bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation Fin Efficiency for One-Dimensional Heat Flow in a Circular Fin
Authors: Chambers R. L. , Somers E. V.
Published: May 2019

The one-dimensional steady-state solution for radiation from one side of an annular fin has been computed for values of the two design parameters 0⩽ϵσθi3Kro-ri⩽2.0 and 1.001⩽ρ=rori⩽15.0. The solution supplies design information needed for satellite thermal-power dissipating surfaces.
How to Replace Gears by Mechanisms (Linkages)
Authors: Hain Kurt , Marx Gerhard
Published: May 2019

A practical method is shown for designing four-bar mechanisms having a prescribed transmission ratio held within prescribed tolerances, for a limited range of motion. Such mechanisms may economically replace gears in many applications. Charts enable the designer to choose the mechanism having the best transmission angle possible.
Controlled Contact Cutting Tools
Authors: Chao B. T. , Trigger K. J.
Published: May 2019

A substantial reduction in power consumption, an increase in tool life, more effective utilization of cutting fluids, and improved surface finish on the machined workpiece have been achieved by suitably controlling the length of tool-chip contact. Reasons for these findings are discussed in terms of basic variables in chip formation mechanics.

Artificially restricted contact tools open new avenues for metal cutting research. Machining data obtained with such tools provide further evidence of the invariant behavior of the dynamic shear stress of metals under high-speed cutting conditions, and unfold interesting information on the intricate nature of tool-chip contact.
Synthesis of Path-Generating Mechanisms by Means of a Programmed Digital Computer
Authors: Freudenstein Ferdinand , Sandor George N.
Published: May 2019

A general method is presented for synthesizing plane, linked mechanisms obtainable from a single, closed kinematic chain. Using complex numbers and the matrix theory of linear systems, these methods have been applied to 4-link mechanisms for generating a path through up to five arbitrary points with prescribed corresponding crank rotations. The five-point synthesis is programmed for automatic computation on the IBM 650 digital computer, which determines all existing solutions (a maximum of 12 linkages), selects one on the basis of a quality index, and completes the generated path.
Self-Excited Vibrations in Metal Cutting
Authors: Cook Nathan H.
Published: May 2019

The basic mechanisms which cause self-excited vibrations of a cutting tool relative to the work are discussed in a qualitative manner. Similarly, mechanisms inherent in the cutting process which can damp or limit vibrations are discussed. Experiments are presented which are in agreement with the theory.
Observations on the Angle Relationships in Metal Cutting
Authors: Eggleston D. M. , Herzog R. , Thomsen E. G.
Published: May 2019

Orthogonal-cutting experiments using SAE 1112 free-cutting steel, 2024-T4 and 6061-T6 aluminum alloys, and alpha-brass (85 Cu-15 Zn) at feeds of 0.002 to 0.010 ipr, were performed on a lathe with 18-4-1 high-speed-steel cutting tools. The mean cutting speeds and rake angles for SAE 1112 varied from 33.7 to 170.8 fpm and 5 to 40 deg, respectively, while the remainder of the alloys were tested at conditions yielding a continuous chip without a built-up edge at speeds ranging from approximately 470 to 790 fpm. It was found that the angle λ between the shear plane and the resultant tool force R was only approximately constant for each test condition and varied with cutting speed. Hence the equation λ = ϕ + β − α = const and the linear relationship between ϕ and β − α are only approximately satisfied. Furthermore, neither the Ernst and Merchant minimum-energy criterion, nor the Lee and Shaffer nor the Hill ideal plastic-solid solution, is in agreement with all the experimental observations.
Power Heat Balance Considerations in Design and Operation of Industrial Plants
Authors: Hudson J. I.
Published: May 2019

Relations between design of process equipment and power-service facilities for industrial plants and the effect of each on over-all investment and operating costs are shown by typical examples. A brief discussion is given of a method of controlling manufacturing costs by application of power-performance standards once a plant is in operation.
The Influence of the Molecular Mean Free Path on the Performance of Hydrodynamic Gas Lubricated Bearings
Authors: Burgdorfer Albert
Published: May 2019

A modified Reynolds equation is derived for gas-lubricated hydrodynamic bearings operating under “slip flow” conditions. Closed analytical solutions are given for a Rayleigh type step-bearing and an inclined plane slider bearing for the case of two-dimensional flow.

The influence of the molecular mean free path on the performance of bearings of arbitrary form is obtained by means of a small parameter, perturbation technique.
The Unsteady Wake Interaction in Turbomachinery and Its Effect on Cavitation
Authors: Yeh Hsuan , Eisenhuth J. J.
Published: May 2019

This paper attempts first to predict theoretically the influence on the nonsteady pressure perturbations on a blade row as a result of periodic wakes shed from an upstream blade row, and then to compare such theoretical predictions with a series of carefully conducted cavitation experiments at the Garfield Thomas Water Tunnel of the Ordnance Research Laboratory. The results indicate that the experimental values of pressure perturbations are somewhat lower than theoretically predicted values. The general trend, e.g., the influence of wake width and wake spacing, is in substantial agreement between theory and experiments.
The Failure of Structural Metals Subjected to Strain-Cycling Conditions
Authors: Swindeman R. W. , Douglas D. A.
Published: May 2019

