5% (SE). The next injection is possible in 11 min, and the coefficients of variation are 4.2-8.9% for interday precision, and 5.2-10.6% for day-to-day reproducibility. An HPLC method has been developed that has a low limit of detection and a high extraction yield. This technique was successfully applied in a clinical pharmacokinetic study of 5-FU.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

[Effect of combined radioactive and chemical (heavy metals, herbicides) pollution on the yield of cytogenetic disruptions in the intercalary meristem of spring barley].

The yield of aberrant cells and their loading with lesions of intercalary meristem of spring barley in conditions of the combined action of 137Cs, heavy metals and 2.4-D herbicide was studied. At simultaneous insertion of 137Cs and Cd into the soil, the type of non-linearity of the yield of aberrant cells was determined by radioactive pollution: in a range of low concentrations the synergistic effects took place, in a range of higher ones the antagonistic effects did. In the presence of cadmium, the severity of radiation induced damage to aberrant cells was significantly less. The interaction in 137Cs-Pb pair had an antagonistic character. The yield of aberrant cells was determined mainly by lead, whereas the radioactive pollution played the main role in loading of the aberrant cells with lesions. At the combined pollution with 137Cs and other contaminants, the antagonistic effects were more pronounced with Pb than with Cd, and further increased with the herbicide, both in the test on frequency of aberrant cells and the test on the loading of aberrant cells with lesions. In case of combination of the chemical agents the non-linear effects in test on loading of aberrant cells with lesions were mainly synergistic, whereas in the test on frequency of aberrant cells they were antagonistic. Only Pb-Cd pair and only in the test on loading of aberrant cells with lesions no significant non-linear effects were found. The results show high rate of the induction of synergistic and antagonistic effects in conditions of the combined action of low concentrations of the investigated agents on plants. These effects substantially determined the yield of cytogenetic disturbances in the studied range.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2002

[Influence of saltwater irrigation on the yield and quality of Cynodon dactylon under desert conditions].

Responses of six varieties (Suwannee, Coast cross, Tifton44, Tifton68, Tifton78 and Tifton85) of Cynodon dactylon to irrigation-water salinity were investigated in field by means of a double line source experimental design. The digestibility of the grass by goat was analyzed using the rumen gastric justice digestion method. The results showed that the six varieties grew well, and had a high yield of fresh grass when eletro-conductivity (Eci) < 10 ds.m-1. Particularly when Eci = 4.4 ds.m-1, the fresh grass yield of Coast cross, Suwannee, Tifton44, Tifton68, Tifton78 and Tifton85 was respectively increased by 142.1%, 61.1%, 136%, 121.1%, 202.3% and 109.7%, in comparison with fresh water (Eci = 1.2) irrigation. Dry matter yield was also elevated with the increasing salinity of irrigated water. There was no obvious effect of salinity on crude protein, fiber and ash contents in the six varieties. Goats were fond of eating the hay irrigated by saline water, perhaps because of its higher digestibility. At least, the yield and quality of Cynodon dactylon were not effected by saltwater irrigation.

Crops, Agricultural↗
PubMed2003

[Effects of forms and application rate of nitrogen fertilizer on yield and qualities of tobacco in southeast Tibet].

Field experiments in southeast Tibet were conducted to study the effect of nitrogenous fertilizer supply and its forms on tobacco. The result indicated that the yield, production value, and the contents of nicotine, potassium oxide and total nitrogen of the cured leaves were positively correlated to the amount of N application, and significantly and negatively correlated to the percentage of superior-medium class leaves of tobacco and contents of deoxidize sugar. The highest yield and best quality of tobacco were obtained by applying 75 kg N per hectare. Inorganic nitrogenous fertilizer could significantly improve the yield and quality of tobacco, compared with organic nitrogenous fertilizer. Although there was no significant difference among ammonium N, nitrate N and nitrate-ammonium N application, the effects of ammonium N, nitrate N, and nitrate-ammoniun N application were significantly higher than that of urea application. The effect of ammoniun N application on tobacco yield and quality was better than that of nitrate N application, and the important reason was the great difference in the process of absorption and assimilation of ammoniun N and nitrate N.

Biomass↗
PubMed2003

[Minimum application rates for high-yielding rice production system in the Taihu Lake region as a field measure for controlling N and P agricultural loading].

