bluuebunny/crossref_metadata_2025 huggingface dataset:
Student Exchange Program With Siemens-Westinghouse
Authors: Rogers Hugh K.
Published: November 2021

A Student Exchange Program began with four students from Germany visiting Siemens-Westinghouse and the University of Central Florida in Summer, 1999, as an initiative from Siemens training officials in Muelheim, Germany. In Summer 2000, a program with four German apprentices coming to the U.S. and four U.S. interns working and studying in Germany was very successful. The initial UCF students continued part-time work at Siemens during their senior year and were offered full-time employment upon graduation. Not only did the German students complete their work, but some of them returned for employment in the U.S.

Siemens, as a multinational enterprise, is preparing technologists and engineers to understand product design and manufacturing for integrated systems in international markets. Students will benefit from an understanding of the systems, standards, and cultures involved. The internship model being developed uses the best from the German and U.S. systems and merits further study and implementation.
The Use of Spreadsheets for Significant Engineering Analysis in Engineering Technology and Physical (and Natural) Science Courses: The Development of an Instructional Primer of Spreadsheet Solution Techniques in Applied Mechanical Engineering Technology Subjects
Authors: Di Bella Francis A.
Published: November 2021

The course work in any engineering discipline is necessarily based on an assumption that the student has a good foundation of fundamental engineering mathematics. Yet, many Engineering Technology courses have been born out of the desire to provide the student with the more straightforward and practical application of the art and science of engineering to realistic engineering problems while minimizing the need for sophisticated mathematical solutions.

This dilemma can be resolved by utilizing an inexpensive mathematical tool that is virtually omnipresent in even the least expensive PC: the spreadsheet. It is a software package that even the most mathematically challenged student is well aware and is comfortable in using for routine mathematical if not specifically, engineering applications: data reduction, curve-fitting, plug-in iterative solutions, etc.

This paper will describe the author’s effort, with the support from Northeastern University’s Provost Office and The Center for Effective University Teaching (CEUT), in providing the ET student (and in the future, the physical science student) with a powerful tool for solving non-trivial engineering and physical science problems while also helping the student understand the engineering and scientific fundamentals behind the solutions. This effort will hopefully culminate in the development of an instructional Primer that can be used by engineering and Arts and Science students when studying engineering and physical (and natural) sciences.
Using Discrete Event Simulation Software in a MET Program
Authors: Verma Alok K.
Published: November 2021

Discrete event simulation software can be an effective tool for teaching comparative analysis of manufacturing systems for improving performance. ProModel software is used in a computer integrated manufacturing course in the Mechanical Engineering Technology Program for this purpose. Use of this tool allows an instructor to demonstrate the pros and cons of various manufacturing scenarios and recommend a solution. Student interest is enhanced by assigning simulation of real life problems from local industries.
The Development of an Inexpensive and Easy Natural Convection Experiment
Authors: Vlcek Brian L.
Published: November 2021

With a simple, inexpensive apparatus natural convective heat transfer is determined experimentally and compared to theoretical values as part of an undergraduate laboratory. A cylindrical heating cartridge is placed horizontally through the wall of a clear plastic tank. The tank contains water. Surface temperature is measured along the axis of the heating cartridge, and bulk water temperature is determined. Power input to the cartridge heater is known, and no losses are assumed. Theoretical convective heat transfer from the cartridge heaters is determined by finding the Nusselt number using conventional relationships in the literature, calculating the convective heat transfer coefficient, and solving for heat transfer. Agreement between experimental and theoretical heat transfer values is good, and a basic concept in heat transfer is thus demonstrated in the classroom. Comparisons are made between different Nusselt correlations, students gain an appreciation for the range of acceptable answers, and a simple, calculus-based analytical correction is applied to the result.
Co-Simulation of Power Steering Control and Vehicle Dynamic Responses
Authors: Liao Gene Y.
Published: November 2021

Many general-purpose and specialized simulation codes are becoming more flexible which allows analyses to be carried out simultaneously in a coupled manner called co-simulation. Using co-simulation technique, this paper develops an integrated simulation of an Electric Power Steering (EPS) control system with a full vehicle dynamic model. A full vehicle dynamic model interacting with EPS control algorithm is concurrently simulated on a single bump road condition. The effects of EPS on the vehicle dynamic behavior and handling responses resulting from steer and road input are analyzed and compared with proving ground experimental data. The comparisons show reasonable agreement on tie-rod load, rack displacement, steering wheel torque and tire center acceleration. This developed co-simulation capability may be useful for EPS performance evaluation and calibration as well as for vehicle handling performance integration.
Ultrasonic Interfacial Waves in a Finitely Strained Elastic Structure
Authors: Sotiropoulos D. A.
Published: November 2021

