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International audience; The pathogenic bacterium Streptococcus pneumoniae (S. pneumoniae) can invade the cerebrospinal fluid (CSF) and cause meningitis with devastating consequences. Whether and how sensory cells in the central nervous system (CNS) become activated during bacterial infection, as recently reported for the peripheral nervous system, is not known. We find that CSF infection by S. pneumoniae in larval zebrafish leads to changes in posture and behavior that are reminiscent of pneumococcal meningitis, including dorsal arching and epileptic-like seizures. We show that during infection, invasion of the CSF by S. pneumoniae massively activates in vivo sensory neurons contacting the CSF, referred to as “CSF-cNs” and previously shown to detect spinal curvature and to control posture, locomotion, and spine morphogenesis. We find that CSF-cNs express orphan bitter taste receptors and respond in vitro to bacterial supernatant and metabolites via massive calcium transients, similar to the ones observed in vivo during infection. Upon infection, CSF-cNs also upregulate the expression of numerous cytokines and complement components involved in innate immunity. Accordingly, we demonstrate, using cell-specific ablation and blockade of neurotransmission, that CSF-cN neurosecretion enhances survival of the host during S. pneumoniae infection. Finally, we show that CSF-cNs respond to various pathogenic bacteria causing meningitis in humans, as well as to the supernatant of cells infected by a neurotropic virus. Altogether, our work uncovers that central sensory neurons in the spinal cord, previously involved in postural control and morphogenesis, contribute as well to host survival by responding to the invasion of the CSF by pathogenic bacteria during meningitis.

Canards, special trajectories that follow invariant repelling slow manifolds for long time intervals, have been frequently observed in slow-fast systems of either biological, chemical and physical nature. Here, collective canard explosions are demonstrated in a population of globally-coupled phase-rotators subject to adaptive coupling. In particular, we consider a bimodal Kuramoto model displaying coexistence of asynchronous and partially synchronized dynamics subject to a linear global feedback. A detailed geometric singular perturbation analysis of the associated mean-field model allows us to explain the emergence of collective canards in terms of the stability properties of the one-dimensional critical manifold, near which the slow macroscopic dynamics takes place. We finally show how collective canards and related manifolds gradually emerge in the globally-coupled system for increasing system sizes, in spite of the trivial dynamics of the uncoupled rotators., Comment: 6 figures

