2,428 research outputs found
Recommended from our members
Preoperative Skin Conditioning: Extracellular Matrix Clearance and Skin Bed Preparation, A New Paradigm.
This paper introduces the concept of "skin bed preparation" prior to surgical procedures. Following the theory of chronic wound bed preparation and adapting the skin model to one of chronic wound changes related to extrinsic and intrinsic factors, a topical formulation aimed at recycling the extracellular matrix (ECM) from accumulated waste products is evaluated and discussed. The clearance of these products and stimulation of new replacements has the potential to change the regenerative milieu of the skin so that when procedures are carried out, cellular signaling and cross-talk at the dermal level are improved and healing is optimized. By introducing a combination of peptides and other synergistic active agents, a sequence of clearance, regeneration, and remodeling is initiated. This is confirmed and validated by a series of biopsies and clinical studies that demonstrate changes in the ECM as early as 2 to 3 weeks after application. Clinical studies related to resurfacing procedures show accelerated healing and improved symptomatic relief compared with standard of care by preconditioning the skin 2 weeks prior to the procedure. A similar approach is suggested as a potential advantage for invasive surgical procedures based on similar scientific principles elucidated on in the text
Affleck-Dine (Pseudo)-Dirac Neutrinogenesis
We consider the Affleck-Dine mechanism for leptogenesis in the minimal MSSM
with Dirac or Pseudo-Dirac neutrinos. The rolling of scalars along D-flat
directions generates a left-right asymmetry in the sneutrino sector, only the
left part of which is transferred to a baryon asymmetry via sphaleron
transitions. In the pure Dirac case the baryon asymmetry of the Universe is
thus mirrored by an equal and opposite asymmetry in the leptons. The mechanism
is also found to work when the neutrinos are pseudo-Dirac. No additional field
needs to be added to the MSSM other than the right-handed neutrino.Comment: Latex, 3 figures, 1 bib file, 2 added reference, 1 minor correction,
1 added commen
New Generation of Massless Dirac Fermions in Graphene under External Periodic Potentials
We show that new massless Dirac fermions are generated when a slowly varying
periodic potential is applied to graphene. These quasiparticles, generated near
the supercell Brillouin zone boundaries with anisotropic group velocity, are
different from the original massless Dirac fermions. The quasiparticle
wavevector (measured from the new Dirac point), the generalized pseudospin
vector, and the group velocity are not collinear. We further show that with an
appropriate periodic potential of triangular symmetry, there exists an energy
window over which the only available states are these quasiparticles, thus,
providing a good system to probe experimentally the new massless Dirac
fermions. The required parameters of external potentials are within the realm
of laboratory conditions.Comment: 4 pages, 4 figure
Community-based social determinants of three measures of mortality in Rhode Island cities and towns
Background: Efforts to understand and address the causes of place-based health disparities have focused primarily on understanding the social determinants of health on a large geographic level, such as the region, state, or county. However, there is a growing need to assess and understand how place-based characteristics at smaller geographic areas relate to of local place-based neighborhood characteristics on population health. Therefore, the objective of this study was to evaluate the magnitude of the associations between social determinants of health and life expectancy (LE) and related measures on the community level.
Methods: LE at birth (LE0), remaining LE at age 65 (LE65), and age-specific mortality rates (ASMR) were calculated from mortality data (2009–2011) collected by the Rhode Island Department of Health (RIDoH) using abridged life table methods for each RI city/town. The city/town-specific LE and ASMR were linked to data collected by the US Census, RIDoH, the Federal Bureau of Investigation, and other databases that include information about multiple social, environmental, and demographic determinants of health. Bivariate correlations between city/town-level LE0, LE65, and ASMR and social determinants: demographics, household composition, income and poverty, education, environment, food insecurity, crime, transportation, and rural-urban status were examined.
