899 resultados para additive representability
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BACKGROUND AND AIMS: Parental history (PH) and genetic risk scores (GRSs) are separately associated with coronary heart disease (CHD), but evidence regarding their combined effects is lacking. We aimed to evaluate the joint associations and predictive ability of PH and GRSs for incident CHD. METHODS: Data for 4283 Caucasians were obtained from the population-based CoLaus Study, over median follow-up time of 5.6 years. CHD was defined as incident myocardial infarction, angina, percutaneous coronary revascularization or bypass grafting. Single nucleotide polymorphisms for CHD identified by genome-wide association studies were used to construct unweighted and weighted versions of three GRSs, comprising of 38, 53 and 153 SNPs respectively. RESULTS: PH was associated with higher values of all weighted GRSs. After adjustment for age, sex, smoking, diabetes, systolic blood pressure, low and high density lipoprotein cholesterol, PH was significantly associated with CHD [HR 2.61, 95% CI (1.47-4.66)] and further adjustment for GRSs did not change this estimate. Similarly, one standard deviation change of the weighted 153-SNPs GRS was significantly associated with CHD [HR 1.50, 95% CI (1.26-1.80)] and remained so, after further adjustment for PH. The weighted, 153-SNPs GRS, but not PH, modestly improved discrimination [(C-index improvement, 0.016), p = 0.048] and reclassification [(NRI improvement, 8.6%), p = 0.027] beyond cardiovascular risk factors. After including both the GRS and PH, model performance improved further [(C-index improvement, 0.022), p = 0.006]. CONCLUSION: After adjustment for cardiovascular risk factors, PH and a weighted, polygenic GRS were jointly associated with CHD and provided additive information for coronary events prediction.
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UNLABELLED: Trabecular bone score (TBS) seems to provide additive value on BMD to identify individuals with prevalent fractures in T1D. TBS did not significantly differ between T1D patients and healthy controls, but TBS and HbA1c were independently associated with prevalent fractures in T1D. A TBS cutoff <1.42 reflected prevalent fractures with 91.7 % sensitivity and 43.2 % specificity. INTRODUCTION: Type 1 diabetes (T1D) increases the risk of osteoporotic fractures. TBS was recently proposed as an indirect measure of bone microarchitecture. This study aimed at investigating the TBS in T1D patients and healthy controls. Associations with prevalent fractures were tested. METHODS: One hundred nineteen T1D patients (59 males, 60 premenopausal females; mean age 43.4 ± 8.9 years) and 68 healthy controls matched for gender, age, and body mass index (BMI) were analyzed. The TBS was calculated in the lumbar region, based on two-dimensional (2D) projections of DXA assessments. RESULTS: TBS was 1.357 ± 0.129 in T1D patients and 1.389 ± 0.085 in controls (p = 0.075). T1D patients with prevalent fractures (n = 24) had a significantly lower TBS than T1D patients without fractures (1.309 ± 0.125 versus 1.370 ± 0.127, p = 0.04). The presence of fractures in T1D was associated with lower TBS (odds ratio = 0.024, 95 % confidence interval (CI) = 0.001-0.875; p = 0.042) but not with age or BMI. TBS and HbA1c were independently associated with fractures. The area-under-the curve (AUC) of TBS was similar to that of total hip BMD in discriminating T1D patients with or without prevalent fractures. In this set-up, a TBS cutoff <1.42 discriminated the presence of fractures with a sensitivity of 91.7 % and a specificity of 43.2 %. CONCLUSIONS: TBS values are lower in T1D patients with prevalent fractures, suggesting an alteration of bone strength in this subgroup of patients. Reliable TBS cutoffs for the prediction of fracture risk in T1D need to be determined in larger prospective studies.
