bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prévenir le risque infectieux à l’hôpital ?
Authors: d’Alessandro Eugénie 
Published: May 2012

En Afrique, la maîtrise du risque infectieux en milieu hospitalier reste une question cruciale. Bien souvent, les analyses se limitent à une évaluation des décalages entre des normes techniques et des pratiques hospitalières. L’insuffisance des connaissances théoriques est régulièrement invoquée, conduisant à un cycle de formation-évaluation qui semble largement voué à l’échec. Une approche anthropologique peut aider à la résolution de ces problèmes. En proposant une lecture des dimensions sociales et culturelles des risques sanitaires, le rôle de l’anthropologue est d’élargir la compréhension de ces dysfonctionnements. Il s’agit de penser l’hôpital comme un espace où s’articulent diverses dimensions sociales, éthiques, médicales et techniques. Témoignant de cet apport complémentaire dans le champ de la santé, de nouvelles pistes émergent d’une enquête menée à l’Hôpital National de Niamey. D’abord, la superposition d’espaces techniques et sociaux se traduit par une confusion dans les gestes. Les obligations sociales brouillent alors les chaînes gestuelles techniques. Ensuite, la prégnance d’un héritage historique définit un certain mode de délivrance des biens publics dont les manifestations se retrouvent dans le quotidien d’un hôpital. Enfin, des « mondes sensibles » différents et les normes techniques élaborées dans le contexte de la médecine moderne deviennent des abstractions en l’absence de correspondances perceptives. Ici, l’anthropologie jette un pont interdisciplinaire entre les préoccupations de santé publique et les questions d’économie morale et décisionnelle.
La mort, l’oubli et les plaisirs
Authors: Vega Anne 
Published: May 2012

L’article porte sur l’origine des divergences entre les normes véhiculées par les campagnes de santé, les aspirations du personnel hospitalier et celles de patientes atteintes d’un cancer du sein. Fondé sur une étude qualitative, il souligne plusieurs décalages généralement peu investigués dans les travaux recensés. Ainsi, le discours dominant exhortant les malades à combattre la maladie et à rester sereins s’accorde mal avec les fluctuations du « moral » et l’épuisement éprouvés par les personnes interviewées, quelle que soit l’évolution de leur pathologie. De plus, elles réagissent en fonction de leur propre expérience de vie et la plupart cherchent à rester elles-mêmes « malgré tout ». Aussi, il leur est vital de choisir leurs soutiens et de retrouver des sensations agréables éprouvées avant la maladie. L’étude souligne alors un paradoxe : ce sont les patientes qui adhèrent le plus aux normes du « bon malade » qui expriment le plus de difficultés à composer avec la maladie, puis à l’oublier, ou à envisager la mort.
Identification of Resting and Type I IFN-Activated Human NK Cell miRNomes Reveals MicroRNA-378 and MicroRNA-30e as Negative Regulators of NK Cell Cytotoxicity
Authors: Wang Pin , Gu Yan , Zhang Qian , Han Yanmei , Hou Jin , Lin Li , Wu Cong , Bao Yan , Su Xiaoping , Jiang Minghong , Wang Qingqing , Li Nan , Cao Xuetao 
Published: May 2012

AbstractNK cells are important innate immune cells with potent cytotoxicity that can be activated by type I IFN from the host once infected. How NK cell cytotoxicity is activated by type I IFN and then tightly regulated remain to be fully elucidated. MicroRNAs (miRNAs, or miRs) are important regulators of innate immune response, but the full scale of miRNome in human NK cells remains to be determined. In this study, we reported an in-depth analysis of miRNomes in resting and IFN-α–activated human NK cells, found two abundant miRNAs, miR-378 and miR-30e, markedly decreased in activated NK cells by IFN-α, and further proved that miR-378 and miR-30e directly targeted granzyme B and perforin, respectively. Thus, IFN-α activation suppresses miR-378 and miR-30e expression to release cytolytic molecule mRNAs for their protein translation and then augments NK cell cytotoxicity. Importantly, the phenomena are also confirmed in human NK cells activated by other cytokines and even in the sorted CD16+CD56dimCD69+ human NK cell subset. Finally, miR-378 and miR-30e were proved to be suppressors of human NK cell cytotoxicity. Taken together, our results reveal that downregulated miR-378 and miR-30e during NK cell activation are negative regulators of human NK cell cytotoxicity, providing a mechanistic explanation for regulation of NK cell function by miRNAs.
CD8+ Foxp3+ Regulatory T Cells Are Induced during Graft-versus-Host Disease and Mitigate Disease Severity
Authors: Beres Amy J. , Haribhai Dipica , Chadwick Alexandra C. , Gonyo Patrick J. , Williams Calvin B. , Drobyski William R. 
Published: May 2012

