22 research outputs found
The Light Microscopy of Triglyceride Digestion
During fat digestion (lipolysis) a number of physiochemical events can be seen directly by light microscopy. Hydrolysis of emulsified fat droplets bylipases at pHs above about 6.5 proceeds with the formation of visible product phases that may include both crystalline as well as liquid crystalline phases. The crystalline phase is primarily calcium-fatty acid soap and its formation is favored by high calcium concentrations, alkaline pHs, and inhibited by low pH and monoglycerides. The formation of liquid crystalline product phases are favored by low calcium-concentrations. monoglycerides and lipid saturated bile salt solutions. Both phases are solubilized by bile salts but the crystalline phase to a much lesser degree. Colored and fluorescent hydrophobic solutes that a re dissolved in long cha in triglyceride appear to flow directly into the liquid crystalline product phases where they can be codispersed with the digested lipid by bile salts. Measurements of the shrinking diameters of digesting fat droplets show that enzyme activity on individual droplet~ falls rapidly during lipolysis. This suggests that lipase molecules a re physically displaced from the substrate interface during lipolysis and dispersed in the product phases
‘A synergy model of health’ - an integration of salutogenesis and the health assets model
This article proposes to advance the connections between salutogenic theory and assets models for health improvement. There is a need to integrate their use in public health and health promotion so that their respective potentials can be fully developed. This requires their synergies to be made more explicit so that a more coherent approach can be taken to their utilization. A mechanism is therefore needed that helps to raise awareness of them and their value as a resource together. Bronfenbrenner’s bioecological theory provides one framework that can support better integration of salutogenesis with the applied nature of assets-based models. This paper proposes a new ‘synergy model for health’ that integrates key concepts associated with salutogenic theory—generalized and specific resistance resources (GRRs/SRRs) and generalized and specific resistance deficits and the sense of coherence (SOC). In doing so, it highlights those GRRs and SRRs which are assets that, either individually or collectively, help to develop a stronger SOC. Higher levels of SOC can then support the transformations of potential resources into available assets (that people can understand, manage and make sense of), capable of producing positive health development. The proposed ‘Synergy model of health’ aims to contribute to a deeper theoretical understanding of health and development through the integration of the key elements of both salutogenesis and assets models. This can facilitate a better contextualization of the ideas into public health policy and practice by making the salutogenic theory more action-oriented and the assets model more theoretical.This paper is supported by the Vice-Rectory for Research and Development, University of Concepción (VRID 217.089.007-1.0IN)
Effect of pancreatic phospholipase A2 and gastric lipase on the action of pancreatic carboxyl ester lipase against lipid substrates in vitro
Preincubation of a triolein/phospholipid/cholesteryl oleate-emulsion in vitro with either pancreatic phospholipase A2 (PLA2) or gastric lipase (GL) resulted in hydrolysis (measured by pH-stat-titration) of cholesteryl [3H]oleate only after human pancreatic carboxyl ester lipase (CEL) was added to the system. No appreciable hydrolysis was observed when CEL was added alone. Consequently, a concerted action either of PLA2 and CEL or of GL and CEL made the substrate cholesteryl oleate available for hydrolysis by CEL. This was the case when cholesteryl oleate was solubilised in a phospholipid-stabilised triglyceride emulsion, which is the physico-chemical form in which the major part of dietary cholesteryl esters are presented to the gastro-intestinal tract of man
Electrically active point defects in n-type 4H¿SiC
An electrically active defect has been observed at a level position of ∼ 0.70 eV below the conduction band edge (Ec) with an extrapolated capture cross section of ∼ 5×10−14 cm2 in epitaxial layers .