Ultrasonic interfacial waves in a finitely strained elastic structure are examined. The structure consists of an incompressible surface layer and a compressible half-space both materials being non-linear elastic and isotropic with otherwise general strain energy densities. On the underlying strain which is in general different in the two materials are superposed ultrasonic interfacial waves. The dispersion equation is obtained in explicit form for pre-strain with common principal axes in the two materials. For a small surface layer, the wave speed is derived in explicit form yielding material parameter conditions for the non-existence of interfacial waves.
IR Thermography Scanning Technique in the Assessment of Airport Pavements
Authors: Moropoulou Antonia , Avdelidis Nicolas P. , Koui Maria
Published: November 2021

Corrosion of asphalt pavements is a major problem involved with materials engineering and transportation engineering. Asphalt pavements frequently start to deteriorate slowly primarily, gradually progressing to failure. Such failure can be expensive in terms of both money and lives, but can also be prevented. For that reason, intelligent techniques should be suggested, with the intention of examining the condition of such engineering structures. IR thermography is a non-destructive technique that has the ability to inspect effectively substantial areas, such as airport pavements. It has been used successfully in the detection of cracks, voids and other imperfections appearing either from the aging of the materials or due to poor workmanship. Investigation of asphalt overlays by the means of IR thermography is possible, given that subsurface defects in a material influence the heat flow through that material, generating surface temperature alterations. Despite that, other issues such as, environmental conditions and surface temperatures should also be considered, in an attempt to obtain reliable results. In this research work, a selection of asphalt pavements located at the International Airport of Athens, in Greece, are investigated by the use of scanning IR thermography. In conclusion, this paper describes the problem of deteriorated airport pavements, the process and the apparatus used for the in situ tests, whilst the results obtained lead to the suggestion of a predictive monitoring non-destructive technique for the inspection and appropriateness of airport pavements.
On Establishing the Limits of a Virtual Test Rig
Authors: Hill D. Lee , Liu Zheji , Sorokes Jim
Published: November 2021

The use of a virtual test rig to numerically test turbomachinery hardware can be extremely cost effective if the results obtained are physically correct and relatively accurate. The literature clearly shows that a lot of emphasis has been placed on single component validation optimized for a single operation point. There are few studies, however, that have clearly documented the numerical issues surrounding the modeling of a complete stage of a centrifugal compressor across its operating range. This effort uses a generic low flow stage design to demonstrate the accuracy to expect from the current state-of-the-art technology found in both commercial and research computational fluid dynamics (CFD) software. Even effects stemming from secondary flow paths are considered in this study. For design and off-design operation toward surge, 360-degree transient calculations are compared to those obtained from using the steady state fixed-rotor approximation. Finally, all work is ultimately compared to detailed test data obtained from single stage testing.
Experimental Measurement of the Natural Convection Heat Transfer for Horizontal Helicoidal Pipes
Authors: Kidane Getnet S. , Fakheri Ahmad
Published: November 2021

The natural convection heat transfer coefficient for the helicoidal coils are experimentally measured and compared with those for horizontal cylinders. It is found that when the coil pitch to pipe diameter ratio is less than around 1.2, the heat transfer coefficient of the coils approaches that of a horizontal cylinder having a diameter equal to the coil diameter. For the P/d ratio greater than 1.4, the heat transfer coefficient approaches that for horizontal cylinder of diameter d. A modified characteristic, length which incorporates the tube diameter, the coil diameter, and the coil spacing, is used to define Nusselt and Rayleigh numbers. Using the proposed characteristic length, it is shown that the Nusselt number for horizontal helicoidal pipes can be determined using the available Nusselt and Rayleigh number correlation for straight horizontal cylinders in the range of the experimental and available data, Ra ≤ 105, within a maximum deviation of 15.4%.
A New Method to Improve Pyrometry Results
Authors: Haque Zakirul , Huque Ziaul , Jahingir Md. N.
Published: November 2021

The paper shows how appropriate selection of the expression of sound speed as a function of temperature can improve the results obtained using acoustic pyrometers. Sound propagation within high temperature hydrocarbon combustion products was considered. Three different mathematical models for calculating sound speed were discussed. Results obtained using all three methods were presented. The paper observed that, it is important to consider the effects of chemical kinetics for a certain frequency range to obtain better results.
Evaporation Heat Transfer and Pressure Drop of HFC-134a Inside a Plate Heat Exchanger
Authors: Ouazia B.
Published: November 2021

An experimental investigation was carried out to provide data on heat transfer coefficient and pressure drop for upward flow of refrigerant 134a in a typical plate heat exchanger. Upflow boiling of R-134a in one channel receives heat from the hot downflow of water in the two adjacent channels. Measurements were conducted on three sets of plates with chevron angles of 0°, 30°, and 60°, and the effects of mean vapor quality, mass flux, and heat flux on the evaporation heat transfer and pressure drop were explored. It was found that the channels with small chevron angle have higher heat transfer than channels with large chevron angle, for both subcooling and vapor quality inlet conditions. It was clear that the heat transfer coefficients were not sensitive to the heat flux but were dependent on the flow conditions (mass velocity and vapour quality). Based on the experimental data, empirical correlations for the evaporation heat transfer enhancement factor and the two-phase pressure drop multipliers were proposed.
Study of Pressure Drop of Refrigerant Mixtures Inside Enhanced Surface Tubing
Authors: Sami S. M. , Grell J.
Published: November 2021

Two phase flow pressure drop characteristics observed during condensation and boiling of azeotropic refrigerant mixtures R-404A (R125/R134a/R143a:44/4/52), R-407B (R32/R125/ R134a:10/70/20), R407C (R32/R125/R134a:23/25/52) and R408A (R22/R125/R143a:46/7/47) are presented in this paper.

