7Li NMR of Normal Human Erythrocytes

Lithium has been known to be an effective medication for people with bipolar disorder. The mechanisms of action of lithium in the brain is not very well understood. NMR spectroscopy and imaging are effective both in determining lithium levels in tissue and brain. We have monitored lithium levels in red blood cells. We have been able to separate intra- and extracellular compartments of lithium using shift reagents, thereby obtaining T^1 \u27s of both the compartments. Lithium uptake as a function of hematocrit was monitored weekly over a 3 week period. The time constant of 50 mM lithium uptake at 25°C and 85% hematocrit was found to be 16.5 hrs. The time constant of 1.8 mM lithium uptake at 37 °C and 45% hematocrit was found to be 11.6 hrs. Experiments on the visibility of the quadrupolar nuclei indicate that it is only 74-90% visible and the visibility decreased with decreasing concentrations

Advance crew procedures development techniques: Procedures generation program requirements document

The Procedures Generation Program (PGP) is described as an automated crew procedures generation and performance monitoring system. Computer software requirements to be implemented in PGP for the Advanced Crew Procedures Development Techniques are outlined

Thin Film Deposition of Silicon for Solar Cell Applications

Thin films of silicon have been formed using a patented electrostatic deposition method which utilizes charged particle motion in an electric field. After deposition, the films are heat treated for varying times and temperatures in a programmable furnace maintained under a purified argon atmosphere. X-ray diffraction (XRD) confirmed that these films were polycrystalline in nature. These films were found to have grain sizes of about 50 microns. Solar cells were fabricated using these large grained polycrystalline silicon films by sputtering pure gold as both front and back contacts. The cells have shown efficiencies of 1.8%. This paper reports on the growth of these large-grained polycrystalline thin silicon films and on the laser recrystallization setup to be used to increase the grain size up to 100 microns. Films grown via this electrostatic deposition method and subsequent laser recrystallization have a great potential for use in the solar cell industry

Field‐dependent relaxation and absolute nuclear shielding of 207Pb in liquid PbCl4

Relaxation times T1 and T2 of 207Pb in liquid PbCl4 have been studied for the purpose of establishing an absolute nuclear shielding scale for lead. T1 has been decomposed into scalar and spin‐rotation contributions using variable temperature measurements at the two field strengths 6.59 and 16.90 kG. T2 is much shorter than T1 and is strongly dominated by scalar coupling to chlorine. Knowledge of the scalar contributions to T1 and T2 determines the halogen relaxation times (τ35 = 7.15 μsec at 25°C), the lead‐chlorine coupling constant [(J(207Pb−35Cl) = 705 Hz)], and the reorientational correlation time (τθ = 1.72 × 10−11 sec at 25°C). A correlation time τJ for the angular momentum vector has been computed using J diffusion theory, but the value obtained appears to be too short (0.8–2.9 × 10−14 sec) to be meaningful in terms of classical diffusion of rigid molecules. Nevertheless, the known range of 207Pb chemical shifts places an absolute upper limit on τJ of 6 × 10−14 sec at 263°K. The physical significance of such short correlation times is discussed, and it is concluded that τJ probably describes collision‐induced distortions in the molecular structure. Experimental values of the spin‐rotation contribution to (T1)−1 are used in conjunction with estimated values of τJ to compute limiting values for the spin‐rotation constant that place limits on the paramagnetic part of the magnetic shielding constant. A shielding scale previously deduced from optical pumping data is discussed, and a source of possibly substantial error in this scale is pointed out.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70479/2/JCPSA6-60-3-1009-1.pd

Computer-Controlled Programmable Pulse Generator for a JEOL JNM-FT-1A Radio Frequency Amplifier Section of a Nuclear Magnetic Resonance Spectrometer