Data showing the isothermal strain-cycling capacity of three metals, Inconel, Hastelloy B, and beryllium are presented. It is noted that at frequencies of 0.5 cycle per min the data satisfied an equation of the form Nαϵp = K, where N is the number of cycles to failure, ϵp is the plastic strain per cycle, and α and K are constants whose values depend on the material and test conditions. Data on Inconel are given to establish the effect of grain size, specimen geometry, temperature, and frequency. It is found that, at temperatures above 1300 F, grain size and frequency exert a pronounced effect on the rupture life. Fine-grained metal survives more cycles before failure than coarse-grained material. Long time cycles shorten the number of cycles to failure when the strain per cycle is low. Thermal-strain-cycling data for Inconel are compared to strain-cycling data at the same mean temperature. Good correlation is found to exist between the two types of tests.
Energy Losses of Balls Rolling on Plates
Authors: Drutowski R. C.
Published: May 2019

The apparatus for measuring the rolling force of a ball supported between two plates is described. The rolling force is an extremely small quantity compared to the normal force. Instantaneous values of the rolling force vary greatly from point to point on the sample surface and this variation is explained in terms of surface roughness and material homogeneity. The energy losses of balls rolling on plates are shown as functions of load, material, and surface roughness. The rolling of a ball on a plate is examined as a cyclic process in which elastic hysteresis losses appear to be the primary source of energy dissipation. An analysis involving the Hertzian contact stress field is used to derive an equation relating the rolling force and the material damping capacity.
On the Effect of Lubricant Inertia in the Theory of Hydrodynamic Lubrication
Authors: Milne A. A.
Published: May 2019

A theoretical study is made of the corrections required to the basic lubrication equations to allow for small effects of lubricant inertia in the laminar regime. The problem is approached by first determining the stream function for a wedge-shaped oil film with purely viscous flow and then obtaining the first-order correction for inertia. For the particular case when the convergence of the film is small, the resulting expressions for pressure gradient and tangential drag are compared with those obtained by other methods. Close agreement is found with Kahlert’s equations, but the present expressions are more general in form. It would appear that, in general, the effect of lubricant inertia is to cause a slight increase in the load capacity of a bearing.
Optimum Design of Straight-Walled Diffusers
Authors: Kline S. J. , Abbott D. E. , Fox R. W.
Published: May 2019

The four common optimum problems in diffuser design are defined. These optima are located in relation to the over-all flow regimes in terms of geometrical parameters for straight-walled units. Using an empirically derived transformation of variables between the conical and two-dimensional geometries, all available data for optimum recovery at constant ratio of wall length to throat width are correlated by a single straight line. This line lies slightly above and parallel to the line of onset of large transitory stall on the chart of over-all flow regimes. The correlated results are based on a literature survey. The range of conditions for each investigation is tabulated for convenient future reference.
Studies of Jet Compression—I: Apparatus and Methods. Results With Air at Room Temperature
Authors: Hoge Harold J. , Eichacker Suzanne S. , Fiske David L.
Published: May 2019

An experimental jet compressor (ejector) employing gases at subatmospheric pressures is described and data are presented showing efficiencies obtained with air used as both the driving and the driven fluid. A technique is described by means of which efficiency may be determined as a function of outlet pressure and entrainment ratio. Curves are presented showing that efficiency passes through a maximum as outlet pressure is increased. The compression ratio of the driven fluid likewise passes through a maximum as the outlet pressure is increased, but the maximum of efficiency occurs at a slightly higher pressure than the maximum of compression ratio. The highest efficiency achieved was 20.6 per cent, at an entrainment ratio of 1.3 and a compression ratio of 1.14. The ratio of pressure of driven stream to pressure of driving stream at time of contact has been determined. The value of this pressure ratio corresponding to maximum efficiency was found to increase linearly with entrainment ratio, over most of the range of the measurements.
Large Water-Level Displacements in the Simple Surge Tank
Authors: Marris A. W.
Published: May 2019

The nondimensional unapproximated form of the equation describing the motion of the water level in a simple nonthrottled open surge tank operating under the condition of constant hydraulic power to the turbine is shown to have two singular points. One of these is at the steady-flow hydraulic grade-line level and accounts for small displacement phenomena. The other is at a lower elevation and accounts for the occurrence of drainage due to insufficient power being available at the turbine.

An approximate condition for the occurrence of drainage of this type is given for the case of sudden acceptance of full load from a zero-flow condition. This result and the condition for the perpetuation of oscillations of constant amplitude are compared with experimental data obtained by the author from a hydraulic model.
The Response of Pneumatic Transmission Lines to Step Inputs
Authors: Schuder C. B. , Binder R. C.
Published: May 2019

An equation was derived which describes the pressure-time relationship that occurs at the end of a dead-ended or volume-terminated pneumatic transmission line following a sudden pressure change at its input. The two partial differential equations which are solved are basic for transient fluid flow in pipes and analogous to the equations for transient electric current in lines without leakage. The derivation was based on a one-dimensional uniformly distributed system, small, reversible, adiabatic-pressure changes, and laminar flow. Experimental results obtained from tests on 3/8-in. and 1/4-in. tubing showed good agreement with the theoretical results.
A General Approach to the Practical Solution of Creep Problems
Authors: Mendelson A. , Hirschberg M. H. , Manson S. S.
Published: May 2019