Experiments showed that for liquid Reynolds numbers higher than 3.00 E06, R-408A appears to have greater heat transfer rates than the other blends under investigation. Furthermore, it is quite evident from this data that R-407C has the highest specific pressure drop among the refrigerants under investigation.
Novel Lightweight Metal Foam Heat Exchangers
Authors: Haack David P. , Butcher Kenneth R. , Kim T. , Lu T. J.
Published: November 2021

An overview of open cell metal foam materials with application to advanced heat exchange devices is presented. The metal foam materials considered consist of interconnected cells in a random orientation. Metal foam materials, manufacture and fabrication into complex heat exchange components are described. Experiments with flat foam panels brazed to copper sheets shows increasing heat removal effectiveness with decreasing product pore size at equivalent coolant flow rates. However, the high-pressure drop associated with flow through small pore-size material makes the use of larger pore size material more attractive.
Experimental Results on the Application of a High-Voltage Capacitance-Based Technology to Reduce Biofouling in Reverse Osmosis Systems
Authors: Fiadjoe T. , Chau D. S. , Phelan P. E.
Published: November 2021

As the use of reverse osmosis (RO) machines becomes prevalent in our society, more attention is being paid to reducing their operational and maintenance costs. One method of improving efficiency is by adequate pretreatment of the feed water to the RO system. A proposed alternative to current chemical treatment methods is a novel high-voltage, capacitance-based system that utilizes electrostatic dispersion techniques. This alternative method of treatment was experimentally evaluated and was found to be effective in certain aspects of RO pretreatment. An experimental apparatus was designed based on two nominally identical household RO systems. The two systems were subject to identical, but variable, feed conditions. The technology proved effective in reducing the bacterial contamination levels in an RO system, although it did not completely eliminate the formation of biofilm.
Effect of Hydrostatic Pressure on Damage in Particulate Composites
Authors: Kwon Y. W. , Liu C. T.
Published: November 2021

Hydrostatic pressure affects the damage growth in a particulate composite. As a result, an analytical model was presented to represent the damage growth in a particulate composite under various hydrostatic pressures. The model was based on a multi-level approach with damage description at the micro-level. A damage theory was presented to describe the material behavior under hydrostatic pressure. The effect of hydrostatic pressure was introduced to the damage theory through the damage function that was assumed to be a function of both deviatoric and volumetric strain energy densities. The predicted stress-strain curves with hydrostatic pressure compared well with the experimental data. Furthermore, the initial crack size at a notch tip was studied with and without hydrostatic pressure. The initial crack size determined from the computer modeling and simulation agreed well with the measured data with or without hydrostatic pressure.
Experimental Evaluation of Fatigue Parameters Using Constant K Fracture Specimens
Authors: Cammino R. , Gosz M. , Mostovoy S.
Published: November 2021

We explore the use of constant K fracture specimens for experimental determination of fatigue properties of aluminum alloys. The shape of the contoured portions of the fracture specimens (required to keep the mode I stress intensity factor constant during crack propagation under constant cyclic loading) was obtained by a combined finite element-least squares minimization procedure. After conducting the experiments, the crack growth rate versus ΔK data was observed to exhibit significantly less scatter than fatigue data for the same material taken from the literature. In addition, the experimental procedure is much simpler to carry out than traditional closed-loop computer controlled procedures.
Free-Vibration of Rotating Composite Beams Incorporating Higher-Order Transverse Shear Effects
Authors: Chandiramani N. K. , Librescu L. I. , Shete C. D.
Published: November 2021

The free vibration behavior of a rotating blade modeled as a laminated composite hollow (single celled) box beam is studied. The geometrically nonlinear structural model developed herein incorporates a number of non-classical effects such as anisotropy, heterogeneity, transverse shear flexibility, and warping inhibition. The centrifugal and Coriolis force field effects are also included. The main focus here being the refinement of the existing model, the traction-free boundary conditions are satisfied here in contrast to the existing model. The resulting linearized equations and numerical results based on them are presented. Results obtained for the present higher-order shearable model are compared with those of the existing first-order shearable and the non-shearable models. Tailoring studies using the present model reveal an enhancement of eigenfrequency characteristics.
Probabilistic HCF Life Estimation of a Mechanical Component
Authors: Singh Murari P.
Published: November 2021

Goodman Diagram method or similar methods are used to estimate safety of a mechanical structure under high cycle fatigue loading for any combination of alternating and mean stresses. Magnitude of the factor of safety (FS) indicates margin from nominal design capable of desired performance. The value of larger than one of FS is desired to account for uncertainty and variability in loads and material properties. This FS based on stress does not provide any direct knowledge about the life of the mechanical structure. A FS based on life can be derived and used in conjunction with Goodman concept. This method yields an estimate of FS based on life (FN) for a given stress based FS for any combination of alternating and mean stresses.

