Thermally Responsive Selenide-containing Materials Based on Transalkylation of Selenonium Salts.

Covalent adaptable networks (CANs) possess unique properties as a result of their internal dynamic bonds, such as self-healing and reprocessing abilities. In this study, we report a thermally responsive C-Se dynamic covalent chemistry (DCC) that relies on the transalkylation exchange between selenonium salts and selenides, which undergo a fast transalkylation reaction in the absence of any catalyst. Additionally, we demonstrate the presence of a dissociative mechanism in the absence of selenide groups. After incorporation of this DCC into selenide-containing polymer materials, it was observed that the cross-linked networks display varying dynamic exchange rates when using different alkylation reagents, suggesting that the reprocessing capacity of selenide-containing materials can be regulated. Also, by incorporating selenonium salts into polymer materials, we observed that the materials exhibited good healing ability at elevated temperatures as well as excellent solvent resistance at ambient temperature. This novel dynamic covalent chemistry thus provides a straightforward method for the healing and reprocessing of selenide-containing materials.

Covalent Fluorination Strategies for the Surface Modification of Polydienes.

Nonreactive additives are widely applied to enhance polymer properties but can leach out of the material over time. In this work, two essentially different fluorinated additives bearing a triazolinedione moiety are synthesized and grafted on several polydiene backbones (acrylonitrile-butadiene-styrene, styrene-butadiene, and styrene-isoprene-styrene (SIS) copolymers), either by dip-coating or by reaction in solution. The resulting polymers are analyzed by contact angle goniometry, size exclusion chromatography, and NMR, infrared, and X-ray photoelectron spectroscopy. Independent of the modification procedure, the fluorophilic perfluoroalkyl additive is found at the material surface, thereby yielding a more hydrophobic surface. For SIS thermoplastic elastomers, for example, contact angles up to 125° can be obtained.

2D-DIGE proteomic analysis of changes in estrogen/progesterone-induced rat breast hyperplasia upon treatment with the Mongolian remedy RuXian-I.

RuXian-I has traditionally been used as a remedy for breast hyperplasia in the Inner Mongolia Autonomous Region of China. As a first step toward the investigation of biomarkers associated with RuXian-I treatment, a proteome-wide analysis of rat breast tissue was conducted. First, rat breast hyperplasia was induced by injection of estradiol and progesterone. After treatment with RuXian-I, there is a marked decrease in the hyperplasia, as can be shown by decreases in the nipple diameter and the pathological changes in breast. Subsequently, we used an approach that integrates size-based 2D-DIGE, MALDI-TOF/TOF-MS, and bioinformatics to analyze data from the control group, the model group and the RuXian-I treatment group. Using this approach, seventeen affected proteins were identified. Among these, 15 (including annexin A1, annexin A2, superoxide dismutase [Mn], peroxiredoxin-1, translationally-controlled tumor protein and a B-crystallin) were significantly up-regulated in the model group and down-regulated upon treatment with RuXian-I, and two (Tpil protein and myosin-4) have the opposite change trend. The expression of annexin A1 was confirmed using immunohistochemistry. The expression of superoxide dismutase (SOD) activity was confirmed biochemically. These results indicated that RuXian-I treats rat breast hyperplasia through regulation of cell cycle, immune system, metabolic, signal transduction, etc. The differential expressions of these proteins (annexin A1, superoxide dismutase [Mn], alpha B-crystallins and translationally controlled tumor protein, among others) were associated with occurrence and metastasis of breast cancer. These findings might provide not only far-reaching valuable insights into the mechanism of RuXian-I action, but also leads for prognosis and diagnosis of breast hyperplasia and breast cancer.

[National information campaigns on depression. A biopsychosocial anthropology?]. / Les campagnes nationales d'information sur la dépression. Une anthropologie biopsychosociale?