Excess application with the poor efficiency of fertilizers is one of the major problems confronting the sustainable agricultural development. Whereas, loss of N and P nutrients from farmlands to surface waters is considered as one of the major sources inducing eutrophication. In order to work out a minimum fertilizer application rate for both keeping conventional yield and reducing nutrient loading of non point source pollution, an experiment of formulated fertilization scheme on rice at different rates and nutrient ratios by incorporating the soil supply potential was conducted in a paddy soil Wunitu in Kunshan City, Suzhou. The soil nutrient can supply a yield at 6.75 t/hm2 at least for one cropping season. Among the fertilization treatments, a maximum yield of 9.79 t/hm2 was obtained at fertilization (N + P) rate of 300 kg/hm2kg N and P at a ratio of N to P being 3:2 or 1:1. However, with much lower fertilization (N + P) rate at 240 kg/hm2 with the same ratio a high yield of 9.69 t/hm2 was reached. The fertilizer efficiency of the later was 3 times as that of the former rate. Thus, a economical and environmentally sound mode of fertilization in such paddy soils as total N and P 240 kg/hm2, with N:P:Kratio being 3:2:0 or 1:1:0 was developed. Further study would be directed to a innovation of combination of reducing fertilization rate with rotated fertilization for alternative crops.

Crops, Agricultural↗
PubMed2003

Effects of ground-level ozone (O3) pollution on the yields of rice and winter wheat in the Yangtze River Delta.

Effects of elevated O3 on the yields of rice and winter wheat were studied by using open-top chambers (OTCs). Results showed that compared to the control treatment, 200 ppb, 100 ppb, 50 ppb treatments caused a 80.4%, 58.6% and 10.5% decrease in grain yields per winter wheat plant and a 49.1%, 26.1% and 8.2% decrease in grain yield per rice plant, respectively. According to the dose-response relation educed from OTCs experiment and the monitor data of O3 concentrations in spots, it was estimated that the yield losses of rice and winter wheat resulted by O3 pollution in the Yangtze River Delta region in 1999 were 0.599 million ton and 0.669 million ton, economic losses were 0.539 billion RMB Yuan and 0.936 billion RMB Yuan, respectively.

Agriculture↗
PubMed2004

Correlations and heritability of the characters determining the seed yield of the long-raceme alfalfa (Medicago sativa L.).

Phenotypic correlation coefficients and heritability of the characters controlling seed yield of long-raceme forms of alfalfa was determined. It was found that seed yield per plant, which was positively correlated with 10 out of 12 analysed characters, depended upon the number of pods per raceme and the number of seeds per pod. Variability of these characters determined about 60% of the variability of seed yield. Multiple linear regression and phenotypic correlations show that simultaneous selection for increased pod number per raceme and increased seed number per pod and raceme length resulted in enhanced seed yield potential. The share of the additive genetic effects in the phenotypic variance for number of pods per raceme was low and about 21-23%, while for number of seeds per pod and per raceme amounted to about 50%. The expected genetic progress in recombination breeding for number of seeds per pod and number of seeds per raceme will be of medium magnitude, while one cannot expect any rapid and considerable progress in the number of pods per raceme. Considering the high positive correlation between raceme length and number of pods and seeds per raceme, one should conclude that raceme length can be an important criterion in selection of plants showing a high seed productivity.

Hybridization, Genetic↗
PubMed2003

Evaluation of a method for high yield purification of largely intact mitochondrial DNA from human placentae.

We developed, and quantitatively and qualitatively evaluated an easily reproducible method for high yield purification of mitochondrial DNA (mtDNA) from human placentae by mechanical tissue disruption, differential centrifugation of mitochondria, enzymatic digestion, phenol extraction and ethanol precipitation. Average mtDNA yields were 2.5 microg/g tissue (without an RNAse treatment step) and 1.5 microg/g tissue (with an RNAse treatment step). This mtDNA migrated as a 16.5-kb isolated band in agarose gels; it yielded fragments of expected sizes after digestion with restriction enzymes; it successfully served as a template in long PCR for amplification of mtDNA sequences, and hybridized to an mtDNA probe in a predictable fashion. MtDNA yields of this method were 10-fold higher than those of previously reported ones for mtDNA purification from freshly obtained human cells and tissues, with the advantage that more placental tissue can be obtained for mtDNA purification than other types of tissue, at lower cost, and with minimal or no ethical issues.

Base Sequence↗
PubMedDate not supplied

Infective endocarditis: improving the diagnostic yield.