A procedure is described in this paper that helps in estimating reliability of a mechanical structure. Reliability depends on the magnitude of stresses and material properties. Usually variability in load and in material properties can be quantified by a statistical distribution. Methods of probabilistic theories can be used to determine the influence of these variations on the reliability.

The procedure utilizes established methods and theories to yield practical evaluation of reliability. First, the modified Goodman equation of factor of safety is combined with the life equation proposed by Jo Dean Morrow (Dowling, 1999). This provides a relationship between calculated factor of safeties based on stress and life. Finally, the developed equations are utilized in a probabilistic approach that incorporates statistical distribution of uncertainties. This procedure yields reliability assessment of a mechanical structure to perform an expected task.
Investigation of Nanomechanical Properties of the Interphase in a Fiber Reinforced Plastic Composite
Authors: Khanna Sanjeev K. , Winter Robb M. , Ranganathan P. , Yedla S. B. , Paruchuri K.
Published: November 2021

Glass fiber reinforced plastic composites are widely used as structural materials. These two phase materials can be tailored to suit a large variety of applications. A better understanding of the properties of the fiber-matrix ‘interphase’ can enable more optimum design of composites. The interphase is a microscopic region around the fiber and hence nano-scale investigation using nano-indentation techniques is appropriate to determine mechanical property variations. In this study the atomic force microscope with the Hysitron indenter has been used to determine the variation of the elastic modulus across the interphase for different silane coated glass fiber reinforced polyester composites. A comparative study of the elastic modulus variation in the interphase is reported. The results are discussed in the light of the current limitations of the instrumentation and analysis.
Eigenvalue Analysis of Oscillatory Variable State Paper Winder
Authors: Launis Sirpa , Keskinen Erno
Published: November 2021

Winding is a paper finishing process, in which the full paper web is longitudinally cut and wound in narrower paper rolls to fit later to printing machines. The quality of the paper roll is measured in terms of uniform roundness and axially symmetric internal stress and stiffness distribution. Unfortunately dynamic effects disturb winding process so that out-of-roundness shape error profiles may accumulate to the rolls. The reason for this phenomenon is mechanical oscillation, in which the set of rolls and the three winding drums are in relative motion in normal direction of their rolling contact plane. The time evolution of this process is extremely complicated since the roll size as well as contact conditions and running frequencies are changing during the complete process. To avoid unwanted resonance crossings the system eigenstates have to be as first step analyzed and compared with the roll speed harmonics at each roll diameter. This analysis is carried out using linearized spring-mass model, whose parameters are updated according to the roll growth. The spring elements represent the local stiffnesses of roll-drum contacts in both normal and tangential directions, the effect of latter ones being actually a novel element introduced in this analysis.
Progress in Railroad Freight Car Engineering
Authors: Punwani Swamidas K.
Published: November 2021

Every year the Rail Transportation Division (RTD), American Society of Mechanical Engineers (ASME) conducts a survey to document progress in the design, construction and use of freight cars and components. The response in 2001 was not overwhelming. New developments were scarce. The industry continued to focus on the evolution of freight equipment in 2001 by adding flexibility and versatility to designs developed in the recent past.
Mitigating the Adverse Effects of Heavy Axle Loads
Authors: Kalay Semih F. , LoPresti Joseph A. , Plotkin Donald
Published: November 2021

Increasing the capacity and gross weight of North American freight cars above the current 263,000-pound car (33-ton axle loads) is one way to improve the productivity of rail freight operations. An increase in expenditures on track and bridge maintenance is normally essential if axle load increases are to provide promised benefits. If each train can carry more net tons of bulk commodity safely, then productivity savings will be achieved by reducing the number of train crews required to haul a given tonnage. If the ratio of net-to-gross tons can be increased, additional savings can be achieved in fuel, track costs, and equipment costs. With fewer trains to move any given tonnage, there will be an improvement in capacity and a reduction in meet-pass delays.

Over the past 15 years, Transportation Technology Center, Inc. (TTCI), a subsidiary of the Association of American Railroads (AAR), has devoted extensive research efforts to safety, technical, and economic issues related to increasing axle loads. Much of the research has been based upon the five phases of the Heavy Axle Load (HAL) test program. More than 1,200 million gross tons (MGT) of HAL traffic was accumulated at the Facility for Accelerated Service Testing (FAST) located at the Federal Railroad Administration’s (FRA) Transportation Technology Center near Pueblo, Colorado. AAR and the FRA jointly fund the HAL program with significant cooperation from railroads and suppliers.