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AMPK, a master metabolic switch, mediates the observed increase of glucose uptake in locomotory muscle of mammals during exercise. AMPK is activated by changes in the intracellular AMP:ATP ratio when ATP consumption is stimulated by contractile activity but also by AICAR and metformin, compounds that increase glucose transport in mammalian muscle cells. However, the possible role of AMPK in the regulation of glucose metabolism in skeletal muscle has not been investigated in other vertebrates, including fish. In this study, we investigated the effects of AMPK activators on glucose uptake, AMPK activity, cell surface levels of trout GLUT4 and expression of GLUT1 and GLUT4 as well as the expression of enzymes regulating glucose disposal and PGC1α in trout myotubes derived from a primary muscle cell culture. We show that AICAR and metformin significantly stimulated glucose uptake (1.6 and 1.3 fold, respectively) and that Compound C completely abrogated the stimulatory effects of the AMPK activators on glucose uptake. The combination of insulin and AMPK activators did not result in additive nor synergistic effects on glucose uptake. Moreover, exposure of trout myotubes to AICAR and metformin resulted in an increase in AMPK activity (3.8 and 3 fold, respectively). We also provide evidence suggesting that stimulation of glucose uptake by AMPK activators in trout myotubes may take place, at least in part, by increasing the cell surface and mRNA levels of trout GLUT4. Finally, AICAR increased the mRNA levels of genes involved in glucose disposal (hexokinase, 6-phosphofructokinase, pyruvate kinase and citrate synthase) and mitochondrial biogenesis (PGC-1α) and did not affect glycogen content or glycogen synthase mRNA levels in trout myotubes. Therefore, we provide evidence, for the first time in non-mammalian vertebrates, suggesting a potentially important role of AMPK in stimulating glucose uptake and utilization in the skeletal muscle of fish.
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Rapid manufacturing is an advanced manufacturing technology based on layer-by-layer manufacturing to produce a part. This paper presents experimental work carried out to investigate the effects of scan speed, layer thickness, and building direction on the following part features: dimensional error, surface roughness, and mechanical properties for DMLS with DS H20 powder and SLM with CL 20 powder (1.4404/AISI 316L). Findings were evaluated using ANOVA analysis. According to the experimental results, build direction has a significant effect on part quality, in terms of dimensional error and surface roughness. For the SLM process, the build direction has no influence on mechanical properties. Results of this research support industry estimating part quality and mechanical properties before the production of parts with additive manufacturing, using iron-based powders
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Proteases are important for regulating multiple tumorigenic processes, including angiogenesis, tumor growth, and invasion. Elevated protease expression is associated with poor patient prognosis across numerous tumor types. Several multigene protease families have been implicated in cancer, including cysteine cathepsins. However, whether individual family members have unique roles or are functionally redundant remains poorly understood. Here we demonstrate stage-dependent effects of simultaneously deleting cathepsin B (CtsB) and CtsS in a murine pancreatic neuroendocrine tumor model. Early in tumorigenesis, the double knockout results in an additive reduction in angiogenic switching, whereas at late stages, several tumorigenic phenotypes are unexpectedly restored to wild-type levels. We identified CtsZ, which is predominantly supplied by tumor-associated macrophages, as the compensatory protease that regulates the acquired tumor-promoting functions of lesions deficient in both CtsB and CtsS. Thus, deletion of multiple cathepsins can lead to stage-dependent, compensatory mechanisms in the tumor microenvironment, which has potential implications for the clinical consideration of selective versus pan-family cathepsin inhibitors in cancer.
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BACKGROUND: Several distributions of country-specific blood pressure (BP) percentiles by sex, age, and height for children and adolescents have been established worldwide. However, there are no globally unified BP references for defining elevated BP in children and adolescents, which limits international comparisons of the prevalence of pediatric elevated BP. We aimed to establish international BP references for children and adolescents by using 7 nationally representative data sets (China, India, Iran, Korea, Poland, Tunisia, and the United States). METHODS AND RESULTS: Data on BP for 52 636 nonoverweight children and adolescents aged 6 to 19 years were obtained from 7 large nationally representative cross-sectional surveys in China, India, Iran, Korea, Poland, Tunisia, and the United States. BP values were obtained with certified mercury sphygmomanometers in all 7 countries by using standard procedures for BP measurement. Smoothed BP percentiles (50th, 90th, 95th, and 99th) by age and height were estimated by using the Generalized Additive Model for Location Scale and Shape model. BP values were similar between males and females until the age of 13 years and were higher in males than females thereafter. In comparison with the BP levels of the 90th and 95th percentiles of the US Fourth Report at median height, systolic BP of the corresponding percentiles of these international references was lower, whereas diastolic BP was similar. CONCLUSIONS: These international BP references will be a useful tool for international comparison of the prevalence of elevated BP in children and adolescents and may help to identify hypertensive youths in diverse populations.