Abstract
Regulatory T cells (Tregs), in particular CD4+ Foxp3+ T cells, have been shown to play an important role in the maintenance of tolerance after allogeneic stem cell transplantation. In the current study, we have identified a population of CD8+ Foxp3+ T cells that are induced early during graft-versus-host disease (GVHD), constitute a significant percentage of the entire Treg population, and are present in all major GVHD target organs. These cells expressed many of the same cell surface molecules as found on CD4+ Tregs and potently suppressed in vitro alloreactive T cell responses. Induction of these cells correlated positively with the degree of MHC disparity between donor and recipient and was significantly greater than that observed for CD4+-induced Tregs (iTregs) in nearly all tissue sites. Mice that lacked the ability to make both CD8+ and CD4+ iTregs had accelerated GVHD mortality compared with animals that were competent to make both iTreg populations. The absence of both iTreg populations was associated with significantly greater expansion of activated donor T cells and increased numbers of CD4+ and CD8+ T cells that secreted IFN-γ and IL-17. The presence of CD8+ iTregs, however, was sufficient to prevent increased GVHD mortality in the complete absence of CD4+ Tregs, indicating at least one functional iTreg population was sufficient to prevent an exacerbation in GVHD severity, and that CD8+ iTregs could compensate for CD4+ iTregs. These studies define a novel population of CD8+ Tregs that play a role in mitigating the severity of GVHD after allogeneic stem cell transplantation.
The Prescription of Allopurinol in a Tertiary Care Centre: Appropriate Indications and Dose Adjustment
Authors: Jamal Al-Bishri , Salma Al-Harthi , Wafa Al-Sofiani , Ghadah Almutairi , Roaa AlOsaimi 
Published: May 2012

Objective To determine the appropriateness (both indications and adequate dosage regimen via creatinine clearance estimation) of allopurinol by physicians of different specialties in a tertiary care centre. Patients and Methods In this cross sectional study computerized clinical records of 156 adult patients who were prescribed allopurinol from 12th November to 11th December, 2011 were retrieved from Al Hada Hospital Taif Saudi Arabia. Main outcome variables were approprsiate indications of allopurinol, prescribing physician's specialty, and dosage of allopurinol. The prescribed dosages were categorized into correct and incorrect dose adjustments based on creatinine clearance estimation. The SPSS version 16 was utilized for data analyses. Results The mean (±SD) age was 58.15 (±14.99) years. There were 105 (67.3%) males and 51 (32.7%) females with male to female ratio being 2:1. Allopurinol was frequently prescribed by nephrologists and family physicians in this study. Out of 156 patients, 46 (29.5%) patients received allopurinol with appropriate indications. Eighty-five (54.5%) patients were received allopurinol without dose adjustment based on their creatinine clearance estimation; among them, 21 (13.5%) received allopurinol with appropriate indications. Conclusion The inappropriate use of allopurinol (both the indication and prescribed dosage) is still a major problem in a large tertiary care centre. Furthermore, the specialty of physicians is also a contributory factor in this inappropriateness.
Enhanced Lithium-Induced Brain Recovery Following Cranial Irradiation Is Not Impeded by Inflammation
Authors: Malaterre Jordane , McPherson Cameron S. , Denoyer Delphine , Lai Emily , Hagekyriakou Jim , Lightowler Sally , Shudo Koishi , Ernst Matthias , Ashley David M. , Short Jennifer L. , Wheeler Greg , Ramsay Robert G. 
Published: May 2012