Results show that, in general, heavier axle loads will increase track and facility costs, but decrease operating and equipment costs. Since track costs are much smaller than combined operating and equipment costs, HAL operations can be economically beneficial even if the percentage increase in track costs is far greater than the percentage decrease in operating plus equipment costs. However, it should be emphasized again that in situations where track and bridges need upgrading for heavier axle loads, investment in track and bridges needs to be made first in order to realize the operating benefits from HAL operations. Total track costs were predicted to rise 5 to 10 percent under 286,000-pound cars (36-ton axle loads) and 15 to 18 percent under 315,000-pound cars (39-ton axle loads). Bridge costs, which were included as their own separate category, were predicted to rise faster than track costs. While the predicted increases for bridges were extremely high, bridge costs were only 10 to 15 percent of track costs in the base case, so they did not dominate the analysis.
ECP Brake: Transitioning From Development to Deployment
Authors: Wright Eric C.
Published: November 2021

While the AAR and the rail supply industry have focused a great deal of energy on developing and validating Electronically Controlled Pneumatic (ECP) brake technology; to date, very little attention has been paid to developing strategies for post-development deployment of the technology. A simple model and implementation strategy for deploying ECP brakes in the AAR freight car fleet is presented.
Ultrasonography on the non-living. Current approaches.
Authors: Thomsen Thomas , Blaivas Michael , Sadiva Paulo , Kripfgans Oliver D. , Chan Hsun-Liang , Dong Yi , Chammas Maria Cristina , Hoffmann Beatrice , Dietrich Christoph F.
Published: November 2021

The vast majority of clinicians associate diagnostic ultrasound with a tool that is designed for the living patient. However, it is of course possible to apply this imaging technology to evaluate the recently deceased patient for postmortem diagnosis, or even just examine postmortem tissue. We describe several cases in which ultrasound-enabled providers obtain answers in postmortem examinations and discuss potential future strategies and applications. In addition, we will also illustrate the use of sonography in minimally invasive post-mortem tissue sampling (MITS), an approach that can be used in post-mortem minimally invasive autopsies as well as for establishing ultrasound diagnostic parameters in new medical fields such as periodontal and dental implant specialties.
Myelin: A gatekeeper of activity-dependent circuit plasticity?
Authors: Bonetto Giulia , Belin David , Káradóttir Ragnhildur Thóra
Published: November 2021

Insulation for circuit regulation

Lipid-rich myelin, which wraps around and insulates neuronal axons, improves the speed and efficiency of signal propagation. Myelination is not universally applied in the central nervous system, and even axons within the same circuit can vary in the amount of myelination they carry. Bonetto
et al
. reviewed what is known about how such variability can affect computational functions in brain circuits. Myelin plasticity may be one mechanism linking experiential learning to modified brain connections. Whether you are learning to juggle or learning to read, changes in myelination may tune the circuits underlying those skills. —PJH
Bioactive scaffolds with enhanced supramolecular motion promote recovery from spinal cord injury
Authors: Álvarez Z. , Kolberg-Edelbrock A. N. , Sasselli I. R. , Ortega J. A. , Qiu R. , Syrgiannis Z. , Mirau P. A. , Chen F. , Chin S. M. , Weigand S. , Kiskinis E. , Stupp S. I.
Published: November 2021

Fibril motion improves peptide signaling

Artificial scaffolds that bear the peptide-signaling sequences of proteins for tissue regeneration often have limited effectiveness. Álvarez
et al
. synthesized supramolecular peptide fibril scaffolds bearing two peptide sequences that promote nerve regeneration, one that reduces glial scarring and another that promotes blood vessel formation (see the Perspective by Wojciechowski and Stevens). In a mouse model of paralyzing human spinal cord injury, mutations in a tetrapeptide domain outside of the signaling regions improved recovery by promoting intense supramolecular motion within the fibrils. The mutation with the most intense dynamics resulted in corticospinal axon regrowth and myelination, functional revascularization, and motor neuron survival. —PDS
Toward constructive disagreement about geoengineering
Authors: Keith David W.
Published: November 2021

A shared taxonomy of concerns may help
Iterations of evolution
A (Very) Short History of Life on Earth
Henry Gee
St. Martin’s Press, 2021. 288 pp.
Authors: Yanai Itai , Lercher Martin J.
Published: November 2021

A paleontologist’s history of life highlights the recurring role played by geological, climatic, and atmospheric forces
The politics of epigenetics
The Maternal Imprint: The Contested Science of Maternal-Fetal Effects
Sarah S. Richardson
University of Chicago Press, 2021. 376 pp.
Authors: Saldaña-Tejeda Abril
Published: November 2021

Maternal bodies are more than mediators of fetal environments, cautions a historian
Cash incentives, ethics, and COVID-19 vaccination
Authors: Jecker Nancy S.
Published: November 2021

We can pay people to vaccinate, but should we?
In Other Journals
Authors: Jiang Di , Lopez Bianca , Hines Pamela J. , Yeston Jake , Smith Keith T. , McCartney Melissa , Stern Peter
Published: November 2021

Editors’ selections from the current scientific literature
Influential U.S. wish list calls for $11 billion space telescope
Authors: Clery Daniel
Published: November 2021

