Obesity and contraceptive use: impact on cardiovascular risk.

Obesity and oestrogen containing contraceptive products are well-known independent cardiovascular risk factors. However, a significant number of obese women continue to receive prescriptions of hormonal products that contain oestrogens for their contraception. We have conducted a narrative review to discuss the latest evidence, ongoing research, and controversial issues on the synergistic effect of obesity and contraceptive use, in terms of cardiovascular risk. There is compelling evidence of an interplay between obesity and contraception in increasing cardiovascular risk. Women who present both obesity and use of combined oral contraceptives (COCs) have a greater risk (between 12 and 24 times) to develop venous thromboembolism than non-obese non-COC users. Data here discussed offer new insights to increase clinicians' awareness on the cardiovascular risk in the clinical management of obese women. The synergistic effect of obesity and COCs on deep venous thrombosis risk must be considered when prescribing hormonal contraception. Progestin-only products are a safer alternative to COCs in patients with overweight or obesity. Obese women taking contraceptives should be viewed as an 'at risk' population, and as such, they should receive advice to change their lifestyle, avoiding other cardiovascular risk factors, as a form of primary prevention. This indication should be extended to young women, as data show that COCs should be avoided in obese women of any age

A qualitative study of anticipated barriers and facilitators to the implementation of nurse-delivered alcohol screening, brief intervention, and referral to treatment for hospitalized patients in a Veterans Affairs medical center

Background: Unhealthy alcohol use includes the spectrum of alcohol consumption from risky drinking to alcohol use disorders. Routine alcohol screening, brief intervention (BI) and referral to treatment (RT) are commonly endorsed for improving the identification and management of unhealthy alcohol use in outpatient settings. However, factors which might impact screening, BI, and RT implementation in inpatient settings, particularly if delivered by nurses, are unknown, and must be identified to effectively plan randomized controlled trials (RCTs) of nurse-delivered BI. The purpose of this study was to identify the potential barriers and facilitators associated with nurse-delivered alcohol screening, BI and RT for hospitalized patients. Methods: We conducted audio-recorded focus groups with nurses from three medical-surgical units at a large urban Veterans Affairs Medical Center. Transcripts were analyzed using modified grounded theory techniques to identify key themes regarding anticipated barriers and facilitators to nurse-delivered screening, BI and RT in the inpatient setting. Results: A total of 33 medical-surgical nurses (97% female, 83% white) participated in one of seven focus groups. Nurses consistently anticipated the following barriers to nurse-delivered screening, BI, and RT for hospitalized patients: (1) lack of alcohol-related knowledge and skills; (2) limited interdisciplinary collaboration and communication around alcohol-related care; (3) inadequate alcohol assessment protocols and poor integration with the electronic medical record; (4) concerns about negative patient reaction and limited patient motivation to address alcohol use; (5) questionable compatibility of screening, BI and RT with the acute care paradigm and nursing role; and (6) logistical issues (e.g., lack of time/privacy). Suggested facilitators of nurse-delivered screening, BI, and RT focused on provider- and system-level factors related to: (1) improved provider knowledge, skills, communication, and collaboration; (2) expanded processes of care and nursing roles; and (3) enhanced electronic medical record features. Conclusions: RCTs of nurse-delivered alcohol BI for hospitalized patients should include consideration of the following elements: comprehensive provider education on alcohol screening, BI and RT; record-keeping systems which efficiently document and plan alcohol-related care; a hybrid model of implementation featuring active roles for interdisciplinary generalists and specialists; and ongoing partnerships to facilitate generation of additional evidence for BI efficacy in hospitalized patients

On the Performance of Spatially Correlated Large Antenna Arrays for Millimeter-Wave Frequencies

A spatially correlated large antenna array operating at millimeter-wave (mmWave) frequencies is considered. Based on a Saleh-Valenzuela channel model, closed-form expressions of the 3-D spatial correlation (SC) for wide, narrow, and Von Mises power elevation spectra (PESs) are analytically derived. The effects of the PES on the convergence to massive multiple-input-multiple-output properties are then illustrated by defining and deriving a diagonal dominance metric. Numerically, the effects of antenna element mutual coupling (MC) are shown on the effective SC, eigenvalue structure, and mmWave user rate for different antenna topologies. It is concluded that although MC can significantly reduce SC for side-by-side dipole antenna elements, the change in antenna effective gain (and, therefore, signal-to-noise ratio) caused by MC becomes a dominating effect and ultimately determines the antenna array performance. The user rate of an mmWave system with hybrid beamforming, using an orthogonal matching pursuit (OMP) algorithm, is then shown for different antenna topologies with dipole and cross-polarized (x-pol) antenna elements. It is seen that even for small numbers of radio frequency chains, the OMP algorithm works well relative to the fully digital case for channels with high SC, such as the x-pol antenna array

Giant aneurysm of the atrial septum associated with premature closure of foramen ovale