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Current obesity prevention strategies recommend increasing daily physical activity, assuming that increased activity will lead to corresponding increases in total energy expenditure and prevent or reverse energy imbalance and weight gain [1-3]. Such Additive total energy expenditure models are supported by exercise intervention and accelerometry studies reporting positive correlations between physical activity and total energy expenditure [4] but are challenged by ecological studies in humans and other species showing that more active populations do not have higher total energy expenditure [5-8]. Here we tested a Constrained total energy expenditure model, in which total energy expenditure increases with physical activity at low activity levels but plateaus at higher activity levels as the body adapts to maintain total energy expenditure within a narrow range. We compared total energy expenditure, measured using doubly labeled water, against physical activity, measured using accelerometry, for a large (n = 332) sample of adults living in five populations [9]. After adjusting for body size and composition, total energy expenditure was positively correlated with physical activity, but the relationship was markedly stronger over the lower range of physical activity. For subjects in the upper range of physical activity, total energy expenditure plateaued, supporting a Constrained total energy expenditure model. Body fat percentage and activity intensity appear to modulate the metabolic response to physical activity. Models of energy balance employed in public health [1-3] should be revised to better reflect the constrained nature of total energy expenditure and the complex effects of physical activity on metabolic physiology.
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The advent of simple and affordable tools for molecular identification of novel insect invaders and assessment of population diversity has changed the face of invasion biology in recent years. The widespread application of these tools has brought with it an emerging understanding that patterns in biogeography, introduction history and subsequent movement and spread of many invasive alien insects are far more complex than previously thought. We reviewed the literature and found that for a number of invasive insects, there is strong and growing evidence that multiple introductions, complex global movement, and population admixture in the invaded range are commonplace. Additionally, historical paradigms related to species and strain identities and origins of common invaders are in many cases being challenged. This has major consequences for our understanding of basic biology and ecology of invasive insects and impacts quarantine, management and biocontrol programs. In addition, we found that founder effects rarely limit fitness in invasive insects and may benefit populations (by purging harmful alleles or increasing additive genetic variance). Also, while phenotypic plasticity appears important post-establishment, genetic diversity in invasive insects is often higher than expected and increases over time via multiple introductions. Further, connectivity among disjunct regions of global invasive ranges is generally far higher than expected and is often asymmetric, with some populations contributing disproportionately to global spread. We argue that the role of connectivity in driving the ecology and evolution of introduced species with multiple invasive ranges has been historically underestimated and that such species are often best understood in a global context.
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The macroscopic effects caused by sun radiation and the mankind-nature interactions in a ecosystem are firstly presented. However, the importance of calorimetric determinations to clarify some phenomena related to the living microorganism populations and their interactions with the food additive or inhibitor agents are reported. The collect values illustrate the occurence a great deal of effects in this microscopic world. For this subject, the reachest Latosol soil was selected due to the content of organic matter and consequently in microorganisms. Microbial activity was stimulated by addition of glucose, which showed to be the best nutrient source. Inhibitory effect was detected with many compounds used in the agriculture like some herbicides and fungicides. Although the assays are based on the use of the microcalorimetry, other techniques like respirometry contributes strongly to the understanding of the ecosystem. The main objective in this exposition is to stimulate by means of many interesting examples, the importance of preserving the environment in order to establish direct analogies by using the Chemistry in the daily life.
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Genome-wide linkage studies have identified the 9q22 chromosomal region as linked with colorectal cancer (CRC) predisposition. A candidate gene in this region is transforming growth factor beta receptor 1 (TGFBR1). Investigation of TGFBR1 has focused on the common genetic variant rs11466445, a short exonic deletion of nine base pairs which results in truncation of a stretch of nine alanine residues to six alanine residues in the gene product. While the six alanine (*6A) allele has been reported to be associated with increased risk of CRC in some population based study groups this association remains the subject of robust debate. To date, reports have been limited to population-based case-control association studies, or case-control studies of CRC families selecting one affected individual per family. No study has yet taken advantage of all the genetic information provided by multiplex CRC families. Methods: We have tested for an association between rs11466445 and risk of CRC using several family-based statistical tests in a new study group comprising members of non-syndromic high risk CRC families sourced from three familial cancer centres, two in Australia and one in Spain. Results: We report a finding of a nominally significant result using the pedigree-based association test approach (PBAT; p = 0.028), while other family-based tests were non-significant, but with a p-value < 0.10 in each instance. These other tests included the Generalised Disequilibrium Test (GDT; p = 0.085), parent of origin GDT Generalised Disequilibrium Test (GDT-PO; p = 0.081) and empirical Family-Based Association Test (FBAT; p = 0.096, additive model). Related-person case-control testing using the 'More Powerful' Quasi-Likelihood Score Test did not provide any evidence for association (M-QL5; p = 0.41). Conclusions: After conservatively taking into account considerations for multiple hypothesis testing, we find little evidence for an association between the TGFBR1*6A allele and CRC risk in these families. The weak support for an increase in risk in CRC predisposed families is in agreement with recent meta-analyses of case-control studies, which estimate only a modest increase in sporadic CRC risk among 6*A allele carriers.