Chemical nature and surface properties of plant disperse fillers are investigated: buckwheat (BH) and oat (OH) husk, wood (WF) and conifer flour (CF). Using IR spectroscopy, it was found that oxygen-containing atomic groups –OH, –C–O–, –C=O prevail in the filler components. It was found that a hydroxyl-hydrate layer of functional groups is present on the surface of air-dry fillers. By potentiometric titration of aqueous suspensions using the Parks–Bobyrenko method, it was determined that all fillers are of the «polyfunctional solid» type. It is shown that the hydroxyl-hydrate surface layer consists of functional groups with similar values of acid-base characteristics. Functional groups of acidic nature were additionally found on the surface of the fillers: groups with pKa≈4.37−5.66 on the BH surface, groups with pKa≈4.49−4.90 on the CF surface and groups with pKa≈3.91−4.30 on the WF surface. As a result of potentiometric titration, it was shown that the surface acidity of the fillers decreases in the WF>CF>BH>ОH series, which coincides with the one in which the total cellulose and lignin content decreases, and the resistance of fillers to thermal-oxidative breakdown increases. It was found that the rate of hydrolytic processes in aqueous suspensions at the interface decreases in the ОH>CF>BH>WF series and inversely depends on the concentration of functional groups on the surface of the fillers, and also that the change in the rate of hydrolytic processes at the interface depending on the content of fillers is described by step functions. It is revealed that for the effective use of the studied disperse waste in composite materials and as adsorbents for the extraction of pollutants, dispersion media with the following ranges of the hydrogen index are required: for BH − pH>4.4; OH − pH>6.4; WF − pH>3.9; CF − pH>4.5. The results obtained make it possible to predict and control acid-base interfacial interactions, as well as reasonably approach the development of new effective technologies, Исследованы химическая природа и поверхностные свойства дисперсных наполнителей растительного происхождения: гречневой (ГШ) и овсяной (ОШ) шелухи, древесной (ДМ) и хвойной муки (ХМ). Методом ИК-спектроскопии установлено, что в составе компонентов наполнителей преобладают кислородсодержащие атомные группы –ОН, −С−О−, −С=O. Обнаружено, что на поверхности воздушно-сухих наполнителей присутствует гидроксильно-гидратный слой функциональных групп. Методом потенциометрического титрования водных суспензий по способу Паркса – Бобыренко установлено, что все наполнители относятся к типу «полифункциональное твердое тело». Показано, что гидроксильно-гидратный поверхностный слой состоит из функциональных групп с близкими значениями кислотно-основных характеристик. На поверхности наполнителей дополнительно обнаружены функциональные группы кислотного характера: на поверхности ГШ группы с pKa≈4,37−5,66, на поверхности ХМ группы с pKa≈4,49−4,90 и на поверхности ДМ группы с pKa≈3,91−4,30. В результате потенциометрического титрования показано, что кислотность поверхности наполнителей уменьшается в ряду ДМ>ХМ>ГШ>ОШ, который совпадает с рядом, в котором уменьшается суммарное содержание целлюлозы и лигнина, и увеличивается стойкость наполнителей к термоокислительной деструкции. Обнаружено, что скорость гидролитических процессов в водных суспензиях на границе раздела фаз уменьшается в ряду ОШ>ХМ>ГШ>ДМ и обратнопропорционально зависит от концентрации функциональных групп на поверхности наполнителей, а также, что изменение скорости гидролитических процессов на границе раздела фаз в зависимости от содержания наполнителей описывается степенными функциями. Установлено, что для эффективного применения исследуемых дисперсных отходов в композиционных материалах и в качестве адсорбентов для извлечения загрязнителей необходимы дисперсионные среды со следующими диапазонами водородного показателя: для ГЛ – рН>4,4; ВЛ − рН>6,4; ДБ − рН>3,9; БХ − рН>4,5. Полученные результаты позволяют прогнозировать и регулировать кислотно-основные межфазные взаимодействия, а также обоснованно подходить к разработке новых эффективных технологий, Досліджено хімічну природу та поверхневі властивості дисперсних наповнювачів рослинного походження: гречаного (ГЛ) та вівсяного (ВЛ) лушпиння, деревного (ДБ) та хвойного (ХБ) борошна. Методом ІЧ-спектроскопії встановлено, що у складі компонентів наповнювачів переважають кисневмісні атомні групи –ОН, −С−О−, −С=O. Виявлено, що на поверхні повітряно-сухих наповнювачів присутній гідроксильно-гідратний шар функціональних груп. Методом потенціометричного титрування водних суспензій за способом Паркса – Бобиренка встановлено, що усі наповнювачі відносяться до типу «поліфункціональне тверде тіло». Показано, що гідроксильно-гідратний поверхневий шар складається з функціональних груп, які мають близькі величини кислотно-основних характеристик. На поверхні наповнювачів додатково виявлені функціональні групи кислотного характеру: на поверхні ГЛ групи з pKa≈4,37−5,66, на поверхні БХ групи з pKa≈4,49−4,90, а на поверхні ДБ групи з pKa≈3,91−4,30. В результаті потенціометричного титрування показано, що кислотність поверхні наповнювачів знижується у ряду ДБ>ХБ>ГЛ>ВЛ, який співпадає з рядом, в якому зменшується сумарний вміст целюлози і лігніну та зростає стійкість наповнювачів до термоокислювальної деструкції. Виявлено, що швидкість гідролітичних процесів у водних суспензіях на межі поділу фаз зменшується у ряду ВЛ>ХБ>ГЛ>ДБ та оберненопропорційно залежить від концентрації функціональних груп на поверхні наповнювачів, а також, що зміна швидкості гідролітичних процесів на межі поділу фаз в залежності від вмісту наповнювачів описується ступеневими функціями. Встановлено, що для ефективного застосування досліджуваних дисперсних відходів у композиційних матеріалах та в якості адсорбентів для вилучення забруднюючих речовин з рідин необхідні дисперсійні середовища з наступними діапазонами водневого показника: для ГЛ – рН>4,4; ВЛ − рН>6,4; ДБ − рН>3,9; БХ − рН>4,5. Отримані результати дозволяють прогнозувати та регулювати кислотно-основні міжфазні взаємодії, а також обґрунтовано підходити до розробки нових ефективних технологій

