111 research outputs found
Comparison of the structure and flexural properties of Moso, Guadua and Tre Gai bamboo
Bamboo is an underutilized resource widely available in countries with rapidly developing economies. Structural bamboo products, analogous to wood products, allow flexibility in the shape and dimensions of bamboo structural members. Here, the ultrastructure, microstructure, cell wall properties and flexural properties of three species of bamboo (Moso, Guadua and Tre Gai) are compared. At a given density, the axial modulus of elasticity of Guadua is higher than that of Moso or Tre Gai, which are similar; ultrastructural results suggest that Guadua has a higher solid cell wall stiffness. At a given density, their moduli of rupture are similar.National Science Foundation (U.S.) (OISE-1258574
Generic health literacy measurement instruments for children and adolescents:a systematic review of the literature
Background Health literacy is an important health promotion concern and recently children and adolescents have been the focus of increased academic attention. To assess the health literacy of this population, researchers have been focussing on developing instruments to measure their health literacy. Compared to the wider availability of instruments for adults, only a few tools are known for younger age groups. The objective of this study is to systematically review the field of generic child and adolescent health literacy measurement instruments that are currently available. Method A systematic literature search was undertaken in five databases (PubMed, CINAHL, PsycNET, ERIC, and FIS) on articles published between January 1990 and July 2015, addressing children and adolescents ?18 years old. Eligible articles were analysed, data was extracted, and synthesised according to review objectives. Results Fifteen generic health literacy measurement instruments for children and adolescents were identified. All, except two, are self-administered instruments. Seven are objective measures (performance-based tests), seven are subjective measures (self-reporting), and one uses a mixed-method measurement. Most instruments applied a broad and multidimensional understanding of health literacy. The instruments were developed in eight different countries, with most tools originating in the United States (n =?6). Among the instruments, 31 different components related to health literacy were identified. Accordingly, the studies exhibit a variety of implicit or explicit conceptual and operational definitions, and most instruments have been used in schools and other educational contexts. While the youngest age group studied was 7-year-old children within a parent-child study, there is only one instrument specifically designed for primary school children and none for early years. Conclusions Despite the reported paucity of health literacy research involving children and adolescents, an unexpected number of health literacy measurement studies in children?s populations was found. Most instruments tend to measure their own specific understanding of health literacy and not all provide sufficient conceptual information. To advance health literacy instruments, a much more standardised approach is necessary including improved reporting on the development and validation processes. Further research is required to improve health literacy instruments for children and adolescents and to provide knowledge to inform effective interventionspublishersversionPeer reviewe
Respiratory -Opioid and benzodiazepine interactions in the understrained rat
lnteractions of p-opioid receptors with the benzodiazepine system were studied by examining the modulatory effects of flumazenil (a benzodiazepine antagonist) and alprazolam (a benzodiazepine agonist) on the respiratory effects ofthe opioid peptide dermorphin. Dermorphin, 1-30 nmol administered i.c.v., to conscious, unrestrained rats decreased ventilation rate (VR) and minute volume (MV) dose-dependently. The ventilatory depression was antagonized by naloxone and by the benzodiazepine antagonist flumazenil. The benzodiazepine alprazolam potentiateri the respiratory inhibition of a small (I nmol) dose of dermorphin but antagonized that of a higher dos:~ (3 nmol). The results suggest that the benzodiazepine/GABA receptor complex modulates respiratory depression induced by centrat p-receptor Stimulation in the rat
Respiratory and locomotor stimulation by low doses of dermorphin - a Mu-receptor mediated effect
The selective opioid mu receptor agonist dermorphin increased the locomotor activity of rats dose dependently at 1 0 to 1 00 pmol/kg i.c.v. Respiratory rate, relative tidal volume and respiratory minute volume also increased unrelated to changes in locomotor activity. Higher doses, on the other hand, produced catalepsy and respiratory depression. Pretreatment of the rats with the mu,-selective antagonist naloxonazine (10 mg/kg i.v.) blocked the stimulant locomotor and respiratory effects of low doses of dermorphin (1 0--1 00 pmol/kg), but potentiated the respiratory depressant effect of a high dose (1 0 nmol/kg) of dermorphin. The selective benzodiazepine antagonist flumazenil (5 mg/kg), which has been shown previously to antagonize catalepsy and respiratory depression produced by relatively high doses of dermorphin, did not antagonize the respiratory or locomotor stimulant effect of dermorphin. The data suggest that mu-opioid receptors are responsible for the low dose stimulant effects of dermorphin on locomotor activity and respiration whereas mu receptors mediate the respiratory depressant effect of dermorphin
Dermorphin analog Tyr-D-Arg-Phe-sarcosine-induces opioid analgesia and respiratory stimulation - the role of Mu- receptors?