A general method is presented for the solution of creep problems by the use of successive approximations. The method is equally applicable to different creep laws and loading paths. Examples are presented for the creep in a flat plate with a temperature gradient and for several cases of rotating disks. In these disk problems the transient conditions prior to the establishment of steady-state stress distribution are included and shown to have an appreciable effect on the total creep strains. The use of different cumulative creep laws such as the time-hardening and strain-hardening laws are illustrated.
Creep-Rupture Strength of Austenitic Cr-Ni-Mo Steels in Sheet and Bar Form
Authors: Smith G. V. , Garofalo F. , Whitmore R. W. , Burt R. R.
Published: May 2019

Creep-rupture tests at 1100, 1300, and 1500 F on seven bar-stock and seven sheet-stock, 18 Cr-8 Ni-Mo steels show that small variations in C, N, and P measurably influence both 100 and 1000-hr creep-rupture strength. Variation in amounts of C, N, and P accounts for at least one third of the variability in creep-rupture strength. The additional variability may be related to differences in thermal and mechanical history and in the inherent variability in creep-rupture testing. The bar-stock steels are slightly stronger at 1100, 1300, and 1500 F for rupture in 100 hr and at 1300 and 1500 F for rupture in 1000 hr. At 1100 F, essentially no difference is found between bar and sheet steels for the 1000-hr rupture strength.
Bending and Stretching of Corrugated Diaphragms
Authors: Dressler Robert F.
Published: May 2019

Solutions of the exact linear elastic-shell equations for all stresses and displacements are presented for a typical corrugated-diaphragm shape for three thicknesses varying over a 9 to 1 range. Results were obtained by numerical integration using an electronic digital computer. The effect of thickness-diameter-ratio variation is discussed with respect to both stresses and resultants, and peak values needed for design purposes are presented. Circumferential and meridional stresses are found to be equally important throughout the thickness range analyzed. Bending and membrane stresses are likewise equally important throughout the range. Peak values in some cases occur near the outer rim.
Heat and Mass Transfer Processes and the Performance Evaluation in Single-Slope Solar Stills
Authors: Aderibigbe David A.
Published: May 2019

The paper reviews the present understanding of the analysis of the heat and mass transfer processes in single-slope solar stills. By using the results of published experiments, it is proposed that the heat and mass transfer phenomena from the basin water to the glass cover are coupled. This coupling makes it possible to derive the dependence of the heat transfer coefficient for condensation on the inclination of the glass cover of the still. The derived relation, i.e., Nucon = 0.738 (Grcon*Prcon*sin β/Ja*)¼ A−1 where A is the aspect ratio, has been demonstrated to be an important expression for predicting the heat transfer coefficient for condensation hcon necessary for a more realistic evaluation of the overall efficiency of single-slope solar still of a given cover angle β.
Application of Certification/Safety Experience Gained in Fuel Cell Public Transportation With Buses Towards Marine Applications of Fuel Cells
Authors: Bawa Daljit , DeVaal Jake
Published: May 2019

Fuel cells with hydrogen fuel have now been demonstrated in public transportation for over 15 years worldwide. During this time Ballard-powered fuel cell buses have clocked more than 300,000 hours while accumulating over 5 million kilometers. These public transport buses have been certified and homologated in the USA, Europe, Australia and China. While certification agencies such as TUV, CHP, NHTSA, and other local governing bodies have been involved with the approval process for ensuring safety of personnel and equipment, the components themselves have met stringent requirements of NFPA, NGV, SAE, ASME, ANSI and other governing organizations.

This paper highlights the various standards and safety concepts used in the approval process of public transportation using fuel cell buses. Since marine ferries involve movement of personnel, it is recommended that many of the requirements used for public buses can be easily adapted for marine applications of fuel cells.

Paper published with permission.
Shore Power Supply (Cold Ironing) for Ships: Reducing Ship Engine Emissions
Authors: Gilman Thane
Published: May 2019

Cold Iron: Receipt of shore power, along with other utilities such as potable water and steam, is part of the process of placing the engineering plant in a status known as “cold iron.” The term originates from the steamship era, when ship boilers and engines would go relatively cold after being secured. To bring a steam plant back online, supplying its own power after a “cold iron” period, would involve a substantial light-off, warm-up, and transition period compared to modern, fully automated plants.

Onshore power supply (OPS, sometimes referred to as “cold ironing”) is a system of procedures and equipment that provides ships with a source of electrical power as an alternative to the ship’s service electrical power system. The primary benefit is that, since the ship no longer has main or auxiliary engines operating, the engine emissions are virtually eliminated in the port area. Many ports around the world are located near large populations, and engine emissions from ships unfortunately contribute to unwanted levels of nitrogen oxides, sulphur oxides, particulate matter, and even the “greenhouse gas” carbon dioxide. Onshore power supply achieves a better total emissions reduction result than ship-installed emissions equipment, because the engines are off-line. On the other hand, there are difficulties associated with high voltage, varying frequencies, safety and infrastructure costs that must be addressed in order to justify an onshore power supply installation.

