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PubMedDate not supplied

Yield of endoscopy in children with hematemesis.

Upper gastrointestinal (UGI) endoscopy is an important tool in the evaluation of patients presenting with haematemesis. The objective of this study was to report the yield of this procedure in a Saudi Arabian population. We analysed the result UGI endoscopy in children and adolescents of 0-18 years of age who presented with haematemesis over a period of 10 years. From 1993 to 2003, endoscopy was performed on 60 consecutive children presenting with haematemesis. This group represented 12% of the indications during the same period. The majority (98%) were Saudi nationals, with an age range from 4 days to 18 years, and a male to female ratio of 1:1.5. The overall yield of endoscopy was 75%; however, the yield was higher (91%) in children below 12 years of age. Gastritis was the commonest cause of haematemesis (44%), followed by oesophagitis (36%). However, age-related analysis shows that oesophagitis was a more common cause of haematemesis in the younger age group (45%) than gastritis in adolescents (30%). In contrast, gastritis was more common in older children (56%) than oesophagitis (28%). Peptic ulcer disease and oesophageal varices were seen in only 3 (7%) and 2 children (4.3%), respectively. The overall yield of endoscopy in our patients is similar to that in most reports. However, oesophagitis and gastritis were the commonest causes of haematemesis, whereas oesophageal varices and peptic ulcer disease were much less common.

Adolescent↗
PubMed2004

Indications and yield of upper gastrointestinal endoscopy in children.

OBJECTIVE: Knowledge of the pattern of gastrointestinal tract (GIT) disorders detected by endoscopy is important for clinicians. The objective of this paper is to report on the indications and yield of endoscopy. METHODS: Retrospective analysis of data of all patients below 18 years of age who underwent upper GIT endoscopy from 1414 H (1993 G) through to 1424 H (2002 G) over a 10-year period at King Khaled University Hospital, Riyadh, Kingdom of Saudi Arabia. RESULTS: One thousand and fifteen upper GIT endoscopies were performed, of which 851 diagnostic procedures were performed on 851 children. The majority (96%) were Saudi nationals, the age range was between 4 days and 18-years, and the male to female ratio was 0.7: 1. The 2 most common indications were duodenal biopsy (29%) and abdominal pain (24%). The best diagnostic yield was in children presenting with ingestion of caustic substances, followed by hematemesis, and vomiting in 86%, 75% and 67%. The overall yield, however, was 43%. Finally, the most common diagnoses were gastritis and esophagitis occurring in 32% and 30% of the children. Age related variations are reported. CONCLUSION: The increasing practice of endoscopy in children resulted in the development of new indications such as endoscopic small bowel biopsy. The differences in indications and yield of endoscopy with age reflecting the varying pattern of diseases.

Adolescent↗
PubMed2004

[Principle of "multiple ecological niche of one-species (variety)" and its application in high yield cotton cultivation].

The multiple ecological niche of one-species (variety) (MENOS) population is formed by one species (variety), but the ecological units have different temporal, spatial, nutritional, temperature, or water ecological niche. The formation of MENOS population is characterized by its specific object, one species (variety), multiple layer canopy, human being's active adjustment, specific niche breadth, and overlap and separation of ecological units. This paper analyzed the characteristics of the super high yield cotton population with dual ecological niche of one-species (variety) (DENOS). As for the yield components, MENOS has the characteristics of high yield canopy and different yield plants.

Adaptation, Biological↗
PubMed2004

[Effect of nitrogen fertilization and square loss on cotton aphid population, cotton leafhopper population and cotton yield].

The study on the effects of nitrogen fertilization (0-450 kg x hm(-2)) and square loss (0-12 x plant(-1)) on cotton aphid population, cotton leafhopper population and cotton yield showed that there were no significant differences in cotton aphid population, cotton leafhopper population, and numbers of effective bolls between transgenic Bt cotton and non-transgenic cotton. Cotton aphid populations on the two cottons were significantly influenced by nitrogen fertilization and by the interaction of nitrogen fertilization and square loss, while leafhopper populations were not significantly influenced by them. Nitrogen fertilization at squaring and flowering stage was one of important factors affecting cotton yield. There was a positive correlation between the application rate of nitrogen fertilizer and cotton yield, but a negative correlation between the number of lost square per plant and the yield of the two cottons.