INTRODUCTION: Isolating aetiological agents in patients with infective endocarditis (IE) remains problematical. We postulated that the high local incidence of culture-negative IE resulted from antibiotic exposure prior to blood cultures and that a structured delay in therapy in the subacute presentation would improve the diagnostic yield. AIM: We aimed to prospectively observe the diagnostic approach and give an overview of supplementary laboratory tests. STUDY DESIGN: Patients with suspected IE were enrolled into this analytical observational study and followed up for six months (n = 92). We compared the diagnostic yield and outcome in cases where antibiotics were withheld for 72 hours, with those cases who received early antimicrobials, despite being deemed safe for delayed therapy. RESULTS: Definitive diagnoses (definite or excluded IE) were made in 92.8% of patients where antibiotics were delayed, compared to 60% of patients who received empirical treatment (p = 0.08). The mortality rates were 18.4% and 30.0% (p = 0.18). Twenty-three of 26 patients with definite culture-negative IE received antibiotics during the 48 hours preceding cultures, compared to eight of 21 culture-positive patients (P < 0.001). Screening for atypical bacteria did not improve the yield. C-reactive protein (CRP) had a sensitivity of 97.0% (negative predictive value 87.5%), whereas a positive rheumatoid factor (RF) had a specificity of 93.8% (positive predictive value 91.7%). CONCLUSIONS: We observed tendencies towards a greater diagnostic yield and lower mortality where antibiotics were initially withheld. Antibiotic prior to blood cultures were an important cause of culture-negative IE. A normal CRP proved useful in excluding IE; a positive RF strongly favoured IE.

Anti-Bacterial Agents↗
PubMed2003

[Effects of long-term fertilization on wheat yield on Loess Plateau].

The effect of long-term fertilization on the yield of winter wheat was studied on the basis of 18-year located experiment on the Loess Plateau. The results showed that the winter wheat yield increased 418.1 kg.hm-2 under N fertilization, and the average increasing rate was different with precipitation. In average and rain rich year, the average increasing rate were 30.3% and 58.9%, respectively, but in drought year, the yield decreased, and its average decreasing rate was 13.9%. The winter wheat yield under P fertilizer increased in drought year, and decreased in average and rain rich year. The average increasing rate was 6.5% in drought year, and the average decreasing rate was 15.4% and 10.0%, respectively. The average increasing rate in M, NP, PM, NM and NPM was 82.8%, 127.8%, 18.9%, 144.4%, and 169.3%, respectively. In addition, precipitation affected the amount of spike, grains per spike, and weight of thousand-grains.

Crops, Agricultural↗
PubMed2003

[Effects of potash fertilizer on nutrient absorption by peanut and its yield and benefit].

Studies in Jianghuai hilly region showed that at definite N and P levels, applying potash fertilizer could regulate the transportation and distribution of nutrients in peanut plants, accelerate their absorption of N, P and K, increase the dry matter accumulation in their reproductive organs, and increase their yield, quality, and disease resistance. For each 100 kg pod products, the absorption of N, P and K was 3.08-5.35 kg, 0.6-1.2 kg and 3.45-6.66 kg, respectively. The K absorption was the biggest, and it was accumulated mainly in nutritive organs. The absorbed N and P were mainly accumulated in pods and other reproductive organs. The contents of N, P and K in all organs were increased with increasing potassium levels, and the amount of increased K was the biggest. The yield and economic benefit were the highest when the amount of applied potassium reached to 150-180 kg.hm-2 and N:P:K = 2:1:2. The highest pod yield was 5425.5 kg.hm-2, the highest benefit was 13,878.7 yuan.hm-2, and the ratio of output/input reached 6.75:1. The yield and economic benefit of peanut were decreased obviously when the amount of applied potassium was over 225 kg.hm-2. Thus, the prescription of N150, P75 and K150 was recommended for the balance fertilization of peanut production in this region.

Absorption↗
PubMed2004

[Diagnostic yield in studies of autism. The contribution made by neuroimaging, metabolic tests and genetic studies].

AIMS: We reviewed the literature on the diagnostic yield of the different medical tests carried out on autistic patients in order to determine the aetiology of the process. DEVELOPMENT: Although it is generally said that a causation of the process can be determined in 10 30% of cases, the actual diagnostic yield of autism when a routine diagnosis is applied is between 2 and 7%. The diagnostic yield of radiology, metabolic studies and genetic studies was analysed. Genetic tests are the ones that offer the highest efficiency, and carrying out a karyotype and molecular study of fragile X chromosome syndrome is indicated in all patients with mental retardation associated to autism. The next most efficient are metabolic studies, which become particularly important mainly in populations where no screening has previously been conducted for metabolic disorders. CONCLUSIONS: Despite their being capable of showing up a large number of disorders, neuroimaging studies are unspecific and the diagnostic yield of radiological studies is very low when they are conducted on a routine basis.