Chemical nature and surface properties of plant disperse fillers are investigated: buckwheat (BH) and oat (OH) husk, wood (WF) and conifer flour (CF). Using IR spectroscopy, it was found that oxygen-containing atomic groups –OH, –C–O–, –C=O prevail in the filler components. It was found that a hydroxyl-hydrate layer of functional groups is present on the surface of air-dry fillers. By potentiometric titration of aqueous suspensions using the Parks–Bobyrenko method, it was determined that all fillers are of the «polyfunctional solid» type. It is shown that the hydroxyl-hydrate surface layer consists of functional groups with similar values of acid-base characteristics. Functional groups of acidic nature were additionally found on the surface of the fillers: groups withpKa≈4.37−5.66 on the BH surface, groups withpKa≈4.49−4.90 on the CF surface and groups withpKa≈3.91−4.30 on the WF surface. As a result of potentiometric titration, it was shown that the surface acidity of the fillers decreases in the WF>CF>BH>ОH series, which coincides with the one in which the total cellulose and lignin content decreases, and the resistance of fillers to thermal-oxidative breakdown increases. It was found that the rate of hydrolytic processes in aqueous suspensions at the interface decreases in the ОH>CF>BH>WF series and inversely depends on the concentration of functional groups on the surface of the fillers, and also that the change in the rate of hydrolytic processes at the interface depending on the content of fillers is described by step functions. It is revealed that for the effective use of the studied disperse waste in composite materials and as adsorbents for the extraction of pollutants, dispersion media with the following ranges of the hydrogen index are required: for BH − pH>4.4; OH − pH>6.4; WF − pH>3.9; CF − pH>4.5. The results obtained make it possible to predict and control acid-base interfacial interactions, as well as reasonably approach the development of new effective technologies

FeCoNiCrMn(Al)-based powdered high entropy alloys were synthesized by a short time mechanical alloying process in a high energy planetary ball milling from mixtures of elemental powders, and subsequently sintered by a pressureless procedure. The composition and microstructure of the HEA phases before and after the sintering process were studied by X-ray diffraction, energy dispersive X-ray analysis (EDX) and scanning electron microscopy. The microhardness and tensile strength values for FeCoNiCrMnAl HEA sintered at 1400 °C sample were 3,7 GPa and 1011 MPa, respectively. Statistical Fisher-Pearson coefficient of skewness and kurtosis were played to determine the optimum synthesis milling time. The use of NaCl as additive led on to a reduction of the as-milled grain size. After sintering, SEM study confirmed a segregation of the initial HEA phase directly related to the melting temperature of the elements. Three melting temperature groups were described (Cr, FeCoNi and Mn) and they agree with the observation in the elemental mapping study. The presence of Al favored the segregation of Cr., This work was supported by the Spanish government under grant MAT2014-52407-R, financed in part by the European Regional Development Fund and through the Ramón y Cajal Program RYC-2013-12437.

A high entropy alloy (HEA, CoCrFeNiMn) synthesized by mechanical alloying was used as the binder for the densification of WC by a pressureless high temperature procedure. Three different WC were used by modifying its microstructure with a high energy ball milling treatment. The alloy content in the HEA-WC mixture was varied from 10 to 30% vol. The microstructure and properties of the sintered composites were studied by X-ray diffraction, scanning electron microscopy and microindentation., This work was supported by the Spanish government under grant MAT2014-52407-R, financed in part by the European Regional Development Fund and through the Ramón y Cajal Program RYC-2013-12437. MINECO/ICTI2013-2016/RYC-2013-12437

This report documents the delivered demonstrator “D2.2 Tunable UV photoelectric setup”, a prototype instrument developed in the frame of WP2 “Technology development”, Task 2.2 “Tunable UV laser photoelectric charger composition-specific aerosol charging” of the SUREAL-23 project. It describes the current state of the art, the innovation and the principle of operation of the developed setup and it presents some preliminary results performed with an aerosol generated by a propane diffusion flame. This prototype will continue to undergo improvements and will be available for sub-23 nm combustion aerosol characterisation in the SUREAL-23 project.

