bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Secondary Inertia Terms on Natural Frequencies of Rotating Beams
Authors: Bogdanoff J. L.
Published: June 2021

The equations of small motion of a straight cantilever beam attached to the rim of a rotating disk are determined assuming the Bernoulli-Euler theory of bending and the Saint Venant theory of torsion are valid, the mass and elastic axes coinciding and retaining all inertia terms. Influence of the secondary inertia terms on the fundamental torsional and lateral frequencies is then examined at two angular settings for a uniform beam having a length to disk-radius ratio in the range usually encountered in gas-turbine buckets and axial-flow compressor blades.
Large Deflections of Elliptical Plates
Authors: Weil N. A. , Newmark N. M.
Published: June 2021

A solution is obtained by means of the Ritz method for the “large-deflection” problem of a clamped elliptical plate of constant thickness, subjected to a uniformly distributed load. Two shapes of elliptical plate are treated, in addition to the limiting cases of the circular plate and infinite strip, for which the exact solutions are known. Center deflections as well as total stresses at the center and edge decrease as one proceeds from the infinite strip through the elliptical shapes to the circular plate, holding the width of the plates constant. The relation between edge-stress at the semiminor axis (maximum stress in the plate) and center deflection is found to be practically independent of the proportions of the elliptical plate. Hence the governing stress may be determined from a single curve for a given load on an elliptical plate of arbitrary dimensions, if the center deflection is known.
The Load-Carrying Capacity of Circular Plates at Large Deflection
Authors: Onat E. T. , Haythornthwaite R. M.
Published: June 2021

This paper presents an approximate analysis for the load carrying capacities of initially flat circular plates under various loading and edge conditions and subjected to slowly increasing load. As a plate deforms, the carrying capacity is increased as a result of favorable changes in geometry. In this study, the load capacity after finite deflection is estimated by assuming a velocity field based on the boundary conditions and on the incipient velocity field of the flat plate, the analysis being made for a rigid plastic, nonstrain-hardening material that yields according to the maximum shear-stress criterion. In several cases the results obtained compare favorably with test data for mild-steel plates; however, for very thin plates, better agreement is obtained by means of a purely membrane-type analysis, which also is presented.
The Pattern of Plastic Deformation in a Deeply Notched Bar With Semicircular Roots
Authors: Garr L. , Lee E. H. , Wang A. J.
Published: June 2021

The plastic deformation in a notched bar with deep semicircular roots pulled in plane strain is determined theoretically. The finite deformation is analyzed according to plastic-rigid theory. The motion is unsteady, and the velocity field at any instant is given in terms of the current geometry of the deformed free surface. A graphical step-by-step method is used to determine the deformation of a square grid scribed on the undeformed cross section. The deformed pattern details the regions of large plastic strain, and may be useful in considering the initiation of fracture cracks.
The Solution of Multiple-Branch Piping-Flexibility Problems by Tensor Analysis
Authors: Soule J. W.
Published: June 2021

A general method of flexibility analysis is presented which, by the use of tensors, makes it possible to derive the equations of performance of highly complex piping systems by a routine procedure.
On Some Problems in Bending of Thick Circular Plates on an Elastic Foundation
Authors: Frederick Daniel
Published: June 2021

The governing equations and solutions for the nonsymmetrical bending of circular plates resting on an elastic foundation are presented using the theory developed by E. Reissner. Also included are two examples in which numerical comparisons have been made with the predictions of the classical theory. These are (a) the axially symmetric bending of a finite circular plate on an elastic foundation under a partial uniform loading, and (b) the nonsymmetric bending of an infinite plate on an elastic foundation with a rigid circular inclusion.
Effect of Hub Radius on the Vibrations of a Uniform Bar
Authors: Boyce W. E.
Published: June 2021

Methods are discussed for obtaining upper and lower bounds on the frequencies of a uniform beam, rotating at a constant speed about an axis at one end, and vibrating transversely to the plane of rotation. Previous results are extended to include the case of a nonzero hub radius. Bounds on the first two frequencies are given for several ratios of hub radius to beam length. These show that the frequencies depend almost linearly on the hub radius for various rotational speeds.
On the Role of Extension in the Flexural Vibrations of Rings
Authors: Philipson L. L.
Published: June 2021

In a generalization of the classical analysis of A. E. H. Love, equations describing the flexural vibrations of thin rings are derived without making use of the usual assumption of no extension of the central line. Direct comparison with the nonextensional formulas of Love leads to a criterion for the validity of the assumption. In the process, the forced-vibration problem is shown to require the possibility of extension in certain cases in which its neglecting in a free-vibration analysis is valid.
The Modes of Vibration of a Certain System Having a Number of Equal Frequencies
Authors: Johnson D. C. , Bishop R. E. D.
Published: June 2021

