Subject Retention in Prehospital Stroke Research Using a Telephone-Based Physician-Investigator Driven Enrollment Method.

Background and purposeSubject retention into clinical trials is vital, and prehospital enrollment may be associated with higher rates of subject withdrawal than more traditional methods of enrollment. We describe rates of subject retention in a prehospital trial of acute stroke therapy.MethodsAll subjects were enrolled into the NIH Field Administration of Stroke Therapy-Magnesium (FAST-MAG) phase 3 clinical trial. Paramedics screened eligible subjects and contacted the physician-investigator using a dedicated in-ambulance cellular phone. Physician-investigators obtained explicit informed consent from the subject or on-scene legally authorized representative (LAR) who reviewed and signed a consent form. Exception from informed consent (EFIC) was utilized in later stages of the study.ResultsThere were 1,700 subjects enrolled; 1,017 provided consent (60%), 662 were enrolled via LAR (39%), and 21 were enrolled via EFIC (1%). Of the 1,700 patients, 1,413 (83%) completed the 90-day visit, 265 (16%) died prior to the 90-day visit, and 22 (1.3%) withdrew from the study before completion. There were no differences in rates of withdrawal by method of study enrolment, i.e., self-consent (n = 14), 1.4%; LAR (n = 8), 1.2%; EFIC (n = 0) 0%.ConclusionThere was a high rate of retention when subjects were enrolled into prehospital stroke research using a phone-based method to obtain explicit consent

Imaging of Osteoarthritis

Osteoarthritis (OA) is the most prevalent joint disorder in the elderly, and there is no effective treatment. Imaging is essential for evaluating the synovial joint structures (including cartilage, meniscus, subchondral bone marrow and synovium) for diagnosis, prognosis, and follow-up. This article describes the roles and limitations of both conventional radiography and magnetic resonance (MR) imaging, and considers the use of other modalities (eg, ultrasonography, nuclear medicine, computed tomography [CT], and CT/MR arthrography) in clinical practice and OA research. The emphasis throughout is on OA of the knee. This article emphasizes research developments and literature evidence published since 2008

In-situ strain tuning of the Dirac surface states in Bi2Se3 films

Elastic strain has the potential for a controlled manipulation of the band gap and spin-polarized Dirac states of topological materials, which can lead to pseudo-magnetic-field effects, helical flat bands and topological phase transitions. However, practical realization of these exotic phenomena is challenging and yet to be achieved. Here, we show that the Dirac surface states of the topological insulator Bi2Se3 can be reversibly tuned by an externally applied elastic strain. Performing in-situ x-ray diffraction and in-situ angle-resolved photoemission spectroscopy measurements during tensile testing of epitaxial Bi2Se3 films bonded onto a flexible substrate, we demonstrate elastic strains of up to 2.1% and quantify the resulting reversible changes in the topological surface state. Our study establishes the functional relationship between the lattice and electronic structures of Bi2Se3 and, more generally, demonstrates a new route toward momentum-resolved mapping of strain-induced band structure changes

Side Differences of Thigh Muscle Cross-Sectional Areas and Maximal Isometric Muscle Force in Bilateral Knees with the Same Radiographic Disease Stage, but Unilateral Frequent Pain – Data from the Osteoarthritis Initiative

Objective To determine whether anatomical thigh muscle cross-sectional areas (MCSAs) and strength differ between osteoarthritis (OA) knees with frequent pain compared with contra-lateral knees without pain, and to examine the correlation between MCSAs and strength in painful vs painless knees. Methods Forty-eight subjects (31 women; 17 men; age 45–78 years) were drawn from 4,796 Osteoarthritis Initiative (OAI) participants, in whom both knees displayed the same radiographic stage (KLG2 or 3), one with frequent pain (most days of the month within the past 12 months) and the contra-lateral one without pain. Axial MR images were used to determine MCSAs of extensors, flexors and adductors at 35% femoral length (distal to proximal) and in two adjacent 5 mm images. Maximal isometric extensor and flexor forces were used as provided from the OAI database. Results Painful knees showed 5.2% lower extensor MCSAs (P = 0.00003; paired t-test), and 7.8% lower maximal extensor muscle forces (P = 0.003) than contra-lateral painless knees. There were no significant differences in flexor forces, or flexor and adductor MCSAs (P > 0.39). Correlations between force and MCSAs were similar in painful and painless OA knees (0.44 < r < 0.66). Conclusions Knees with frequent pain demonstrate lower MCSAs and force of the quadriceps (but not of other thigh muscles) compared with contra-lateral knees without knee pain with the same radiographic stage. Frequent pain does not appear to affect the correlations between MCSAs and strength in OA knees. The findings suggest that quadriceps strengthening exercise may be useful in treating symptomatic knee OA

Tibial coverage, meniscus position, size and damage in knees discordant for joint space narrowing - data from the Osteoarthritis Initiative.