Animals↗
PubMed2004

[Study on cultivating technology of high yield and quality of Plantago asiatica of Jiangxi geo-herbalism].

OBJECTIVE: To study the high-yield and high-quality cultivating technology of Plantago asiatica, adapt to the demands of GAP. METHOD: The main factors which influenced the yield and quality in the production process of P. asiatica was studied. RESULT: The standard system cultivating technology of high yield and quality of P. asiatica was established. CONCLUSION: The seeds of P. asiatica can reach the objective of high yield and high quality on the basis of this cultivating technology.

China↗
PubMed2005

Economic assessment of the negative impacts of ozone on crop yields and forest production. A case study of the estate Ostads Säteri in southwestern Sweden.

Ground level ozone concentrations, in combination with the prevailing climate, at the estate Ostads Säteri in southwestern Sweden were estimated to reduce the yield of wheat and potato ranging between 5% and 10%. Occasionally, in years with the highest ozone concentrations and/or climatic conditions favoring high rates of ozone uptake to the leaves, yield loss levels above 10% may occur. Based on simple extrapolation, these ozone-induced reductions of crop yields at Ostads Säteri represent a potential total annual yield loss in Sweden in the range of 24.5 million Euro for wheat and 7.3 million Euro for potato, respectively. A simulation of forest growth at Ostad Säteri predicted that prevailing mean ozone exposure during 1993-2003 had the potential to reduce forest growth by 2.2% and the economic return of forest production by 2.6%. Using this value for extrapolation to the national level, the potential annual economic loss for Sweden due to negative impacts of ozone on forest production would be in the range of 56 million Euro (2004 prices).

Agriculture↗
PubMed2004

[The gene wxcA of Xanthomonas campestris pv. campestris 8004 strain involved in EPS yield].

Xanthomonas campestris pv. campestris (Xcc), the pathogenic agent of black rot disease in cruciferous plants, produces large amount of extracellular polysaccharide (EPS), which has found wide applications in industry. For the great commercial value of the xanthan gum, many of the genes involved in EPS biosynthesis have been cloned and the mechanism of EPS biosynthesis also has been studied. In order to clone genes involved in EPS biosynthesis, Xcc wild-type strain 8004 was mutagenized with transposon Tn5 gusA5, and a number of EPS-defective mutants were isolated in our previous work. The Tn5 gusA5 inserted sites of these mutants were located by using thermal asymmetric interlaced PCR, and results showed that two EPS-defective mutants were insertion mutants of the gene wxcA which involved in lipopolysaccharide (LPS) biosynthesis. The gene wxcA involved in lipopolysaccharide biosynthesis but dose not extracellular polysaccharide in others' report. wxcA::Tn5 gusA5 mutant 021C12, the polar mutant, was complemented with recombinant plasmid pLATC8570 harboring an intact wxcA gene in this work, but the yield of EPS of the wxcA::Tn5 gusA5 mutant was not restored. In order to identify the function of wxcA gene of Xcc 8004 strain, the gene wxcA was deleted by gene replacement strategy, and the no-polar mutant of wxcA was obtained. DeltawxcA mutant strain, named Xcc 8570, was confirmed by using both PCR and southern analysis. Beside the LPS biosynthesis of deltawxcA mutant was affected, The EPS yield of deltawxcA mutant strain reduced by 50% as compared with the wild-type strain 8004. DeltawxcA mutant could be complemented in trans with the intact wxcA gene, and the EPS yield of the mutant was restored. The combined data showed that wxcA gene not only involved in LPS biosynthesis but also EPS yield in Xcc 8004 strain.

Cell Proliferation↗
PubMed2005

[Effects of irrigation and nitrogen fertilization on winter wheat yield under straw mulch].

