What are gene patents and why are people worried about them?

This article examines what it means to patent a gene. Numerous ethical concerns have been raised about the effects of such patents on clinical medical practice as well as on research and development. We describe what kinds of inventions are covered by human gene patents, give several examples and summarize the small body of empirical research performed in the US examining the effects of these patents. There is little evidence that early fears about gene patenting placing substantial restraints on research and clinical medicine have come to fruition. Nonetheless, there are areas of concern, and policy makers, physicians and the public should be alert to ensure that the net social benefits of patenting human genes are maintained.     

X‐Ray Spectroscopic Investigation of Chlorinated Graphene: Surface Structure and Electronic Effects

Chemical doping of graphene represents a powerful means of tailoring its electronic properties. Synchrotron‐based X‐ray spectroscopy offers an effective route to investigate the surface electronic and chemical states of functionalizing dopants. In this work, a suite of X‐ray techniques is used, including near edge X‐ray absorption fine structure spectroscopy, X‐ray photoemission spectroscopy, and photoemission threshold measurements, to systematically study plasma‐based chlorinated graphene on different substrates, with special focus on its dopant concentration, surface binding energy, bonding configuration, and work function shift. Detailed spectroscopic evidence of C–Cl bond formation at the surface of single layer graphene and correlation of the magnitude of p‐type doping with the surface coverage of adsorbed chlorine is demonstrated for the first time. It is shown that the chlorination process is a highly nonintrusive doping technology, which can effectively produce strongly p‐doped graphene with the 2D nature and long‐range periodicity of the electronic structure of graphene intact. The measurements also reveal that the interaction between graphene and chlorine atoms shows strong substrate effects in terms of both surface coverage and work function shift.     

Optical absorption of EuTe in high magnetic fields

For the first time, the optical absorption edge of the magnetic semiconductor europium telluride has been studied at low temperature (1.7 K) as a function of magnetic field in the high field range 0 ≤ H ≤ 9.5 Tesla, and related to the magnetic phase diagram of this material. The exponential absorption edge has been parameterized using a magnetic field dependent extension of Urbach's rule, and the observations are found to be consistent with a simple dependence of the gap parameter on polarization and magnetic field.     

Laser emission study of the pressure dependence of the energy gap in tellurium

The pressure dependence of the band gap of tellurium has been precisely measured to 8 kbar in a study of the laser emission of an optically-pumped sample at liquid nitrogen temperatures. A large negative pressure tuning coefficient is observed along with an anomalous nonlinearity in the tuning. These measurements are compared to previous studies using other optical and electrical techniques and are related to current theoretical models of the band structure of tellurium.     

Temperature dependence of C-axis electrical resistivity and thermopower of graphite intercalation compounds

Results on the temperature variation from 2 ? T ? 300 K of the c-axis electrical resistivity and thermopower of a donor stage-5 potassium and an acceptor stage-2 FeCl₃ graphite intercalation compounds are reported. Comparing the data with those of the literature reveals for both compounds a different qualitative behavior for low and high stages.     

Light scattering lineshape in opaque materials

The wavevector distribution excited by light scattering in opaque materials is calculated and compared to recently observed asymmetrical Brillouin lineshapes.     

Low temperature thermal conductivity of graphite-FeCl3 intercalation compounds

The low-temperature variation of the in-plane thermal conductivity of graphite- FeCl₃ intercalation compounds is reported. Around room temperature, though holes are participating, there is an important lattice contribution, but much smaller than in pristine graphite. The electronic contribution dominates in the liquid helium range. These preliminary results suggest lattice thermal conductivity measurements as a new tool to investigate defects introduced by intercalation.     

Chemisorbed phases of H2O on TiO2 and SrTiO3

Ultraviolet photoemission spectroscopy in ultrahigh vacuum has been used to study the interaction of H₂O with argon-ion-bombarded and annealed TiO₂(110) and SrTiO₃ (100) surfaces. At low exposure, evidence is found for the presence of the OH free radical on both bombarded and annealed TiO₂. At high exposure, a spectrum of slightly perturbed adsorbed H₂O is observed, with the a₁ molecular orbital shifted 0.5–1 eV toward tighter binding. This suggests that H₂O binds to the surface of TiO₂ via its a₁, in-plane O lone-pair orbital. No evidence is found for OH on the surface of SrTiO₃. The spectrum of H₂O adsorbed on bombarded SrTiO₃ shows both the a₁ and b₂ molecular orbitals shifted 0.4 toward tighter binding, indicating a more complicated bonding to the surface. For SrTiO₃ that has been bombarded and then annealed, the spectrum of adsorbed H₂O shows no significant bonding effects.     

Nanostructured Bulk Silicon as an Effective Thermoelectric Material

Thermoelectric power sources have consistently demonstrated their extraordinary reliability and longevity for deep space missions and small unattended terrestrial systems. However, more efficient bulk materials and practical devices are required to improve existing technology and expand into large‐scale waste heat recovery applications. Research has long focused on complex compounds that best combine the electrical properties of degenerate semiconductors with the low thermal conductivity of glassy materials. Recently it has been found that nanostructuring is an effective method to decouple electrical and thermal transport parameters. Dramatic reductions in the lattice thermal conductivity are achieved by nanostructuring bulk silicon with limited degradation in its electron mobility, leading to an unprecedented increase by a factor of 3.5 in its performance over that of the parent single‐crystal material. This makes nanostructured bulk (nano‐bulk) Si an effective high temperature thermoelectric material that performs at about 70% the level of state‐of‐the‐art Si_0.8Ge_0.2 but without the need for expensive and rare Ge.     

Microstructure of Milled Mesophase Pitch-Based Carbon Fibers as an Anode Material for Li-ion Batteries

Abstract

The microstructure of milled mesophase pitch-based carbon fibers (mMPCFs) that have been developed as an anode material for Li ion batteries have been studied as a function of heat treatment temperature (HTT), by SEM, X-ray diffraction, and Raman spectroscopy. And the results obtained are compared with those by X-ray diffraction (XRD) and SEM observations, for the characterization of specific structural features of mMPCFs as a promising anode material.