Importance of initial aortic properties on the evolving regional anisotropy, stiffness and wall thickness of human abdominal aortic aneurysms

Complementary advances in medical imaging, vascular biology and biomechanics promise to enable computational modelling of abdominal aortic aneurysms to play increasingly important roles in clinical decision processes. Using a finite-element-based growth and remodelling model of evolving aneurysm geometry and material properties, we show that regional variations in material anisotropy, stiffness and wall thickness should be expected to arise naturally and thus should be included in analyses of aneurysmal enlargement or wall stress. In addition, by initiating the model from best-fit material parameters estimated for non-aneurysmal aortas from different subjects, we show that the initial state of the aorta may influence strongly the subsequent rate of enlargement, wall thickness, mechanical behaviour and thus stress in the lesion. We submit, therefore, that clinically reliable modelling of the enlargement and overall rupture-potential of aneurysms may require both a better understanding of the mechanobiological processes that govern the evolution of these lesions and new methods of determining the patient-specific state of the pre-aneurysmal aorta (or correlation to currently unaffected portions thereof) through knowledge of demographics, comorbidities, lifestyle, genetics and future non-invasive or minimally invasive tests.     

Densified biomass can cost-effectively mitigate greenhouse gas emissions and address energy security in thermal applications

Regional supplies of biomass are currently being evaluated as feedstocks in energy applications to meet renewable portfolio (RPS) and low carbon fuel standards. We investigate the life cycle greenhouse gas (GHG) emissions and associated abatement costs resulting from using densified switchgrass for thermal and electrical energy. In contrast to the large and positive abatement costs for using biomass in electricity generation ($149/Mg CO(2)e) due to the low cost of coal and high feedstock and power plant operation costs, abatement costs for replacing fuel oil with biomass in thermal applications are large and negative (-$52 to -$92/Mg CO(2)e), resulting in cost savings. Replacing fuel oil with biomass in thermal applications results in least cost reductions compared to replacing coal in electricity generation, an alternative that has gained attention due to RPS legislation and the centralized production model most often considered in U.S. policy. Our estimates indicate a more than doubling of liquid fuel displacement when switchgrass is substituted for fuel oil as opposed to gasoline, suggesting that, in certain U.S. locations, such as the northeast, densified biomass would help to significantly decarbonize energy supply with regionally sourced feedstock, while also reducing imported oil. On the basis of supply projections from the recently released Billion Ton Report, there will be enough sustainably harvested biomass available in the northeast by 2022 to offset the entirety of heating oil demand in the same region. This will save NE consumers between $2.3 and $3.9 billion annually. Diverting the same resource to electricity generation would cost the region $7.7 billion per year. While there is great need for finding low carbon substitutes for coal power and liquid transportation fuels in the U.S., we argue that in certain regions it makes cost- (and GHG mitigation-) effective sense to phase out liquid heating fuels with locally produced biomass first.     

Exploring the anticancer properties of essential oils from family Lamiaceae

Lamiaceae is among the largest families of flowering plants with about 250 genera and over 7,000 species distributed around the world. It is considered as the important source of essential oils, for example, menthol, geraniol, eucalyptol, camphor and thymol. Therefore, it is imperative to study these economically important compounds under in vitro conditions for their sustainable and enhanced production. In addition to proven biological activities, essential oils from this family have recently been evaluated for anticancer activities and considered as a source of anticancer drugs. Mechanisms involved in the essential oils-mediated antiproliferative activity include cell cycle arrest, apoptosis and DNA repair mechanisms. Essential oils also act in the reduction of tumors, inhibiting metastasis and as anti-multidrug resistance molecules. The aim of this review is to assess the anticancer properties of essential oils obtained from different members of family Lamiaceae. The available reports on active components of essential oils and their effect on cancer type and cell line have been discussed. Biotechnological studies to improve the production of essential oils have also been highlighted. Various methods have been adopted to obtain essential oils under in vitro conditions from different plant species of family Lamiaceae, and their production is affected by culture conditions, cultivation mode, utilization of nutrient media and plant growth regulators. The literature survey suggests that essential oils obtained from family Lamiaceae have perspective for the development of new alternatives for disease treatment and prevention.     