A field experiment was conducted on a Hongyou soil of Yangling to investigate the effects of irrigation and nitrogen fertilization on wheat yield under straw mulch. The results showed that under straw mulch, N fertilization contributed more to the increase of wheat yield than irrigation, because soil moisture condition was improved greatly. The interaction between irrigation and nitrogen fertilization was negative in no-mulch treatment, but positive under straw mulch. For dryland, more attention should be paid to the input of nutrients when straw mulch was applied. High moisture content in soil profile before sowing and sufficient N input were essential for good harvest when field was not mulched. Under straw mulch, the irrigation rate for a maximum yield was reduced, and the optimum time of irrigation was postponed. Wheat grain yield had no relation to the irrigation during jointing stage in both no-mulch and straw mulch treatments.

Fertilizers↗
PubMed2005

[Effects of N fertilization on winter wheat grain yield and its crude protein content and apparent N losses].

Field experiments were conducted at four sites in 2002 to study the effects of N fertilization on winter wheat yield and its crude protein content and apparent N losses. The results showed that at these sites, the N application rate for maximum grain yield was 0, 0, 79 and 118 kg x hm(-2), and that for maximum grain crude protein content was 122, 100, 127 and 174 kg x hm(-2), respectively. The residual nitrate-N content in 0 approximately 90 cm soil layer after harvest was linearly increased, while the apparent N losses during wheat growth season was exponentially increased with increasing N application rate. Under the N application rate for maximum yield, soil residual nitrate-N content ranged from 86 to 115 kg x hm(-2) and apparent N losses ranged from 2 to 32 kg x hm(-2), which were much lower than the residual nitrate-N content (106 approximately 168 kg x hm(-2))and apparent N losses(14 approximately 56 kg x hm(-2)) when the maximum grain crude protein content was achieved. The results showed that the maximum wheat grain yield and the environment effects of N fertilization could be harmonized by an optimized N application rate, but, if considering the importance of wheat grain protein, more research in the future should be needed.

Biomass↗
PubMed2006

[Effects of shading on the growth, development and grain yield of summer maize].

Under field condition, this paper studied the effects of shading on the growth, development, and grain yield of summer maize varieties ND108 and YD13. The results showed that shading decreased maize yield significantly, and the effect was differed with different shading period and intensity. With a shading intensity of 50% and 90%, the grain yield of ND108 and YD13 was decreased by 67.5% and 79.4%, and 82.9% and 86.7% when shading at flowering-maturing stage, and by 34.1% and 55.3%, and 47.2%, 65.7% when shading at joining-flowering stage, respectively. Shading at seedling-joining stage had a relatively smaller effect, with the grain yield decreased by 16.9% and 24.5%, and 18.9% and 24.3%, respectively. Shading had a larger effect on YD13 than on ND108, and the effect of shading period was larger than that of shading intensity. Under shading, the growth and development of maize was retarded, and the effect was increased with increasing shading intensity. Shading at joining-flowering stage affected spike differentiation significantly, reflecting in the marked decrease of the numbers of silks and tassels, and the effect was also larger on YD13 than on ND108. The leaf and plant growth was restrained significantly when shading at seedling stage and at flowering-maturing stage.

Biomass↗
PubMed2006

Genetic trend for milk yield in Guzerat herds participating in progeny testing and MOET nucleus schemes.

Genetic trends for 305-day milk yield (P305) in Brazilian Guzerat herds under selection were compared. Data from 4898 lactations of 3179 purebred and crossbred cows from various regions of Brazil were used. Milk yield was adjusted for mature age and the contemporary groups were defined as herd and calving year. Genetic parameters were estimated using the MTDFREML program. The model included the random effects of animals and permanent environment, and herd-calving year, calving season and genetic composition as fixed effects. Genetic trends were estimated by linear regression of weighted average estimated breeding values as a function of calving year. The average P305 was 2065 +/- 922 kg and the heritability was 0.23 +/- 0.03. The annual genetic trend in estimated breeding values of cows for P305 was 7.09 +/- 0.71 kg between 1987 and 2004, and 6.47 +/- 2.35 kg between 1997 and 2004. For cows born and raised in the multiple ovulation and embryo transfer (MOET) nucleus, this trend was 36.46 +/- 24.54 kg/year between 1997 and 2004, 183.14 +/- 47.94 kg/year between 1997 and 2000, and 9.13 +/- 19.19 kg/year between 2001 and 2004. An average inbreeding coefficient of 0.04 was found for inbred MOET cows in 2004. Increasing the size of the family and introducing new progenies changed reliabilities and predicted transmitting ability estimates of MOET sires. In conclusion, there was a positive genetic trend for milk yield in the MOET nucleus at low inbreeding coefficients due to the increased accuracy and estimated genetic merit, but no changes in the average milk yield were observed.