INTRODUCTION: Meniscal extrusion is thought to be associated with less meniscus coverage of the tibial surface, but the association of radiographic disease stage with quantitative measures of tibial plateau coverage is unknown. We therefore compared quantitative and semi-quantitative measures of meniscus position and morphology in individuals with bilateral painful knees discordant on medial joint space narrowing (mJSN). METHODS: A sample of 60 participants from the first half (2,678 cases) of the Osteoarthritis Initiative cohort fulfilled the inclusion criteria: bilateral frequent pain, Osteoarthritis Research Society International (OARSI) mJSN grades 1-3 in one, no-JSN in the contra-lateral (CL), and no lateral JSN in either knee (43 unilateral mJSN1; 17 mJSN2/3; 22 men, 38 women, body mass index (BMI) 31.3 + 3.9 kg/m(2)). Segmentation and three-dimensional quantitative analysis of the tibial plateau and meniscus, and semi-quantitative evaluation of meniscus damage (magnetic resonance imaging (MRI) osteoarthritis knee score = MOAKS) was performed using coronal 3T MR images (MPR DESSwe and intermediate-weighted turbo spin echo (IW-TSE) images). CL knees were compared using paired t-tests (between-knee, within-person design). RESULTS: Medial tibial plateau coverage was 36 + 9% in mJSN1 vs 45 + 8% in CL no-JSN knees, and was 31 + 9% in mJSN2/3 vs 46 + 6% in no-JSN knees (both P < 0.001). mJSN knees showed greater meniscus extrusion and damage (MOAKS), but no significant difference in meniscus volume. No significant differences in lateral tibial coverage, lateral meniscus morphology or position were observed. CONCLUSIONS: Knees with medial JSN showed substantially less medial tibial plateau coverage by the meniscus. We suggest that the less meniscal coverage, i.e., less mechanical protection may be a reason for greater rates of cartilage loss observed in JSN knees. Copyright 2012 Osteoarthritis Research Society International. All rights reserved

Impact of Diet and/or Exercise Intervention on Infrapatellar Fat Pad Morphology: Secondary Analysis from the Intensive Diet and Exercise for Arthritis (IDEA) Trial

The infrapatellar fat pad (IPFP) represents intra-articular adipose tissue that may contribute to intra-articular inflammation and pain by secretion of pro-inflammatory cytokines. Here we examined the impact of weight loss by diet and/or exercise interventions on IPFP volume

Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant

Jet event rates in deep inelastic ep scattering at HERA are investigated applying the modified JADE jet algorithm. The analysis uses data taken with the H1 detector in 1994 and 1995. The data are corrected for detector and hadronization effects and then compared with perturbative QCD predictions using next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2) is determined evaluating the jet event rates. Values of alpha_S(Q^2) are extracted in four different bins of the negative squared momentum transfer~\qq in the range from 40 GeV2 to 4000 GeV2. A combined fit of the renormalization group equation to these several alpha_S(Q^2) values results in alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).Comment: 17 pages, 4 figures, 3 tables, this version to appear in Eur. Phys. J.; it replaces first posted hep-ex/9807019 which had incorrect figure 4

Multiplicity Structure of the Hadronic Final State in Diffractive Deep-Inelastic Scattering at HERA

The multiplicity structure of the hadronic system X produced in deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY vertex, t, is limited to |t|<1 GeV^2, is studied as a function of the invariant mass M_X of the system X. Results are presented on multiplicity distributions and multiplicity moments, rapidity spectra and forward-backward correlations in the centre-of-mass system of X. The data are compared to results in e+e- annihilation, fixed-target lepton-nucleon collisions, hadro-produced diffractive final states and to non-diffractive hadron-hadron collisions. The comparison suggests a production mechanism of virtual photon dissociation which involves a mixture of partonic states and a significant gluon content. The data are well described by a model, based on a QCD-Regge analysis of the diffractive structure function, which assumes a large hard gluonic component of the colourless exchange at low Q^2. A model with soft colour interactions is also successful.Comment: 22 pages, 4 figures, submitted to Eur. Phys. J., error in first submission - omitted bibliograph