“竹纤维”说法准确性的评析

<正>引言在2006年末至2007年,网络上出现大量商户销售声称使用竹纤维制作的服装。他们在广告中宣称竹纤维非常柔软,同时比棉纤维更易染色,并具有天然抗菌性能;而且由于生长过程中没有使用农药;要远比棉花纤维等其他纤维更环保。     

Burden and cost of gastroenteritis in a Canadian community

This study estimated the health burden and costs associated with gastroenteritis in the City of Hamilton (Ontario, Canada). The number of cases, number of different resource units used, and cost per resource unit were represented by probability distributions and point estimates. These were subsequently integrated in a stochastic model to estimate the overall burden and cost in the population and to depict the uncertainty of the estimates. The estimated mean annual cost per capita was Can dollar 115. The estimated mean annual cost per case was Can dollar 1,089 and was similar to other published figures. Gastroenteritis represented a significant burden in the study population, with costs high enough to justify prevention efforts. These results, currently the most accurate available estimates for a Canadian population, can inform future economic evaluations to determine the most cost effective measures for reducing the burden and cost of gastroenteritis in the community.     

Observations of mercury-containing aerosols

In situ analyses with a laser ionization mass spectrometer have shown that a large fraction of aerosols in the bottom few kilometers of the stratosphere contain small amounts of mercury (1). Electron microscopy of particles collected near the tropopause has also detected mercury. The distribution of mercury onto many particles, including those less than 20 nm in diameter, indicates that the mercury is from local condensation of mercury compounds onto particles rather than transport of mercury-rich aerosols from surface sources. Although the results are only semiquantitative, they suggest that most of the mercury in the lower stratosphere is converted into the particulate phase. Mercury-containing particles were present at both middle latitudes and the tropics in two seasons. There is therefore good reason to believe that particulate mercury above the tropopause is global and could affect the atmospheric lifetime of mercury. There are indications that bromine and/ or iodine may be involved in the conversion of mercury from the gas to particle phase. Measurements at altitudes below 5 km did not find mercury in any particles despite sampling some particles that clearly originated in the stratosphere. This indicates that the particulate mercury from the lower stratosphere may be volatile enough to evaporate or decompose once particles reach warmer temperatures.     

Role of Exogenous Oxytocin in Eliciting Milk Ejection in Dairy Cows

The efficacy of small doses of exogenous oxytocin in eliciting milk ejection was measured in eight lactating Holstein cows. Treatments comprised intravenous administration of .02, .05, .10, and .30 IU of oxytocin. The smallest dose of oxytocin that induced milk ejection in all cows was .10 IU. Administration of .10 and .30 IU produced greater peak rates of milk flow and shorter milking times. Ranges for these two variables were 2.9 to 3.9 kg/min and 4.8 to 5.6 min. Variations in milk yield (8.2 to 9.1 kg/milking) were not significant, but more fat was harvested after administration of the two higher doses. Differences in peak concentrations of serum oxytocin were 17.7 to 21.2 μU/ml. Differences in latent time before peak concentration was reached were 1.3 to 4.0 min.     

The yield,fatty acid composition and physical properties of milk fat obtained by feeding soya oil to dairy cows

The presence in the bovine mammary gland of a desaturase specific for the conversion of stearic to oleic acid allows the manipulation of the physical properties of milk fat by varying the dietary intake of C₁₆ and C₁₈ fatty acids. In particular, feeding the dairy cow an oil with a high C₁₈: C₁₆ ratio should allow the proportion of milk fat that is liquid at 5°C to be increased, with a consequent improvement in the low-temperature spreadability of butter. In this paper, the effect of feeding concentrate rations containing (a) soya oil as the free oil and as cracked soya beans; (b) various levels of soya oil, the ration being offered twice or 24-times daily, on the thermal properties of the milk fat and on the yield of milk constituents is examined in detail. Feeding ratios containing free soya oil greatly increased the proportion of milk fat liquid at 5°C, whereas cracked soya oil gave only slight increases. Proportion and yield of milk fat were decreased by feeding soya oil twice daily but were increased by continuous feeding.     

Susceptibility of Escherichia coli isolated from intramammary infections to phagocytosis by bovine neutrophils.

Thirteen Escherichia coli isolated from naturally occurring IMI were tested for susceptibility to phagocytosis by bovine blood neutrophils. Isolates were opsonized in pooled serum collected from nine healthy lactating cows. Bacteria isolated from IMI first diagnosed within 3 d after calving were more resistant to phagocytosis than were isolates from IMI originating during either the first half of the dry period or later during lactation. Duration of the IMI was negatively correlated with both phagocytic index and percentage of neutrophils phagocytizing within bacterial isolates from IMI originating at calving and during lactation. Phagocytosis was independent of duration of IMI within isolates from IMI originating during the first half of the dry period. Susceptibility to in vitro phagocytosis by neutrophils was not related to O antigen serotype, encapsulation, or growth in dry cow secretion.