CT dose reduction factors in the thousands using X-ray phase contrast

Phase-contrast X-ray imaging can improve the visibility of weakly absorbing objects (e.g. soft tissues) by an order of magnitude or more compared to conventional radiographs. Previously, it has been shown that combining phase retrieval with computed tomography (CT) can increase the signal-to-noise ratio (SNR) by up to two orders of magnitude over conventional CT at the same radiation dose, without loss of image quality. Our experiments reveal that as radiation dose decreases, the relative improvement in SNR increases. We discovered this enhancement can be traded for a reduction in dose greater than the square of the gain in SNR. Upon reducing the dose 300 fold, the phase-retrieved SNR was still almost 10 times larger than the absorption contrast data. This reveals the potential for dose reduction factors in the tens of thousands without loss in image quality, which would have a profound impact on medical and industrial imaging applications

Evaluation of the angiotensin II receptor blocker azilsartan medoxomil in African-American patients with hypertension

The efficacy and safety of azilsartan medoxomil (AZL-M) were evaluated in African-American patients with hypertension in a 6-week, double-blind, randomized, placebo-controlled trial, for which the primary end point was change from baseline in 24-hour mean systolic blood pressure (BP). There were 413 patients, with a mean age of 52years, 57% women, and baseline 24-hour BP of 146/91mmHg. Treatment differences in 24-hour systolic BP between AZL-M 40mg and placebo (-5.0mmHg; 95% confidence interval, -8.0 to -2.0) and AZL-M 80mg and placebo (-7.8mmHg; 95% confidence interval, -10.7 to -4.9) were significant (P.001 vs placebo for both comparisons). Changes in the clinic BPs were similar to the ambulatory BP results. Incidence rates of adverse events were comparable among the treatment groups, including those of a serious nature. In African-American patients with hypertension, AZL-M significantly reduced ambulatory and clinic BPs in a dose-dependent manner and was well tolerated

Elevated Mechanical Loading When Young Provides Lifelong Benefits to Cortical Bone Properties in Female Rats Independent of a Surgically Induced Menopause

Exercise that mechanically loads the skeleton is advocated when young to enhance lifelong bone health. Whether the skeletal benefits of elevated loading when young persist into adulthood and after menopause are important questions. This study investigated the influence of a surgically induced menopause in female Sprague-Dawley rats on the lifelong maintenance of the cortical bone benefits of skeletal loading when young. Animals had their right forearm extrinsically loaded 3 d/wk between 4 and 10 weeks of age using the forearm axial compression loading model. Left forearms were internal controls and not loaded. Animals were subsequently detrained (restricted to cage activities) for 94 weeks (until age 2 years), with ovariectomy (OVX) or sham-OVX surgery being performed at 24 weeks of age. Loading enhanced midshaft ulna cortical bone mass, structure, and estimated strength. These benefits persisted lifelong and contributed to loaded ulnas having greater strength after detraining. Loading also had effects on cortical bone quality. The benefits of loading when young were not influenced by a surgically induced menopause because there were no interactions between loading and surgery. However, OVX had independent effects on cortical bone mass, structure, and estimated strength at early postsurgery time points (up to age 58 weeks) and bone quality measures. These data indicate skeletal loading when young had lifelong benefits on cortical bone properties that persisted independent of a surgically induced menopause. This suggests that skeletal loading associated with exercise when young may provide lifelong antifracture benefits by priming the skeleton to offset the cortical bone changes associated with aging and menopause

Technology Estimating: A Process to Determine the Cost and Schedule of Space Technology Research and Development

NASA is investing in new technologies that include 14 primary technology roadmap areas, and aeronautics. Understanding the cost for research and development of these technologies and the time it takes to increase the maturity of the technology is important to the support of the ongoing and future NASA missions. Overall, technology estimating may help provide guidance to technology investment strategies to help improve evaluation of technology affordability, and aid in decision support. The research provides a summary of the framework development of a Technology Estimating process where four technology roadmap areas were selected to be studied. The framework includes definition of terms, discussion for narrowing the focus from 14 NASA Technology Roadmap areas to four, and further refinement to include technologies, TRL range of 2 to 6. Included in this paper is a discussion to address the evaluation of 20 unique technology parameters that were initially identified, evaluated and then subsequently reduced for use in characterizing these technologies. A discussion of data acquisition effort and criteria established for data quality are provided. The findings obtained during the research included gaps identified, and a description of a spreadsheet-based estimating tool initiated as a part of the Technology Estimating process

Induced magnetic moment of Eu3+ ions in GaN

Magnetic semiconductors with coupled magnetic and electronic properties are of high technological and fundamental importance. Rare-earth elements can be used to introduce magnetic moments associated with the uncompensated spin of 4f-electrons into the semiconductor hosts. The luminescence produced by rare-earth doped semiconductors also attracts considerable interest due to the possibility of electrical excitation of characteristic sharp emission lines from intra 4f-shell transitions. Recently, electroluminescence of Eu-doped GaN in current-injection mode was demonstrated in p-n junction diode structures grown by organometallic vapour phase epitaxy. Unlike most other trivalent rare-earth ions, Eu3+ ions possess no magnetic moment in the ground state. Here we report the detection of an induced magnetic moment of Eu3+ ions in GaN which is associated with the 7F2 final state of 5D0→7F2 optical transitions emitting at 622 nm. The prospect of controlling magnetic moments electrically or optically will lead to the development of novel magneto-optic devices

Bone cell-independent benefits of raloxifene on the skeleton: A novel mechanism for improving bone material properties

