Learning form Nature to improve the heat generation of iron-oxide nanoparticles for magnetic hyperthermia applications.

The performance of magnetic nanoparticles is intimately entwined with their structure, mean size and magnetic anisotropy. Besides, ensembles offer a unique way of engineering the magnetic response by modifying the strength of the dipolar interactions between particles. Here we report on an experimental and theoretical analysis of magnetic hyperthermia, a rapidly developing technique in medical research and oncology. Experimentally, we demonstrate that single-domain cubic iron oxide particles resembling bacterial magnetosomes have superior magnetic heating efficiency compared to spherical particles of similar sizes. Monte Carlo simulations at the atomic level corroborate the larger anisotropy of the cubic particles in comparison with the spherical ones, thus evidencing the beneficial role of surface anisotropy in the improved heating power. Moreover we establish a quantitative link between the particle assembling, the interactions and the heating properties. This knowledge opens new perspectives for improved hyperthermia, an alternative to conventional cancer therapies.

Gas analysis of exhumed cadavers buried for 30 years: a case report about long time alteration.

Due to important alteration caused by long time decomposition, the gases in human bodies buried for more than a year have not been investigated. For the first time, the results of gas analysis sampled from bodies recently exhumed after 30 years are presented. Adipocere formation has prevented the bodies from too important alteration, and gaseous areas were identified. The sampling was performed with airtight syringes assisted by multi-detector computed tomography (MDCT) in those specific areas. The important amount of methane (CH4), coupled to weak amounts of hydrogen (H2) and carbon dioxide (CO2), usual gaseous alteration indicators, have permitted to confirm methanogenesis mechanism for long period of alteration. H2 and CO2 produced during the first stages of the alteration process were consumed through anaerobic oxidation by methanogenic bacteria, generating CH4.

Carbon sources and polyethylene glycol on soybean somatic embryo conversion

Somatic embryogenesis is an efficient method for the production of target cells for soybean genetic transformation. However, this method still offers low percentages of plant regeneration, and perhaps is related to the maturation process and high morphological abnormalities of the matured embryos. This study aimed to identify a maturation medium that could contribute to the outcome of more efficient plant regeneration results. Embryogenic clusters, derived from cotyledons of immature seeds of the soybean cultivars Bragg and IAS5, were used as starting material for embryos development. Different maturation media were tested by using 6% maltose, 3% sucrose or 6% sucrose, combined with or without 25 g L-1 of the osmotic regulator polyethylene glycol (PEG-8000). The histodifferentiated embryos were quantified and classified in morphological types. Percentages of converted embryos were analyzed. Cultivar Bragg resulted in higher matured embryo quantities, but lower percentages were obtained for the conversion in comparison to cultivar IAS5. While the addition of PEG did not affect the number of embryos converted into plants, 6% sucrose enhanced the conversion percent significantly.

2009 Cancer in Iowa Report: Data Sources, 2009

Cancer is a reportable disease as stated in the Iowa Administrative Code. Cancer data are collected by the State Health Registry of Iowa, located at The University of Iowa in the College of Public Health’s Department of Epidemiology. The staff includes more than 50 people. Half of them, situated throughout the state, regularly visit hospitals, clinics, and medical laboratories in Iowa and neighboring states to collect cancer data. A follow-up program tracks more than 99 percent of the cancer survivors diagnosed since 1973. This program provides regular updates for follow-up and survival. The Registry maintains the confidentiality of the patients, physicians, and hospitals providing data. In 2009 data will be collected on an estimated 16,000 new cancers among Iowa residents. In situ cases of bladder cancer are included in the estimates for bladder cancer, to be in agreement with the definition of reportable cases of the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute. Since 1973 the Iowa Registry has been funded primarily by the SEER Program of the National Cancer Institute. Iowa represents rural and Midwestern populations and provides data included in many National Cancer Institute publications. Beginning in 1990 between 5 and 10 percent of the Registry’s annual operating budget has been provided by the state of Iowa. Beginning in 2003, the University of Iowa has been providing cost-sharing funds. The Registry also receives funding through grants and contracts with university, state, and national researchers investigating cancer-related topics.

Development of Non-Petroleum Based Binders for Use in Flexible Pavements, TR-594, 2010

Most bituminous adhesives or binders that are used for pavement materials are derived primarily from fossil fuels. With petroleum oil reserves becoming depleted and the drive to establish a bio-based economy, there is a push to produce binders from alternative sources, particularly from biorenewable resources. However, until now, no research has studied the applicability of utilizing bio-oils as a bitumen replacement (100% replacement) in the pavement industry. The main objective of this research was to test various properties of bio-oils in order to determine the applicability of using bio-oils as binders in the pavement industry. The overall conclusions about the applicability of using bio-oils as bio-binders in the pavement industry can be summarized as follows: 1. Bio-oils cannot be used as bio-binders/pavement materials without any heat pre-treatment/upgrading procedure. 2. Current testing standards and specifications, especially Superpave procedures, should be modified to comply with the properties of bio-binders. 3. The temperature range of the viscous behavior for bio-oils may be lower than that of bitumen binders by about 30°–40° C. 4. The rheological properties of the unmodified bio-binders vary in comparison to bitumen binders, but the rheological properties of these modified bio-binders change significantly upon adding polymer modifiers. 5. The high-temperature performance grade for the developed bio-binders may not vary significantly from that of the bitumen binders, but the low-temperature performance grade may vary significantly

Bone histomorphometry of broilers submitted to different phosphorus sources in growing and finisher rations

