To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Background: There is an unmet need for blood-based biomarkers that can reliably detect MS disease activity. Serum Biomarkers of interest includ Neurofilament-light-chain (NfL), Glial-fibrillary-strocyte-protein(GFAP) and Tau. Bone Marrow Transplantation (BMT) is reserved for aggressive forms of MS and has been shown to halt detectable CNS inflammatory activity for prolonged periods. Significant pre-treatment tissue damage at followed by inflammatory disease abeyance should be reflected longitudinal sera collected from these patients. Methods: Sera were collected from 23 MS patients pre-treatment, and following BMT at 3, 6, 9 and 12-months in addition from 33 non-inflammatory neurological controls. Biomarker quantification was performed with SiMoA. Results: Pre-AHSCT levels of serum NfL and GFAP but not Tau were elevated compared to controls (p=0.0001), and NfL correlated with lesion-based disease activity (6-month-relapse, MRI-T2 and Gadolinium-enhancement). 3-months post-treatment, while NfL levels remained elevated, Tau/GFAP paradoxically increased (p=0.0023/0.0017). These increases at 3m correlated with MRI ‘pseudoatrophy’ at 6-months. NfL/Tau levels dropped to that of controls by 6-months (p=0.0036/0.0159). GFAP levels dropped progressively after 6-months although even at 12-months remained higher than controls (p=0.004). Conclusions: NfL was the closest correlate of MS disease activity and treatment response. Chemotherapy-related toxicity may account for transient increases in NfL, Tau and MRI brain atrophy post-BMT.
We present a preliminary report on radial–velocity and infrared interferometric observations, with emphasis on the newly resolved nearby sources Gl 609.2 and Gl 804. We briefly discuss their low–mass companions, their luminosities, and their individual masses inferred from the combined solution of their spectroscopic and visual orbits.
Plasma silicon nitride (P-SiN) films were prepared from SiH4/NH3 mixtures in a large volume microwave plasma (LMP) apparatus, at substrate temperatures T2 ranging from ambient to 250°C.Under otherwise nominally identical fabrication conditions, deposition rates were 10 to 25 times greater than those reported by others for radio- or audio-frequency plasmas.Based on film compositions, determined by elastic recoil detection (ERD), and measurements of such properties as density, refractive index, etch rate in dilute HF, and moisture permeation coefficient, our best P-SiN films (produced at T2 ≥ 200°C) are very similar to those reported in the literature.
Both single layers (SL) of Tb-Fe and multilayer (ML) TbFe/Al2O3 films have been prepared and the magnetic and magnetooptical properties have been studied as a function of Tb-Fe layer thickness (d,) and modulation characteristics. Perfect rectangular loop is observed only for d1 > 20 na. However in ML, even for d1 -8 nm such characteristics are obtained. Hc shows a stronger dependence on d1 particularly in ML samples. The properties of ML samples are determined by d1 A12O3 layer thickness and the number of bi-layers. The Faraday rotation for Tb19Fe81 films at 633 nm is found to be 2×105 deg.cm-1. Magnetic inhomogeneities cause steps and peaks in Faraday and Kerr loops respectively.
To lower the cost of multichip module packaging, hybridized substrate technologies have recently been reported which blend the desirable aspects of D and L fabrication (MCM-D/L). High performance dielectrics such as Cyclotene™3022 and photosensitive BCB have been shown to be compatible with laminate substrates used in MCM-DIL, however the cure levels of the dielectric on the laminates must be known for optimum processing.
In this paper, the capability of attenuated reflection IR microscopy (micro-ATR-IR) to probe thin films of BCB polymers is demonstrated. This technique enables the polymer layer to be probed regardless of the characteristics of the substrate. Cure levels of both Cyclotene™ 3022 and photodefinable BCB polymer films are obtained with micro-ATR-IR on both silicon and laminate substrate. Micro-ATR-IR is also used to probe a rapid thermal cure of Cyclotene Tm 3022 and photodefinable BCB layers on copper-clad polyimide laminate; these measurements cannot be made with transmission IR due to the high reflectivity of the substrate.
We have prepared Co/Pt multilayers by evaporation in UHV on MgO (100) substrates kept at various temperatures. Most of the samples were grown on a Pt buffer layer. Magnetic and magneto-optical properties have been studied. The surface anisotropy Ks for MgO substrates is 0.35 erg.cm−2 which is smaller than 0.6 erg.cm−2 obtained for glass substrates. The effect of the growth conditions on Ks is observed only for t(Co)<10 Å where the crossover to Keff>O occurs. Deposition at higher temperature leads to an increase in the coercivity. The magnetization and the anisotropy is practically temperature independent in the range 5 to 295 K. However the coercivity increases sharply below 100K.