Paper published with permission.
Development of ASME Section X Code for High Pressure Vessels
Authors: Newhouse Norman L. , Rawls George B.
Published: May 2019

ASME has a project to meet industry needs for pressure vessel Code updates to address storage of high pressure hydrogen. This has resulted in updates to existing B&PV Code, new Code Cases, and new Code requirements. One of the tasks was to develop requirements for high pressure composite reinforced vessels with non-load sharing liners. Originally developed as a Code Case, the requirements have been approved as mandatory Appendix 8 of ASME Section X of the B&PV Code, to be published in July 2010. The allowed pressures of this new Code are from 0.7 MPa (3,000 psi) to 103.4 MPa (15,000 psi). Qualification testing addresses expected operating conditions. Inspection requirements are being developed in cooperation with NBIC. Pressure vessels are being developed that meet the new ASME requirements. Efforts will be made to include additional gases, including compressed natural gas, and additional operational requirements in future revisions.

Paper published with permission.
Composite Pressure Vessels for Marine and Land Based Applications
Authors: Newhouse Norman L. , Patel Harish N.
Published: May 2019

Composite pressure vessels have been used for over 40 years in a variety of military, aerospace, marine, transportation, stationary, and vehicle applications. Codes, standards, and guidelines have been developed to address vessel performance in these high pressure applications by ASME and American Bureau of Shipping (ABS). A risk or hazard identification analysis may be conducted during qualification and approval process. Prototype and qualification testing in these standards validate the design and anticipated operating conditions. Knowledge has been gained from qualification testing, field experience, and inspection that supports selection of materials and design configurations for marine and land based applications. Periodic inspection of vessels mitigates risk, particularly in terms of detecting environmental and mechanically induced damage before failure can occur. This paper was written jointly between ABS and Lincoln Composites through the certification process of Lincoln’s Titan™ project. This paper will outline qualification of technology and, testing requirements, as well as discuss the basis for hazard mitigation and material selection in the marine environment.

Paper published with permission.
Review of the Applicability of Nuclear Regulatory Commission Information Notice (IN) 2012-14, “Motor Operated Valve Inoperable Because of Stem-Disc Separation,” to Constellation Energy Nuclear Group’s Ginna Station
Authors: Garofoli David , Joss Gregg
Published: May 2019

U.S. Nuclear Regulatory Commission (NRC) Information Notice (IN) 2012-14, “Motor-Operated Valve Inoperable Because of Stem-Disc Separation”, was issued to inform nuclear power-plant licensees of recent operating experience involving a motor-operated valve (MOV) that failed at the connection between the valve stem and disc. The NRC expectation was that recipients would review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. Additional regulatory suggestions and insights contained in the IN are not NRC requirements.

On closer examination of the events involved, it became apparent that the undetected stem-disc separation observed with the subject MOV was not necessarily limited to that type or style of valve. In fact, the vast majority of inservice testing (IST) valves, and the manner in which they are tested, could also be susceptible to loss of functionality going undetected. The intent of the compliance project performed at the R.E. Ginna Station nuclear power plant was to examine the current testing performed on each IST program valve and determine the level of confidence that stem-disc separation would be detected. If the level of confidence was deemed less than acceptable for a subject valve, one or more augmented actions, as deemed both practicable and viable, were recommended for implementation.

The purpose of this presentation paper is to describe the systematic methodology that was employed to validate the effectiveness of the current periodic IST valve testing conducted at the R.E. Ginna Station and the corrective-action recommendations that were made as deemed appropriate. The corrective action(s) were designed to preclude the occurrence of future stem-disc separation issues going undetected, which could result in the loss of valve and potentially the loss of the associated accident-mitigation system’s operational readiness condition.

Paper published with permission.
Motor-Operated Valve Performance
Authors: Farnan Michael F.
Published: May 2019

Motor-operated valves (MOVs) play an important role in the safe and reliable operation of today’s nuclear power plants. The purpose and scope of this paper is to review recent MOV operational experience events. The paper will discuss current findings and trends that relate to operation, maintenance, and surveillance testing of MOVs.

Paper published with permission.
Effective Diaphragm Area Test Program for Air-Operated Valve Actuators
Authors: Leutwyler Zachary , Thidavanh Lisa , Estep Neal
Published: May 2019

Kalsi Engineering, Inc. (KEI), initiated an independent test program that includes a number of actuator manufacturers, models, and sizes based on a survey of United States (U.S.) nuclear power plants. The test matrix includes evaluation of the effect of the key parameters on the effective diaphragm area (EDA) throughout the stroke. These parameters include stroke position, pressure, materials, measurement uncertainty, and manufacturing tolerances. Because of differences in the test data obtained by different sources for the same actuator type and size, systematic test procedures have been developed by KEI to address differences in the testing methods and test configurations, including testing of a balanced actuator (no spring in the actuator) vs. a spring-return actuator of the same diaphragm size. The effect of elevated temperature and aging may also be included later by testing a selected number of actuators based on industry input. The benefit of this program is to provide reliable data for air-operated valve (AOV) design-basis evaluations as required by U.S. Nuclear Regulatory Commission (NRC) Regulatory Issue Summary (RIS) 2000–03. This paper presents the results for the Masoneilan Model 38 Size 18 diaphragm actuator, which show that EDA is both position- and pressure-dependent.

