bluuebunny/crossref_metadata_2025 huggingface dataset:
The Performance of Modern Steam-Generating Units
Authors: Hirshfeld C. F. , Moran G. U.
Published: April 2023

There has been much speculation during the past as to those factors which seem to be most responsible for steam-generating-unit outage. This is a question which always arises when a plant is being designed for a certain capacity factor, where the reliability or availability of the boiler units must be accurately foreseen.

Some have held that the outage increases directly with the severity of use. Others contend that the method of burning the fuel has a definite bearing on reliability. Others still have set different values for unit reliability on different kinds of fuel.

As the probable availability of units operating under certain conditions is a matter of utmost importance to the power-station designer and owner, it was thought that a complete and thorough study of the facts obtaining in the power-generating industry would be of great value. With that idea in mind the authors were requested by the Central Stations Committee of the Power Division to prepare this paper.

The study was made along the same general lines as the steam-turbine investigation made by the Prime Movers Committee of the N.E.L.A. The methods used in collecting information were as nearly identical as circumstances and the character of the units studied would permit. Daily operation logs were filled out for the period of one year by the operators of some two hundred boilers scattered about the country in sixty-odd stations. The data resulting were compiled by one group of men in such a manner that the results might be readily compared.

The units have been arranged in groups or classes according to methods of fuel burning and the working steam pressures, and then numbered in order according to their average rates of evaporation. With the data arranged in such a manner it has been possible to arrive at some rather definite conclusions.
Increased Kilowatt Output of Adjustable-Blade Propeller Turbines
Authors: Martin C. R.
Published: April 2023

The commercial development of the adjustable-blade propeller-type hydraulic-turbine runner has been in a slow and careful manner, with the idea first of solving its mechanical difficulties and later of taking full advantage of the possibilities of high efficiency. The principal problem of the engineer in introducing a new design is to keep to a safe and reasonable program of development such as will not incur serious financial losses. In addition to the mechanical difficulties of the adjustable runner, there also have been many problems of regulation to be solved as well as the determination of a correct design of draft tube. This paper covers the gradual development and placing in service of the adjustable-blade runner in the United States to the time when the European design of automatic adjustable-blade runner was brought to this country.

The objectionable feature of the fixed-blade type of propeller runner is the peaked efficiency curve and the low efficiency at part-gate openings. By adjusting the runner blades one can operate at all the peak points of efficiency, reducing the disadvantage of part-gate operation. It is now possible to obtain a peak efficiency on a propeller-type runner that is within 1 to 2 per cent of the peak efficiency of Francis-turbine runners. The blades of a Francis runner are not adjustable, resulting in one-peak efficiency. The adjustable runner, therefore, with the possibility of adjusting its peak over a considerable range in load, makes it possible to obtain an average plant efficiency as high as that of the Francis runner.
Changing Requirements in Hydraulic Turbine Speed Regulation
Authors: Nagler Forrest
Published: April 2023

Flyball control of units such as are now operated in the plants of large systems may be of secondary importance for normal conditions. It is a control for large or sudden changes, a shutdown device for emergency purposes, and it effects certain conveniences in operation. It is of real use only in emergency conditions, it is entirely ineffective when a unit is on the load limit, and it is entirely ineffective when the gate position is controlled by frequency under gradual load change conditions. It comes into play in case of line troubles or when load changes are faster than the frequency control can meet.

Practically complete governing equipment can be built without a large flyball, and with probable ultimate simplification of governing equipment. It would consist of frequency control operating the gate through regulating cylinders and distributing valve, a load limit positioning device for that valve, just as is done nowadays, except that no main-relay connections would be required, no dashpot necessary, and all question of flyball drive eliminated. Emergency stop and emergency start would be obtained simply by making secondary contact at an abnormally high or low frequency point that would take the unit off the line or at least close it to “speed-no-load” condition.

It is not suggested that governors be eliminated. Many of their elements are very satisfactory. The oil-pressure systems now in use are probably the best form of speed-reducing mechanism for the purpose, reducing 600- to 1200-r.p.m. motor speed to as low as 1 r.p.m. It is suggested that they no longer be governors from a normal speed-control standpoint with its possible wide range of gate movement. They should be control mechanisms designed for the duties that they are to accomplish. The design of such controls would rapidly modify governors as they are designed today, and would also begin to modify turbine structures themselves, simplifying and cheapening them, a large portion of their cost being due to details which are not necessary or even desirable for the production of the maximum number of kilowatt-hours for a given stream flow or for a given amount of storage water.
German and American Steel-Plant Practice
Authors: Estep F. L.
Published: April 2023

The United States leads the world in the production of steel and Germany has again become second. The greater percentage of the total amount of steel made in the United States is used domestically, whereas, on the other hand, a very large percentage made in Germany is exported. This in itself has had a certain influence upon the processes developed, methods pursued in the two countries, and the supply and cost of raw materials. Another factor which has affected the methods and the equipment used is the quantity and quality of labor available and the wages which must be paid.