Authors' accepted manuscript. Bone Biology Laboratory http://www.iupui.edu/~bonelab/ Department of Anatomy and Cell Biology Indiana University School of Medicine Department of Biomedical Engineering IUPUIRaloxifene is an FDA approved agent used to treat bone loss and decrease fracture risk. In clinical trials and animal studies, raloxifene reduces fracture risk and improves bone mechanical properties, but the mechanisms of action remain unclear because these benefits occur largely independent of changes to bone mass. Using a novel experimental approach, machined bone beams, both from mature male canine and human male donors, were depleted of living cells and then exposed to raloxifene ex vivo. Our data show that ex vivo exposure of non-viable bone to raloxifene improves intrinsic toughness, both in canine and human cortical bone beams tested by 4-point bending. These effects are cell-independent and appear to be mediated by an increase in matrix bound water, assessed using basic gravimetric weighing and sophisticated ultrashort echo time magnetic resonance imaging. The hydroxyl groups (-OH) on raloxifene were shown to be important in both the water and toughness increases. Wide and small angle x-ray scattering patterns during 4-pt bending show that raloxifene alters the transfer of load between the collagen matrix and the mineral crystals, placing lower strains on the mineral, and allowing greater overall deformation prior to failure. Collectively, these findings provide a possible mechanistic explanation for the therapeutic effect of raloxifene and more importantly identify a cell-independent mechanism that can be utilized for novel pharmacological approaches for enhancing bone strength.The authors would like to thank Dr. Paul K. Hansma (Department of Physics, University of California, Santa Barbara), for suggesting the soaking technique and Dr. John Okasinski, Advanced Photon Source, for helping collect the WAXS data. Raloxifene was kindly provided by Eli Lilly (Indianapolis, IN, USA) under a Material Transfer Agreement to D.B.B. Eli Lilly was not involved in the study design, analyses or interpretation of the results. We are grateful to Dr. Susan J. Gunst for sharing dog tissue. Use of the Advanced Photon Source was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. This work was supported by NIH grants to D.B.B. and M.R.A

The Contact Structure of Great Britain's Salmon and Trout Aquaculture Industry

We analyse the network structure of the British salmonid aquaculture industry from the perspective of infectious disease control. We combine for the first time live fish transport (or movement) data covering England and Wales with data covering Scotland and include network layers representing potential transmission by rivers, sea water and local transmission via human or animal vectors in the immediate vicinity of each farm or fishery site. We find that 7.2% of all live fish transports cross the England-Scotland border and network analysis shows that 87% of English and Welsh sites and 72% of Scottish sites are reachable from cross-border connections via live fish transports alone. Consequently, from a disease-control perspective, the contact structures of England and Wales and of Scotland should not be considered in isolation. We also show that large epidemics require the live fish movement network and so control strategies targeting movements can be very effective. While there is relatively low risk of widespread epidemics on the live fish transport network alone, the potential risk is substantially amplified by the combined interaction of multiple network layers

The direct medical costs of epilepsy in children and young people: a population-based study of health resource utilisation

We described the health resource utilisation (HRU) and associated direct medical costs of managing epilepsy in children and young people (CYP) using population-level data from the United Kingdom. The study cohort were CYP born between 1988 and 2004 who were newly diagnosed with epilepsy and identified using a nationally representative primary care database from the United Kingdom. Reference unit costs were applied to each element of HRU to calculate annual direct medical costs per child. We assessed whether HRU and costs differed by time from diagnosis, age, sex and socioeconomic deprivation. Of 798 CYP newly diagnosed with epilepsy, 56% were male and the mean age at diagnosis was 5.6 years. The highest burden of HRU was in the first year following diagnosis with a mean annual cost of £930 (95% confidence interval (CI) £839–1022) per child in this first year. This decreased to £461 (95%CI 368–551) in the second year which remained fairly constant each subsequent year (£413 (95% CI 282–540) in the 8th year). The highest contribution to the annual medical costs was from inpatient hospital admissions followed by the costs of AEDs. Mean annual medical costs were significantly higher in children under 6 years of age compared with older children (p < 0.01), but were similar across socioeconomic groups (p = 0.62). The direct medical costs of HRU in CYP with epilepsy are higher in the first year after diagnosis compared to subsequent years, reflecting HRU related to the diagnostic process in the first year. Medical costs did not vary substantially by sex or socioeconomic deprivation indicating a similar level of consultation and care across these groups

Perspectives on Andean Prehistory and Protohistory: Papers from the Third Annual Northeast Conference on Andean Archaeology and Ethnohistory

This volume represents eight of the eighteen papers presented at the Third Northeast Conference on Andean Archaeology and Ethnohistory held at the University of Massachusetts, Amherst on October 27 and 28, 1984. It also includes a paper presented at the Second NCAAE held at the American Museum of Natural History on November 19-20, 1983. The papers include: Wandering Shellfish: New Insights from Southeastern Coastal Ecuador by Patricia Netherly, Late Prehistoric Terracing at Chijra in the Collca Valley, Peru: Preliminary Report I by Michael A. Malpass, The Topara Tradition: An Overview by Dwight T. Wallace, The Peruvian North Central Coast During the Early Intermediate Period: An Emerging Perspective by Richard E. Daggett, A Sequence of Monumental Architecture from Huamanchuco by John R. Topic, Duality in Public Architecture in the Upper Zena Valley by Patricia J. Netherly and Tom D. Dillehay, Piruru: A Preliminary Report on the Archaeological Botany of a Highland Andean Site by Lawrence Kaplan and Elisabeth Bonnier, Analysis of Organic Remains from Huamachuco Qollqas by Coreen E. Chiswell, Aspects of Casting Practice in Prehispanic Peru by Stuart V. Arnold, and Representations of the Cosmos: A Comparison of the Church of San Cristobal de Pampachiri with the Coricancha Drawing of Santacruz Pachacuti Yamqui Salcamaygua by Monica Barnes.https://digitalcommons.library.umaine.edu/andean_past_special/1000/thumbnail.jp