Validation of the Distress Thermometer in a Swedish population of oncology patients; accuracy of changes during six months
Purpose: To validate the Swedish version of the Distress Thermometer (DT) against the Hospital Anxiety and Depression Scale (HADS) for screening of distress and to explore how well DT measures changes of distress during six months in a population of heterogeneous oncology patients. Methods: The DT was translated into Swedish according to the forward- and back-translation procedure. HADS total score >= 15 was used as gold standard. Consecutive patients were invited to participate at their first visit to the Oncology department. The HADS and the DT were completed at baseline and after I, 3 and 6 months. Results: 462 baseline and 321 six-month assessments were completed. The patients had a variety of cancer diagnoses (n = 42). Most patients (95%) received active treatment. The DT compared favourably with the HADS. The area under the curve was 0.86 (95% CI, 0.82-0.90). DT >= 4 showed a sensitivity of 87%, a specificity of 73%, a positive predictive value (PPV) of 52% and a negative predictive value (NPV) of 95% at baseline. The results from the 1, 3 and 6 months assessments were equivalent baseline results. The DT means changed in the same direction as HADS at all points of assessment. Patients with distress reported statistically significantly more problems in all categories on the associated 'Problem List' compared to non-distressed patients. Conclusion: The Swedish version of the DT with a score >= 4 is valid for screening of distress in heterogeneous oncology patients. Its ability to measure changes in distress over time is comparable to HADS. (c) 2012 Elsevier Ltd. All rights reserved
Oscillatory behaviour in Galvanostatic Formaldehyde Oxidation on Nanostructured Pt/Glassy Carbon Model Electrodes
The electrocatalytic oxidation of formaldehyde, which results in CO, and HCOOH formation, was investigated under galvanostatic conditions on nanostructured Pt/glassy carbon (GC) electrodes fabricated by employing colloidal lithography (CL). The measurements were performed on structurally well-defined model electrodes of different Pt surface coverages under different applied currents (current densities) and at constant electrolyte transport in a thin-layer flow cell connected to a differential electrochemical mass spectrometry (DEMS) setup to monitor the dynamic response of the reaction selectivity under these conditions. Periodic oscillations of the electrode potential and the CO, formation rate appear not only for a continuous Pt film, but also for the nanostructured Pt/GC electrodes when a critical current density is exceeded. The critical current density for achieving regular osillation patterns increased with decreasing Pt nanodisk density. Lower oscillation frequencies of the electrode potential and lower CO2 formation rate for nanostructured Pt/GC electrodes compared to continuous Pt film at similar applied current densities suggest that transport processes play an essential role. Moreover, from the simple periodic response of the nanostructured electrodes it follows that all individual Pt disks in the array oscillate in synchrony. This result is discussed in terms of the different modes of spatial coupling present in the system: global coupling, migration coupling and mass transport of the essential chemical species, and the coverage of corresponding adsorbates
Psychometric Properties of Occupational Self-Assessment for Injured Workers with Musculoskeletal Disorders
Maternal plasma levels of oxytocin during physiological childbirth – a systematic review with implications for uterine contractions and central actions of oxytocin
Background:Oxytocin is a key hormone in childbirth, and synthetic oxytocin is widely administered to induce orspeed labour. Due to lack of synthetized knowledge, we conducted a systematic review of maternal plasma levelsof oxytocin during physiological childbirth, and in response to infusions of synthetic oxytocin, if reported in theincluded studies.Methods:An a priori protocol was designed and a systematic search was conducted in PubMed, CINAHL, andPsycINFO in October 2015. Search hits were screened on title and abstract after duplicates were removed (n=4039), 69 articles were examined in full-text and 20 papers metinclusion criteria. As the articles differed in designand methodology used for analysis of oxytocin levels,a narrative synthesis was created and the material wascategorised according to effects.Results:Basal levels of oxytocin increased 3–4-fold during pregnancy. Pulses of oxytocin occurred with increasingfrequency, duration, and amplitude, from late pregnancy through labour, reaching a maximum of 3 pulses/10 mintowards the end of labour. There was a maximal 3- to 4-fold rise in oxytocin at birth. Oxytocin pulses also occurred inthe third stage of labour associated with placental expulsion. Oxytocin peaks during labour did not correlate in timewith individual uterine contractions, suggesting additional mechanisms in the control of contractions. Oxytocin levelswere also raised in the cerebrospinal fluid during labour, indicating that oxytocin is released into the brain, as well asinto the circulation. Oxytocin released into the brain induces beneficial adaptive effects during birth and postpartum.Oxytocin levels following infusion of synthetic oxytocin up to 10 mU/min were similar to oxytocin levels inphysiological labour. Oxytocin levels doubled in response to doubling of the rate of infusion of synthetic oxytocin.Conclusions:Plasma oxytocin levels increase gradually during pregnancy, and during the first and second stages oflabour, with increasing size and frequency of pulses of oxytocin. A large pulse of oxytocin occurs with birth. Oxytocin inthe circulation stimulates uterine contractions and oxytocin released within the brain influences maternal physiologyand behaviour during birth. Oxytocin given as an infusion does not cross into the mother’s brain because of the bloodbrain barrier and does not influence brain function in the same way as oxytocin during normal labour does