In Germany today the greater percentage of ore used comes from foreign countries, while in the United States the great bulk of the ore is mined at home. Coal is plentiful and of good quality in Germany, but its price for metallurgical purposes is higher today than the coals commonly used in the United States for the same purpose. This paper shows to some extent where the processes differ.
Aeronautical and Automotive Service Mechanics
Authors: Althouse A. D.
Published: April 2023

This paper describes the training courses for airplane and automobile mechanics as taught at the Cass Technical High School, Detroit, Mich. They have more than doubled the minimum training requirements for airplane mechanics as set forth by the United States Department of Commerce. The course for airplane-engine mechanics includes specifications of various types and gives shop work in tuning, adjusting, and overhauling engines. The course gives skill in the use of various hand tools and also teaches technical details. Automotive training includes machine fitting, internal-combustion engines, chassis details, automotive electricity, welding and engine testing.
Suggestions for Encouraging Education and Training for Industry
Authors: Falk Harold S.
Published: April 2023

Training of artisans and mechanics for American industry has been very much neglected in past years, and the movement for the revival of apprenticeship and industrial training can justly expect support. One of the great problems of apprenticeship and industrial training is to give the movement greater publicity, and to bring the subject before manufacturers and business men.

Local branches of the Society can effectively promote the movement by holding contests of various kinds related to industrial training. Because of the interest of engineers in drafting work, a contest in skill for drafting apprentices is suggested.

Such a contest may be conducted by a local committee, and if given extensive publicity will be very effective. Another possibility for the local branches is to give an award for the best paper written by an engineer on an assigned subject in the field of industrial training. The successful papers might be read before meetings of local branches of the Society. Also local branches might award a medal or cup every year to the corporations in their respective communities which have made the greatest advance in industrial training in a given year. Such a contest might be the most effective of all, but would need to be more carefully directed than the others.

Contests of this kind could be carried on without extensive study or research, and experience in similar contests conducted under other auspices has proved that they are very effective for purposes of publicity. Through contests the influence of the Society would force attention to the problems of industrial training on those who are most directly concerned.
The Training and Recruitment of Auto Mechanics Through Factory Sources
Authors: Rasche William F.
Published: April 2023

This paper treats of the selection and training of automobile mechanics through factory sources and outlines what the evolution in development of service facilities and service workers has been, what the present-day requirements are, what type of individual should be selected for training, and how a factory training school must be set up with respect to places of instruction, the preparation of a curriculum, the organization of instructional material, and the training and supervision of instructors.
Measuring Office-Machine Output as a Basis for Wage Incentives
Authors: Mitchell John
Published: April 2023

The author describes the procedure to employ in installing sound standards for office-machine work. After elimination of the unnecessary operations which a study of process sheets reveals, the various jobs are analyzed and the units in which their elements are to be measured are determined. He then takes up the determination of the value of the unit, the basis of payment and method of its calculation, the maintenance of standards set up, etc. An extensive appendix gives time allowances, rates, methods of bonus determination, and other data derived from various sources and covering a wide range of office-machine operations—addressing, typing, tabulating, duplicating, calculating, bookkeeping, etc.
Recent Developments in Material Handling at the Western Electric Company’s Merchandise Buildings at Kearny, N. J.
Authors: Pevear C. K.
Published: April 2023

A description is given of the Western Electric Company’s merchandise buildings at Kearny, N. J., their purpose, and the methods used in material handling in these buildings. A thorough study was made of the purpose of these buildings, the type of the material to be handled, and the possible future changes that might be made in the amount of work to be done and the dimension of units handled. Then the warehouse activities were laid out, and a building was designed to enclose them. Approaching the problem in this manner provided unusual design opportunities not generally met, as in most cases equipment has to be fitted into an existing building.
What Does the Materials-Handling Equipment Manufacturer Need to Know to Make a Successful Installation?
Authors: Preble N. H.
Published: April 2023

The answer to the problem of making a successful installation of material-handling equipment is not always simple and, due to varying conditions, is not always the same. In general, however, the following conditions must be examined: (1) Purpose of proposed handling installation. (2) Nature, weight, size, etc., of material or articles to be handled. (3) Capacity required. (4) The path which the material must follow. (5) Details of building or space within which the equipment is to be used. (6) General information as to power available; unusual conditions of temperature, moisture, etc.; erection conditions; and the like. The paper outlines in detail these various items, with a view to assisting the buyer.
Materials Handling in the Plant of the Goodyear Tire and Rubber Company
Authors: Stuber C. C.
Published: April 2023

In the plant described, 964 people are kept busy transporting an average of 1,863,269 lb. of material in process of manufacture over a floor space of 6,443,419 sq. ft. by the use of 17,000 electric power trucks, industrial hand trucks, and platform skids. This equipment would make a train 19 miles long. There are 81 elevators and 29,654 ft. of conveyors. The industrial trucks are under centralized control.
Economies Which May Be Effected in Power Transmission
Authors: Nichols W. W.
Published: April 2023