Tyr-o-Arg-Phe-sarcosine (TAPS), a mu-selective tetrapeptide analog of dermorphin, induced sustained antinociception and stimulated ventilatory minute volume (MV) at the doses of 3 to 100 pmol i.c.v. The doses of 30 and 100 pmol i.c.v. induced catalepsy. The effect of TAPS on MV was in negative correlation with the dose and the maximal response was achieved by the lowest (3 pmol) dose (+63 ± 23%, P < .05). Morphine, an agonist at both mu and mu sites, at a dose of 150 nmol i.c.v. (equianalgetic to 100 pmol of TAPS decreased the MV by 30%, due to a decrease in ventilatory tidal volume. The antinociceptive effect of TAPS was antagonized by naloxone and the mu, receptor antagonist, naloxonazine. Naloxonazine also attenuated the catalepsy produced by 1 00 pmol of TAPS i.c. v. and the respiratory Stimulation produced by 3 pmol of TAPS i.c.v. Pretreatment with 30 pmol of TAPS antagonized the respiratory depression induced by the mu opioid agonist dermorphin (changes in MV after dermorphin alone at 1 or 3 nmol were -22 ± 1 0% and -60 ± 9% and, after pretreatment with TAPS, +44 ± 11 % and -18 ± 5%, respectively). After combined pretreatment with naloxonazine and TAPS, 1 nmol of dermorphin had no significant effect on ventilation. In contrast, pretreatment with a low respiratory stimulant dose (10 pmol i.c.v.) of dermorphin did not modify the effect of 1 nmol of dermorphin. ln conclusion, the antinociceptive, cataleptic and respiratory stimulant effects of TAPS appear to be a related to its agonist action at the mu, opioid receptors. TAPS did not induce respiratory depression (a mu opioid effect) but antagonized the respiratory depressant effect of another mu agonist. Thus, in vivo TAPS appears to act as a mu receptor antagonist
Effect of fat-contamination and fat-suppression on T2 quantitation of knee articular cartilage in vivo
This study aims to investigate the effect of fat contamination and fat suppression (FS) on in vivo T2 mapping of knee articular cartilage. T2 mapping is a technique used in magnetic resonance imaging (MRI) and it has advantages over radiography techniques, such as no ionizing radiation and T2 maps give information about cartilage content and structure. Knee articular cartilage has high water concentration and near the cartilage, there is fat tissue, i.e. bone marrow and subcutaneous fat. Fat causes chemical shift artifact and can contaminate T2 values of T2 maps. To minimize chemical shift artifacts, FS is needed to suppress the fat signal.
Four volunteers were imaged on a 3 Tesla MRI clinical scanner and T2 values were calculated in several regions of tibiofemoral cartilage using a multi-echo spin-echo sequence (MSME) with and without FS (NoFS). Two frequency encoding directions, superior-inferior (SI) and inferior-superior (IS), were used to evaluate the effects of FS on chemical shift artifact.
Sagittal slices of the knee were manually segmented to 18 region of interests (ROIs) and then T2 maps were calculated with MATLAB based scripts. The repeatability of segmentation was evaluated, which was achieved by segmenting same slices multiple times.
Differences between NoFS T2-SI and NoFS T2-IS ranged widely and in 11 out of 18 ROIs the differences were high, suggesting that the chemical shift artifact affects most of the cartilage regions. Particularly affected were the superficial and deep femoral cartilage and deep tibia. Differences between FS T2-SI and FS T2-IS values were low to moderate in most of the ROIs, with the highest differences observed in deep parts of anterior and central femur. Comparing NoFS T2 and FS T2 values with the same frequency encoding direction, differences were on average higher using SI direction than IS direction, and the deep ROIs were the most affected.
Repeatability of segmentation was great in eight ROIs without FS and six ROIs with FS and the average differences were low for both NoFS and FS T2 mapping. For NoFS T2 mapping, segmentation repeatability was high in deep tibial cartilage. On the contrary, FS T2 mapping showed that the repeatability of the segmentation was low to moderate in superficial parts of posterior femur and deep parts of posterior tibia.
The use of FS improved slightly repeatability of the cartilage segmentation in several regions and reduced the chemical shift artifacts. However, the regional heterogeneity in FS sequence introduced further uncertainties in T2 measurements
Hengitystahdistuksen merkitys rintasyövän sädehoidossa ja sydämen säteilyannoksen vähentämisessä
Rintasyöpä on yleisin syöpä Suomessa ja sitä esiintyy lähinnä naisilla, mutta myös muutama tapaus vuodessa esiintyy miehillä. Rintasyöpää hoidetaan usein osaresektiolla, johon yhdistetään sädehoito, mutta myös mastektomiaan voidaan yhdistää sädehoitoa. Sädehoidossa pitää huomioida terve kudos ja huolehtia siitä, että sädetettävän kohdealueen vieressä oleva terve kudos saa mahdollisimman vähän säteilyä. Toisaalta samalla kohdealueelle pitää saada tarpeeksi suuri säteilyannos, jotta sädehoito on tehokasta ja toimivaa.