Premature closure or restriction of foramen ovale (PCFO) is a rare congenital anomaly that can lead to a wide spectrum of cardiac malformations. This spectrum of secondary malformations appears to depend on the gestational timing of closure of the foramen ovale and to the degree of restriction. Earlier in the gestation, closure of the foramen has been associated with severe hypoplasia of the left ventricle whereas later closure has been associated with right heart failure and rarely with the formation of an aneurysm of the atrial septum. We describe the case of a 1 day old infant in whom PCFO resulted in severe right heart failure in addition to the formation of a giant atrial septal aneurysm

Tuning ultrafast electron thermalization pathways in a van der Waals heterostructure

Ultrafast electron thermalization - the process leading to Auger recombination, carrier multiplication via impact ionization and hot carrier luminescence - occurs when optically excited electrons in a material undergo rapid electron-electron scattering to redistribute excess energy and reach electronic thermal equilibrium. Due to extremely short time and length scales, the measurement and manipulation of electron thermalization in nanoscale devices remains challenging even with the most advanced ultrafast laser techniques. Here, we overcome this challenge by leveraging the atomic thinness of two-dimensional van der Waals (vdW) materials in order to introduce a highly tunable electron transfer pathway that directly competes with electron thermalization. We realize this scheme in a graphene-boron nitride-graphene (G-BN-G) vdW heterostructure, through which optically excited carriers are transported from one graphene layer to the other. By applying an interlayer bias voltage or varying the excitation photon energy, interlayer carrier transport can be controlled to occur faster or slower than the intralayer scattering events, thus effectively tuning the electron thermalization pathways in graphene. Our findings, which demonstrate a novel means to probe and directly modulate electron energy transport in nanoscale materials, represent an important step toward designing and implementing novel optoelectronic and energy-harvesting devices with tailored microscopic properties.Comment: Accepted to Nature Physic

Magnesium intake and colorectal cancer risk in the Netherlands Cohort Study

Energy-adjusted magnesium intake was nonsignificantly inversely related to risk of colorectal cancer (n=2328) in the Netherlands Cohort Study on Diet and Cancer that started in 1986 (n=58 279 men and 62 573 women). Statistically significant inverse trends in risk were observed in overweight subjects for colon and proximal colon cancer across increasing quintiles of magnesium uptake (P-trend, 0.05 and 0.02, respectively). Although an overall protective effect was not afforded, our results suggest an effect of magnesium in overweight subjects, possibly through decreasing insulin resistance

Identification of Class I HLA T Cell Control Epitopes for West Nile Virus

The recent West Nile virus (WNV) outbreak in the United States underscores the importance of understanding human immune responses to this pathogen. Via the presentation of viral peptide ligands at the cell surface, class I HLA mediate the T cell recognition and killing of WNV infected cells. At this time, there are two key unknowns in regards to understanding protective T cell immunity: 1) the number of viral ligands presented by the HLA of infected cells, and 2) the distribution of T cell responses to these available HLA/viral complexes. Here, comparative mass spectroscopy was applied to determine the number of WNV peptides presented by the HLA-A*11:01 of infected cells after which T cell responses to these HLA/WNV complexes were assessed. Six viral peptides derived from capsid, NS3, NS4b, and NS5 were presented. When T cells from infected individuals were tested for reactivity to these six viral ligands, polyfunctional T cells were focused on the GTL9 WNV capsid peptide, ligands from NS3, NS4b, and NS5 were less immunogenic, and two ligands were largely inert, demonstrating that class I HLA reduce the WNV polyprotein to a handful of immune targets and that polyfunctional T cells recognize infections by zeroing in on particular HLA/WNV epitopes. Such dominant HLA/peptide epitopes are poised to drive the development of WNV vaccines that elicit protective T cells as well as providing key antigens for immunoassays that establish correlates of viral immunity. © 2013 Kaabinejadian et al

Radio Emission from Ultra-Cool Dwarfs

The 2001 discovery of radio emission from ultra-cool dwarfs (UCDs), the very low-mass stars and brown dwarfs with spectral types of ~M7 and later, revealed that these objects can generate and dissipate powerful magnetic fields. Radio observations provide unparalleled insight into UCD magnetism: detections extend to brown dwarfs with temperatures <1000 K, where no other observational probes are effective. The data reveal that UCDs can generate strong (kG) fields, sometimes with a stable dipolar structure; that they can produce and retain nonthermal plasmas with electron acceleration extending to MeV energies; and that they can drive auroral current systems resulting in significant atmospheric energy deposition and powerful, coherent radio bursts. Still to be understood are the underlying dynamo processes, the precise means by which particles are accelerated around these objects, the observed diversity of magnetic phenomenologies, and how all of these factors change as the mass of the central object approaches that of Jupiter. The answers to these questions are doubly important because UCDs are both potential exoplanet hosts, as in the TRAPPIST-1 system, and analogues of extrasolar giant planets themselves.Comment: 19 pages; submitted chapter to the Handbook of Exoplanets, eds. Hans J. Deeg and Juan Antonio Belmonte (Springer-Verlag