From an economical standpoint of maintenance, power-transmission equipment is not given careful consideration by management. It should not be left to the supervision of some old-time millwright. Belting is not given a close enough inspection upon its receipt to determine if it meets all the requirements laid down by the specifications for its purchase. Many machines upon production work are over-belted, and little attention is given to the correct determination of the size of belt necessary for the work. Heavier belts could be installed profitably. By this means unnecessary wear and tear upon countershaft clutches would be eliminated. More attention should be given to the application of the correct size of motor to individually motor-driven machine tools. Great loss and low power factor result from the methods now pursued. The question of group driving and the economies effected thereby are deserving of being more closely considered and of having their cost compared with individually motor-driven tools, both from an initial standpoint and a maintenance standpoint.
Some Practical Deductions From the Theory of Lubrication of Short Cylindrical Bearings
Authors: Cardullo F. E.
Published: April 2023

In this paper the author tells of desirable characteristics which a fluid lubricant should have, and explains the effects of viscosity. He develops a theory with many mathematical equations on the phenomena of longitudinal flow of lubricants in bearings. Conclusions are given regarding general design and operation of bearings, the load carrying capacity, the power loss, and the ultimate rise in temperature of a bearing operating continuously with a particular eccentricity ratio.
Research of the National Advisory Committee for Aeronautics on Aircraft Diesel Engines
Authors: Kemper Carlton
Published: April 2023

The National Advisory Committee for Aeronautics has studied the theoretical performance possible with a Diesel engine operating upon a dual-combustion cycle. It has investigated the great number of factors which control the injection characteristics of fuel sprays, and coordinated and applied results from test information on fuel injection and combustion to the design of combustion chambers. Considerable progress has been made.
Nitride Hardening of Alloy Steel for Diesel-Engine Use
Authors: Alden C. R.
Published: April 2023

In this paper the author discusses metallurgical developments in the nitride hardening of alloy steels and the advantages that may be expected from increased use. With correct analysis of the steel, freedom from distortion in hardening depends upon the operations preceding nitriding. A sequence of operations is given, and nitriding equipment is described. Time necessary to produce and the cost of the nitrided product are given.
Purification of Diesel-Engine Lubricating Oil
Authors: Flowers A. E. , Dietrich M. A.
Published: April 2023

The paper is a continuation of earlier research on a 10 by 12 Diesel engine. Its most important novelty appears to be a reference to avoiding dilution of the lubricating oil from mechanical leakage, an explicit statement upon this subject being contained in the paper. Deterioration of the lubricating oil and its increasing contamination with various substances not originally present are again shown as a function of operating power, and emphasis is placed on the large percentage of products resulting from cracking. It is not stated, however, whether the cracking products are traceable to the fuel or to the lubricating oil.
Lubrication of Power Cylinder of Diesel Engines and Causes of Cylinder Wear
Authors: Harshman J. B. , McGregor John M.
Published: April 2023

To determine methods of reducing Diesel cylinder-liner wear and to establish reasons for great differences in the rate of wear, a series of tests and experiments, extending over a period of four years, were carried out by the authors. The cost of the renewal of liners on a large pipe-line system is very considerable, but it is only a portion of the total losses. Added to liner-renewal expenses are the troubles likely to accrue from contamination of the oil in the crankcase, from loss of power, etc., which add greatly to operating costs.

In this paper the authors attempt to show how liner life may be lengthened with a resulting greater economy in the operation of the Diesel engine. Methods adopted for applying the cylinder oil and other causes allied to poor lubrication are discussed. The tables in the paper show what can be effected by changing the grade of oil in use and by correct treatment of fuel oil and the air.
Economics of Pumping Oil at Low Friction Losses
Authors: Karge Fritz
Published: April 2023

A study of California pipe lines and perusal of many articles in magazines of the oil industry indicate that most trunk-line systems are operated at pressures ranging around 750 lb. per sq. in. These pressures result from high friction losses in 8-in. pipe, which appears to be the predominantly favored size. This paper shows that the greater cost of larger pipe lines for pumping oil at lower friction losses will be returned in a comparatively short time by the saving in power cost. It also indicates the way toward a proper estimate of the power-operating costs for new lines.

Application of these principles to the redesign of existing pipe lines is not attempted since the wide variation in the arrangements and characteristics of such lines does not permit generalization. The principles apply nevertheless.

A number of California trunk pipe lines are too small in size. This is particularly evident in winter when the oil becomes cold and viscous. Many of these lines were laid before any definite knowledge had been developed concerning the friction losses in oil pipe lines. It is a more or less common occurrence that while holding the pressure at 800 lb. per sq. in. or higher, the pumps will move less and less oil until the line “freezes.” It then becomes necessary to plug it out with light oil. Several means of improving this condition have been under consideration from time to time, such as steam-heating stations and booster stations at intermediate points between pump stations. Electric heaters were tested out on at least two lines. Looping of lines has also been suggested and resorted to more or less. None of these means, however, is entirely satisfactory and most of them cost more than can be justified.