Vasemman rinnan rintasyövän sädehoidossa täytyy ottaa huomioon sydämen sijainti. Vapaassa hengityksessä sydän sijaitsee hyvin lähellä vasenta rintaa eli lähellä sädetettävää aluetta. Sydän ja sen pinnalla kulkevat verisuonet voivat saada helposti suuren sädeannoksen, jollei tätä oteta huomioon sädehoidon annossuunnittelussa. Säderasitteesta voi seurata myöhemmin komplikaatioita ja siksi tähän ongelmaan on kehitetty hengitystahdistus tekniikoita, joista tässä tutkielmassa keskitytään DIBH -tekniikka (Deep Inspiration Breath-Hold). DIBH-tekniikassa potilas hengittää syvään sisään ja pidättää hengitystä hetken, jonka aikana vasenta rintaa säteilytetään. Syvällä sisäänhengityksellä sydämen ja vasemman rinnan väliin saadaan välimatkaa muutamia senttejä ja sydämeen kohdistuva sädeannos pienenee.
Tässä tutkielmassa päätavoitteena oli selvittää DIBH -tekniikan hyötyjä ja haittoja sekä vertailla DIBH -tekniikkaa vapaaseen hengitykseen, painottaen sydämen ja sydämen pinnalla olevan vasemman sepelvaltimon, Left Anterior Descending arteryn eli LAD:n, saamaa sädeannosta vasemman rinnan sädehoidossa.
Tutkimustuloksien perusteella DIBH-tekniikan käyttö vasemman rinnan rintasyövän sädehoidossa on suositeltavaa, mikäli potilas siihen kykenee. DIBH -tekniikan käyttö vaati potilailta hieman harjoittelua sekä siinä määrin hyvän perusterveydentilan, että noin 15–20 sekuntia pitkät syvät sisäänhengitykset onnistuvat ongelmitta. Lisäksi DIBH -tekniikan käyttö vaatii myös hoitohenkilökunnalta hieman enemmän aikaa ja vaivaa kuin vapaa hengitys, mutta hyödyt ovat huomattavat potilaan kannalta. Sydämen ja LAD:n keskiarvoiset sädeannokset laskevat DIBH-tekniikalla noin puoleen siitä, mitä ne olisivat vapaassa hengityksessä
Evidence for differential opioid µ- and µ-receptor regulation of heart rate in the conscious rat
The possibility that Opioid-induced tachycardia and bradycardia could be mediated by different subtypes of the ·receptor was studied in conscious Sprague-Dawley rats. The selective ·receptor agonist dermorphin and its analog, TAPS (Tyr-o-Arg-Phe-sarcosine), a putative -receptor agonist, were given centrally. Tyr-o-Arg-Phe-sarcosine increased the heart rate, the response being inversely correlated to the dose (an increase of 71 ± 22, 49 ± 14 and 30 ± 17 beats/min at doses of 0.3, 3 and 30 pmol, respectively). Dermorphin induced less clear changes in heart rate (maximum increase of 39 ± 14 beats/min at the dose of 1 pmol). Aftertreatment with the Jl 1-selective antagonist naloxonazine (NAZ), TAPS 30 pmol and dennorphin I pmol decreased heart rate by -22 ± 10 and -24 ± 7 bpm, respectively. The bradycardic effect oflarger doses of dennorphin was potentiated by NAZ (from -25 ± 8 to -97 ± 22 bpm) but abolished by the non-selective antagonist naloxone. These data suggest that the high affinity -opioid receptors mediate tachycardic responses and -receptors mediate bradycardic responses
Mechanism of central hemodynamic and sympathetic regulation by µ-opioid receptors: Effects of dermorphin in the conscious rat
The effects of i.c.v. administered dermorphin, a highly selective -opioid agonist, on cardiac function and renal, mesenteric and hindquarter blood ftow were studied in conscious rats. Core temperature, blood gases, arterial plasma levels of norepinephrine, epinephrine, dopamine, 3,4-dihydroxyphenylalanine and dihydroxyphenylacetic acid (DOPAC) also were examined. Cardiac output was rneasured using a thermodilution technique and regional blood ftows using directional pulsed Doppler velocimetry. Dermorphin, at doses of 0.1-100 nmol/kg, increased blood pressure and hindquarter blood flow, renal and mesenteric resistance, and core temperature. Higher doses (1-5 mol/kg) caused respiratory depression, acidosis, and shock despite profaund sympatho-adrenomedullary stimulation. Circulating Ieveis of catecholamines were significantly increased at the dermorphin doses of 0.1-1 00 nmol/kg. At the 100 nmol/kg dose, plasma levels of epinephrine, norepinephrine, the dopamine metabellte dihydroxyphenylacetic acid and the catecholamine precursor 3,4,-dihydroxyphenylalanine were increased by 2-15-fold. The data indicate that mu opioid receptor Stimulation exerts potent effects on cardiorespiratory functions, activates the sympathoadrenomedullary system and produces a pattem of blood flow changes consistent with the stress-induced •detense· response (skeletal muscle vasodilation and splanchnic vasoconstriction). Excessive mu opioid receptor Stimulation Ieads to shock due to respiratory and hemodynamic collapse
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