Paper published with permission.
AOV Quarter-Turn Efficiency Models and Validation
Authors: Leutwyler Zachary , Leutwyler Emil , Estep Neal
Published: May 2019

Common quarter-turn (QT) mechanisms used in nuclear plant air-operated valves (AOVs) include scotch yoke, lever, and link-and-lever mechanisms coupled to diaphragms and pistons. QT mechanism efficiency varies as a function of valve position and is a critical design input used to determine AOV margin. Because of the lack of publicly available data of a quality commensurate with “nuclear QA [quality assurance],” Kalsi Engineering, Inc. (KEI), initiated an independent QT-mechanism efficiency test program that includes a number of commonly used actuator manufacturers, models, and sizes based on a survey of U.S. nuclear power plants.

The first test specimen was a diaphragm actuator with a lever QT mechanism. The diaphragm rod of the test specimen was instrumented with strain gauges so that a direct measurement of the net actuator force transmitted to the QT mechanism could be measured. In addition to the net thrust, the output torque, diaphragm pressure, and actuator position were measured. Measuring the net thrust, diaphragm pressure, and position allowed the spring rate, spring preload, and effective diaphragm area to be quantified.

This test specimen was tested using two different types of bearings at the actuator shaft-to-lever connection. Needle bearings were used to provide torque results for a nearly frictionless QT mechanism, and bronze bearings were used to simulate a more realistic QT-mechanism configuration. Predictions made using the first-principles efficiency model are compared to efficiencies extracted from test. The predicted efficiency using a realistic range for the friction coefficient of the bronze bearings is in good agreement with the extracted efficiencies.

Paper published with permission.
Distinguishing mummified thyroid nodules from malignant thyroid nodules
Authors: Tan Xiao Qu , Qian LinXue , Wang YunHong
Published: May 2019

Aim: To study the ultrasonographic (US) differences between “mummified” thyroid nodules and malignant thyroid nodules in order to achieve a more accurate imaging-based diagnosis and to avoid unnecessary biopsy.Material and methods: We retrospectively reviewed the US features of mummified thyroid nodules, as confirmed by fine-needle aspiration cytology (FNAC), in 193 cases. The US features included content, echo, shape, margin, microcalcification, suspicious lymph nodes and some characteristic features, including the cystic wall shrinkage sign, the concentric configuration or finger sign, calcification and halo. All of these features were classified and compared with those of 109 malignant lesions. The changes of these mummified nodules during the follow-up period were also examined.Results: The cystic wall shrinkage sign and the concentric configuration or finger sign were highly specific indicators of mummified thyroid nodules and could be used to distinguish mummified nodules from thyroid cancer with a specificity of 91.7% and 99.9%, respectively. A continuous decrease in the cyst size was observed during follow-up.Conclusions: Mummified thyroid nodules are characterized by the cystic wall shrinkage sign and the concentric configuration or finger sign on US and a continuous decrease in size during follow-up. These features may be useful for the differential imaging-based diagnosis of mummified versus malignant thyroid nodules.
Feasibility of Ultrafast Doppler technique for cranial ultrasound in neonates
Authors: Kim Hyun Gi , Lee Jang Hoon
Published: May 2019

Aims: The aim of this study was to compare the performances of Ultrafast Doppler ultrasound (US) with classic Doppler US, for cranial ultrasound in neonates.Materials and methods: We measured the peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) of the anterior cerebral artery (ACA), middle cerebral artery (MCA) and posterior cerebral artery (PCA) in neonates using both conventional and Ultrafast Doppler US and acquisition times were compared. Distal ACA branches were assessed with Ultrafast Doppler US.Results: A total of 138 neonates were included. The PSV and EDV of the cranial arteries were comparable between the two Doppler methods (PSV, 64.6-85.5 cm/s vs. 63.4-84.1 cm/s, p=0.100-0.510; EDV, 19.1-26.5 cm/s vs. 17.8-24.2 cm/s, p=0.100-0.981). The RIs of the ACA and PCA were not significantly different (0.69-0.73 vs 0.68-0.74, p=0.174-0.810). Ultrafast Doppler US required shorter acquisition times than conventional Doppler US (6.7 s vs. 11.0 s, p=0.003). The PSV and EDV of the distal ACA were higher than the proximal ACA (20.1-63.3 cm/s vs. 9.4-36.7, p<0.001) although the RI was similar (0.69 vs. 0.68, p=0.251).Conclusions: Ultrafast Doppler US provides comparable values to conventional Doppler US with shorter acquisition times. This novel imaging technique provides quantitative information and is suitable for distal cranial artery evaluation.
Loss of PRC1 activity in different stem cell compartments activates a common transcriptional program with cell type–dependent outcomes
Authors: Pivetti Silvia , Fernandez-Perez Daniel , D’Ambrosio Alessandro , Barbieri Caterina Maria , Manganaro Daria , Rossi Alessandra , Barnabei Laura , Zanotti Marika , Scelfo Andrea , Chiacchiera Fulvio , Pasini Diego
Published: May 2019