The laying of larger lines to improve pumping conditions has also been thought of, having in view the use of standard line pipe. The cost of such heavy large lines has usually been considered prohibitive. Now changes in the art of making and joining pipe of lighter weight have brought the larger sized lines within economic reach.
Temperature Observations for One Year on Streams of Petroleum Flowing in Mid-Continent Oil Pipe Lines
Authors: Martin Bert , Heltzel William G.
Published: April 2023

The designer of an oil-pipe-line system could obtain valuable data on the contraction of the lines if he knew more about the temperature variations of the oil flowing through them. In the transportation of oil over long distances through pipe lines, a change in the temperature of the oil is likely to occur, thus affecting the volume. It is valuable to be able to predict the amount of change in volume for temperature changes over long distances. An important factor is the viscosity of the petroleum, for temperature variations in the oil stream cause the viscosity to vary. The paper shows how these results may be obtained, and gives charts as an indication of the temperature conditions of the oil flowing through the oil-pipe-line systems of the Mid-Continent.
The Munder System for Paper Selection
Authors: Munder Norman T. A.
Published: April 2023

There are many makers of paper, and each one sends out sample books. These books are generally addressed to some individual in a printing or advertising house and become his property. The Munder system for paper selection provides a cabinet containing the paper-sample books of 54 paper makers. These books, over 400 in number, are indexed by uses, qualities, and prices, and provide an easy reference for all in an office who are interested in the selection of paper for various uses.
Design of the New Harris Automatic Two-Color Flat-Bed Press
Authors: Harris Alfred S.
Published: April 2023

A recent design of two presses, one a single-color and the other a two-color press, includes the standardization of parts and units to such an extent that 72 per cent of these parts are common to both presses. A few of the points described in the design are those contributing to rigidity of frame, impressional strength, uniformity of bed travel during the printing stroke, evenness of ink distribution, and accuracy of register. Accessibility to its adjustments and convenience for make-ready also received attention.
Design and Application of Rail Motor Cars
Authors: Guernsey Charles O.
Published: April 2023

The rail car is capable of performing certain services to better advantage than motive power of any other current type. It is not a competitor of the locomotive in the locomotive’s proper field. It is capable of performing services within its scope at a cost and with an availability and reliability at least equal to other railroad equipment.

Satisfactory operation depends on correct design, correct application, proper handling by the operators, and intelligent and thorough maintenance. The maintenance should be in the hands of an intelligent, properly trained supervisor, who has sufficient authority to handle his work without clearing details through other officials. The design must be such that all wearing parts are renewable, at the minimum of expense, and with a minimum of time out of service. The exhaust valves are apt to require attention more frequently than other features of the engine, therefore the design should be such as to give maximum exhaust-value life. Twin exhaust valves have been found desirable for this purpose.

Cooling systems must be designed to operate effectively regardless of car speed or direction. Transmission equipment should be capable of delivering to the rails the maximum possible percentage of engine power throughout the range of car speeds, at least to 60 m.p.h. The parasites and accessories can be handled to best advantage by the use of a small separate power plant. Cars of current designs are proving their worth in millions of miles of service annually on many different railroads in various parts of the world. The rail car is generally accepted as a proved tool for the reduction of operating costs and improvement of service within its field.

This paper gives the field for application of motor cars, some problems of design and use, and conclusions as to design, operation, and maintenance.
High-Pressure Locomotive Developments
Authors: Stuebing A. E.
Published: April 2023

This paper discusses two types of high-pressure locomotives recently built, the Loeffler type and the Winterthur locomotive. The former is an express locomotive of about 2500 hp. with a pressure of 1470 lb. per sq. in. and the latter of about 1200 hp. with a boiler pressure of 850 lb. per sq. in. The Loeffler locomotive is expected to result in a fuel saving of from 40 to 45 per cent compared with modern superheated locomotives. In a road test of the Winterthur locomotive, but 330 lb. of coal was necessary for firing up as compared with double the amount necessary for a conventional locomotive of equivalent output.
High-Pressure and High-Temperature Steam for Locomotives
Authors: Hirshfeld C. F.
Published: April 2023

The author states his position as that of giving to railroad men the benefit of experience had in stationary steam-power-plant practice and not as that of telling them what to do in locomotive practice. The advantages of high pressures and temperatures in stationary practice are considered separately for condensing operation and for back-pressure operation, respectively, and the differences are stressed. Certain experiences and observations regarding the behavior of metals and the boiler circulation under extreme conditions are given, and these are followed by speculations regarding the possible lines of development of locomotives.
Airplane Spruce
Authors: Fishbaugh E. J.
Published: April 2023