We report the use of bis-catecholic polymers as candidates for obtaining effective, tunable gatekeeping coatings for mesoporous silica nanoparticles (MSNs) intended for drug release applications. In monomers, catechol rings act as adhesive moieties and reactive sites for polymerization, together with middle linkers which may be chosen to tune the physicochemical properties of the resulting coating. Stable and low-toxicity coatings (pNDGA and pBHZ) were prepared from two bis-catechols of different polarity (NDGA and BHZ) on MSN carriers previously loaded with rhodamine B (RhB) as a model payload, by means of a previously reported synthetic methodology and without any previous surface modification. Coating robustness and payload content were shown to depend significantly on the workup protocol. The release profiles in a model physiological PBS buffer of coated systems (RhB@MSN@pNDGA and RhB@MSN@pBHZ) showed marked differences in the “gatekeeping” behavior of each coating, which correlated qualitatively with the chemical nature of their respective linker moieties. While the uncoated system (RhB@MSN) lost its payload almost completely after 2 days, release from RhB@MSN@pNDGA was virtually negligible, likely due to the low polarity of the parent bis-catechol (NDGA). As opposed to these extremes, RhB@MSN@pBHZ presented the most promising behavior, showing an intermediate release of 50% of the payload in the same period of time., This work was supported by Projects MAT2015-70615-R from the Spanish Government and by FEDER funds. ICN2 acknowledges support from the Severo Ochoa Program (MINECO, Grant SEV-2013-0295) and the CERCA Programme/Generalitat de Catalunya. UCM acknowledges support by the European Research Council (Advanced Grant VERDI; ERC-2015-AdG Proposal No. 694160) and Project MAT2015-64831-R.

Five natural faceted diamond samples, considered to have inherent submicroscopic and nanometric inclusions, were studied using various techniques such as Raman spectroscopy, Raman microscopy, scanning electron microscopy (SEM), and energy dispersive analysis of X-rays (EDAX). The principal focus was to find out the chemical nature of the inclusions and their distribution. As a confirmative tool, laser desorption ionization mass spectrometry (LDI MS) was used for the characterization of the inclusions. Our study suggests that the inclusions in diamond belong to the pyroxene group of silicate minerals with Fe, Mg, Ca, Ru, and Cr as the major elements. As evidenced by the absence of alkali, aluminum, and rare earth elements in the inclusion, the diamond can be of peridotitic origin. Interestingly, we found that chromium scavenges Ru, a platinum group element (PGE), and other metals such as Nb, Co, and Ni, entrained into the pyroxene inclusions. We established that the diamond sample in which inclusions are found is of Kimberlitic origin. � 2011 Elsevier B.V. All rights reserved.

The ballistic behavior of four different armor ceramic materials with thicknesses varying from 3 mm to 14 mm has been investigated. These are two types of alumina Al2O3 armor grades and two types of SiC armor grades produced by different armor ceramic producers. The ballistic study has been performed using the standard DoP technique with two types of AP projectiles. The microstructure and the mechanical properties of the armor ceramics are investigated with SEM (Scanning Electron Microscopy), X-ray microanalysis, impulse excitation methods and Vickers hardness method. The microstructures are characterized by the number and chemical nature of the phases, the grain size, the type of fracture mode identified from SEM investigation of fragments. The measured mechanical properties are hardness, fracture toughness, flexural strength and the speed of sound (transversal and longitudinal). The ballistic tests are performed with two 7.62 mm projectiles AP8 (WC core) at 930 m/s and APM2 (hard steel core) at 800 m/s. The mass efficiency factor has been determined for each of the armor ceramics. The difference in the ballistic performance of the two alumina types is marginal. The two silicon carbide types are indistinguishable from ballistic point of view. The gained knowledge can be used two-fold: first, to understand better the influence of the microstructure on the ballistic performance of armor ceramics and second, as reference material for the development of a new class of armor ceramics.

The ballistic behavior of four different armor ceramic materials with thicknesses varying from 3 mm to 14 mm has been investigated. These are two types of alumina Al2O3 armor grades and two types of SiC armor grades produced by different armor ceramic producers. The ballistic study has been performed using the standard DoP technique with two types of AP projectiles. The microstructure and the mechanical properties of the armor ceramics are investigated with SEM (Scanning Electron Microscopy), X-ray microanalysis, impulse excitation methods and Vickers hardness method. The microstructures are characterized by the number and chemical nature of the phases, the grain size, the type of fracture mode identified from SEM investigation of fragments. The measured mechanical properties are hardness, fracture toughness, flexural strength and the speed of sound (transversal and longitudinal). The ballistic tests are performed with two 7.62 mm projectiles AP8 (WC core) at 930 m/s and APM2 (hard steel core) at 800 m/s. The mass efficiency factor has been determined for each of the armor ceramics. The difference in the ballistic performance of the two alumina types is marginal. The two silicon carbide types are indistinguishable from ballistic point of view. The gained knowledge can be used two-fold: first, to understand better the influence of the microstructure on the ballistic performance of armor ceramics and second, as reference material for the development of a new class of armor ceramics.