Abstract
Radiation-induced brain injury occurs in many patients receiving cranial radiation therapy, and these deleterious effects are most profound in younger patients. Impaired neurocognitive functions in both humans and rodents are associated with inflammation, demyelination, and neural stem cell dysfunction. Here we evaluated the utility of lithium and a synthetic retinoid receptor agonist in reducing damage in a model of brain-focused irradiation in juvenile mice. We found that lithium stimulated brain progenitor cell proliferation and differentiation following cranial irradiation while also preventing oligodendrocyte loss in the dentate gyrus of juvenile mice. In response to inflammation induced by radiation, which may have encumbered the optimal reparative action of lithium, we used the anti-inflammatory synthetic retinoid Am80 that is in clinical use in the treatment of acute promyelocytic leukemia. Although Am80 reduced the number of cyclooxygenase-2-positive microglial cells following radiation treatment, it did not enhance lithium-induced neurogenesis recovery, and this alone was not significantly different from the effect of lithium on this proinflammatory response. Similarly, lithium was superior to Am80 in supporting the restoration of new doublecortin-positive neurons following irradiation. These data suggest that lithium is superior in its restorative effects to blocking inflammation alone, at least in the case of Am80. Because lithium has been in routine clinical practice for 60 years, these preclinical studies indicate that this drug might be beneficial in reducing post-therapy late effects in patients receiving cranial radiotherapy and that blocking inflammation in this context may not be as advantageous as previously suggested.
Concise Review: The Periosteum: Tapping into a Reservoir of Clinically Useful Progenitor Cells
Authors: Chang Hana , Knothe Tate Melissa L. 
Published: May 2012

AbstractElucidation of the periosteum and its regenerative potential has become a hot topic in orthopedics. Yet few review articles address the unique features of periosteum-derived cells, particularly in light of translational therapies and engineering solutions inspired by the periosteum's remarkable regenerative capacity. This review strives to define periosteum-derived cells in light of cumulative research in the field; in addition, it addresses clinical translation of current insights, hurdles to advancement, and open questions in the field. First, we examine the periosteal niche and its inhabitant cells and the key characteristics of these cells in the context of mesenchymal stem cells and their relevance for clinical translation. We compare periosteum-derived cells with those derived from the marrow niche in in vivo studies, addressing commonalities as well as features unique to periosteum cells that make them potentially ideal candidates for clinical application. Thereafter, we review the differentiation and tissue-building properties of periosteum cells in vitro, evaluating their efficacy in comparison with marrow-derived cells. Finally, we address a new concept of banking periosteum and periosteum-derived cells as a novel alternative to currently available autogenic umbilical blood and perinatal tissue sources of stem cells for today's population of aging adults who were “born too early” to bank their own perinatal tissues. Elucidating similarities and differences inherent to multipotent cells from distinct tissue niches and their differentiation and tissue regeneration capacities will facilitate the use of such cells and their translation to regenerative medicine.
Fabrication of a Large‐Area Al‐Doped ZnO Nanowire Array Photosensor with Enhanced Photoresponse by Straining
Authors: Wang Ruey‐Chi , Lin Hsin‐Ying , Wang Chao‐Hung , Liu Chuan‐Pu 
Published: May 2012

AbstractThe photosensing properties of flexible large‐area nanowire (NW)‐based photosensors are enhanced via in situ Al doping and substrate straining. A method for efficiently making nanodevices incorporating laterally doped NWs is developed and the strain‐dependent photoresponse is investigated. Photosensors are fabricated by directly growing horizontal single‐crystalline Al‐doped ZnO NW arrays across Au microelectrodes patterned on a flexible SiO2/steel substrate to enhance the transportation of carriers and the junction between NWs and electrodes. The Raman spectrum of the Al:ZnO NWs, which have an average diameter and maximum length of around 40 nm and 6.8 μm, respectively, shows an Al‐related peak at 651 cm−1. The device shows excellent photosensing properties with a high ultraviolet/visible rejection ratio, as well as extremely high maximum photoresponsivity and sensitivity at a low bias. Increasing the tensile strain from 0 to 5.6% linearly enhances the photoresponsivity from 1.7 to 3.8 AW−1 at a bias of 1 V, which is attributed to a decrease in the Schottky barrier height resulting from a piezo‐photonic effect. The high‐performance flexible NW device presented here has applications in coupling measurements of light and strain in a flexible photoelectronic nanodevice and can aid in the development of better flexible and integrated photoelectronic systems.
Conducting Domain Walls in Lithium Niobate Single Crystals
Authors: Schröder Mathias , Haußmann Alexander , Thiessen Andreas , Soergel Elisabeth , Woike Theo , Eng Lukas M. 
Published: May 2012

