874 research outputs found
Percutaneous closure of ventricular septal defects in childhood
Ventricular septal defect is the most common congenital cardiac lesion. Surgery was, until recently, the only modality of treatment available. Since the first percutaneous closure was attempted, new devices have been developed and used to close these defects. The procedure is safe and effective if the defects are selected correctly with closure being achieved in more than 90% of patients. Morbidity and mortality are acceptable and comparable to surgery. However, percutaneous ventricular septal defect closure is difficult, technically challenging and should only be attempted in units with adequate experience, equipment and support
Blood profiles of indigenous Pedi goats fed varying levels of Vachellia karroo leaf meal in Setaria verticillata hay-based diet
Vachellia karroo (Acacia karroo) is promising fodder for goats in the critical dry season in communal rangelands. The only limitation to the use of this fodder tree is the presence of phenolic compounds, such as condensed tannins. A study was conducted to investigate the effects of tanniniferous V. karroo leaf meal feeding on blood profiles of indigenous Pedi goats fed a basal diet of Setaria verticillata grass hay. Twenty indigenous Pedi goats, weighing 18 ± 2 kg, were allocated in a completely randomized design to five dietary treatments containing V. karroo leaf meal at 20% (S80A20), 25% (S75A25), 30% (S70A30), 40% (S60A40) and 50% (S50A50) of the total diet in a 22-day trial. Twelve ml of blood were collected from the jugular vein from each goat before and after the experiment for haematological and serum biochemical assays. Daily dry matter intake (DMI) was similar across treatments, ranging from 633 g to 765 g per goat per day. There was no difference in initial and final bodyweights of goats consuming various experimental diets. However, bodyweight gains were significantly higher in goats fed a diet with 50% leaf meal as compared with other treatment groups. There were no differences in haematological indices of Pedi goats except for mean corpuscular haemoglobin (Hb) concentration. Goats fed 50% leaf meal had significantly lower mean corpuscular haemoglobin concentration (MCHC) values as compared with other treatment groups. Similarly, there were no differences in the blood serum chemistry of goats that consumed various inclusion levels of V. karroo, except for serum total protein (TP) and alanine aminotransferase (ALT). Goats fed 50% leaf meal had depressed serum TP, while serum enzyme Alanine aminotransferase (ALT) concentration decreased significantly in goats fed 25% leaf meal as compared with those on the 20% dietary treatment. Tannin concentration of 8.2 g/kg dry matter (DM) had no toxic effect on experimental animals. A 40 % inclusion of V. karroo in a Setaria verticillata hay-based diet may be fed to indigenous Pedi goats without compromising the immunity system and health of the animals.Keywords: Condensed tannin, fodder, haematology, seru
The use of small stents to delay surgical intervention in very young children with critical congenital heart disease
Introduction: Surgery in very young children with critical obstructive congenital heart disease has a high morbidity and mortality. The aim of this study was to determine whether the use of small stents is feasible and if it could delay surgery. Materials and methods: Nineteen children were included in a retrospective review spanning 7 years. Patients were included in circumstances where surgery needed to be delayed and the use of a small stent could alleviate the underlying obstruction. Results: All attempts at stenting were successful (100%). Indications were diverse and included: aortic obstruction (n=9), right ventricular outfl ow tract obstruction (n=3), systemic-to-pulmonary artery shunt occlusion (n=5), infradiaphragmatic pulmonary vein obstruction (n=1) and salvage of a discontinuous left pulmonary artery (n=1). Reasons patients were not fi t for surgical intervention included: low weight (n=4), poor general clinical condition (n=12), surgical technical diffi culty (n=2) and unavailability of a critical care bed (n=1). Median age and weight at procedure was 4.6 months (range: 0.1 - 18.3) and 4.5kg (range: 1.7 - 9.5), respectively. Pressure gradients and saturations showed signifi cant improvement post stenting. Periprocedural complications were few (n=3) and there were no fatalities. Last follow-up was at a median of 7.8 months (range: 0.1 -9.0) post initial procedure. Nine cases proceeded to corrective surgery. Surgery was delayed by a median 13.5 months (range: 0.3 - 69.0 months) and weight increased to a median of 10.3kg (p<0.001). Five cases demised at a median of 73 days (range: 1 - 422) post initial stent placement, most at home secondary to unknown causes. Four patients remain in follow-up. One patient was lost to follow-up. Conclusion: The placement of stents in small, ill children is feasible. It immediately relieves the obstruction and improves the general clinical condition. Surgery can be delayed for weeks or months, thus giving the opportunity for somatic growth
Avaliação do incremento em volume de madeira de Quassia amara L.- Simaroubaceae, em cultivo agroecológico no trópico úmido da Costa Rica.