Platinum nanoparticles ( d Pt = 1.0–1.2 nm) supported on single CeO 2 and La 2 O 3 metal oxides and Ce 0.8 La 0.2 O 2− δ solid solution were prepared to investigate for the first time the effect of La 3+ -doping of ceria on important mechanistic and kinetic aspects of the water-gas shift (WGS) reaction, namely: (i) the concentration and chemical structure of active adsorbed reaction intermediates present in the C-path and H-path of WGS at 250 and 300 °C, (ii) the chemical nature of inactive species formed during WGS, and (iii) the prevailing mechanistic path among “redox” and “associative” both proposed in the literature. For this, steady-state isotopic transient kinetic analysis (SSITKA) experiments coupled with in situ DRIFTS and mass spectrometry were performed to follow the H-path (use of D 2 O) and C-path (use of 13 CO) of the WGS. In addition, other transient isotopic experiments using operando methodology (use of DRFTS and mass spectrometry) were designed to follow with time on stream the reactivity toward water of the various adsorbed species formed under WGS. It is proposed that on Pt/Ce 1− x La x O 2− δ ( x = 0.0, 0.2 and 1.0) the WGS reaction follows both the “redox” and “associative” mechanisms but the extent of participation of each mechanism to the overall WGS reaction rate depends on the support chemical composition. The WGS kinetic rate (μmol CO g −1 s −1 ) increased by a factor of 2.0 and 2.8 at 300 °C on 0.5 wt% Pt supported on Ce 0.8 La 0.2 O 2− δ compared to CeO 2 and La 2 O 3 , respectively. This was explained by (i) the larger concentration of active surface intermediates formed around each Pt nanoparticle (larger extent of reactive zone) and (ii) the higher reactivity of sites ( k , s −1 ) responsible for CO 2 and H 2 formation on Pt/Ce 0.8 La 0.2 O 2− δ compared to Pt/CeO 2 and Pt/La 2 O 3 . Active OH groups is suggested to be formed on defect sites (Ce 3+ □ s ) of Ce 0.8 La 0.2 O 2− δ as a consequence of the introduction of La 3+ into the ceria lattice, the latter enhancing the concentration of labile oxygen and its surface mobility, important characteristics of the “redox” mechanism.

A noncontact chemical and electrical measurement X-ray photoelectron spectroscopy (XPS) technique is performed to investigate a CdS-based photoresistor during its operation. The main objective of the technique is to trace chemical- and location-specified surface potential variations as shifts of the XPS Cd 3d 5/2 peak position without and under photoillumination with four different lasers. The system is also modeled to extract electrical information. By analyzing the measured potential variations with this model, location-dependent resistance values are represented (i) two dimensionally for line scans and (ii) three dimensionally for areal measurements. In both cases, one of the dimensions is the binding energy. The main advantage of the technique is its ability to assess an element-specific surface electrical potential of a device under operation based on the energy deviation of core level peaks in surface domains. Detection of the variations in electrical potentials and especially their responses to the energy of the illuminating source in operando, is also shown to be capable of detecting, locating, and identifying the chemical nature of structural and other types of defects. © 2012 American Chemical Society.

International audience; The temperature and pressure dependence of isobaric thermal expansivity,α p, in liquids is discussed in this paper. Reported literature data allow general trends in this property that are consistent with experimental evidence to be established. Thus, a negative pressure dependence is to be expected except around the critical point. On the other hand, α p exhibits broad regions of negative and positive temperature dependence in the (T, p) plane depending on the nature of the particular liquid. These trends are rationalized here in terms of various molecular-based equations of state. The analysis of the Lennard-Jones, hard sphere square well and restricted primitive model equations allows understanding the differences in the α p behavior between liquids of diverse chemical nature (polar, nonpolar, and ionic): broader regions of negative temperature and positive pressure dependencies are obtained for liquids characterized by larger ranges of the interparticle potential. Also, using the statistical associating fluid theory (SAFT) allowed the behavior of more complex systems (basically, those potentially involving chain and association effects) to be described. The effect of chain length is rather simple: increasing it is apparently equivalent to raise the interaction range. By contrast, association presents a quite complex effect on α p, which comes from a balance between the dispersive and associative parts of the interaction potential. Thus, if SAFT parameters are adjusted to obtain low association ability, α p is affected by each mechanism at clearly separate regions, one at low temperature, due to association, and the other to dispersive forces, which has its origin in fluctuations related with vapor-liquid transition.