The author seeks to prove that wood is a better material than metal in airplane construction where strength is required, airplane spruce being the material against which all other materials are checked for suitability. The paper indicates that airplane spruce gives the least possible weight with the greatest possible strength. There is a stand of Sitka spruce available for airplane manufacture, the author attempts to show by statistics, that will outlast the present generation of builders.
Simulation of Liquor Blow, Thrust Force, and Risk of Condensation Hydraulic Shock in a Pulp-Digester Piping System
Authors: Carlson Andrew , Narayanan Chidambaram , Lakehal Djamel
Published: April 2023

This study is an industrial case study for the application of a validated flashing and hydraulic shock modeling approach to the safety and design of a reactor blow line. The maximum flowrate is important for sizing of downstream components. The high pressure of the blow and flashing of the liquid can result in significant forces on pipe bends and other geometrical features. Analysis and prediction of such forces are of importance for the structural design and anchoring of the piping. Another concern for a liquid blow under high pressure is the potential for condensation-induced hydraulic shock. The collapse of the flashed vapor to the liquid phase creating shock waves of large amplitudes is a serious safety concern. The computational fluid dynamics model used the homogeneous mixture model with a flashing model for phase change of the fluid. The properties of the fluid were defined by a custom function which interpolated between tabulated values of the thermodynamic and transport properties. The simulations predicted the occurrence of a condensation hydraulic shock when the blow down is initiated with empty pipes and demonstrated that a hydraulic shock could be prevented with liquid-filled condition. The pipework geometry was also optimized to reduce the forces acting at the junctions. The vapor quality at the outlet as a result of flashing was estimated, which is necessary for the design of downstream systems.
Effect of Heating Power on Ball Grid Array Thermal Shock Reliability for a Fanout Package
Authors: Zhong Ke , Wang Huanpeng , Wang Jingrou , Xu Yuehang
Published: April 2023

The reliability of Fanout package with a ball grid array (BGA) for microsystem is studied under thermal shock. Different heat source powers are applied to the silicon substrate to imitate the power dissipation induced heat of power devices and the thermal fatigue life of the package are studied using the Anand constitutive model and Darveaux life model. The finite element method simulation results show that the thermal fatigue life is not positively correlated with the heat source power. In a certain power range, the life first increases and then decreases. To explain this abnormal phenomenon, the fatigue analysis of solder balls with different heating power (10–55 W) is carried out. The results show that in the low temperature stage, with the increase of the heat source power, the heat source offsets the low temperature effect to a certain extent, and the stress value of the solder balls decreases. And during the high temperature stage, the stress of the ball is hardly affected. However, with the increase of the heat source power, the thermal deformation of the structure is gradually serious, the effect of offsetting the low temperature effect is reduced, and the thermal fatigue life increases with the increase of the heat source power. The results of the paper can be useful for microsystem package design.
Depletion of Extracellular Chemokines by Aspergillus Melanin
Authors: Graf Karen T. , Liu Hong , Filler Scott G. , Bruno Vincent M.
Published: April 2023

Aspergillus fumigatus
is the major airborne fungal pathogen that affects humans. In order to cause an invasive infection, inhaled spores must avoid killing by innate immune cells that are recruited to the site of infection.
Draft Genome Sequences and Genome Characterization of Three Toxigenic and Two Nontoxigenic Clostridioides difficile Clinical Isolates from Florida, USA
Authors: Wickramage Ishani , Heuler Joshua , Peng Zhong , Alrabaa Sally , Sun Xingmin
Published: April 2023

Draft genome sequences of five
Clostridioides difficile
clinical isolates were obtained in Florida, USA. Three isolates, designated TGH29 (sequence type 1 [ST1]/clade 2), TGH79 (ST11/clade 5), and TGH91 (ST35/clade 1), contained toxin-encoding genes. The two nontoxigenic strains were classified as TGH114 (ST109/clade 4) and TGH132 (ST15/clade 1). Antimicrobial resistance determinants and plasmids were detected and putative prophages predicted in some isolates.
Characterization of DNA Gyrase Activity and Elucidation of the Impact of Amino Acid Substitution in GyrA on Fluoroquinolone Resistance in Mycobacterium avium
Authors: Thapa Jeewan , Chizimu Joseph Yamweka , Kitamura Soyoka , Akapelwa Mwangala Lonah , Suwanthada Pondpan , Miura Nami , Toyting Jirachaya , Nishimura Tomoyasu , Hasegawa Naoki , Nishiuchi Yukiko , Gordon Stephen V. , Nakajima Chie , Suzuki Yasuhiko
Published: April 2023

The emergence of fluoroquinolone (FQ) resistance has further compounded the control of emerging
Mycobacterium avium
-associated nontuberculous mycobacteria infections worldwide. For
M. avium
, the association of FQ resistance and mutations in the quinolone resistance-determining region (QRDR) of
gyrA
is not yet clearly understood.
Oculo auriculo vertebral spectrum and CHARGE association
Authors: Bathula Shruthi , Bhate Manjushree
Published: April 2023