Decadal survey says NASA should be frugal and build a series of optical, x-ray, and far-infrared observatories
Complete Genome Sequence of Bacillus badius NBPM-293, a Plant Growth-Promoting Strain Isolated from Rhizosphere Soil
Authors: Zhu Lei , Wang Yueying , Lu Jiancheng , Liu Simeng , Min Yong , Liu Xiaoyan , Qiu Yimin , Hu Hongtao , Zhou Ronghua
Published: November 2021

Bacillus
species have a long history of widespread use in biocontrol and crop growth-promoting fields. Here, we present the genome sequence of the rhizobacterium
B. badius
NBPM-293. The genome sequence will provide valuable information for a better understanding of the mechanism of plant growth promotion.
Comparative Analysis of Three Bradyrhizobium diazoefficiens Genomes Show Specific Mutations Acquired during Selection for a Higher Motility Phenotype and Adaption to Laboratory Conditions
Authors: Lozano Mauricio J. , Redondo-Nieto Miguel , Garrido-Sanz Daniel , Mongiardini Elías , Quelas J. Ignacio , Mengucci Florencia , Dardis Carolina , Lodeiro Aníbal , Althabegoiti M. Julia
Published: November 2021

The genetic and genomic changes that occur under laboratory conditions in
Bradyrhizobium diazoefficiens
genomes remain poorly studied. Only a few genome sequences of this important nitrogen-fixing species are available, and there are no genome-wide comparative analyses of related strains.
Malignant lymphomatous invasion of Meckel’s cave: pathoanatomical considerations of the petrous apex
Authors: Marotta Dario Alfredo , Mason Matthew , Cohen-Gadol Aaron , Kesserwani Hassan
Published: November 2021

Secondary central nervous system lymphoma is rare, occurring in up to 10% of non-Hodgkin's lymphoma patients and in 5% of diffuse large B-cell lymphoma patients. The prognosis is poor, even rarer is metastasis of large B-cell lymphomas into Meckel’s cave and the trigeminal nerve roots. We describe a relapsing case of a large B-cell lymphoma that migrated into Meckel’s cave, the mandibular branch of the trigeminal nerve and the adjacent cavernous sinus. We review petrous apex anatomy, review the literature of metastatic spread into Meckel’s cave and analyse existing pathoanatomical studies that explain the conduits and barriers of tumour spread. Understanding this pathoanatomical relationship is critical for neurologists and neurosurgeons alike to effectively correlate patient signs and symptoms to intracranial pathology and identify origins and sites of metastatic dispersion in similar rare clinical scenarios.
Preoperative hormonal therapy for a patient with appendiceal endometriosis
Authors: Shichiri Keiko , Nishida Kazuhiro , Lefor Alan Kawarai , Kubota Tadao
Published: November 2021

The optimal management of patients with appendiceal endometriosis has not been determined because of the difficulty of establishing a preoperative diagnosis. There are no reports of preoperative hormone therapy for a patient with appendiceal endometriosis. We report a patient who underwent resection of appendiceal endometriosis after hormone therapy. A 40-year-old woman with history of recurrent pelvic abscesses presented to the emergency department with lower abdominal pain. The recurrent pelvic abscesses were synchronised with her menstrual cycle. CT scan demonstrated a 25 mm contrast-enhanced luminal structure adjacent to the cecum, which was thought to be a mucocele of the appendix. Considering the recurrent symptoms during menstruation, endometriosis was suspected. Treatment with a gonadotropin-releasing hormone agonist was started for appendiceal endometriosis, which alleviated the symptoms. After 3 months, elective laparoscopic appendectomy was performed. Preoperative hormonal therapy is an option for patients with appendiceal endometriosis, especially when there is concern for dense adhesions.
Umbilical venous catheterisation: emergency central venous access which saves lives in coarctation of the aorta
Authors: Seigel Amber , Legge Nele , Hughes Gerry , Browning Carmo Kathryn
Published: November 2021

We describe a 9-day-old baby with coarctation of the aorta who required urgent resuscitation including intubation and cardiac compressions. Despite the commencement of prostaglandin E1 (PGE1) to reopen the ductus arteriosus via the intraosseous route, postductal saturations remained unrecordable for a further 45 min. Within 3 min of administration of PGE1via an umbilical venous catheter (UVC), saturations were recordable at 92%. UVC access was the sentinel intervention that irrevocably altered the clinical prognosis. This baby boy has survived with excellent neurodevelopmental outcome. Clinicians are less familiar with UVCs outside of the newborn period. Our data demonstrate successful placement in neonates up to 28 days of age. We hope this case encourages clinicians to consider the UVC as first-line central venous access in collapsed neonates. In cases of suspected left heart obstruction, we argue that UVCs are the optimal route.
Severe acquired hypertriglyceridemia following COVID-19
Authors: Fijen Lauré M , Grefhorst Aldo , Levels Johannes H M , Cohn Danny M
Published: November 2021