Stem cell identity maintenance by PRC1 repressive activity is influenced by TFs and epigenetic landscape of specific cell types.
Mutualistic interactions reshuffle the effects of climate change on plants across the tree of life
Authors: Bascompte Jordi , García María B. , Ortega Raúl , Rezende Enrico L. , Pironon Samuel
Published: May 2019

Species extinctions may trigger coextinctions, leading to a biased pruning of the evolutionary and functional trees.
Dental evolutionary rates and its implications for the Neanderthal–modern human divergence
Authors: Gómez-Robles Aida
Published: May 2019

The analysis of dental evolutionary rates indicates that Neanderthals and modern humans diverged at least 800,000 years ago.
Learning sensorimotor control with neuromorphic sensors: Toward hyperdimensional active perception
Authors: Mitrokhin A. , Sutor P. , Fermüller C. , Aloimonos Y.
Published: May 2019

The theory of hyperdimensional computation facilitates integration of action and perception by using a neuromorphic sensor.
Human sebum requires de novo lipogenesis, which is increased in acne vulgaris and suppressed by acetyl-CoA carboxylase inhibition
Authors: Esler William P. , Tesz Gregory J. , Hellerstein Marc K. , Beysen Carine , Sivamani Raja , Turner Scott M. , Watkins Steven M. , Amor Paul A. , Carvajal-Gonzalez Santos , Geoly Frank J. , Biddle Kathleen E. , Purkal Julie J. , Fitch Mark , Buckeridge Clare , Silvia Annette M. , Griffith David A. , Gorgoglione Matthew , Hassoun Lauren , Bosanac Suzana S. , Vera Nicholas B. , Rolph Timothy P. , Pfefferkorn Jeffrey A. , Sonnenberg Gabriele E.
Published: May 2019

De novo lipogenesis is essential for human sebum production, and increased lipogenic flux accounts for excessive sebum production in acne vulgaris.
Detecting middle ear fluid using smartphones
Authors: Chan Justin , Raju Sharat , Nandakumar Rajalakshmi , Bly Randall , Gollakota Shyamnath
Published: May 2019

To diagnose otitis media, a smartphone system detects middle ear fluid using the built-in microphone and speakers.
A virus-like particle vaccine prevents equine encephalitis virus infection in nonhuman primates
Authors: Ko Sung-Youl , Akahata Wataru , Yang Eun Sung , Kong Wing-Pui , Burke Crystal W. , Honnold Shelley P. , Nichols Donald K. , Huang Yan-Jang S. , Schieber Gretchen L. , Carlton Kevin , DaSilva Luis , Traina-Dorge Vicki , Vanlandingham Dana L. , Tsybovsky Yaroslav , Stephens Tyler , Baxa Ulrich , Higgs Stephen , Roy Chad J. , Glass Pamela J. , Mascola John R. , Nabel Gary J. , Rao Srinivas S.
Published: May 2019

A multivalent VLP vaccine protects against aerosol challenge of three lethal encephalitis viruses in mice and nonhuman primates.
Cediranib suppresses homology-directed DNA repair through down-regulation of BRCA1/2 and RAD51
Authors: Kaplan Alanna R. , Gueble Susan E. , Liu Yanfeng , Oeck Sebastian , Kim Hoon , Yun Zhong , Glazer Peter M.
Published: May 2019

Cediranib directly suppresses homology-directed DNA repair in tumor cells and confers synthetic lethal vulnerability to PARP inhibitors.
Intein-mediated protein trans-splicing expands adeno-associated virus transfer capacity in the retina
Authors: Tornabene Patrizia , Trapani Ivana , Minopoli Renato , Centrulo Miriam , Lupo Mariangela , de Simone Sonia , Tiberi Paola , Dell’Aquila Fabio , Marrocco Elena , Iodice Carolina , Iuliano Antonella , Gesualdo Carlo , Rossi Settimio , Giaquinto Laura , Albert Silvia , Hoyng Carel B. , Polishchuk Elena , Cremers Frans P. M. , Surace Enrico M. , Simonelli Francesca , De Matteis Maria A. , Polishchuk Roman , Auricchio Alberto
Published: May 2019

Adeno-associated viral vectors reconstitute large proteins in the retina via intein-mediated protein trans-splicing.
Advances in therapeutic applications of extracellular vesicles
Authors: Wiklander Oscar P. B. , Brennan Meadhbh Á. , Lötvall Jan , Breakefield Xandra O. , EL Andaloussi Samir
Published: May 2019

Understanding extracellular vesicle biology and production will pave the way for a new type of biotherapeutic.
SHANK3
puts autism to sleep
Authors: Osterweil Emily K.
Published: May 2019

Mutation of autism-associated gene
SHANK3
leads to sleep problems in mice and humans.
Mind the gap: Cx32 and α-synuclein
Authors: Haigh Cathryn
Published: May 2019

α-synuclein oligomer uptake by neurons and oligodendrocytes exploits connexin-32.
Penetrating paediatric neck trauma
Authors: Abdelmasih Monica , Kayssi Ahmed , Roche-Nagle Graham
Published: May 2019

