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Marked Influence (marked + influence)
Selected AbstractsInfluence of shear flow on polymorphic behavior and microstructural development during palm oil crystallizationEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 3 2009Veerle De Graef Abstract The influence of shear on the crystallization of palm oil was studied at four different crystallization temperatures (18, 20, 22 and 25,°C). Time-resolved X-ray analyses were carried out to study the effect of continuous shear on the crystallization kinetics of the fat. Rheological measurements were used to assess the effect of a shear step on crystallization, and finally polarized light microscopy was used to follow changes in microstructure due to the applied initial shear step. It was shown that shear enhanced the primary crystallization, even when low shear rates were applied for a short period. Furthermore, a shear step prior to crystallization without shear has a marked influence on the microstructural development. [source] Effect of a 1-month vs. a 12-month reference period on responses to the 14-item Oral Health Impact ProfileEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2007Saila Sutinen The length of the reference period used in surveys of subjective oral health may have a marked influence on the responses obtained. We aimed to evaluate the effect of a 1-month (RP-1) vs. a 12-month (RP-12) reference period in the Oral Health Impact Profile (OHIP-14) questionnaire. Using a randomized cross-over design, RP-1 and RP-12 OHIP-14 questionnaires were administered, 1 month apart, to two samples of Finnish adults, namely people awaiting orthognathic surgery (n = 104) and non-patient workers (n = 111). The effect of the reference period was computed by subtracting RP-1 OHIP-14 severity scores from RP-12 OHIP-14 severity scores (,RP). Potential order effects were assessed by comparing ,RP between groups completing the RP-1 vs. the RP-12 questionnaire first. Mean OHIP-14 severity scores were slightly higher when the RP-12 questionnaire was administered first, but mean ,RP values were below the value of 2.5 considered clinically meaningful, and all 95% confidence intervals for ,RP included zero. No order effects in the OHIP-14 severity scores were observed. Therefore, although a standardized reference period of 12 months is recommended, in population surveys the use of a shorter reference period does not appear to influence responses. [source] Regulation of cerebral blood flow in mammals during chronic hypoxia: a matter of balanceEXPERIMENTAL PHYSIOLOGY, Issue 2 2010Philip N. Ainslie Respiratory-induced changes in the partial pressures of arterial carbon dioxide and oxygen play a major role in cerebral blood flow (CBF) regulation. Elevations in (hypercapnia) lead to vasodilatation and increases in CBF, whereas reductions in (hypocapnia) lead to vasoconstriction and decreases in CBF. A fall in (hypoxia) below a certain threshold (<40,45 mmHg) also produces cerebral vasodilatation. Upon initial exposure to hypoxia, CBF is elevated via a greater relative degree of hypoxia compared with hypocapnia. At this point, hypoxia-induced elevations in blood pressure and loss of cerebral autoregulation, stimulation of neuronal pathways, angiogenesis, release of adenosine, endothelium-derived NO and a variety of autocoids and cytokines are additional factors acting to increase CBF. Following 2,3 days, however, the process of ventilatory acclimatization results in a progressive rise in ventilation, which increases and reduces , collectively acting to attenuate the initial rise in CBF. Other factors acting to lower CBF include elevations in haematocrit, sympathetic nerve activity and local and endothelium-derived vasoconstrictors. Hypoxia-induced alterations of cerebrovascular reactivity, autoregulation and pulmonary vascular tone may also affect CBF. Thus, the extent of change in CBF during exposure to hypoxia is dependent on the balance between the myriad of vasodilators and constrictors derived from the endothelium, neuronal innervations and perfusion pressure. This review examines the extent and mechanisms by which hypoxia regulates CBF. Particular focus will be given to the marked influence of hypoxia associated with exposure to high altitude and chronic lung disease. The associated implications of these hypoxia-induced integrative alterations for the regulation of CBF are discussed, and future avenues for research are proposed. [source] Interaction of heparin with Ca2+: A model study with a synthetic heparin-like hexasaccharideISRAEL JOURNAL OF CHEMISTRY, Issue 3-4 2000Jesús Angulo The binding of Ca2+ to synthetic hexasaccharide 1, containing the structural motifs