This paper is concerned with a conservative system, which represents an idealized bladed rotor, whose principal modes are indeterminate. The dynamical behavior of the system is discussed and a method of selecting suitable principal modes and co-ordinates is explained.
Impulsive Loading of Elastic-Plastic Beams
Authors: Seiler J. A. , Cotter B. A. , Symonds P. S.
Published: June 2021

A simply supported uniform beam of ductile material, subjected to impulsive loading such that the initial velocity is a half-sine wave, is considered in this paper. The elastic and elastic-plastic motions are discussed under the assumption that plastic flow is confined to one cross section, and the final deformations are compared with those computed from an analysis which neglects all elastic deformations. The purpose of the work is to provide further information which may help in estimating the range of validity of the latter (“rigid-plastic”) type of analysis.
An Experimental Investigation of Beam Stresses Produced by Oblique Impact of a Steel Sphere
Authors: Cunningham D. M. , Goldsmith Werner
Published: June 2021

An experimental investigation designed to study the phenomenaincident to the oblique collision of 1/2-in-diam steel spheres with mild-steel and annealed drill-rod beams at oblique angles of incidence has been undertaken. Initial ball velocities ranged from 30 ft/sec to 150 ft/sec, beam sizes varied from 1/4 in. × 1/4 in. to 3/4 in. × 3/4 in., angles of incidence were chosen from 85 deg to normal incidence, and simply supported, clamped, and free beams were employed. Information is reported concerning the values of maximum bending stress at various positions along the beam as function of the angle of incidence and as a function of beam size for various angles of incidence. The progressive dispersion of the initial transient has been examined in detail. The effect of end supports, effective beam length, and repetitive shots into the same hole upon stress are described.
Axisymmetrical Buckling of Circular Cones Under Axial Compression
Authors: Seide Paul
Published: June 2021

The axisymmetrical buckling of right circular cones under axial compression is investigated. A simple expression is obtained for long cones of constant thickness, relating the cone buckling load to the buckling load of a long cylinder of equal thickness and the cone semivertex angle.
Biezeno Pressure Vessel Heads
Authors: Struble R. A.
Published: June 2021

The equation of thin-walled pressure vessel heads with constant maximum shear stress throughout is derived. Such heads, used on cylindrical vessels with uniform internal pressure, were first conceived by Biezeno in 1922 who gave a semigraphical prescription for determining the head shape.
Augmentation in Tribological Performance of Polyalphaolefins by COOH-Functionalized Multiwalled Carbon Nanotubes as an Additive in Boundary Lubrication Conditions
Authors: Kumar Homender , Harsha A. P.
Published: June 2021

This current study emphasized the tribological performances of COOH-functionalized multiwalled carbon nanotubes (MWCNTs) dispersed in two different grades of polyalphaolefins (i.e., PAO 4 and PAO 6). The friction and wear properties have been estimated using SRV 5 tribometer with “ball-on-disc” configuration. Prior to tribo testing, MWCNTs were characterized by X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HR-TEM), and Fourier-transform infrared spectroscopy (FTIR). The varying dose of MWCNTs (0.025–0.15 wt%) was incorporated into both PAO base oils to obtain the optimized lubrication behavior. The test results revealed that PAO 4 exhibited a reduction in friction coefficient (∼27%) and wear volume (∼88%) at a dose of 0.05 wt% and 0.025 wt% MWCNTs, respectively. However, in PAO 6, the minimum coefficient of friction and wear volume was obtained at a concentration of 0.075 wt% and 0.05 wt% of the additive. The results evidenced that PAO 6 based nanolubricants demonstrated the best frictional characteristics while attained the best anti-wear performance with PAO 4 based nanolubricants. For the better unveiling of the lubrication mechanism of MWCNTs, worn surfaces were characterized using various analytical techniques such as scanning electron microscopy (SEM), scanning probe microscope (SPM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron microscopy (XPS).
Drift-Flux Parameters for High-Viscous-Oil/Gas Two-Phase Upward Flow in a Large and Narrow Vertical and Inclined Annular Duct
Authors: Barbosa Marcel Cavallini , Rodriguez Oscar Mauricio Hernandez
Published: June 2021