Animals↗
PubMed2006

[Effects of nitrogen application level on soil nitrate accumulation and ammonia volatilization in high-yielding wheat field].

The study showed that during the period from sowing to pre-wintering, the soil nitrate in high-yielding wheat field moved down to deeper layers, and accumulated in the layers below 140 cm. An application rate of 96-168 kg N x hm(-2) increased the nitrate content in 0-60 cm soil layer and the wheat grain yield and its protein content, and decreased the proportion of apparent N loss to applied N and the ammonia volatilization loss from basal nitrogen. Applying 240 kg N x hm(-2) promoted the downward movement of soil nitrate and its accumulation in deeper layers, increased the proportion of apparent N loss to applied N and the ammonia volatilization loss from basal nitrogen, had no significant effect on the protein content of wheat grain, but decreased the grain yield. The appropriate application rate of nitrogen on high-yielding wheat field was 132-204 kg N x hm(-2).

Ammonia↗
PubMed1992

Information yield from routine pre-operative chest radiography and electrocardiography.

Studies in First-World settings suggest that routine pre-operative investigations are of minimal usefulness. A retrospective study of 797 case records determined the yield of significant information from routine chest radiography and ECG in a provincial general hospital serving a broad socio-economic sector. The results were in agreement with those of other studies, viz. that routine investigation may be worthwhile only in older patients. Routine chest radiographs showed an overall positive yield of 6%; 17% in those over 60 years but only 2% in those under 60 years. Routine ECGs showed a positive yield of 7% overall; 7.4% in those older than 40 years and 4.5% in those under 40 years. Investigations indicated by history or physical examination had a significantly greater yield: 34% for chest radiography and 31% for ECGs. Positive results of indicated investigations were more evenly spread across the age groups. The pre-eminence of clinical skills in determining which patients require special investigations is reaffirmed.

Adolescent↗
PubMed1991

[High-yield agronomic measures of Curcuma longa L].

A method of orthogonal conic combinatorial design has been employed in the study of high-yield agronomic measures of C. longa. The results show that by increasing plants/mu and postponing sowing date, the yield is 50% higher than before, mathematical model of yield on plants/mu and sowing date were established, which can be used to predict the yield and explore optimal agronomic measures.

Plants, Medicinal↗
PubMed1990

The median daily increment of leukocytes during hematopoietic recovery reflects the myeloid progenitor cell yield during leukapheresis in children.

Twenty-two consecutive patients with a median age of 11 years (range 3-23) underwent 103 leukaphereses for collection of peripheral stem cells. They suffered from various solid tumors and hematologic malignancies. Our aim was to collect at least 2.5 x 10(4) myeloid committed stem cells (CFU-GM) per kg body weight. This stem cell number has reliably resulted in rapid and sustained hematopoietic reconstitution after autografting in our institution. Peripheral stem cell mobilization was induced by myelosuppressive therapy alone. If the stem cell collections were started at the first platelet rise and were continued during the following 8 days, the stem cell yield of one procedure was high - median 1.02 x 10(4) CFU-GM/kg body weight (range 0.02-13.3). In 69 such 'well-timed' collections, a median of only 4 leukaphereses (range 2-6) were needed to collect high numbers of CFU-GM. The yield from leukaphereses carried out at any other time was unsatisfactory. In 34 'random' collections, a median of only 0.27 x 10(4) CFU-GM/kg body weight (range 0.01-1.11) was obtained in one procedure. In 69 well-timed collections the CFU-GM yield depended on the absolute number of circulating leukocytes (r = 0.369, p = 0.002) and mononuclear cells (r = 0.476, p less than 0.001). The median daily increment of leukocytes to the day of apheresis proved to be an excellent parameter for the prediction of the yield and could be used to select the best days for leukaphereses (r = 0.403, p = 0.002). These findings may help to make the collection of blood-derived stem cells more efficient in pediatric patients.