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Tämän työn tavoitteena oli löytää keinot taivekartongin riittävän z-suuntaisen lujuuden saavuttamiseksi tilanteessa, jossa runkokerrokseen annosteltavan hylyn määrää joudutaan pysyvästi vähentämään. Työn kirjallisuusosassa selvitettiin taivekartongin tärkeimmät ominaisuudet, joista tarkemmin tarkasteltiin palstautumislujuutta ja siihen vaikuttavia tekijöitä. Lisäksi käytiin läpi palstautumislujuuden mittausmenetelmät. Merkittävimpiä teoriaosassa käsiteltyjä palstautumislujuuteen vaikuttavia tekijöitä olivat massojen käsittely ja annostelu, kuivalujalisäaineiden käyttö sekä rainanmuodostus. Hylyn annosteluosuuden pienentäminen vähensi taivekartongin paksuussuuntaista lujuutta ja runkomassan vedenpoistovastusta, mutta samanaikaisesti lisääntyivät kartongin paksuus ja taivutusjäykkyys. Hylyn vähäisemmän käytön seurauksena menetettyä lujuutta ei pystytty palauttamaan hylyn jauhatuksen määrää lisäämällä, eikä kartonkikoneen runkoviiraosan vedenpoistoon vaikuttamalla. Kun hylyn annosteluosuus laskettiin 20 %:in, saavutettiin runkokerroksen riittävä lujuus ainoastaan runkomassan pääkomponenttina käytettävän hiokemassaseoksen jauhatusastetta nostamalla tai korvaamalla pieni osa hiokkeesta hyvin hienoksi jauhetulla mäntysellulla. Hiokkeen freeness oli laskettava tasolta 300 ml CSF tasolle 250 ml CSF. Vastaavasti mäntysellu oli jauhettava hyvin pitkälle (°SR 74) tai annosteluosuuden oli oltava vähintään 2 %, jolloin jauhatusaste °SR 49 oli riittävä. Vähäisemmällä hylyn käytöllä saavutettu etu vedenpoistossa saatettaisiin menettää näiden toimenpiteiden vaikutuksesta.
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In this work we obtained microporous and mesoporous silica membranes by sol-gel processing. Tetraethylortosilicate (TEOS) was used as precursor. Nitric acid was used as catalyst. In order to study the affect of N,N-dimethylformamide (NDF) as drying additive, we used a molar ratio TEOS/NDF of 1/3. The performance of N,N-dimethylformamide was evaluated through monolithicity measurements. The structural evolutions occurring during the sol-gel transition and in the interconnected network of the membranes during thermal treatment were monitored by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses and nitrogen sorption. We noted that in the presence of N,N-dimethylformamide, polymerization goes through a temporary stabilization of oligomers. The Si-O(H) bonds are stronger and belong to a more cross-linked structure for the N,N-dimethylformamide containing sol. The membranes obtained in the presence of N,N-dimethylformamide have larger surface area and its pore structure is in the range of mesoporous. The membranes obtained without additive have pore structure in the range of microporous.