A microprocessor controlled programmable pulse generator was specifically designed to interface with the JEOL JNM-FT-1 A Radio Frequency (RF) section of a nuclear magnetic resonance (NMR) spectrometer. The programmable pulse generator was programmed and controlled by an IBM compatible computer. Statis rams were utilized as the programmable pulse generator\u27s on board memory which were used to store the pulse sequences. Pulse widths can be programmed from 0.2 microseconds to 14.3 minutes. The JEOL RF section is unique in that it allows the pulse generator to control the phase of the RF transmitted to the NMR probe and whether the sample will be decoupled. These two items set this programmable pulse generator apart from other pulse generators described in the literature and those systems which are commercially available. This programmable pulse generator was constructed to replace the old JEOL thumb wheel controlled pulse generator. Typical 180 degree pulse lengths for the JEOL NMR are approximately 20 microseconds

Field dependence of nuclear magnetic relaxation of 207Pb in aqueous Pb(ClO4)2

Nuclear magnetic relaxation times of the 207Pb resonance have been measured as a function of temperature and concentration at field strengths of 16.9, 11.7, and 6.56 kG in aqueous Pb(ClO4)2. Longitudinal relaxation is composed of spin‐rotation, chemical shift anisotropy, and dipolar contributions in a 3.5M solution, while spin‐rotation strongly dominates the relaxation at all temperatures between the melting and boiling points in a 1.15M solution. T2 accurately equals T1 at 1.15M, as is expected for a dominant spin‐rotation interaction, but is 20–30% shorter in the 3.5M solution, possibly due to a minor relaxation component arising from scalar coupling to naturally abundant H217OH217O. Chemical shifts of 207Pb have also been measured in aqueous Pb(ClO4)2 and Pb(NO3)2. The chemical shift and relaxation data show that ClO4− penetrates the Pb+2 hydration sphere at concentrations above about 2M, but no effects of such penetration are seen at lower concentration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70168/2/JCPSA6-60-4-1522-1.pd

Integrated Circuits Interconnect Metallization for the Submicron Age

The interconnect metallization being used by the semiconductor industry has been aluminum or aluminum silicon. Aluminum silicon is being replaced by aluminum copper and aluminum copper silicon, due to its superior resistance to electromigration and hillock growth. This paper discusses the implementation of aluminum copper/silicon alloys in semiconductor processing, along with a review of the problems and advantages of the same

Method to Correct the Voxel Size in PRESS Localized NMR Stereoscopy

Two techniques commonly used on human magnetic resonance spectroscopy systems to obtain spectra from localized volumes in the brain are point resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM) spectroscopy. PRESS gives a signal twice as large as that obtained with STEAM, but suffers from longer minimum echo times. While STEAM must be used to detect species with short spin-spin relaxation times, PRESS can be used for species with longer relaxation times to give a spectrum with a better signal to noise ratio. Only STEAM was provided for the GE Omega 4.7 T small animal imager used in this laboratory. Therefore, a PRESS pulse program was written for this instrument. With the standard sequence, the sampled voxel is smaller than the prescribed voxel. A larger voxel can be prescribed to increase the sampled volume. A different approach, involving the modification of the gradient strength, has been used in this laboratory. The resulting pulse sequence, with representative profiles, is discussed

An educational campaign to increase chiropractic intern advising roles on patient smoking cessation

BACKGROUND: Tobacco use, particularly smoking, is the most preventable cause of death in the United States. More than 400,000 premature deaths are associated with its use and the health care costs are in the billions. All health care provider groups should be concerned with patients who continue to smoke and use tobacco. The US Preventive Services Taskforce and Health People 2010 guidelines encourage providers to counsel smokers on cessation. Current studies, though limited regarding chiropractic advising practices indicate a low engagement rate when it comes to providing cessation information. OBJECTIVE: To test a campaign regarding initial impact aimed at increasing chiropractic interns advising on cessation and delivery of information to smokers on cessation. DISCUSSION: Chiropractic interns do engage patients on smoking status and can be encouraged to provide more cessation messages and information to patients. The initial impact assessment of this campaign increased the provision of information to patients by about 25%. The prevalence of smoking among chiropractic patients, particularly at teaching clinics may be lower than the national averages. CONCLUSION: Chiropractic interns can and should be encouraged to advise smokers about cessation. A systematic method of intake information on smoking status is needed and a standardized education protocol for chiropractic colleges is needed. Chiropractic colleges should assess the adequacy of their advising roles and implement changes to increase cessation messages to their patients as soon as possible