Patterns of Medical Cannabis Use among Patients Diagnosed with Multiple Sclerosis.

OBJECTIVE: To survey the pattern and benefits of medical cannabis use (MCU) in a cross section of persons with multiple sclerosis (PWMS). METHODS: One hundred and fifteen subjects completed a 36-question survey online or on paper which queried aspects of their use of cannabis, including frequency of use, effect on symptoms, and changes in their use of prescription medications, as well asa number of key demographic variables such as age, gender, disease duration and clinical course, etc. All subjects were treated at a multiple sclerosis (MS) clinic in Connecticut and enrolled in the Connecticut Medical Marijuana Program (CTMMP). RESULTS: Self-reported benefit from cannabis use for two or more symptoms of MS was associated with relapsing remitting MS (RRMS) vs progressive (PMS) (OR 3.043, 95% CI 1.026-9.028, p=0.038) and less benefit for two or more symptoms for those who required a wheelchair vs. those who ambulated without assistance (OR .246, 95% CI .195-.797, p=0.016). General benefit from cannabis use was reported for mood disorders (p<0.001), insomnia (p<0.001), sensory symptoms, including pain (p<0.001), and muscle cramps and spasms (p<0.001). Furthermore, benefit was also significantly associated with symptom severity in the case of insomnia (OR 9.735, 95% CI 2.751-34.445, p<0.001), and cramps and spasms (OR 5.234, 95% CI 1.261-21.729, p=0.014). A significant proportion of respondents had stopped or reduced prescription medications (86% vs. 55%, p<0.001) as a function of finding cannabis more effective than prescription medications. These included opioids, benzodiazepines, muscle relaxers and other pain medications. CONCLUSION: MCU among PWMS can lead to the reduction or discontinuation of several categories of prescription medications for symptoms of MS. Persons reporting the most benefit from MCU tended to have a milder form of MS with less disability, in contrast to previous studies. This study confirms the benefit of cannabis in several common MS symptoms, extending these findings to show that benefit can be related to baseline severity of some symptoms.

Ultrathin catalyst-free InAs nanowires on silicon with distinct 1D sub-band transport properties.

Ultrathin InAs nanowires (NW) with a one-dimensional (1D) sub-band structure are promising materials for advanced quantum-electronic devices, where dimensions in the sub-30 nm diameter limit together with post-CMOS integration scenarios on Si are much desired. Here, we demonstrate two site-selective synthesis methods that achieve epitaxial, high aspect ratio InAs NWs on Si with ultrathin diameters below 20 nm. The first approach exploits direct vapor-solid growth to tune the NW diameter by interwire spacing, mask opening size and growth time. The second scheme explores a unique reverse-reaction growth by which the sidewalls of InAs NWs are thermally decomposed under controlled arsenic flux and annealing time. Interesting kinetically limited dependencies between interwire spacing and thinning dynamics are found, yielding diameters as low as 12 nm for sparse NW arrays. We clearly verify the 1D sub-band structure in ultrathin NWs by pronounced conductance steps in low-temperature transport measurements using back-gated NW-field effect transistors. Correlated simulations reveal single- and double degenerate conductance steps, which highlight the rotational hexagonal symmetry and reproduce the experimental traces in the diffusive 1D transport limit. Modelling under the realistic back-gate configuration further evidences regimes that lead to asymmetric carrier distribution and breakdown of the degeneracy depending on the gate bias.

Optical absorption of composition-tunable InGaAs nanowire arrays.

InGaAs nanowire (NW) arrays have emerged as important active materials in future photovoltaic and photodetector applications, due to their excellent electronic properties and tunable band gap. Here, we report a systematic investigation of the optical absorption characteristics of composition-tunable vertical InGaAs NW arrays. Using finite-difference time-domain simulations we first study the effect of variable composition (Ga-molar fraction) and NW array geometry (NW diameter, period, fill factor) on the optical generation rate. NWs with typical diameters in the range of ∼100-250 nm lead to generation rates higher than the equivalent bulk case for moderate fill factors (NW period of ∼0.3-0.8 µm), while slightly smaller fill factors and increased diameters are required to maintain high generation rates at increased Ga-molar fraction. The optical absorption was further measured using spectrally resolved ultraviolet-visible-near-infrared (UV-vis-NIR) spectroscopy on NW arrays transferred to transparent substrates. Interestingly, large variations in Ga-molar fraction (0 < x(Ga) < 0.5) have a negligible influence, while minute changes in NW diameter of less than ±20 nm affect the absorption spectra very strongly, leading to pronounced shifts in the peak absorption energies by more than ∼700 meV. These results clearly highlight the much larger sensitivity of the optical absorption behavior to geometric parameters rather than to variations in the electronic band gap of the underlying NW array.