A boy in his early childhood was brought for a comprehensive eye examination as advised by a paediatrician. The child had plagiocephaly, absent left ear (anotia), facial asymmetry, deviation of mouth to the left side, receding chin and teeth, scoliosis and a Mongolian spot on the lower back. There was also absence of seventh and eighth cranial nerves on the left side on MRI of the brain. Echocardiography showed a small ventricular septal defect and a single umbilical artery. Gross motor milestones were delayed and on ocular examination, the child showed right eye preference and retinochoroidal coloboma in the left eye. The child was managed with a multidisciplinary approach involving the paediatrician, ENT specialist, ophthalmologist, clinical geneticist and rehabilitative services. The child was managed conservatively with spectacles and occlusion therapy of the right eye, and genetic counselling was given along with a left hearing aid and rehabilitation.
RECAST: Study protocol for an observational study for the understanding of the increased REsilience of Children compared to Adults in SARS-CoV-2 infecTion
Authors: Stricker Sebastian , Ziegahn Niklas , Karsten Martin , Boeckel Thomas , Stich-Boeckel Heike , Maske Jakob , Rugo Evelyn , Balazs Anita , Millar Büchner Pamela , Dang-Heine Chantip , Schriever Valentin , Eils Roland , Lehmann Irina , Sander Leif E , Ralser Markus , Corman Victor M , Mall Marcus A , Sawitzki Birgit , Roehmel Jobst
Published: April 2023

Introduction

The SARS-CoV-2 pandemic remains a threat to public health. Soon after its outbreak, it became apparent that children are less severely affected. Indeed, opposing clinical manifestations between children and adults are observed for other infections. The SARS-CoV-2 outbreak provides the unique opportunity to study the underlying mechanisms. This protocol describes the methods of an observational study that aims to characterise age dependent differences in immune responses to primary respiratory infections using SARS-CoV-2 as a model virus and to assess age differences in clinical outcomes including lung function.

Methods and analysis

The study aims to recruit at least 120 children and 60 adults that are infected with SARS-CoV-2 and collect specimen for a multiomics analysis, including single cell RNA sequencing of nasal epithelial cells and peripheral blood mononuclear cells, mass cytometry of whole blood samples and nasal cells, mass spectrometry-based serum and plasma proteomics, nasal epithelial cultures with functional in vitro analyses, SARS-CoV-2 antibody testing, sequencing of the viral genome and lung function testing. Data obtained from this multiomics approach are correlated with medical history and clinical data. Recruitment started in October 2020 and is ongoing.

Ethics and dissemination

The study was reviewed and approved by the Ethics Committee of Charité – Universitätsmedizin Berlin (EA2/066/20). All collected specimens are stored in the central biobank of Charité – Universitätsmedizin Berlin and are made available to all participating researchers and on request.

Trial registration number

DRKS00025715, pre-results publication.
Analysing multimodal data that have been collected using photovoice as a research method
Authors: Mooney Roisin , Bhui Kamaldeep
Published: April 2023

Background

Creative arts practice can enhance the depth and quality of mental health research by capturing and foregrounding participants’ lived experience. Creative methods are emotionally activating and promote multiple perspectives, tolerating ambiguities and uncertainties, which are shared and even celebrated.

Key arguments

Methods such as photovoice use imagery to elucidate narratives that are not easily captured by more traditional interview-based research techniques. However, the use of creative methods and participatory research remains novel as there is little guidance of how to navigate conceptual, practical, and analytical challenges.

Conclusion

This paper considers these challenges, and puts forward practical and theory informed recommendations, using as study of photovoice methods for investigating ethnic inequalities in the use of the mental health act (Co-Pact) as a case study.
Feasibility pilot trial for the Trajectories of Recovery after Intravenous propofol versus inhaled VolatilE anesthesia (THRIVE) pragmatic randomised controlled trial
Authors: Tellor Pennington Bethany R , Colquhoun Douglas A , Neuman Mark D , Politi Mary C , Janda Allison M , Spino Cathie , Thelen-Perry Steven , Wu Zhenke , Kumar Sathish S , Gregory Stephen H , Avidan Michael S , Kheterpal Sachin
Published: April 2023

Introduction

Millions of patients receive general anaesthesia for surgery annually. Crucial gaps in evidence exist regarding which technique, propofol total intravenous anaesthesia (TIVA) or inhaled volatile anaesthesia (INVA), yields superior patient experience, safety and outcomes. The aim of this pilot study is to assess the feasibility of conducting a large comparative effectiveness trial assessing patient experiences and outcomes after receiving propofol TIVA or INVA.