Penetrating injuries to the internal carotid artery are infrequent but potentially devastating and can be a significant challenge to the operating surgeon. In this article, we present a case of an 11-year-old girl who suffered a serious vascular injury when she fell on a pencil. We also discuss the most up-to-date recommendations concerning the management of zone II injuries to the neck of a paediatric patient.
A case of antiphospholipid syndrome presenting cryptogenically as Budd-Chiari syndrome, then fulminantly as Libman-Sacks endocarditis
Authors: Goldhar Hart A , O’Meara Paloma , Castellucci Lana A
Published: May 2019

A 58 year-old left-handed woman was transferred to our hospital with an evolving left middle cerebral artery stroke, severe thrombocytopenia and elevated inflammatory markers. She had a history of chronic Budd-Chiari syndrome (BCS) 16 months prior, attributed to a calcified web in the inferior vena cava that was stented. No thrombophilia testing was performed at that time. The current presentation demonstrated dense right-sided facial and arm paresis and neglect. Erythrocyte sedimentation rate and C-reactive protein were elevated, an autoimmune workup was consistent with a new diagnosis of systemic lupus erythematosus and triple-positive antiphospholipid antibodies. A transesophageal echocardiogram demonstrated a vegetation consistent with Libman-Sacks endocarditis (LSE), thought to have embolised to the brain. The patient was treated acutely with steroids, intravenous immunoglobulin and clopidogrel. This case demonstrates an atypical constellation of the antiphospholipid syndrome, with a novel presentation of BCS and LSE, and reinforces the importance of hypercoagulability screening in this population.
Inferolateral ST-segment elevation with use of Sengstaken-Blakemore tube for variceal bleeding during orthotopic liver transplantation
Authors: Garbett Luke , O’Conghaile Stiofan , Pillai Parameswan
Published: May 2019

Oesophageal balloon tamponade tubes are a rare cause of ST-segment elevation (STE), thought to result from extrinsic compression of coronary arteries. This case describes STE following the use of a Sengstaken-Blakemore tube (SBT) under traction for management of bleeding oesophageal varices during orthotopic liver transplantation. This case is the first to report a significant troponin rise with STE indicative of myocardial injury following the use of SBT. Interestingly, we found that releasing traction from the SBT resulted in resolution of STE within minutes, suggesting that SBT traction may reversibly impede coronary perfusion. We recommend vigilant monitoring of patients following SBT insertion and for clinicians to consider that SBT traction may impair coronary perfusion and result in myocardial injury in patients without pre-existing coronary artery disease.
A very persistent chicken bone: two separate perforations from the same foreign object 2 months apart
Authors: Brown Andrew James , Whitehead-Clarke Thomas , Tudyka Vera
Published: May 2019

A 56-year-old man presented acutely with abdominal pain and raised inflammatory markers. Initial CT images demonstrated acute inflammation in the right upper quadrant surrounding a high-density linear structure. The appearance was of a chicken bone causing a contained small bowel perforation. This was managed conservatively with intravenous antibiotics and the patient was discharged 10 days later. The same patient returned to the hospital 2 months later, once again with an acute abdomen. CT imaging on this occasion showed distal migration of the chicken bone as well as free gas and fluid indicative of a new small bowel perforation. The patient underwent an emergency laparotomy, washout and small bowel resection. No foreign body was found at laparotomy or in the histopathology specimen. The postoperative course was complicated by an anastomotic leak. A further CT on that admission demonstrated that the chicken bone had migrated to the rectum!
Distraction osteogenesis of the humerus: a case of 100% humeral lengthening in a short duration without permanent complications
Authors: Cheng Sheng Da Jowell , Wong Kenneth Pak Leung
Published: May 2019

A 15-year-old boy with right humeral shortening underwent distraction osteogenesis with 1 mm/day lengthening. Preoperative Sauvegrain method showed skeletal maturity and lengthening did not account for future growth. Functional loading was encouraged 2 months before end of consolidation phase to hasten consolidation and fixator removal was done in the clinic without local anaesthesia at the patient’s request 1 month earlier. A Sarmiento brace was made and compliance taught to the patient; however, the patient did not wear the brace and resumed body weight exercise weeks after removal of the fixator. Two months after removal of the external fixator, plain radiographs showed good recanalisation of the humeral shaft with no fracture or distortion. However, the left humerus grew and is now 1 cm longer than the right humerus. Nevertheless, the patient was satisfied with the upper limb length discrepancy.
Reversible dementia, psychotic symptoms and epilepsy in a patient with vitamin B12deficiency
Authors: Silva Bruno , Velosa Ana , Barahona-Corrêa J Bernardo
Published: May 2019

Vitamin B12deficiency is a common condition, typically associated with megaloblastic anaemia, glossitis and neuropsychiatric symptoms. We report the case of a patient presenting with progressive cognitive and functional deterioration, psychosis and seizures, later found to be secondary to pernicious anaemia. Importantly, the diagnosis of pernicious anaemia was only established 5 years after symptom onset and was overlooked even when the patient was under medical care, in part due to the lack of classic neurological and haematological signs associated with the condition. The patient had a remarkable neuropsychiatric recovery after vitamin replacement and psychopharmacological management. We discuss similar presentations of vitamin B12deficiency found in the literature, symptom reversibility and the importance of its early recognition and treatment.
Experiences of support garments following bowel stoma formation: analysis of free-text responses in a cross-sectional survey
Authors: Hubbard Gill , Taylor Claire , Munro Julie , Dames Nicola , Goodman William , Oliphant Raymond , Beeken Rebecca
Published: May 2019

Aim

To explore the experiences of support garments when adjusting to bodily change following bowel stoma formation.