of the regular region of heparin, has been investigated using NMR spectroscopy and molecular modeling. The NMR data of the calcium salt of 1 indicate the existence of specific Ca2+ binding, and molecular modeling results predict three different types of binding sites with different negative potential and preorganized geometry. The presence of Ca2+ does not seem to affect the overall helical structure of hexasaccharide 1, although it seems to have a marked influence on the flexibility of the oligosaccharide backbone. [source] Association of atherosclerotic risk factors with carotid adventitial thickness assessed by ultrasonographyJOURNAL OF CLINICAL ULTRASOUND, Issue 6 2009Radoslaw Kazmierski MD Abstract Purpose. There is increasing evidence that adventitial inflammation may participate in atherosclerosis development. The aim of this study was to investigate which atherosclerotic risk factors correlated with carotid adventitial thickness (AT) and to compare them with those associated with carotid intima-media thickness (IMT). We also set out to test the hypothesis that there is a significant correlation between IMT and AT in the carotid arteries. Methods. The far carotid artery wall IMT and AT were measured by high-resolution B-mode ultrasound in 128 persons (mean, 65 ± 8 years). A number of conventional and novel, clinically and laboratory-derived risk factors were assessed. Results. Significant correlation (r = 0.35, p < 0.0001) was demonstrated between the IMT and AT. The stepwise forward multiple regression analysis revealed correlations between IMT and leukocyte count, C-reactive protein level, and hypertension, whereas the Chlamydia (C.) pneumoniae IgA antibodies and fibrinogen levels, gender, and smoking correlated merely with AT. The homocysteine/methionine ratio correlated with both IMT and AT. Conclusion. The association between IMT and AT may reflect an interaction between intimal, medial, and adventitial pathology. Different risk factors are associated with the increased AT or IMT. It is possible that inflammation and some chronic infections, such as those induced by C.pneumoniae, could have a marked influence on adventitial cell proliferation. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009 [source] Basal cell carcinoma of the nose: An Australian and New Zealand Radiation Oncology patterns-of-practice studyJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2008MJ Veness Summary Patients with a basal cell carcinoma (BCC) of the nose may be recommended radiotherapy (RT) with a wide variation in techniques and prescribed dose fractionation schedules between clinicians. The aim of this study was to ascertain variability in the patterns of practice among Australian and New Zealand radiation oncologists (ROs) when treating BCC arising on the nose. A postal survey was sent to 222 practising ANZ ROs detailing 12 different clinical scenarios of a BCC arising on the nose. The treatment selected for each scenario was analysed according to clinician's attitudes, training, experience and the availability of resources. The response rate was 74% (165/222) with 90 respondents treating non-melanoma skin cancer. Training was perceived to have a marked influence on treatment practice by most (79%). In total, 72% of ROs were ,very certain' in their choice of a dose fractionation schedule for obtaining local control and 61% for a satisfactory cosmetic outcome, respectively. Most (76%) favoured low-voltage photons over electrons as the optimal method of treatment, although for certain clinical scenarios most would use electrons. Dose fractionation schedules were highly variable with a lower total dose and hypofractionation favoured for older patients. Low-voltage photons were favoured for the T1 BCC and electrons for the T2 and T4 BCC. Nearly one-third of the ROs chose megavoltage photons for the T4 lesion. There is marked variation in treatment practices in terms of recommending RT over other treatment options, the choice of RT method, the dose fractionation schedule, the extent of field margins and the point of dose prescription. [source] Absorption of polyethylene glycol (PEG) polymers: The effect of PEG size on permeabilityJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2009Hema Gursahani Abstract Polyethylene glycol (PEG) polymers are large amphiphilic molecules that are highly hydrated in solution. To explore the permeability properties of different sized PEG polymers across epithelial membranes in vivo, we examined the absorption of fluorescently labeled PEG conjugates sized 0.55,20 kDa from the lung, since this system provides a reservoir that limits rapid diffusion of molecules away from the site of delivery and enables permeability over longer