Severe hypertriglyceridemia is a major risk factor for acute pancreatitis. In exceptional cases, it is caused by plasma components inhibiting lipoprotein lipase activity. This phenomenon is predominantly associated with autoimmune diseases. Here, we report a case of severe hypertriglyceridemia due to a transient reduction in lipoprotein lipase activity following an episode of COVID-19 in an otherwise healthy 45-year-old woman. The lipoprotein lipase activity of the patient was markedly reduced compared with a healthy control and did recover to 20% of the healthy control’s lipoprotein lipase activity 5 months after the COVID-19 episode. Mixing tests substantiated reduced lipolytic capacity in the presence of the patient’s plasma at presentation compared with a homozygous lipoprotein lipase-deficient control, which was no longer present at follow-up. Western blotting confirmed that the quantity of lipoprotein lipase was not aberrant. Fibrate treatment and a strict hypolipidemic diet improved the patient’s symptoms and triglyceride levels.
Nitrofurantoin-induced agranulocytosis
Authors: Lopes Vanessa , Ramos Joana , Dias Patrícia , Santos Arsénio
Published: November 2021

Idiosyncratic drug-induced agranulocytosis is a rare life-threatening adverse reaction characterised by an absolute neutrophil count <500 cells/μL of blood. Nitrofurantoin has been associated with haematological adverse events, but few agranulocytosis cases worldwide have been reported. We present a case of a 68-year-old woman who presented with fever and agranulocytosis following treatment with nitrofurantoin. Extensive workup for agranulocytosis, including a bone marrow aspirate, was unremarkable. Treatment with nitrofurantoin was discontinued, which led to a complete recovery of the complete blood count. This case stresses the importance of monitoring treatments, given that widely used drugs are not free from severe adverse reactions.
Photodiagnosis of genital herpes and warts within a specialist online sexual health service: an observational (mixed methods) study of user experience and clinical outcomes
Authors: Engen Jessica , Black Adam , Holdsworth Gillian , Howroyd Chris , Courtenay Mollie , Baraitser Paula
Published: November 2021

Objectives

To evaluate the feasibility and acceptability of a pilot, free, online photodiagnosis service for genital herpes and warts with postal treatment delivered by a specialist digital sexual health service.

Setting

An online sexual health service available free of charge in South East London, UK.

Participants

Routinely collected data from 237 users of the pilot service during the study period and qualitative interviews with a purposive sample of 15 users.

Intervention

A pilot, free, online photodiagnosis service for genital herpes and warts with postal treatment delivered by a specialist digital sexual health service.

Primary and secondary outcome measures

Proportion of users who successfully uploaded photographs and the proportion diagnosed, treated and referred to face-to-face clinical services. User experience of this service.

Results

The service was accessed by 237 users during the study period with assessment possible for 86% of users based on the photographs provided. A diagnosis of genital herpes or warts was made for 40.5% and 89.6% were subsequently treated through the service. Eighteen per cent were diagnosed as normal/not needing treatment and 42% were signposted to clinic for further clinical assessment.

Qualitative data showed that users felt able and willing to provide genital images for diagnosis. Those who were treated or reassured expressed high satisfaction with the service, valuing the convenience, discreetness and support provided. However, users, particularly those who required referral to other services requested more personal and detailed communication when a clinical diagnosis is given remotely.

Conclusions

Findings suggest that online photodiagnosis was feasible and acceptable. However, effective and acceptable management of those who require referral needs careful remote communication.
Metabolic risk factors for non-communicable diseases in Ethiopia: a systematic review and meta-analysis
Authors: Alamnia Tilahun Tewabe , Tesfaye Wubshet , Abrha Solomon , Kelly Matthew
Published: November 2021

Objectives

Non-communicable diseases (NCDs) are causing a new and yetsignificant health challenge in low-income countries. In Ethiopia, although 39% of deaths are NCD related, the health system remains underprepared, highlighting the clear need for evidence on risk factor distributions to inform resource planning and the health response. Therefore, this review investigates prevalence distributions and sex and age variations of metabolic risk factors among Ethiopian adults.

Research design and methods

This systematic review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies published until 6 January 2021 were searched from PubMed, Scopus, ProQuest and Web of Science databases, reference lists of selected studies and grey literature. Studies reporting prevalence of metabolic risk factors: overweight/obesity, hypertension, impaired glucose homoeostasis and metabolic syndrome among Ethiopian adults were eligible for this systematic review and meta-analysis. Two authors independently extracted data and used the Joanna Briggs Institute tool for quality appraisal. The random effects model was used to conduct meta-analysis using Stata V.16. Subgroup analyses examined prevalence differences by region, study year, sample size and settings.

Results

From 6087 records, 74 studies including 104 382 participants were included. Most showed high prevalence of metabolic risk factors. Meta-analysis revealed pooled prevalence of metabolic risk factors from 12% to 24% with the highest prevalence observed for overweight/obesity (23.9%, 95% CI 19.9% to 28.0%) and hypertension (21.1%, 95% CI 18.7% to 23.5%), followed by metabolic syndrome (14.7%, 95% CI 9.8% to 19.6%) and impaired glucose tolerance (12.4%, 95% CI 8.7% to 16.1%). The prevalence of overweight/obesity was higher in women. All metabolic risk factors were higher among people aged above 45 years.