Methods and analysis

This protocol was cocreated by a diverse team, including patient partners with personal experience of TIVA or INVA. The design is a 300-patient, two-centre, randomised, feasibility pilot trial. Patients 18 years of age or older, undergoing elective non-cardiac surgery requiring general anaesthesia with a tracheal tube or laryngeal mask airway will be eligible. Patients will be randomised 1:1 to propofol TIVA or INVA, stratified by centre and procedural complexity. The feasibility endpoints include: (1) proportion of patients approached who agree to participate; (2) proportion of patients who receive their assigned randomised treatment; (3) completeness of outcomes data collection and (4) feasibility of data management procedures. Proportions and 95% CIs will be calculated to assess whether prespecified thresholds are met for the feasibility parameters. If the lower bounds of the 95% CI are above the thresholds of 10% for the proportion of patients agreeing to participate among those approached and 80% for compliance with treatment allocation for each randomised treatment group, this will suggest that our planned pragmatic 12 500-patient comparative effectiveness trial can likely be conducted successfully. Other feasibility outcomes and adverse events will be described.

Ethics and dissemination

This study is approved by the ethics board at Washington University (IRB# 202205053), serving as the single Institutional Review Board for both participating sites. Recruitment began in September 2022. Dissemination plans include presentations at scientific conferences, scientific publications, internet-based educational materials and mass media.

Trial registration number

NCT05346588.
Influence of vascular imaging acquisition at local stroke centers on workflows in the drip-n-ship model: a RACECAT post hoc analysis
Authors: Flores Alan , Garcia-Tornel Alvaro , Seró Laia , Ustrell Xavier , Requena Manuel , Pellisé Anna , Rodriguez Paula , Monterde Angela , Lara Lidia , Gonzalez-de-Echavarri Jose María , Molina Carlos A , Doncel-Moriano Antonio , Dorado Laura , Cardona Pedro , Cánovas David , Krupinski Jerzy , Más Natalia , Purroy Francisco , Zaragoza-Brunet Jose , Palomeras Ernesto , Cocho Dolores , Garcia Jessica , Colom Carla , Silva Yolanda , Gomez-Cocho Manuel , Jiménez Xavier , Ros-Roig Josep , Abilleira Sonia , Pérez de la Ossa Natalia , Ribo Marc
Published: April 2023

Background

The influence of vascular imaging acquisition on workflows at local stroke centers (LSCs) not capable of performing thrombectomy in patients with a suspected large vessel occlusion (LVO) stroke remains uncertain. We analyzed the impact of performing vascular imaging (VI+) or not (VI− at LSC arrival on variables related to workflows using data from the RACECAT Trial.

Objective

To compare workflows at the LSC among patients enrolled in the RACECAT Trial with or without VI acquisition.

Methods

We included patients with a diagnosis of ischemic stroke who were enrolled in the RACECAT Trial, a cluster-randomized trial that compared drip-n-ship versus mothership triage paradigms in patients with suspected acute LVO stroke allocated at the LSC. Outcome measures included time metrics related to workflows and the rate of interhospital transfers and thrombectomy among transferred patients.

Results

Among 467 patients allocated to a LSC, vascular imaging was acquired in 277 patients (59%), of whom 198 (71%) had a LVO. As compared with patients without vascular imaging, patients in the VI+ group were transferred less frequently as thrombectomy candidates to a thrombectomy-capable center (58% vs 74%, P=0.004), without significant differences in door-indoor-out time at the LSC (median minutes, VI+ 78 (IQR 69–96) vs VI− 76 (IQR 59–98), P=0.6). Among transferred patients, the VI+ group had higher rate of thrombectomy (69% vs 55%, P=0.016) and shorter door to puncture time (median minutes, VI+ 41 (IQR 26–53) vs VI− 54 (IQR 40–70), P<0.001).

Conclusion

Among patients with a suspected LVO stroke initially evaluated at a LSC, vascular imaging acquisition might improve workflow times at thrombectomy-capable centers and reduce the rate of futile interhospital transfers. These results deserve further evaluation and should be replicated in other settings and geographies.
Variation in US acute ischemic stroke treatment by hospital regions: limited endovascular access despite evidence
Authors: Stein Laura K , Maillie Luke , Erdman John , Loebel Emma , Mayman Naomi , Sharma Akarsh , Wolmer Sophia , Tuhrim Stanley , Fifi Johanna T , Jette Nathalie , Mocco J , Dhamoon Mandip S
Published: April 2023

Background

Although national organizations recognize the importance of regionalized acute ischemic stroke (AIS) care, data informing expansion are sparse. We assessed real-world regional variation in emergent AIS treatment, including growth in revascularization therapies and stroke center certification. We hypothesized that we would observe overall growth in revascularization therapy utilization, but observed differences would vary greatly regionally.

Methods

A retrospective cross-sectional analysis was carried out of de-identified national inpatient Medicare Fee-for-Service datasets from 2016 to 2019. We identified AIS admissions and treatment with thrombolysis and endovascular thrombectomy (ET) with International Classification of Diseases, 10th Revision, Clinical Modification codes. We grouped hospitals in Dartmouth Atlas of Healthcare Hospital Referral Regions (HRR) and calculated hospital, demographic, and acute stroke treatment characteristics for each HRR. We calculated the percent of hospitals with stroke certification and AIS cases treated with thrombolysis or ET per HRR.