AbstractFerroic materials play an increasingly important role in novel (nano)electronic devices. Recently, research on domain walls (DWs) receives a big boost by the discovery of DW conductivity (DWC) in BiFeO3 and Pb(ZrxTi1‐x)O3 ferroic thin films. Here, it is demonstrated that DWC is not restricted to thin films, but equally applies to millimeter‐thick wide‐bandgap, ferroic single crystals, such as LiNbO3. In this material transport along DWs can be switched by super‐bandgap illumination and tuned by engineering the tilting angle of DWs with respect to the polar axis. The results are consistently obtained using conductive atomic force microscopy to locally map the DWC and macroscopic contacts, thereby in addition investigating the temperature dependence, DW transport activation energies, and relaxation behavior.
In Situ TEM Experiments of Electrochemical Lithiation and Delithiation of Individual Nanostructures
Authors: Liu Xiao Hua , Liu Yang , Kushima Akihiro , Zhang Sulin , Zhu Ting , Li Ju , Huang Jian Yu 
Published: May 2012

AbstractUnderstanding the microscopic mechanisms of electrochemical reaction and material degradation is crucial for the rational design of high‐performance lithium ion batteries (LIBs). A novel nanobattery assembly and testing platform inside a transmission electron microscope (TEM) has been designed, which allows a direct study of the structural evolution of individual nanowire or nanoparticle electrodes with near‐atomic resolution in real time. In this review, recent progresses in the study of several important anode materials are summarized. The consistency between in situ and ex situ results is shown, thereby validating the new in situ testing paradigm. Comparisons between a variety of nanostructures lead to the conclusion that electrochemical reaction and mechanical degradation are material specific, size dependent, and geometrically and compositionally sensitive. For example, a highly anisotropic lithiation in Si is observed, in contrast to the nearly isotropic response in Ge. The Ge nanowires can develop a spongy network, a unique mechanism for mitigating the large volume changes during cycling. The Si nanoparticles show a critical size of ∼150 nm below which fracture is averted during lithiation, and above which surface cracking, rather than central cracking, is observed. In carbonaceous nanomaterials, the lithiated multi‐walled carbon nanotubes (MWCNTs) are drastically embrittled, while few‐layer graphene nanoribbons remain mechanically robust after lithiation. This distinct contrast manifests a strong ‘geometrical embrittlement’ effect as compared to a relatively weak ‘chemical embrittlement’ effect. In oxide nanowires, discrete cracks in ZnO nanowires are generated near the lithiation reaction front, leading to leapfrog cracking, while a mobile dislocation cloud at the reaction front is observed in SnO2 nanowires. This contrast is corroborated by ab initio calculations that indicate a strong chemical embrittlement of ZnO, but not of SnO2, after a small amount of lithium insertion. In metallic nanowires such as Al, delithiation causes pulverization, and the product nanoparticles are held in place by the surface Li‐Al‐O glass tube, suggesting possible strategies for improving electrode cyclability by coatings. In addition, a new in situ chemical lithiation method is introduced for fast screening of battery materials by conventional TEM. Evidently, in situ nanobattery experiments inside TEM are a powerful approach for advancing the fundamental understanding of electrochemical reactions and materials degradation and therefore pave the way toward rational design of high‐performance LIBs.
Optimisation of solid liquid extraction of jatropha oil using petroleum ether
Authors: Sayyar Sepidar , Abidin Zurina Zainal , Yunus Robiah 
Published: May 2012

ABSTRACTJatropha curcas I. is an oil‐bearing seed plant with a wide range of applications. The oil from the seeds of this plant has been used as an industrial raw material for many years. One of the important characteristics of jatropha oil is its potential for fuel and biodiesel production to meet the global energy demand. In this paper, solid–liquid extraction of jatropha oil from seeds using petroleum ether was optimised on the basis of the amount of the extracted oil. Four main factors, namely temperature, the solvent‐to‐solid ratio, the reaction time and the size of the raw material, were investigated to optimise extraction conditions for achieving the highest oil yield under experimental conditions. The kinetics of the extraction using petroleum ether as the solvent were also studied and fitted to a second‐order model. The free fatty acid (FFA) content of the oil was used as an index of the oil quality. The optimum conditions were found to be 7 h of reaction time, a temperature of 68 °C, a coarse particle size of 0.5–0.75 mm and a solvent‐to‐solid ratio of 6 : 1. Storing the ground seeds for one week before extraction had a remarkably negative effect on the quality of the oil produced (FFA ≈ 6.99%), whereas the quality of the oil was satisfactory when extracted from the seeds immediately after grinding (FFA ≈ 0.62%). The experimental data fitted well to the second‐order model with the saturation extraction capacity and the initial extraction rate increasing with increasing temperature. Copyright © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Effect of processing techniques on the performance of Epoxy/MWCNT nanocomposites
Authors: Hosur Mahesh , Barua Rajib , Zainuddin Shaik , Kumar Ashok , Trovillion Jonathan , Jeelani Shaik 
Published: May 2012