times to be examined. Following intratracheal delivery in rats, the PEG polymers underwent absorption with first-order kinetics described by single exponential decay curves. PEG size produced a marked influence on the rate of uptake from the lung, with half-lives ranging from 2.4 to 13 h, although above a size of 5 kDa, no further change in rate was observed. PEG size likewise affected retention in alveolar macrophages and in lung tissue; whereas smaller PEG sizes (<2 kDa) were effectively cleared within 48 h, larger PEG sizes (>5 kDa) remained in lung cells and tissue for up to 7 days. These data demonstrate that PEG polymers can be absorbed across epithelial membranes and that PEG size plays a dominant role in controlling the rate and mechanism of absorption. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:2847,2856, 2009 [source] New insights into the effect of amorolfine nail lacquerMYCOSES, Issue 2 2005C. Flagothier Summary Despite improvements in antifungal strategies, the outcome of treating onychomycoses often remains uncertain. Several factors account for treatment failure, of which the pharmacokinetics and pharmacodynamics of the antifungal are of importance. The taxonomic nature and ungual location of the fungus cannot be neglected, besides the type of nail and its growth rate. In addition, the biological cycle of the fungus and the metabolic activity of the pathogen likely play a marked influence in drug response. The presence of natural antimicrobial peptides in the nail is also probably a key feature controlling the cure rates. There are many outstanding publications that cover the full spectrum of the field. The purpose of this review is to put in perspective some facets of activity of the topical treatment using amorolfine nail laquer. The antifungal activity of the drug is likely less pronounced in onychomycosis than that expected from conventional in vitro studies. However, the nail laquer formulation should reduce the propensity to form antifungal-resistant spores and limit the risk of reinfection. [source] Epidemics of Tomato torrado virus, Pepino mosaic virus and Tomato chlorosis virus in tomato crops: do mixed infections contribute to torrado disease epidemiology?ANNALS OF APPLIED BIOLOGY, Issue 3 2010P. Gómez Torrado disease was first observed in protected tomato crops in the Murcia province of Spain in spring 2001, causing serious concern to regional tomato producers. The disease-causing agent was initially identified as a picorna-like bipartite plant RNA virus, now known as Tomato torrado virus (ToTV), but several additional torradoviruses inducing similar disease symptoms have been described more recently. We studied the incidence of torradoviruses between 2005 and 2008 in two parts of Murcia (Spain) where tomato crops are grown commercially. We also analysed the potential association among ToTV, Pepino mosaic virus (PepMV) and Tomato chlorosis virus (ToCV) in samples showing torrado symptoms of varying severity. ToTV was the only torradovirus found in the samples (predominantly as single infections), but double and triple infections comprising ToTV, PepMV and/or ToCV were also detected. There was no evidence of a specific association among the viruses as the frequencies of mixed infections did not deviate from those expected to occur by chance. Statistical analysis of the potential association between torrado symptoms and the type of infection (single or multiple) was inconclusive. To determine whether co-infections with ToTV and PepMV have any marked influence on the torrado disease, we analysed torrado symptom severity and virus accumulation in tomato plants experimentally infected with ToTV-CE, PepMV-Sp13 and PepMV-PS5 in single and mixed infections. The severity of the torrado symptoms was not affected by the presence of PepMV. In single infections, the ToTV titre remained very low, reaching its maximum in the early stages of infection and declining rapidly thereafter, whereas the disease symptoms became more severe over the same timescale. In mixed infections, the accumulation of both ToTV and PepMV was altered with respect to single infections, and the magnitude of this alteration appeared to be virus and strain specific. Therefore, ToTV and PepMV mixed infections may modulate the epidemiology of both viruses in a complex way by altering virus fitness. The impact of our studies on efforts to track and prevent the spread of torrado disease is discussed. [source] Performance evaluation of concurrent rice,fish,prawn culture with and without cull harvestingAQUACULTURE RESEARCH, Issue 9 2010Rajeeb K Mohanty Abstract This study was carried out in farmers' fields for three experimental culture cycles to evaluate the performance