Results

There were 957 958 AIS admissions. Relative mean (SD) growth in percent of AIS admissions receiving revascularization therapy per HRR from 2016 to 2019 was 13.4 (31.7)% (IQR −6.1–31.7%) for thrombolysis and 28.0 (72.0)% (IQR 0–56.0%) for ET. The proportion of HRRs with decreased or no difference in ET utilization was 38.9% and the proportion of HRRs with decreased or no difference in thrombolysis utilization was 32.7%. Mean (SD) stroke center certification proportion across HRRs was 45.3 (31.5)% and this varied widely (IQR 18.3–73.4%).

Conclusions

Overall growth in AIS treatment has been modest and, within HRRs, growth in AIS treatment and the proportion of centers with stroke certification varies dramatically.
Modeling of age-dependent natural mortality rates for long-lived fishes based on the Richards model family
Authors: Kai Mikihiko , Yokoi Hiroki , Fujinami Yuki
Published: April 2023

Natural mortality rates ( M) are poorly quantified and commonly identified as a key source of uncertainty in fish stock assessments. Increasingly, stock assessments account for size- and age-dependence in M instead of using a constant M for all sizes and ages, as has traditionally been the default assumption. Empirical studies show that M is approximately inversely proportional to body length in fish populations, and this generalization has been used together with a von Bertalanffy growth curve to derive an age-dependent M. Here we extend this approach to the three commonly used growth functions of the Richards family (i.e., Logistic, von Bertalanffy, and Gompertz growth models). These models allow flexible production of various growth curves with a sigmoid shape and an upper asymptote, making them useful for displaying diverse growth curves for various long-lived fishes. The influences of growth parameters on predicted M were investigated, and the outcomes were compared among the three growth models. Age-dependent M for blue sharks ( Prionace glauca) were estimated as an example.
Application of the bomb radiocarbon chronometer with eye lens core Δ14C for age validation in deepwater reef fishes
Authors: Patterson William F. , Chamberlin Derek W.
Published: April 2023

Eye lens core Δ14C of Gulf of Mexico outer shelf and upper slope reef fishes matched a regional Δ14C reference time series, but otolith cores were depleted in 14C relative to the reference series. This is due to C in eye lens protein being derived from metabolic sources, with the ultimate source being epipelagic phytoplankton. In contrast, otolith C is derived mainly (70%–80%) from dissolved inorganic C, which is depleted in 14C beyond the epipelagic. Analyzing Δ14C in eye lens cores provides a novel approach for validating age estimates of deepwater (>200 m) fishes, which were unresolved in earlier applications of the bomb 14C chronometer.
Radioactive decay properties of superheavy element Z = 119
Authors: Sowmya N. , Nagaraja A.M. , Manjunatha H.C.
Published: April 2023

Within the macroscopic approach, investigation of different decay modes such as alpha-decay, cluster-decay (12C to 40Ca), heavy particle radioactivity (HPR) (58Ni to 85Rb), and spontaneous fission (SF) half-lives are investigated in detail in the superheavy element (SHE), Z = 119. The decay energies, penetration probability, and different decay half-lives in the isotopes of synthesized superheavy nuclei (SHN) 290–303119 are evaluated. Both 12C and 40Ar cluster emissions reveal shorter half-lives when compared to other cluster emissions. Furthermore, 85Rb heavy particle emission from the SHN 290–303119 discloses shorter half-lives compared to other heavy particle emissions. From the comparison of different decay half-lives, it is observed that 85Rb HPR is dominant in the region 290–299119, alpha-decay is dominant for the 300–302119, and SF half-lives are predominant in 303119 nuclei. Hence, the prediction of decay modes and decay path in the SHE, Z = 119 are helpful in the identification of experimentally synthesized SHE.
Probing displaced top quark signature at the LHC Run 3
Authors: Andrea Jeremy , Bloch Daniel , Conte Éric , Darej Douja , Ducrocq Robin , Nibigira Emery
Published: April 2023

In the context of prospective studies for searches of new physics at the LHC Run 3, this paper investigates the relevance of using top quarks produced from new long-lived particles, and detected in the tracker volume of the ATLAS and CMS experiments. Such a signature, referred to as displaced top quarks, leads to final states containing displaced vertices and a high multiplicity of displaced jets and tracks, thanks to the top quark decays. Therefore, it is a possible powerful tool for searching for new long-lived particles. Three simplified models based on supersymmetry are explicitly designed for the study of this signature. They differ according to the nature of the long-lived heavy particle which produces at least one top quark: electrically neutral or charged, coloured or non-coloured long-lived particle. For each model, a wide region of parameter space, consistent with a reasonable number of displaced top quarks decaying in a typical tracker volume has been probed. From this study, promising benchmarks are defined and experimental guidelines are suggested.