The objective of this work was to identify alterations in the histomorphology of the cortical bone tissue of broilers submitted to growing and finisher rations formulated with five different sources of phosphorus: dicalcium phosphate, simple superphosphate, triple superphosphate, monoammonium phosphate and Araxá rock phosphate. Histological images had their components segmented, and were called regions of interest (ROI). Images were analyzed through developed algorithms, using the SCILAB mathematical environment. Eleven features were considered in order to obtain a complete description of the bone images: percentage of bone by area, ROI area, ROI perimeters, ROI elongation, ROI angle and their respective standard deviations, besides entropy of ROI angles and a texture-oriented measure (lacunarity). The substitution of dicalcium phosphate in growing and finisher rations for any other tested source of phosphorus caused significant changes on the hystomorphology of the cortical broilers bones, for example: diminution of bone percentage by area, increase of lacuna area and worse matrix homogeneity. Changes were more pronounced in the Araxá rock phosphate treatments, with the highest fluorine content, than in simple superphosphate, triple superphosphate and monoammonium phosphate treatments, which were similar.

Membrane lipid composition affects plant heat sensing and modulates Ca ( 2+) -dependent heat shock response.

Understanding how plants sense and respond to heat stress is central to improve crop tolerance and productivity. Recent findings in Physcomitrella patensdemonstrated that the controlled passage of calcium ions across the plasma membrane regulates the heat shock response (HSR). To investigate the effect of membrane lipid composition on the plant HSR, we acclimated P. patens to a slightly elevated yet physiological growth temperature and analysed the signature of calcium influx under a mild heat shock. Compared to tissues grown at 22°C, tissues grown at 32°C had significantly higher overall membrane lipid saturation level and, when submitted to a short heat shock at 35°C, displayed a noticeably reduced calcium influx and a consequent reduced heat shock gene expression. These results show that temperature differences, rather than the absolute temperature, determine the extent of the plant HSR and indicate that membrane lipid composition regulates the calcium-dependent heat-signaling pathway.

La conception du "dialogue" de Mikhaïl Bakhtine et ses sources sociologiques (l'exemple des "Problèmes de l'oeuvre de Dostoïevski" [1929])

Résumé: L'article porte sur la conception du « dialogue » de Mikhaïl Bakhtine dans laquelle s'articulent deux groupes d'idées : 1) la notion de « dialogue » en tant que forme de l'interaction verbale interindividuelle (l'échange des répliques) et 2) la notion de « dialogisme » comme principe qui prévoit un rapport particulier entre le « Moi » (le « Je ») et l'« Autrui ». Son but consiste à 1) analyser ces notions au sens de Bakhtine, en s'appuyant sur le texte russe des Problèmes de l'oeuvre de Dostoïevski (1929) ; et à 2) montrer leurs sources sociologiques (principalement russes). Il y est également question de la notion de « polyphonie » introduite par Bakhtine pour caractériser la particularité de la construction des romans de Dostoïevski et d'une facette des réflexions bakhtiniennes sur le rôle de la « polyphonie » chez Dostoïevski, contenues dans le texte russe de 1929, abandonnées dans la version de 1963 et, de ce fait, méconnues des chercheurs francophones n'ayant accès qu'à la traduction des Problèmes de la poétique de Dostoïevski (1963). This paper examines the conception of "dialogue" elaborated by Mikhaïl Bakhtin in which are articulated two groups of ideas : 1) the notion of "dialogue" as a form of verbal interindividual interaction (an exchange of speech) and 2) the notion of "dialogism" as a principle which implies a relation between the "Me" (the "I") and the "Other". Its aim is 1) to analyse these notions in the sens of Bakhtin, on the base of russian text of Problems of Dostoyevsky's Art (1929) and 2) to show their sociological (mainly russian) origins. The paper also deals with the notion of "polyphony" introduced by Bakhtin to characterize the particularity of Dostoyevsky's method of constructing novels and with one facet of bakhtinian reflections (expounded in the text of 1929, omitted in the version of 1963, thereby unknown by francophone researchers who have access only to the translation of Problems of Dostoyevsky's Poetics (1963)) on the role of "polyphony" in Dostoyevsky's works.

Sources d'exposition aux phtalates dans une unité de soins néonatals [Phthalate exposure in the neonatal intensive care unit].

There are growing concerns on long-term health consequences, notably on fertility rates, of plasticizers such as phthalates. While di(2-ethylhexyl)phthalate (DEHP) is currently used in several medical devices, newborns in the neonatal intensive care unit are both more exposed and more vulnerable to DEHP. The objectives of this study were to identify, count, and describe possible sources of DEHP in a neonatal care unit. Our method consisted in the listing and the inspection of the information on packaging, complemented by contact with manufacturers when necessary. According to the results, 6% of all products and 10% of plastic products contained some DEHP; 71% of these involved respiratory support devices. A vast majority of the items showed no information on the content of DEHP. Further research is needed, particularly to determine the effects of such an early exposure and to study and develop safer alternatives.

A Thermokinetic approach to radiative heat transfer at the nanoscale

Radiative heat exchange at the nanoscale presents a challenge for several areas due to its scope and nature. Here, we provide a thermokinetic description of microscale radiative energy transfer including phonon-photon coupling manifested through a non-Debye relaxation behavior. We show that a lognormal-like distribution of modes of relaxation accounts for this non-Debye relaxation behavior leading to the thermal conductance. We also discuss the validity of the fluctuation-dissipation theorem. The general expression for the thermal conductance we obtain fits existing experimental results with remarkable accuracy. Accordingly, our approach offers an overall explanation of radiative energy transfer through micrometric gaps regardless of geometrical configurations and distances.