INTRODUCTION: Information and prevention campaigns are privileged tools for public health institutions in their risk reduction policies concerning heath disorders and their consequences. Mental health in general, and depression in particular, have been the focus of several public campaigns in different countries for 20 years. AIM OF THE STUDY: The aim of this paper is to analyse depression campaign messages, to highlight their underlying logics and to show some of their effects, in particular in relation to contextual conflicts between professionals that possibly emerge because of these campaigns. MATERIAL: Previous depression campaign materials were analysed, and the recent French campaign launched in November 2007 was the subject of specific attention. RESULTS: Common messages of the campaigns are centred on the prevention of emergence, recurrence, worsening and individual, social and economic consequences of depressive disorders. Depression is always presented as "a disease"; a position which differs from international classifications describing depression as "a disorder", a much less affirmative statement. This choice, which has important "performance" values is based upon several factors including the difficulty to "popularise" psychological technology, a consensus resulting from a political struggle between professionals, a reaction to the current norms of autonomy implying a new set of rights and responsibilities from and towards the people who are "sick", and the importance given to the reduction of stigmatisation from which the "mentally ill" suffer. From all of these aspects appears a logic of "dementalisation" corresponding to a "deficit" model, in which depression is presented as something external to the individual, and where treatment is supposed to "fix" the deficit. DISCUSSION: The French campaign shares many of those fundamental characteristics: prevalence, seriousness of the disease's consequences, low level of services use, preference for biological monoaminergic theories, and environmental risk factors to explain the disease (an aetiology which is more bioenvironmental than really biopsychosocial), presentation of the main chemotherapeutics and psychological treatments, referring first to a general practitioner, importance of reducing stigmatisation, and presentation of depression as a disease. However, the French campaign differs from other campaigns in its use of an organising concept for the symptoms (slowing down) and a more precise description of the frontiers between normal and pathological functioning. Furthermore, beyond the usual biological and environmental elements, greater importance is given to the psychological mechanisms and to phenomena that are not only in the "real world", such as symbolic losses. Nevertheless, it does not explicitly recommend any psychotherapy "brand". CONCLUSION: This "specificity" reflects the compromise found between the different French professional positions and the opposing paradigms that govern them. The campaign led by the French Institut national de prévention et d'éducation à la Santé (Inpes) on depression is a first step of prevention and heath promotion of mental health in France. The analyses presented in this paper highlight the present orientations in this domain, its underlying tensions and the importance of respecting and preserving the multiple aspects of this domain, which are many different ways to explore the complex object that is mental health. This paper also replaces those campaigns in the complexity of their logic and their context, in an attempt to provide elements for a dispassionate reflection for all of the actors concerned by these questions.

'Click' functionalization of cryogels conveniently verified and quantified using high-resolution MAS NMR spectroscopy.

Chemical modification reactions of alkyne containing polyHEMA-based macroporous network structures (cryogels) by Cu(I) catalyzed azide-alkyne 'click' cycloaddition reactions and their monitoring and quantification with high-resolution magic angle spinning (hr-MAS) NMR spectroscopy are reported. Complete conversion is obtained when benzylazide is reacted with the grafted alkyne function, but only partial conversion is observed when using azide-modified poly(ethylene glycol) (PEG-N(3) ). Subsequent addition of benzylazide consumes all remaining alkyne groups. All chemical modifications are easily monitored at each stage using hr-MAS NMR spectroscopy. The alkyne functionality and the resulting triazole ring provide well resolved (1) H resonances to monitor and quantify the progress of such 'click' reactions in general.

Detoxification mechanisms of honey bees (Apis mellifera) resulting in tolerance of dietary nicotine.

Insecticides are thought to be among the major factors contributing to current declines in bee populations. However, detoxification mechanisms in healthy, unstressed honey bees are poorly characterised. Alkaloids are naturally encountered in pollen and nectar, and we used nicotine as a model compound to identify the mechanisms involved in detoxification processes in honey bees. Nicotine and neonicotinoids have similar modes of action in insects. Our metabolomic and proteomic analyses show active detoxification of nicotine in bees, associated with increased energetic investment and also antioxidant and heat shock responses. The increased energetic investment is significant in view of the interactions of pesticides with diseases such as Nosema spp which cause energetic stress and possible malnutrition. Understanding how healthy honey bees process dietary toxins under unstressed conditions will help clarify how pesticides, alone or in synergy with other stress factors, lead to declines in bee vitality.