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At least 1,081 records · Page 60Linked to original sources
PubMed2000

[Continuous cropping obstacle and rhizospheric microecology. II. Root exudates and phenolic acids].

This paper discussed the effect of main crop root exudates the relationship between the kinds and amounts of root exudates and the growth of different kinds of crops and their environments. From the aspects of the decompostion of crop residues and the excretion of root systems, the source, form and adsorption mechanism of soil phenolic acids and their effect on crop growth and soil bio-activity were also elaborated.

Agriculture↗
PubMed2000

[Continuous cropping obstacle and rhizospheric microecology. III. Soil phenolic acids and their biological effect].

The contents of phenolic acids in the extracts of soil and roots of continuously cropped for five years and normally cropped soybean in Heilongjiang province and their biological effects were studied with HPLC method. The result showed that the contents of p-hydroxy benzoic acid, vanillic acid(extracted by 1 mol.L-1 NaOH) in continuous cropping soil were significant higher than that in normal cropping soil, and the content of vanillin had no significant difference in these soils. The contents of p-hydroxybenzoic acid, vanillic acid, vanillin, ferulic acids, and coumarin of aqueous extracts of soyhean roots were higher in continuous cropping than in normal cropping soil. The activity of polyphenol oxidase in continuous cropping soil was higher than in normal cropping soil. Under conditions of water culture and adding exogenous p-hydroxybenzoic acid, the aqueous extract of soybean roots inhibited the growth of soybean seedlings. After a week of exogenous phenolic acids addition, the residual rates of p-hydroxybenzoic acid, vanillic acid, vanillin, benzoic acid, ferulic acids, and coumarin were 10.4%, 15.3%, 4.1%, 2.3%, 5.2%, 17.5%, respectively. There was a very significant exponential relationship between the addition amount of exogenous phenolic acids and the fungi population in soil.

Agriculture↗
PubMedDate not supplied

Posterior acetabular spike: an obstacle to reduction in long-standing hip dislocations.

The posterior insertion of the transverse acetabular ligament can be transformed into a toothlike bony prominence narrowing the acetabulum in its distal part. This deformity can impede the placement of the femoral head deep in the acetabulum, making a complete reduction impossible. The toothlike spike can be detected by computed tomography or by intraoperative palpation, and can be corrected by pushing it back with a punch under palpatory control.

Acetabulum↗
PubMed2002

Cancer treatment in Pakistan: challenges & obstacles.

INTRODUCTION: There is no population based tumor registry in Pakistan except for Karachi. A Department based tumor registry was established to determine the patterns of cancers in Pakistan especially Punjab. Other objectives were to determine socioeconomic status, disease stage, co-morbid conditions. We also tried to determine if patients had received optimal treatment on diagnosis. MATERIALS & METHODS: 3,274 patients presented to the Department of Oncology between 1995-2000. All patients had histopathologically confirmed diagnosis of cancer. Demographic data included age, sex, socioeconomic status, smoking, other co-morbid and occupation. RESULTS: The Oncology Department drains a catchment area of approximately 400 square kms in Punjab. Breast cancer was the most common cancer in females while leukemias and lymphomas were most common in males. Poor socio-economic status was present in 89% of cases. Illiteracy was present in 76%. Comorbid conditions like hepatitis B & C were present in 37% of patients. Advanced disease was documented in 59% patients. Optimal treatment on initial diagnosis was not provided to 45% patients. DISCUSSION: Advanced stage, poor socio-economic status, illiteracy were common. Associated co-morbid conditions were a major cause in delay in treatment. Optimal treatment was not provided to majority of patients. All these factors are contributing to poor cure rates seen in Pakistan.

Comorbidity↗
PubMed2002

[Suicide prevention strategy and recent data on treatment of depression: obstacles encountered].

Until recently, national strategies have not demonstrated their effectiveness in preventing suicide. A recent series of studies have shown that more aggressive treatment of depression in the population is associated with a significant reduction in the rate of suicide. Proof that a population-based strategy for preventing suicide can be effective should be demonstrating that an etiological factor can be identified on the population level and on the individual level and that this causal factor can be corrected on the individual level. Pertinent data can be put forward and in general demonstrate that treatment of depression is an effective means of preventing suicide on the population level.

Depression↗
PubMed1975

Obstacles to family planning practice in urban Morocco.

Sixty in-depth interviews with mothers living in a urban slum of Morocco probed resistances to practicing modern methods of fertility control and began to shed light on some of the reasons family planning programs often fail to reach illiterate target populations. Economic insecurity and the disintegration of the support networks of the traditional extended family complicate the difficult lives of young mothers in the urban slum. While such factors tend to encourage smaller families, the uncertainties and complexities of the socioeconomic structure contribute to the problems blocking access to modern methods of fertility control.

Abortion, Induced↗
PubMed2002

The presence of unknown layer of skin and fat is an obstacle to a correct estimation of the motor unit size from surface detected potentials.

To overcome problems with a strong distance-dependence of the motor unit potentials (MUPs), different methods to estimate the MU location and size have been proposed. Distance-independence of the exponent of the power function, that describes the MUP distance decline, and homogeneity of the volume conductor, are assumed in all methods. Some of them consider the exponent value as unique, irrespective of persons, muscles and their functional state. One method estimates the current exponent value. We evaluate this method by computer simulation of MUPs in infinite and semi-infinite volume conductor. Our results show that although the first assumption is not fulfilled, it does not affect considerably the estimate of the MU location and size obtained for infinite or semi-infinite homogeneous volume conductor. The errors of the MU location can be insignificant even in inhomogeneous volume conductor with a layer of lower conductivity (skin and fat) between the muscle tissue and electrode. The accurate location of the MU electrical axis is, however, not a sufficient condition for a correct MU size estimation that depends considerably on actual parameters of the layer. Thus, the surface EMG could hardly be considered as non-invasive alternative to macro EMG for detection of the enlarged MUs.

Action Potentials↗
PubMed2001

The collagenous lesion scar--an obstacle for axonal regeneration in brain and spinal cord injury.

After CNS trauma a sheet-like, collagen type IV (Coll IV) immunopositive basement membrane (BM) develops in the lesion zone as well as at newly formed blood vessels. The basic scaffold of this BM is composed of Coll IV, laminin and nidogen but numerous other proteins some of which are discussed to be inhibitory for axonal regeneration, i.e. chondroitin- and heparansufate-proteoglycans, are associated with BM. This review will focus on the collagenous wound healing scar, discuss its composition and summarize the experimental results that demonstrate its role in the failure of axonal regeneration in the injured mammalian CNS.

Animals↗