AbstractThe aim of this study is to investigate the optimum technique to disperse Multi‐Walled Carbon Nanotubes (MWCNTs) in SC‐1 epoxy uniformly and to evaluate the effect of processing technique on the performance of SC‐1 epoxy. To achieve better dispersion, MWCNT was mixed with SC‐1 resin directly or premixed with a solvent and then mixed with SC‐1 resin after evaporating the solvent using sonication, thinky mixing and three‐roll mill methods either in isolation or combination. Flexural tests were performed to evaluate mechanical performances and results exhibit up to 27.13, 13.51, and 21.99% improvement on flexural strength, flexural modulus, and maximum strain, respectively, over neat epoxy with only 0.2 wt % loading. Dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) indicated improvement in storage modulus, Tg, inflection temperature, and residue content, respectively over neat SC‐1 epoxy. Thermal and mechanical properties at higher loading conditions were seen to either reduce or not significantly improve. This was attributed to high viscosity of nanocomposites as determined by rheological analysis which prevents good dispersion of MWNCTs into epoxy system at 0.4 wt % loading. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of electromagnetic interference shielding polyimide foam
Authors: Liu Xiao‐Yan , Zhan Mao‐Sheng , Wang Kai 
Published: May 2012

AbstractThis article focused on the preparation and characterization of ultralight and high‐temperature resistant polyimide foam (PIF) for electromagnetic interference shielding. PIF was first prepared based on a one‐pot process by the primary reactions of derivatives of pyromellitic dianhydride and polyaryl polymethylene isocyanate. Then, PIFs with silver (0) coating were then prepared by spraying silver (0) on the surfaces of PIF through physical spraying method. The surface density of silver coating was 0.18 kg/m2, and the densities of silver‐coated PIFs were less than 23 kg/m3. The scanning electron microscopy coupled with an energy‐dispersive X‐ray spectrometer (EDX) measurement were carried out to investigate the morphological and chemical properties of uncoated and coated PIFs. For coated PIFs, the EDX spectrums indicated increasing higher silver proportions from interior to exterior surface, together with increasing higher carbon proportions from exterior surface to interior. Thermogravimetry/Fourier transform infrared instrument that combined thermogravimetric analysis with pyrolysis product analysis by Fourier transform infrared spectroscopy were applied to investigate the thermal stability and pyrolysis products of uncoated and coated PIFs. The results indicated that the thermal properties of silver‐coated PIFs were improved obviously with the 5% weight loss temperature higher than 400°C and the residual weight retentions at 800°C ∼ 80%. In the frequency range 200–7000 MHz, the EMI shielding efficiency with one surface and two surfaces coated with silver were in the range of 36.4–60.7 dB and 61.6–95.6 dB, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Immobilization of Candida lipolytica lipase on macroporous beaded terpolymers with epoxy groups
Authors: Liu Wentao , Duan Hongdong , Meng Xia , Qin Dawei , Wang Xingjian , Zhang Juan 
Published: May 2012

AbstractA series of macroporous beaded terpolymers with epoxy groups were synthesized by suspension polymerization with glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA), and the third monomers including styrene, methyl methacrylate, n‐butyl acrylate (BA), butyl methacrylate (BMA), and 2‐hydroxyethyl methacrylate for immobilization of Candida lipolytica lipase. The effect of various third monomers on loading and activity recovery of immobilized lipase were studied. Terpolymers with BA as the third monomer were found to give the biggest loading of lipase, and the activity recovery of lipase immobilized on poly(GMA‐EGDMA‐BA) terpolymers reached 79.0%. As the content of BA (%) increasing, the loading of lipase enhanced, but the activity recovery reached 88.5% for the initial stage and decreased to 46.9% at last. The poly(GMA‐EGDMA‐BA‐10) showed an optimal result in lipase immobilization. Lipase immobilized on poly(GMA‐EGDMA‐BA‐10) carriers had broader pH and higher temperature stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013