Blends of chemically readily accessible, small-molecular arylacetylene derivatives with poly(vinylidene fluoride) (PVDF) are presented that allow reliable solution processing of field-effect transistor (FET) architectures with electronic characteristics comparable to those of the neat semiconductors. We demonstrate that having the chemical means and corresponding processing protocols to control solid-state microstructures by either adjusting the chemical nature of the organic semiconductor, blend composition or deposition temperature, permit straight-forward comparison between materials and allow probing if electronic characteristics are affected by the chemical structure of the organic semiconductor and/or selected processing protocols.

The present work reports on the production of H2 and secondary carbon nanotubes (CNTs) during catalytic decomposition of ethylene over a novel catalytic system, namely, nickel supported on carbon nanotubes (Ni/CNTs) at remarkably low-temperatures, e.g. 400 °C. A number of catalyst parameters were investigated, namely the chemical nature of support, the Ni metal loading (0.1-10 wt%), the nature of nickel metal precursor (organometallic vs. inorganic) used during catalyst synthesis, and the nature of transition metal used (e.g. Co, Fe, Cu, Ni). Among the different Ni/CNT supported catalysts investigated, 0.5 wt% Ni/Ros1-B1 (Ros1-B1 a commercial CNT) presented the highest activity in terms of H2 production (296 mol H2/gNi) and carbon capacity (3552 gC/gNi). In terms of transition metal used as active catalytic phase, the activity (moles H2 per gram of metal) was found to decrease in the order Co ≫ Fe > Cu. The activity of supported Ni and Co catalysts was found to strongly depend on the metal loading. The structural and morphological features of primary (catalytic support) and secondary carbon nanotubes produced during ethylene decomposition at 400 °C were studied using X-ray Diffraction (XRD), scanning electron microscopy (SEM), High-resolution Transmission Electron Microscopy (HRTEM), and X-ray Photoelectron Spectroscopy (XPS). The production of secondary carbon nanotubes at 400 °C was confirmed after using HRTEM and after a comparison with the primary carbon nanotubes of catalyst support was made. Different regeneration conditions (use of oxygen or steam) were investigated in order to remove by gasification the amorphous carbon deposited under reaction conditions. Oxygen appeared to be a better regeneration reagent than steam, where after ten consecutive reaction/regeneration cycles the 0.5 wt% Ni/Ros1-B1 catalyst showed high and stable activity with time on stream. © 2009 Elsevier B.V. All rights reserved. 93 3-4 314 324 Cited By :14

The fretting corrosion behaviour of CP-Ti in Ringer's solution was studied as a function of normal load, frequency and number of fretting cycles. The restoration ability of CP-Ti after the passive film is damaged due to fretting and as a function of the on-time/off-time ratio (intermittent fretting) was also evaluated. The change in free corrosion potential measured before the onset of fretting, with the onset of fretting, during fretting and after the fretting motion ceases, as a function of time, was used to evaluate the fretting corrosion behaviour. The restoration ability of CP-Ti after the passive film is damaged was ascertained by performing regression analysis of the potential data measured during repassivation. The morphological features of the fretted zone were assessed using scanning electron microscopy. Energy dispersive X-ray analysis was performed at the centre and edge regions of the fretted zone to identify their chemical nature. The study reveals that the excellent corrosion resistance and biocompatibility of CP-Ti are nullified under fretting conditions. Once the passive oxide layer is damaged due to fretting, repassivation is not instantaneous. The significant time delay in reaching the steady state potential implies that CP-Ti remains active and susceptible for corrosion. The difficulty in the instantaneous formation of passive film after the fretting induced damage of the passive film, dissolution of bare Ti from the damaged areas and the possible accumulation of the debris generated during fretting in the surrounding tissues raises concern on the safer use of CP-Ti as an implant material. � 2009 Elsevier Ltd. All rights reserved.