Results: LE0 (range: 75.9–83.3 years) was strongly associated with the percent of the population with a graduate/professional degree (r = 0.687, p \u3c  0.001), violent crime rate (r = − 0.598, p \u3c  0.001), and per capita income (r = 0.553, p \u3c  0.001). Similar results were observed for ASMR: ASMR was associated with the percent of the population with a graduate/professional degree (r = − 0.596, p \u3c  0.001), violent crime rate (r = 0.450, p = 0.005), and per capita income (r = − 0.533, p \u3c 0.001). The associations between LE65 and social determinants were more attenuated. Of note, none of the measures (LE0, LE65, or ASMR) were associated with any of the race/ethnicity variables.
Conclusions: There are several important place-based characteristics associated with mortality (LE and ASMR) among RI cities/towns. Additionally, some communities had unexpectedly high LE and low ASMR, despite poor social indicators
Electrical Switching in Metallic Carbon Nanotubes
We present first-principles calculations of quantum transport which show that
the resistance of metallic carbon nanotubes can be changed dramatically with
homogeneous transverse electric fields if the nanotubes have impurities or
defects. The change of the resistance is predicted to range over more than two
orders of magnitude with experimentally attainable electric fields. This novel
property has its origin that backscattering of conduction electrons by
impurities or defects in the nanotubes is strongly dependent on the strength
and/or direction of the applied electric fields. We expect this property to
open a path to new device applications of metallic carbon nanotubes.Comment: 4 pages and 4 figure
Pharmacist-Administered Influenza Vaccination in Children and Corresponding Regulations
In our retrospective cohort study, we evaluated trends in pharmacist-administered pediatric influenza vaccination rates in the United States and corresponding state-level pharmacist pediatric vaccination authorization models, including minimum age requirements, vaccination protocols, and/or prescription requirements. An administrative health claims database was used to capture influenza vaccinations in children less than 18 years old with 1 year of continuous enrollment and joinpoint regression was used to assess trends. Of the 3,937,376 pediatric influenza vaccinations identified over the study period, only 3.2% were pharmacist-administered (87.7% pediatrician offices, 2.3% convenience care clinics, 0.8% emergency care, and 6.0% other locations). Pharmacist-administered pediatric influenza vaccination was more commonly observed in older children (mean age 12.65 ± 3.26 years) and increased significantly by 19.2% annually over the study period (95% confidence interval 9.2%-30.2%, p \u3c 0.05). The Northeast, with more restrictive authorization models, represented only 2.2% (n = 2816) of all pharmacist-administered pediatric influenza vaccinations. Utilization of pharmacist-administered pediatric influenza vaccination remains low. Providing children with greater access to vaccination with less restrictions may increase overall vaccination rates. Due to the COVID-19 pandemic and the Public Readiness and Emergency Preparedness Act, pharmacists will play a major role in vaccinating children
Anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft versus allograft in young patients
Objectives: Traditionally, bone-patella tendon-bone (BTB) autograft has been the gold standard graft choice for younger, athletic patients requiring ACL reconstruction. However, donor site morbidity, post-operative patella fracture, and increased operative time have led many surgeons to choose BTB allograft for their reconstructions. Opponents of allografts feel that slower healing time, higher rate of graft failure, and potential for disease transmission makes them undesirable graft choices in athletic patients. The purpose of this study is to evaluate the clinical outcomes, both subjective and objective, of young patients that who have undergone either BTB autograft or allograft reconstructions with a minimum of 2-year follow-up. Methods: One hundred and twenty patients (60 autograft, 60 allograft), age 25 and below at time of surgery, were contacted after being retrospectively identified as patients having an ACL reconstruction with either a BTB allograft or autograft by one senior surgeon. Patients were administered the Lysholm Knee Scoring Scale and IKDC Subjective Knee Evaluation questionnaires. Fifty (25 BTB autograft and 25 BTB allograft) of the 120 returned for physical examination as well as completion of a single leg hop test and laxity evaluation