Autistic Disorder↗
PubMed2003

[Long-term trial on fertilization and on use of recycled nutrients in farming systems V. Response of crop yields to fertilization in different precipitation years and estimates of water and nutrient interaction].

According to the responses of crop yields under fertilizations in 1996 with normal precipitation (456 mm in crop growth season) and in 1998 with higher precipitation (598 mm in growth season), the effect of water and nutrient interaction on crop yields in semihumid-semiarid region of west Liaoning Province were estimated. Under N application and sufficient water supply (more rainfall), the increase of crop yields was 3,056 kg.hm-2, of which, 1,996 kg.hm-2 was estimated from water-nutrient interaction, while in NP and compost treatment with sufficient water supply, the yield increase was 4,703 kg.hm-2, of which, 1,554 kg.hm-2 was estimated from water-nutrient interaction.

Agriculture↗
PubMed2004

Endogenous pancreatic enzyme activity levels show no significant effect on human islet isolation yield.

Despite advances in human islet isolation, islet yield remains inconsistent and unreliable. In recent studies, it has been suggested that serine proteases, in particular trypsin, have been shown to have a damaging effect on islet yield. This study evaluated enzyme activity levels throughout 42 human islet isolation procedures. Trypsin, chymotrypsin, and elastase activity was determined spectrophotometrically using suitable chromophoric substrates. The results of the islet isolations were rated as successful (n = 19) or unsuccessful (n = 23) based on the islet yield and functionality. The enzyme activity profiles of the isolations were compared. No significant differences in donor-related variables were found in this study. However, in the successful isolations, a significantly greater amount (85.6 +/- 1.9%; p = 0.0017) of the pancreas was digested in a significantly shorter digestion time (19.7 +/- 0.6 min; p = 0.0054) compared with 74.8 +/- 2.5% of digested tissue in 22.6 +/- 0.7 min in the poor isolations. This study showed no significant effect of serine protease levels on the outcome of islet isolations, regardless of enzyme inhibitor supplementation. These data suggest that serine protease activity does not sufficiently affect islet yield. However, the data show that the most successful human islet isolations are achieved when the maximum amount of tissue is digested in the shortest amount of time. This suggests that further understanding of the isolation process should focus on the role of the collagenase digestion solution in the dissociation of the endocrine-exocrine tissue connection.

Cell Separation↗
PubMedDate not supplied

[Activation of the chloroplast respiration increases chlorophyll fluorescence yield in Chlorella adapted to darkness at higher temperature].

A tenfold increase in chlororespiration during dark incubation of Chlorella perynoidosa Chick at high temperature doubled the initial chlorophyll fluorescence yield (F0). The presence of iodacetamide or unmetabolizable glucose analog 2-deoxy-D-glucose prevented increase in both chlororespiration and F0 yield. The rates of chlororespiration and F0 yield growth demonstrated a similar pattern of temperature dependence. Inhibition of electron transport between QA and plastoquinone prevented increase in F0 during dark respiration of the cells at high temperature. Apparently, a pool of plastoquinone was restored in the chlororespiratory chain during the dark incubation at 37.5-41 degrees C and plastoquinone exchanged electrons with QA. This is the cause of QA reduction and subsequent increase in F0 yield.

Adaptation, Physiological↗
PubMed2004

[Effects of different application rates of humic acid compound fertilizer on pepper and its mechanism of anti-senility and incremental yield].

The effects of different application rates of humic acid compound fertilizer (HA) on the yield and physiological characteristics of pepper (Capsicum frutescens L.) were studied in this paper. The results showed that different application rates of (HA) could affect the physiological activities and yield of pepper. The nitrate reductase activity (NRA) and peroxidase (POD) activity were improved with increasing application rate, but the change rate of NRA was reduced gradually. POD activity in inorganic compound fertilizer treatment was improved significantly when the application rate of fertilizer was higher than 0.3 g.kg-1, but that in HA treatment changed smoothly. Superoxide dismutase (SOD) activity was improved significantly when the application rate of fertilizer was lower than 0.2 g.kg-1, and decreased gradually when the application rate was higher than 0.2 g.kg-1. The change of transpiration rate was consistent with that of SOD activity. The relationship between the application rate of fertilizer and the yield of pepper could be described with quadratic curve regression model. According to the equation, the highest application rate of HA should be 0.27 g.kg-1, and the highest yield of pepper could reach 165.22 g per pot.

Capsicum↗