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Fine powders of minerals are used commonly in the paper and paint industry, and for ceramics. Research for utilizing of different waste materials in these applications is environmentally important. In this work, the ultrafine grinding of two waste gypsum materials, namely FGD (Flue Gas Desulphurisation) gypsum and phosphogypsum from a phosphoric acid plant, with the attrition bead mill and with the jet mill has been studied. The ' objective of this research was to test the suitability of the attrition bead mill and of the jet mill to produce gypsum powders with a particle size of a few microns. The grinding conditions were optimised by studying the influences of different operational grinding parameters on the grinding rate and on the energy consumption of the process in order to achieve a product fineness such as that required in the paper industry with as low energy consumption as possible. Based on experimental results, the most influential parameters in the attrition grinding were found to be the bead size, the stirrer type, and the stirring speed. The best conditions, based on the product fineness and specific energy consumption of grinding, for the attrition grinding process is to grind the material with small grinding beads and a high rotational speed of the stirrer. Also, by using some suitable grinding additive, a finer product is achieved with a lower energy consumption. In jet mill grinding the most influential parameters were the feed rate, the volumetric flow rate of the grinding air, and the height of the internal classification tube. The optimised condition for the jet is to grind with a small feed rate and with a large rate of volumetric flow rate of grinding air when the inside tube is low. The finer product with a larger rate of production was achieved with the attrition bead mill than with the jet mill, thus the attrition grinding is better for the ultrafine grinding of gypsum than the jet grinding. Finally the suitability of the population balance model for simulation of grinding processes has been studied with different S , B , and C functions. A new S function for the modelling of an attrition mill and a new C function for the modelling of a jet mill were developed. The suitability of the selected models with the developed grinding functions was tested by curve fitting the particle size distributions of the grinding products and then comparing the fitted size distributions to the measured particle sizes. According to the simulation results, the models are suitable for the estimation and simulation of the studied grinding processes.
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Gonadal somatic cell and adrenocortical endocrine tumors are rare. The incidence of adrenocortical carcinomas is only 1-2/1000000 a year. However, they are aggressive, especially in adulthood and currently surgery is the only curative treatment. Cytotoxic agents are in use in advanced cancers, but side effects and multidrug resistance are often problems. Thus there is a need for novel curative treatment methods. In contrast, ovarian granulosa cell tumors and testicular Leydig cell tumors are usually benign, especially at a younger age. The aim of the present thesis was to study a novel targeted treatment method through luteinizing hormone/chorionic gonadotropin receptor (LHCGR) in a transgenic mouse tumor model. The cytotoxic agent was lytic peptide Hecate-CGbeta conjugate where 23 amino acid Hecate, a synthetic form of honeybee venom melittin, was conjugated to 15 amino acid fragment of human chorionic gonadotropin β subunit. Lytic peptides are known to act only on negatively charged cells, such as bacteria and cancer cells and hereby, due to hCGbeta fragment, the conjugate is able to bind directly to LHCGR bearing cancer cells, saving the healthy ones. The experiments were carried out in inhibin-alpha-Simian Virus 40-T-antigen transgenic mice that are known to express LHCGR-bearing gonadal tumors, namely Leydig and granulosa cell tumors by 100% penetrance. If the mice are gonadectomized prepubertally they form adrenocortical tumors instead. Transgenic and wild type mice were treated for three consecutive weeks with control vehicle, Hecate or Hecate-CGbeta conjugate. GnRH antagonist or estradiol was given to a group of mice with or without Hecate-CGbeta conjugate to analyze the additive role of gonadotropin blockage in adrenocortical tumor treatment efficacy. Hecate-CGbeta conjugate was able to diminish the gonadal and adrenal tumor size effectively in males. No treatment related side effects were found. Gonadotropin blockage through GnRH antagonist was the best treatment in female adrenal tumors. The mode of cell death by Hecate-CGbeta conjugate was proven to be through necrosis. LHCGR and GATA-4 were co-expressed in tumors, where the treatment down-regulated their expression simultaneously, suggesting their possible use as tumor markers. In conclusion, the present thesis showed that Hecate-CGbeta conjugate targets its action selectively through LHCGR and selectively kills the LHCGR bearing tumor cells. It works both in gonadal somatic and in ectopic LHCGR bearing adrenal tumors. These results establish a more general principle that receptors expressed ectopically in malignant cells can be exploited in targeted cytotoxic therapies without affecting the normal healthy cells.
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Poly (ethylene) glycol (PEG) and bovine serum albumin (BSA), as additive agents, were used to enhance the activity of immobilized microbial lipase in organic solvent. Controlled pore silica (CPS) was selected as matrix and different immobilization procedures were evaluated: directly lipase binding on CPS and simultaneous addition of lipase and additive agent on the same support. The highest coupling yield (59.6%) was attained when the immobilization procedure was performed at lipase loading of 150 U/g support in the presence of PEG-1.500. This immobilized system was used in esterification reactions under repeated batch cycles and the biocatalyst half-life was found to increase 2.7 times when compared with the control.