Adolescent↗
PubMed1990

Nanosecond transient absorption spectroscopy of coenzyme B12. Quantum yields and spectral dynamics.

Photolysis of adenosylcobalamin leads to homolytic cleavage, similar to many of the B12-dependent enzyme reactions. Therefore, we have used photolysis to study the structure and lability of the cobalt-carbon bond. The nanosecond quantum yield for adenosylcobalamin is 0.23 +/- 0.04, higher than reported previously. The acidified form of adenosylcobalamin, so called "base-off" B12, has a much lower quantum yield at 0.045 +/- 0.015, demonstrating an inverse correlation between cobalt-carbon bond strength and quantum yield. Investigation of the wavelength dependence of the quantum yield shows that there is a highly efficient transmission of energy from the corrin ring to the cobalt-carbon bond. A comparison of nanosecond transient and static spectra showed small spectral differences. Therefore, any spectral relaxation of a sterically distorted corrin ring may be detectable only at sub-nanosecond timescales. Spectral analysis also provides data on the kinetics of recombination. In the absence of enzyme, geminate rebinding must be substantial, since the rate of Co(II) and deoxyadenosyl radical recombination is near the diffusion controlled limit. Therefore, it is likely that the enzyme functions to pull the geminate partners apart, perhaps as suggested previously, through a conformational change. The importance of geminate recombination in the mechanism of homolytic cleavage is further supported by a comparison of our results with picosecond transient absorption studies.

Cobamides↗
PubMed1975

Postillumination adenosine triphosphate synthesis in Rhodospirillum rubrum chromatophores. I. Conditions for maximal yields.

The very low level of postillumination ATP synthesis in chromatophores was markedly stimulated when permeant anions (thiocyanate or perchlorate) or permeant cations (potassium in the presence of valinomycin) were added to the light stage. Although these compounds stimulated also light-induced proton uptake in chromatophores the pH dependence of both photoreactions was different. Proton uptake peaked at pH 6.5 while the amount of postillumination ATP was maximal when the light stage was carried out around pH 7.7. The increased yield of ATP at the more alkaline pH could not be explained by a slower decay of the high energy state at this pH, since the decay rate was faster at pH 7.7 than at pH 6.5. The proton concentration gradient which is maintained across the chromatophore membrane in the light was also found to increase when the external pH was raised from 6.0 to 8.0. Only a minimal amount of postillumination ATP was formed when this gradient was below 2.1 pH units, but above this value the ATP yield rose steeply as a function of the increasing pH gradient. In light of these results it is suggested that in order to obtain a high yield of postillumination ATP synthesis in chromatophores two conditions are required: the particles have to be loaded with a sufficient number of protons and a light-induced pH gradient above a certain threshold value has to be maintained across their membrane. The low yield of postillumination ATP in chromatophores and the increase obtained by adding permeating ions, is thus explained by similar variations in the extent of the pH gradient, which exceeded the threshold value only in the presence of the permeating ions.

Adenosine Diphosphate↗
PubMed1989

Factors influencing the yield of cranial CT scanning in a private neurological practice.

A prospective study was performed to evaluate the yield of cranial CT scanning in 164 patients referred from a private neurological practice between 1986 and 1988. An over all rate of scan abnormality of 19% was noted. The most common presenting symptoms were headache (51) and seizure disorder (36) and the rates of scan abnormality in these disorders were 15% and 25%, respectively. The yield of CT scanning in patients with headache may be increased by taking age, sex and symptom duration into account, abnormalities being significantly more likely in males, those aged over 40 years and those with headache durations shorter than one month. Those with both symptoms and signs of a structural lesion were more likely to have abnormal scans than those with either symptoms alone or signs alone, both in the group as a whole and in the subgroup with headaches. The predictive value of symptoms suggestive of a structural lesion was influenced by age, sex and the presenting symptom. The yield was low in young females with headache and symptoms suggesting a structural lesion. Such symptoms had a higher predictive value for scan abnormality in patients with seizure disorder than in those with headache. Contrast administration demonstrated a low yield of lesions not seen on pre-contrast scans.

Adult↗