Quassia amara é arbusto de 3 a 6 metros de altura, tendo sido retirado indiscriminadamente das florestas para extrair do caule as quassinas usadas na indústria farmacêutica e como inseticida em agricultura orgânica. Não se tem muita informação técnica acerca do crescimento desta espécie para subsidiar estratégias de manejo sustentado. Este trabalho tem como objetivo avaliar o crescimento de Q. amara L. em cultivo agroecológico na Costa Rica. O trabalho consistiu em realizar avaliações do desenvolvimento de indivíduos de Q. amara em parcelas permanentes de medições, instaladas em meio às plantações desta espécie em consórcio com essências arbóreas. Foram efetuadas medições de diâmetro do caule a 10 cm do solo e altura total. Foi observado que em função das taxas de crescimento vegetal e incrementos médio e corrente anuais (IMA e ICA), mesmo após cinco anos de plantio, a madeira de Quassia amara para extração de quassinas não está pronta para colheita
Fiber Optic based Pipeline Oil and Gas Leak and Intruder Detection System with Security Intervention Plan
The accurate and timely localization of the vandalization and leak point on an oil pipeline provides operators with information to aid with the development of robust security response and intervention plans. These plans have the potential of reducing the impact of leaks on the environment by enabling operators to take actions to mitigate their effect. A major challenge with current leak and vandalization detection systems is the generation of spurious signals which in time slows down the response to these alerts. This paper presents results of the field trial of a Fiber Optic Cable based Oil/ Gas leak and intruder detection system. Oil and Gas leaks were simulated on a pipeline section buried in a swamp location with 1mm and 2mm Orifices located at the 0o, 90o and 180o positions on the pipe with a section of the pipe exposed for third party intruder detection tests. The orifices were connected to compressed air and water used in place of Oil and gas. The fiber optic cable was buried on both sides of the pipeline and hooked up to the Helios Integrator. The system was able to detect and localize leaks from the orifices with the signal intensity proportional to the leak intensity. It was able to detect third party activities such as cutting and the use of hammers on the pipeline and also walking near the pipeline. The results coupled with the security intervention plan which is developed to provide varying levels of response will eliminate response to spurious signals thus providing a robust response and intervention plan to oil and gas leak and intruder detection
The Spin-Dependent Structure Functions of Nuclei in the Meson-Nucleon Theory
A theoretical approach to the investigation of spin-dependent structure
functions in deep inelastic scattering of polarized leptons off polarized
nuclei, based on the effective meson-nucleon theory and operator product
expansion method, is proposed and applied to deuteron and . The explicit
forms of the moments of the deuteron and spin-dependent structure
functions are found and numerical estimates of the influence of nuclear
structure effects are presented.Comment: 42 pages revtex, 7 postscript figures available from above e-mail
upon request. Perugia preprint DFUPG 92/9
Photon-Photon Scattering, Pion Polarizability and Chiral Symmetry
Recent attempts to detect the pion polarizability via analysis of
measurements are examined. The connection
between calculations based on dispersion relations and on chiral perturbation
theory is established by matching the low energy chiral amplitude with that
given by a full dispersive treatment. Using the values for the polarizability
required by chiral symmetry, predicted and experimental cross sections are
shown to be in agreement.Comment: 21 pages(+10 figures available on request), LATEX, UMHEP-38
Вивчення процесу синтезу нанокристалічних плівок двооксиду титану в розряді магнетронного типу за його оптичними та плазмодинамічними характеристиками
Наведено результати експериментального дослiдження плазмодинамiчних i оптичних характеристик цилiндричного газового розряду магнетронного типу в умовах безперервного контролю спектра, випромiнюваного плазмою в дiапазонi 350–820 нм. Визначено умови для синтезу бiнарної сполуки TiО₂, якi забезпечуються пiдтримкою величини iнтенсивностi спектральних лiнiй реагуючих компонентiв i плазмоутворюючого газу. Розглянуто можливiсть контролю умов одержання плiвок TiО₂ як по спектральних характеристиках плазми розряду, так i по змiнi розрядної напруги. Елiпсометричнi дослiдження нанокристалiчних плiвок двооксиду титану показали наявнiсть залежностi показника переломлення вiд товщини плiвки.We present the results of experimental researches of plasmodynamic and optical characteristics of a magnetron-type cylindrical gas discharge. The study was carried out provided a permanent monitoring of the spectrum emitted by plasma in the range 350–820 nm. For the synthesis of binary compound TiO₂, we have determined conditions which can be ensured by a support of the intensity of spectral lines emitted by reacting components and plasma-forming gas. A possibility to control the conditions of the fabrication of a TiO₂ film with the use of both the spectral characteristics of a discharge plasma and a variation of the discharge voltage has been analyzed. Ellipsometric and spectral studies of nanocrystalline titanium dioxide films revealed the dependence of the refractive index of a film on the film thickness.Приведены результаты экспериментального исследования плазмодинамических и оптических характеристик цилиндрического газового разряда магнетронного типа в условиях непрерывного контроля спектра, излучаемого плазмой в диапазоне 350–820 нм. Определены условия для синтеза бинарного соединения TiО₂, которые обеспечиваются поддержанием величины интенсивности спектральных линий реагирующих компонент и плазмообразующего газа. Рассмотрена возможность контроля условий получения пленок TiO₂ как по спектральным характеристикам плазмы разряда, так и по изменению разрядного напряжения. Эллипсометрические и спектральные исследования нанокристаллических пленок диоксида титана показали наличие зависимости показателя преломления от толщины пленки
Interventions Targeting Child Undernutrition in Developing Countries May Be Undermined by Dietary Exposure to Aflatoxin
Child undernutrition, a form of malnutrition, is a major public health burden in developing countries. Supplementation interventions targeting the major micronutrient deficiencies have only reduced the burden of child undernutrition to a certain extent, indicating that there are other underlying determinants that need to be addressed. Aflatoxin exposure, which is also highly prevalent in developing countries, may be considered an aggravating factor for child undernutrition. Increasing evidence suggests that aflatoxin exposure can occur in any stage of life, including in utero through a trans-placental pathway and in early childhood (through contaminated weaning food and family food). Early life exposure to aflatoxin is associated with adverse effects on low birth weight, stunting, immune suppression, and the liver function damage. The mechanisms underlying impaired growth and aflatoxin exposure are still unclear but intestinal function damage, reduced immune function, and alteration in the insulin-like growth factor axis caused by the liver damage are the suggested hypotheses. Given the fact that both aflatoxin and child undernutrition are common in sub-Saharan Africa, effective interventions aimed at reducing undernutrition cannot be satisfactorily achieved until the interactive relationship between aflatoxin and child undernutrition is clearly understood, and an aflatoxin mitigation strategy takes effect in those vulnerable mothers and children
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