We have studied the effects of softeners and repeated laundering on the handle of knitted fabrics constructed from poly(lactic acid) (PLA) filament yarns derived from corn-starch. The fabrics were assessed: a) subjectively, via a panel of volunteers, in terms of their perceived softness and 'scroopiness'; and b) objectively, using a Kawabata Evaluation System for Fabrics (KES-F), in terms of their low-stress mechanical properties. The study employed two fabric variants and a range of commercial softeners in an attempt to determine the combination that would provide optimal handle and durability to laundering. We found the standard KES-F parameters B, 2HB, G, 2HG, and SMD to be generally well-correlated with the subjective assessment of softness and scroopiness. Although repeated laundering reduced somewhat the beneficial effects of the softeners, this deterioration was not severe, and we were able to identify specific formulations that can provide good handle coupled with acceptable durability. The fabric handle was seen to be influenced by the chemical nature of the softening agent, the type of emulsion employed and the degree of hydrophobicity (assessed in terms of wettability); on the other hand, the ionicity of the softener appeared not to play a significant role. © 2010 The Korean Fiber Society and Springer Netherlands.

Ties us together: The selectivity and recognition behavior of cucurbit[n]uril (CB[n]) homologues (n = 6,7,8) towards a ditopic guest containing two distinct binding sites is explored. CB6, CB7, and CB8 recognize and self-sort the binding sites according to their size, shape, and chemical nature. In the presence of both CB6 and CB8 a hetero[4]pseudorotaxane is formed. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA.

Commercial synthetic polymers namely Polycarbonate (PC), Low density polyethylene (LDPE), High density polyethylene (HDPE), and Polypropylene (PP) coupons were immersed for a period of 12 months (Feb 2006 - Feb 2007) in Bay of Bengal, East coast, India. Samples were retrieved every month and the extent of biofouling and biodegradation were monitored. Biofouling was found to depend not only on the season but also on the chemical nature of the polymer. Surface energy of all the four polymers is positively correlated with fouling only at the initial stages (three months) while surface roughness had a negative correlation. The later increased during the study period. Total suspended solids and organic matter were more abundant on HDPE, followed by PP and LDPE, indicating that among polyolefins hydrophobic surfaces (lower surface energy) favor biofouling over one year. Maximum fouling was observed on polycarbonate during initial three months. Chlorophyll a showed a decreasing trend during the study, as secondary foulers such as Balanus amphitrite, were dominant after the monsoon (6th month in the present study). Maximum weight loss was seen in LDPE (1.9%), followed by that in HDPE (1.6%), PC (0.69%) and finally in PP (0.65%) samples in the 12 months time period. FTIR spectra of PC displayed a decrease in carbonate carbonyl index, while an initial increase and a decrease in carbonyl index of polyolefins as a function of time indicated biodegradation. � 2009 Elsevier Ltd. All rights reserved.

N,S-co-doped anatase-phase TiO 2 (N,S-TiO 2) nanophotocatalysts were prepared from either benzothiazoline or aminothiol with titanium isopropoxide followed by a systematic thermal decomposition. The chemical nature of S and N in N,S-TiO 2 have been identified by XPS to be sulfate and NO-like, respectively. A significant band broadening and red-shift in the UV-visible absorption spectrum of N,S-TiO 2 suggests a band gap reduction compared to TiO 2. A maximum band-gap narrowing of 0.22�0.02 eV was observed on N,S-TiO 2. Higher energy width observed on N,S-TiO 2 is in contrast to 0.13 eV from N-doped TiO 2 indicating the sulfate-like species might play a major role in narrowing the band-gap to a higher level. It is confirmed that the oxidation of N and S to NO and SO42 occurs in the final stage of preparation of N,S-TiO 2, during calcination in air. It is predicted that the oxygen associated with sulfate and NO structural features could be crucial in bringing down the energy gap and red shift in optical absorption and the role of sulfur is to facilitate the above. Photocatalytic decomposition of methylene blue has been carried out on N,S-TiO 2 shows higher activity than the commercial TiO 2 in the visible region. However, sulfate species seems to enhance the activity of N,S-TiO 2 marginally compared to N-TiO 2, and possible suggestions are given to improve the same. Copyright � 2009 American Scientific Publishers All rights reserved.