using a KT-1000 arthrometer evaluation. Of the 120 patients contacted, there were a total of 7 failures (5.8%) requiring revision, 6 in the allograft group (86%) and 1 in the autograft group (14%). Results: The average Lysholm scores were 89.0 and 89.56 and the average IKDC scores were 90.8 and 92.1 in the autograft and allograft groups respectively. The differences in the Lysholm scores and the IKDC scores were not significant. The single leg hop and KT-1000 scores were also not significantly different. One autograft patient had a minor motion deficit. Three allograft patients had a grade 1 Lachman and pivot glide. One autograft patient and two allograft patients had mild patellafemoral crepitus. There was no significant difference in anterior knee pain between the two groups Conclusion: There is no significant difference in patient-rated outcome between ACL reconstructions using BTB autografts versus allografts. However, the overall study group did reveal an increased failure rate requiring revision in the allograft group. © The Author(s) 2015
Measuring the Primordial Deuterium Abundance During the Cosmic Dark Ages
We discuss how measurements of fluctuations in the absorption of cosmic
microwave background (CMB) photons by neutral gas during the cosmic dark ages,
at redshifts z ~ 7--200, could reveal the primordial deuterium abundance of the
Universe. The strength of the cross-correlation of brightness-temperature
fluctuations due to resonant absorption of CMB photons in the 21-cm line of
neutral hydrogen with those due to resonant absorption of CMB photons in the
92-cm line of neutral deuterium is proportional to the fossil deuterium to
hydrogen ratio [D/H] fixed during big bang nucleosynthesis (BBN). Although
technically challenging, this measurement could provide the cleanest possible
determination of [D/H], free from contamination by structure formation
processes at lower redshifts, and has the potential to improve BBN constraints
to the baryon density of the Universe \Omega_{b} h^2. We also present our
results for the thermal spin-change cross-section for deuterium-hydrogen
scattering, which may be useful in a more general context than we describe
here.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let
Recommended from our members
High resolution HLA analysis reveals independent class I haplotypes and amino-acid motifs protective for multiple sclerosis.
We investigated association between HLA class I and class II alleles and haplotypes, and KIR loci and their HLA class I ligands, with multiple sclerosis (MS) in 412 European American MS patients and 419 ethnically matched controls, using next-generation sequencing. The DRB1*15:01~DQB1*06:02 haplotype was highly predisposing (odds ratio (OR) = 3.98; 95% confidence interval (CI) = 3-5.31; p-value (p) = 2.22E-16), as was DRB1*03:01~DQB1*02:01 (OR = 1.63; CI = 1.19-2.24; p = 1.41E-03). Hardy-Weinberg (HW) analysis in MS patients revealed a significant DRB1*03:01~DQB1*02:01 homozyote excess (15 observed; 8.6 expected; p = 0.016). The OR for this genotype (5.27; CI = 1.47-28.52; p = 0.0036) suggests a recessive MS risk model. Controls displayed no HW deviations. The C*03:04~B*40:01 haplotype (OR = 0.27; CI = 0.14-0.51; p = 6.76E-06) was highly protective for MS, especially in haplotypes with A*02:01 (OR = 0.15; CI = 0.04-0.45; p = 6.51E-05). By itself, A*02:01 is moderately protective, (OR = 0.69; CI = 0.54-0.87; p = 1.46E-03), and haplotypes of A*02:01 with the HLA-B Thr80 Bw4 variant (Bw4T) more so (OR = 0.53; CI = 0.35-0.78; p = 7.55E-04). Protective associations with the Bw4 KIR ligand resulted from linkage disequilibrium (LD) with DRB1*15:01, but the Bw4T variant was protective (OR = 0.64; CI = 0.49-0.82; p = 3.37-04) independent of LD with DRB1*15:01. The Bw4I variant was not associated with MS. Overall, we find specific class I HLA polymorphisms to be protective for MS, independent of the strong predisposition conferred by DRB1*15:01
A Pilot Survey for the HO Southern Galactic Plane Survey (HOPS)
We describe observations with the Mopra radiotelescope designed to assess the
feasibility of the HO maser southern Galactic plane survey (HOPS). We
mapped two one-square-degree regions along the Galactic plane using the new 12
mm receiver and the UNSW Mopra spectrometer (MOPS). We covered the entire
spectrum between 19.5 and 27.5 GHz using this setup with the main aims of
finding out which spectral lines can be detected with a quick mapping survey.
We report on detected emission from HO masers, NH inversion transitions
(1,1), (2,2) and (3,3), HCN (3-2), as well as several radio recombination
lines.Comment: accepted by PAS
- …