Design

Thematic analyses of free-text responses in a cross-sectional survey of the stoma population in 2018.

Methods

Free-text responses were invited so that respondents could describe their experiences in more detail. A process of induction was chosen to allow for themes to emerge directly from the data. The concept ‘embodiment’ was used as a theoretical framework during interpretation.

Results

1425 people with a bowel stoma responded to the survey, of whom 598 provided free-text responses. Four themes about experiences of support garments in the context of changed bodily experiences following stoma formation were identified:body complications, which is about experiences of using support garments to prevent or self-manage parastomal hernia;body appearance, which is about hiding the stoma and stoma appliance;body function, which is about managing stoma appliance complications; andbody sensation, which is mainly about negative experiences of ill-fitting garments.

Conclusion

Support garments can be understood as items that are used by people during an ongoing process of adjusting to bodily changes following stoma formation and as part of an ongoing process of reconstructing new embodied selves.

Impact

This is the first study to explore people’s experiences of support garments following bowel stoma formation. Support garments are used in the self-management of body complications, appearance, function and sensations. Stoma nurses may draw on the findings of this study to advise patients about the benefits of garments for adjusting to bodily change, and garment suppliers should address people’s negative experiences by improving garments.
Association between spatial accessibility to fire protection services and unintentional residential fire injuries or deaths: a cross-sectional study in Dallas, Texas
Authors: Min Soojin , Kim Dohyeong , Lee Chang Kil
Published: May 2019

Objectives

In addition to neighbourhood characteristics encompassing racial composition, socioeconomic status and housing environments, it was unclear if location characteristics relating to the accessibility of fire protection services were risk factors for unintentional residential fire-related injuries in urban areas. This study was aimed to measure spatial accessibility to fire protection services at the census block group level, and examine whether it is associated with unintentional residential fire-related injuries.

Design

A cross-sectional study.

Setting

Unintentional residential fire incidents between 2012 and 2015 in Dallas City, Texas, USA.

Main outcome measures

Using multiple logistic regression, the study analysed association between unintentional residential fire incidents in the city and risk factors, including spatial accessibility to fire protection services, measured by the two-step floating catchment area method.

Results

Compared with incidents without any injuries, fire incidents involving injuries were significantly more likely to include unconfined fire, fire originating in a cooking area, a bedroom for less than five people or a common family area, census block groups with >75% African American residents, >25% elderly single-person households and positive population growth rates <25% or >25%. Incidents involving injuries were significantly less likely to occur in areas with high spatial accessibility, as measured by spatial accessibility score.

Conclusions

In addition to fire characteristics and neighbourhood demographics, spatial accessibility to fire protection services was significantly associated with unintentional residential fire-related injuries. The findings can be used to help select locations of additional fire stations.
Willingness of patients to use unused medication returned to the pharmacy by another patient: a cross-sectional survey
Authors: Bekker Charlotte , van den Bemt Bart , Egberts Toine CG , Bouvy Marcel , Gardarsdottir Helga
Published: May 2019

Objectives

Redispensing by pharmacies of medication unused by another patient could contribute to optimal use of healthcare resources. This study aimed to assess patient willingness to use medication returned by another patient and patient characteristics associated with this willingness.

Design

Cross-sectional survey.

Setting

A total of 41 community and 5 outpatient pharmacies in the Netherlands.

Participants

Total of 2215 pharmacy visitors.

Primary and secondary outcome measures

Patients completed a questionnaire regarding their willingness to use medication returned unused to the pharmacy by another patient, assuming quality was guaranteed. Secondary outcome measures included patient sociodemographic characteristics that were associated with patient willingness, analysed using logistic regression analysis and reported as ORs with 95% CIs.

Results

Of the 2215 patients (mean (SD) age 50.6(18.0) years; 61.4% female), 61.2% were willing to use medication returned unused to the pharmacy by another patient. Patients who were unwilling mostly found it risky. Men were more willing to use returned medication (OR 1.3 95% CI 1.1 to 1.6), as did patients with a high educational level (OR 1.8 95% CI 1.3 to 2.5), those who regularly use 1–3 medications (OR 1.3 95% CI 1.1 to 1.7), those who returned medication to the pharmacy for disposal (OR 1.5 95% CI 1.0 to 2.3) and those who ever had unused medication themselves (OR 1.3 95% CI 1.1 to 1.6)). Patients with non-Dutch cultural background were less willing to use returned medication (OR 0.395% CI 0.3 to 0.4)).

Conclusions

When quality is guaranteed, a substantial proportion of patients are willing to use medication returned unused to the pharmacy by another patient. This suggests that implementation of redispensing may be supported by patients.