Conclusions

A signficant proportion of Ethiopian adults have at least one metabolic risk factor for NCDs. Despite heterogeneity of studies limiting the certainty of evidence, the result suggests the need for coordinated effort among policymakers, healthcare providers, non-governmental stakeholders and the community to implement appropriate preventive measures to reduce these factors.
Paediatric elbow fractures and public play spaces: adherence to standards for children’s playground equipment and surfacing
Authors: Smith Jennifer , Chhina Harpreet , Sidhu Pardeep , Brussoni Mariana , Pike Ian , Cooper Anthony
Published: November 2021

Background

Supracondylar humerus fractures (SCHF) are the most common fractures sustained following a fall onto an outstretched hand among healthy children, and one of the leading causes of hospital admission and surgical intervention. The aim of this study was to examine SCHF occurring at public play spaces—particularly to determine whether or not the playground equipment implicated in injurious falls aligned with Canadian playground safety standards.

Methods

Cases of children who attended the provincial paediatric orthopaedic clinic following SCHF at a public playground between April 2017 and October 2019 were included in the study. A research assistant visited each playground to measure the play structure type and dimensions, height of the equipment at the point from which the child fell and the type and depth of the surface material, and compare measurements to the 2016 safety standards. Child demographics and injury classification were also noted. Descriptive statistics were calculated and a scatterplot of fall height and surface depth was generated.

Results

Forty-three sites, representing 47 SCHF cases (18 female, 29 male), were included in the final analysis. Fourteen children sustained type 1 fracture, 23 had type 2 fracture and the remaining 10 had type 3 fracture. Five children with type 2 fracture and all 10 children with type 3 fracture required surgery. The majority of sites had engineered wood fibre surfacing, with surfacing at 35 sites being less than 300 mm deep. Twenty-six play structures were upper body equipment (ie, monkey bars or similar), seven were track rides, five were rotating structures and the rest comprised a variety of classified and unclassified structures. Twenty-seven children fell from a height exceeding 2 m.

Conclusions

The majority of SCHF cases occurred at playgrounds with insufficient surface depth and/or non-compliant equipment. Upper body equipment, track rides and rotating play structures were of particular concern, as the children fell from heights exceeding the recommended standard, likely reflecting the degradation and compaction of the surfacing material over time.
Post-COVID-19 assessment in a specialist clinical service: a 12-month, single-centre, prospective study in 1325 individuals
Authors: Heightman Melissa , Prashar Jai , Hillman Toby E , Marks Michael , Livingston Rebecca , Ridsdale Heidi A , Roy Kay , Bell Robert , Zandi Michael , McNamara Patricia , Chauhan Alisha , Denneny Emma , Astin Ronan , Purcell Helen , Attree Emily , Hishmeh Lyth , Prescott Gordon , Evans Rebecca , Mehta Puja , Brennan Ewen , Brown Jeremy S , Porter Joanna , Logan Sarah , Wall Emma , Dehbi Hakim-Moulay , Cone Stephen , Banerjee Amitava
Published: November 2021

Introduction

Post-COVID-19 complications require simultaneous characterisation and management to plan policy and health system responses. We describe the 12-month experience of the first UK dedicated post-COVID-19 clinical service to include hospitalised and non-hospitalised patients.

Methods

In a single-centre, observational analysis, we report the demographics, symptoms, comorbidities, investigations, treatments, functional recovery, specialist referral and rehabilitation of 1325 individuals assessed at the University College London Hospitals post-COVID-19 service between April 2020 and April 2021, comparing by referral route: posthospitalised (PH), non-hospitalised (NH) and post emergency department (PED). Symptoms associated with poor recovery or inability to return to work full time were assessed using multivariable logistic regression.

Results

1325 individuals were assessed (PH: 547, 41.3%; PED: 212, 16%; NH: 566, 42.7%). Compared with the PH and PED groups, the NH group were younger (median 44.6 (35.6–52.8) years vs 58.3 (47.0–67.7) years and 48.5 (39.4–55.7) years), more likely to be female (68.2%, 43.0% and 59.9%), less likely to be of ethnic minority (30.9%, 52.7% and 41.0%) or seen later after symptom onset (median (IQR): 194 (118–298) days, 69 (51–111) days and 76 (55–128) days; all p<0.0001). All groups had similar rates of onward specialist referral (NH 18.7%, PH 16.1% and PED 18.9%, p=0.452) and were more likely to require support for breathlessness (23.7%, 5.5% and 15.1%, p<0.001) and fatigue (17.8%, 4.8% and 8.0%, p<0.001). Hospitalised patients had higher rates of pulmonary emboli, persistent lung interstitial abnormalities and other organ impairment. 716 (54.0%) individuals reported <75% optimal health (median 70%, IQR 55%–85%). Less than half of employed individuals could return to work full time at first assessment.

Conclusion

Post-COVID-19 symptoms were significant in PH and NH patients, with significant ongoing healthcare needs and utilisation. Trials of interventions and patient-centred pathways for diagnostic and treatment approaches are urgently required.