The influence of the interfacial structure on the solid state reaction products in Fe-Ti multilayers has been studied using various preparation conditions and characterization techniques. Sharp and diffused interfaces were produced by using either sequential or co-evaporation in the interfacial region. The reaction product, in the case of the sharp interface, is the bcc supersaturated solid solution of Ti(Fe) while, in the case of the diffused interface, an amorphous phase is formed. Therefore, nucleating the amorphous phase at the interface by local co-evaporation alters the reaction path observed in Fe-Ti multilayers. The solid state reactions were studied using low and high angle X-ray diffraction and Mossbauer measurements. The results are discussed in light of recent thermodynamic calculations on the Fe-Ti system.
Thermoreflectance is an non contact optical method using the local reflectivity variations induced by heating to infer temperature mappings, and can be conducted at virtually any wavelength. In the visible, the technique is now well established. It can probe temperatures through several micrometers of transparent encapsulation layers, with sub-micron spatial resolution and 100 mK thermal resolution. In the ultraviolet range, dielectric encapsulation layers are opaque and thermoreflectance gives access to the surface temperature. In the near infrared, thermoreflectance is an interesting solution to examine chips turned upside down, since these wavelengths can penetrate through silicon substrates and give access to the temperature of the active layers themselves. Here, we explore the possibilities of each wavelength range and detail the CCD-based thermal imaging tools dedicated to the high resolution inspection of integrated circuits.
The crystalline, optical and electrical properties of In2S3 containing copper thin films are investigated. Increasing the amount of copper within the In2S3 crystalline matrix yields reduced bandgap value and hindered conductivity. The films investigated being synthesized at low temperature (200 °C), it is likely they have similar properties as the materials formed at the CuIn1-xGaxSe2/In2S3 interface.
Plasmas are energetic media that can give birth to dust particles due to the presence of reactive gases or plasma-surface interactions. Industrial plasmas are often concerned by these dust particles that can be either unwanted or useful for the process. For fusion plasmas, production of dust particles from wall erosion is a serious issue for performance and safety reasons. In this article, some aspects of dusty plasmas with potential implications for plasma experimenters will be discussed. Convenient ways for detecting the presence or the growth of dust particles will be presented. The spatial distribution of the dust cloud during the plasma phase determines the subsequent dust particle deposition. It will be shown that some reactor regions can attract or repeal these dust particles. Finally, the dust particle dynamics after the plasma extinction will be investigated. A special attention will be paid on the residual electric charge that can stay attached on the dust particle surface and on its implications for dust particle control or deposition.
Since the detection of nanoparticles is a major issue in nano sciences, we have developed two instruments for the fast imaging of individual nano objects. The first one is based on a spatial modulation of the sample using an incoherent dark field illumination and a multiplexed lock in detection.
The second instrument uses digital heterodyne holography. Both instruments make it possible to achieve a high signal-to-noise ratio and therefore to detect very low signal.
Most applications involving metallic nanoparticle labelling necessitate both fast imaging and local spectroscopy of individual beads. We present an imaging method based on a guided laser illumination associated to spatial modulation which allows the detection of gold particles down to 10 nm. Using an imaging spectrometer and white incoherent illumination, the same system delivers individual spectroscopy of several gold beads simultaneously, allowing a fast and selective discrimination between individual metal particles and aggregates or dust.
The purpose of this study was to investigate the clay mineral phases in a Rhodic Acrisol soil and to discuss their evolution in subtropical conditions. Prairie and forest soil profiles were sampled and clay fractions of the parent material and soil horizons analysed by X-ray diffraction (XRD) at the Federal University of Santa Maria, Rio Grande do Sul-Brazil. The XRD results show the presence of interstratified kaolinite-smectite and illite-smectite as well as illite in the parent material. These minerals were also found in the soil samples but with two new phases: hydroxy-aluminium interlayered vermiculite (HIV), which showed incomplete collapse with treatment at 550ºC, and a newly formed kaolinite (d = 7.17 Å). Under a subtropical climate and a sandy lithology, HIV and kaolinite appear to be a result of a specific pedogenic clay formation, related to the natural vegetation. Originally, under the prairie area, the intensity of the weathering processes was weak (within 2:1 clay minerals), as only small quantities of kaolinite and Fe oxides, and no evidence of gibbsite, were found.
Hexagonal AlN thin films have been deposited by DC reactive magnetron
sputtering at room temperature. For a first set of samples, sputtered AlN
films were deposited on silicon Si (100) substrates. For a second set, AlN
films were deposited on 200 nm (002) oriented AlN epitaxial layer obtained
by Molecular Beam Epitaxy (MBE) on Si (111).