of rice,fish,prawn culture. The treatments carried out were deepwater rice mono-cropping (R), and rice,fish,prawn culture with cull harvesting (R,FC) and without cull harvesting (R,F). Water pH and total alkalinity were significantly higher (P<0.05) in R,FC than in R,F, while the concentrations of total suspended solids, plankton and chlorophyll a were higher in R,F. Cull harvesting in R,FC had no marked influence on the concentrations of dissolved oxygen, NH4+, nitrite, nitrate and phosphate compared with the R,F treatment. The significantly higher fish and prawn yields (P<0.05) and species-wise faster individual growth performance in R,FC than in R,F were probably due to periodic cull harvesting, which minimized the competition for food and space as well as physiological stress at reduced density. The paddy yield and percentage increase in paddy yield over rice mono-crop was significantly higher (P<0.05) in R,FC (25%), followed by R,F (16.9%), probably due to lower chlorophyll a (36.7 mg m,3) and plankton density (1.4 × 104 L,1), which minimized the competition for nutrients with rice plants. The highest rice equivalent yield (38.5), output value,cultivation cost ratio (1.56) and enhanced net return (28%) in deepwater rice,fish culture were recorded when cull harvesting was practiced. [source] Population pharmacokinetics of imatinib and the role of ,1 -acid glycoproteinBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 1 2006N. Widmer Aims The aims of this observational study were to assess the variability in imatinib pharmacokinetics and to explore the relationship between its disposition and various biological covariates, especially plasma ,1 -acid glycoprotein concentrations. Methods A population pharmacokinetic analysis was performed using NONMEM based on 321 plasma samples from 59 patients with either chronic myeloid leukaemia or gastrointestinal stromal tumours. The influence of covariates on oral clearance and volume of distribution was examined. Furthermore, the in vivo intracellular pharmacokinetics of imatinib was explored in five patients. Results A one-compartment model with first-order absorption appropriately described the data, giving a mean (± SEM) oral clearance of 14.3 l h,1 (± 1.0) and a volume of distribution of 347 l (± 62). Oral clearance was influenced by body weight, age, sex and disease diagnosis. A large proportion of the interindividual variability (36% of clearance and 63% of volume of distribution) remained unexplained by these demographic covariates. Plasma ,1 -acid glycoprotein concentrations had a marked influence on total imatinib concentrations. Moreover, we observed an intra/extracellular ratio of 8, suggesting substantial uptake of the drug into the target cells. Conclusion Because of the high pharmacokinetic variability of imatinib and the reported relationships between its plasma concentration and efficacy and toxicity, the usefulness of therapeutic drug monitoring as an aid to optimizing therapy should be further investigated. Ideally, such an approach should take account of either circulating ,1 -acid glycoprotein concentrations or free imatinib concentrations. [source] Enhancement Boiling Heat Transfer Study of a Newly Compact In-line Bundle Evaporator under Reduced Pressure ConditionsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 3 2006Z.-H. Liu Abstract For common flooded-type evaporators, nucleate boiling heat transfer cannot occur on the heated tubes since heat fluxes and wall superheats of heated tubes are generally quite low. However, when the tube spacing is very small, nucleate boiling in restricted spaces can occur easily under low heat flux or low wall superheat conditions. The generation of nucleate boiling can effectively enhance the heat transfer performance of bundle evaporators. This study investigated experimentally the boiling heat transfer enhancement effects of the restricted space in compact in-line tube bundles with smooth tubes under various reduced pressures. The experimental results show that the compact in-line tube bundles have a significantly enhanced heat transfer compared to those of the common tube bundles, and there is an optimum tube spacing that provides the greatest heat transfer enhancement effect. The test pressures have a marked influence on the boiling heat transfer enhancement in the compact bundles. The heat transfer enhancement effect decreases with decreasing test pressure. In addition, the heat transfer enhancement effects of the in-line tube bundles are also compared with those of the staggered bundles. Under reduced pressure, there is no significant difference between the heat transfer enhancement effects for the two types of bundles. [source] | ||||||||||||||||