Monolithically Integrated High-ß Nanowire Lasers on Silicon.

Reliable technologies for the monolithic integration of lasers onto silicon represent the holy grail for chip-level optical interconnects. In this context, nanowires (NWs) fabricated using III-V semiconductors are of strong interest since they can be grown site-selectively on silicon using conventional epitaxial approaches. Their unique one-dimensional structure and high refractive index naturally facilitate low loss optical waveguiding and optical recirculation in the active NW-core region. However, lasing from NWs on silicon has not been achieved to date, due to the poor modal reflectivity at the NW-silicon interface. We demonstrate how, by inserting a tailored dielectric interlayer at the NW-Si interface, low-threshold single mode lasing can be achieved in vertical-cavity GaAs-AlGaAs core-shell NW lasers on silicon as measured at low temperature. By exploring the output characteristics along a detection direction parallel to the NW-axis, we measure very high spontaneous emission factors comparable to nanocavity lasers (ß = 0.2) and achieve ultralow threshold pump energies ≤11 pJ/pulse. Analysis of the input-output characteristics of the NW lasers and the power dependence of the lasing emission line width demonstrate the potential for high pulsation rates ≥250 GHz. Such highly efficient nanolasers grown monolithically on silicon are highly promising for the realization of chip-level optical interconnects.

Outcomes of a cardiovascular nutrition counseling program in African-Americans with elevated blood pressure or cholesterol level.

OBJECTIVE: To evaluate a cardiovascular nutrition education package designed for African-American adults with a wide range of literacy skills. DESIGN: Comparison of a self-help group and a full-instruction group; each group received nutrition counseling and clinical monitoring every 4 months. SUBJECTS: Three hundred thirty African-American adults, aged 40 to 70 years, with elevated cholesterol level or high blood pressure were randomly assigned to the self-help or full-instruction group; 255 completed the 12-month follow-up. INTERVENTIONS: Counseling to reduce intake of dietary fat, cholesterol, and sodium was based on Cardiovascular Dietary Education System (CARDES) materials, which included food-picture cards, a nutrition guide (self-help and full-instruction group), a video and audiotape series, and 4 classes (full-instruction group only). MAIN OUTCOME MEASURES: Changes in lipid levels and blood pressure after 12 months. STATISTICAL ANALYSES PERFORMED: Primary analyses consisted of repeated-measures analysis of variance to examine effects of time and randomization group on outcomes. RESULTS: Total cholesterol and low-density lipoprotein cholesterol level decreased by 7% to 8% in the self-help and full-instruction groups of men and women (P < .01). The ratio of total cholesterol to high-density lipoprotein cholesterol (HDL-C) decreased in both groups of women and in the men in the full-instruction group (P < .01). In full-instruction and self-help participants with elevated blood pressure at baseline, systolic blood pressure decreased by 7 to 11 mm Hg and diastolic blood pressure decreased by 4 to 7 mm Hg (P < .01). Outcomes did not differ by literacy scores but were positively related to the reported initial frequency of using CARDES materials. APPLICATIONS/CONCLUSIONS: These results suggest that periodic nutrition counseling based on CARDES materials used for home study can enhance management of lipid levels and blood pressure in African-American outpatients.

Mie scattering, Maxwell Garnett theory, and the Giaever immunology slide.

The physical mechanism whereby adsorbed layers of transparent material cause a visual darkening of thin indium films is investigated. The indium is observed to be in the form of discrete islands. The wavelength of minimum optical transmission through the indium film does not vary proportionately with the size of the indium island size, as would be expected if Mie scattering were the dominant optical effect. Instead, this wavelength depends on the fractional volume of the indium film occupied by the indium islands themselves, in the manner predicted by Maxwell Garnett theory.