X-ray Diffraction (XRD) and High Resolution Transmission Electron Microscopy
(HRTEM) analysis of the synthesized films on Si (100) substrate have shown
an amorphous phase close to the interface followed by a nano-crystalline
layer exhibiting (100) and (002) orientations of the hexagonal AlN
crystalline phase. Finally a relatively well crystallised layer with a
single (002) orientation has been observed for the thickest films. This
improvement of crystalline quality with film thickness has been consistent
with a drastic decrease of the films stress from –1.2 GPa at 300 nm to no
stress around 800 nm and even 0.3 GPa tensile stress for 1.5 μm thick
film. This behaviour was different when epitaxial AlN was used as substrate.
In fact, we have observed thanks to HRTEM images and Selected Area Electron
Diffraction (SAED) patterns, that the AlN film deposited on such a substrate
exhibits the same crystalline quality and have the same orientation as the
AlN epitaxial layer during the first 500 nm of thickness. A further increase
of film thickness has caused a decrease on the crystalline quality. The
films became polycrystalline while preserving a (002) preferential
In small populations of monogamous species sex ratio bias and sex-skewed demographic traits could lead to higher extinction probabilities than in other mating systems. Therefore a knowledge of bias in sex ratio, mortality and movement would be useful to determine the optimal strategy for sampling founders prior to reintroduction. We used molecular sexing to sex wild-hatched cohorts of two colonies (one native and one reintroduced) and four released groups of griffon vultures Gyps fulvus in France. In wild-hatched cohorts the sex ratio was not different from equilibrium whatever the year. Similarly no bias was detected in the sex ratio of founding stocks. Recoveries, recaptures, movements and philopatry were not skewed according to sex in wild-hatched and released groups. Our study revealed that no sex bias occurred during the griffon vulture life cycle (i.e. birth, death and movement). Consequently, random sampling may be appropriate to constitute founding stock in reintroduction programmes for monomorphic vultures.
The purpose of this study was to investigate the impact of redox-induced changes in the organization of the clay fraction of a bulk vertisol using transmission electron microscopy. Chemical and X-ray powder diffraction (XRD) analyses indicated that the oxidized clay was composed of 32% kaolinite and 68% non-pure smectitic material, mostly a dioctahedral beidellite with octahedral Fe, according to Quantarg2 and DecompXR models.
The cation exchange capacity of the soil increased from 26.1 to 65 cmolc+ kg-1 due to structural iron (FeStr) reduction and dissolution of oxide coatings. Transmission electron micrographs revealed dramatic changes upon reduction. Oxides were dissolved and the smectite increased in particle darkness, lateral extension, thickness, compactness and stacking order. These changes were interpreted to be a consequence of sorption of ferrous Fe and reduction of FeStr, as found in previous studies on pure Fe-bearing smectites.
The standard enthalpy of formation of InN at 298 K has been determined using high-temperature oxidative drop solution calorimetry in a molten sodium molybdate solvent at 975 K. Calorimetric measurements were performed on six InN samples with varying nitrogen contents. The samples were characterized using x-ray diffraction, chemical analysis, electron microprobe analysis, and Brunauer–Emmett–Teller surface area measurement. The variation of the enthalpy of drop solution (kJ/g) with nitrogen content is approximately linear. The data, when extrapolated to stoichiometric InN, yield a standard enthalpy of formation from the elements of ?28.6 ± 9.2 kJ/mol. The relatively large error results from the deviation of individual points from the straight line rather than uncertainties in each set of data for a given sample. This new directly measured enthalpy of formation is in good agreement with the old combustion calorimetric result by Hahn and Juza (1940). However, this calorimetric enthalpy of formation is significantly different from the enthalpy of formation values derived from the temperature dependence of the apparent decomposition pressure of nitrogen over InN. A literature survey of the enthalpies of formation of III–N nitride compounds is presented.
The aim of this study was to characterize polypeptide components of the capture net spun by trichopteran larvae Hydropsyche slossonae (Banks) (Trichoptera: Hydropsychidae). Thirty-one polypeptide bands were identified by SDS – polyacrylamide gel electrophoresis (SDS–PAGE) from extracted net material, with molecular weights ranging from 8500 to 179 000. Comparison with published data on Bombyx mori (L.) (Lepidoptera: Bombycidae) silk, treated under similar denaturing conditions, shows that six low molecular weight polypeptides ranging between 8500 and 18 800 in the silk of H. slossonae are absent from that of B. mori; furthermore, two high molecular weight polypeptides (210 000 and 220 000) detected in the silk of B. mori are not present in that of H. slossonae. Differences between both groups are probably related to their mode of living and to the specific use of silk (in air versus under water). Our findings are consistent with the current trend in the literature that silk spun by aquatic and terrestrial insects, as well as those spun by different species, is apparently made of different biopolymers according to the protein constituents. Hence, the polypeptide characterization of silk, combined with sequence data and (or) antibodies cross-reactivity data, could represent a potential tool for taxonomic classification improvement of aquatic insects. These results could eventually be used to characterize hydropsychid capture net anomalies induced by environmental pollution.