Proper sizing of flow lines in the upstream energy industry depends on accurate modeling of gas–liquid flow, which has a common occurrence in production wells and has been studied thoroughly for many decades. However, data of flow in duct geometries different from circular pipes and when the liquid viscosity is much higher than that of water are scarce. Proper prediction of pressure gradient, heat and mass transfer, and corrosion depends on the accuracy of the model used to calculate the volumetric phase fraction. In pumped directional wells with inverted-shroud gravitational separators, there is flow through an annular duct formed between the wells’ casing and the separator itself that can have some tens of meters. The present work is an investigation on upward vertical/inclined high-viscous-oil/gas flow in a large and narrow annulus (30 mm hydraulic diameter with an outer diameter equal to 155 mm), using a radial geometry comparable with those found in real production systems. Air–water and air–oil mixtures, the latter with two oil viscosity ranges, were used as working fluids. The experimental test section used was 9.67 m long positioned at 90 deg (vertical) and 45 deg and made of two concentric pipes. Flow pattern transitions from the literature were analyzed and compared with the collected experimental data. Drift-flux parameters were obtained from multiple working conditions. These drift-flux parameters were used in the development of a novel flow pattern-independent correlation, compared against the present data and other data sets from the literature in which other geometries and fluids were used. The predictions of the proposed drift-flux correlation are significantly superior in comparison with correlations selected from the literature in all cases.
Variability in Submaximal Self-Paced Exercise Bouts of Different Intensity and Duration
Authors: O’Grady Ciaran , Passfield Louis , Hopker James G.
Published: June 2021

Purpose: Rating of perceived exertion (RPE) as a training-intensity prescription has been extensively used by athletes and coaches. However, individual variability in the physiological response to exercise prescribed using RPE has not been investigated. Methods: Twenty well-trained competitive cyclists (male = 18, female = 2, maximum oxygen consumption = 55.07 [11.06] mL·kg−1·min−1) completed 3 exercise trials each consisting of 9 randomized self-paced exercise bouts of either 1, 4, or 8 minutes at RPEs of 9, 13, and 17. Within-athlete variability (WAV) and between-athletes variability (BAV) in power and physiological responses were calculated using the coefficient of variation. Total variability was calculated as the ratio of WAV to BAV. Results: Increased RPEs were associated with higher power, heart rate, work, volume of expired oxygen (VO2), volume of expired carbon dioxide (VCO2), minute ventilation (VE), deoxyhemoglobin (ΔHHb) (P < .001), and lower tissue saturation index (ΔTSI%) and ΔO2Hb (oxyhaemoglobin; P < .001). At an RPE of 9, shorter durations resulted in lower VO2 (P < .05) and decreased ΔTSI%, and the ΔHHb increased as the duration increased (P < .05). At an RPE of 13, shorter durations resulted in lower VO2, VE, and percentage of maximum oxygen consumption (P < .001), as well as higher power, heart rate, ΔHHb (P < .001), and ΔTSI% (P < .05). At an RPE of 17, power (P < .001) and ΔTSI% (P < .05) increased as duration decreased. As intensity and duration increased, WAV and BAV in power, work, heart rate, VO2, VCO2, and VE decreased, and WAV and BAV in near-infrared spectroscopy increased. Conclusions: Self-paced intensity prescriptions of high effort and long duration result in the greatest consistency on both a within- and between-athletes basis.
New fluctuation theorems on Maxwell’s demon
Authors: Zeng Qian , Wang Jin
Published: June 2021

Because of dissipative information, Maxwell’s demon can extract less work or generate more heat than expected.
Quantitative In Vitro Assay for “Corncob” Formation
Authors: Lancy P. , Appelbaum B. , Holt S. C. , Rosan B.
Published: June 2021

The interaction of
Bacterionema matruchotii
with strains of
Streptococcus sanguis
produces a structure which morphologically resembles a corncob. To determine the specific bacterial surface receptors involved in the interaction, we developed a quantitative assay. The assay consisted of mixing saline suspensions of [CH
3
-
3
H]thymidine-labeled streptococci and
B. matruchotii
, incubating at 37°C for 2 h, and filtering the mixture through a 5-μm polycarbonate membrane filter. The free cocci and filaments passed through the filter, but the corncobs were retained. Estimates of the number of corncobs formed were obtained by quantitating the radioactivity retained on the membranes relative to that of controls of streptococci alone. Although saturation of the
Bacterionema
occurred at a ratio of streptococci to
Bacterionema
of 10:1 (Klett units), a 2:1 ratio was chosen because of the increased sensitivity of the assay at this ratio. The percentage of streptococci binding at this ratio was 18.6 ± 8.1 (standard deviation). All five
Bacterionema
strains tested formed corncobs; in contrast, only three strains of
S. sanguis
were positive. These were serotype 1 strains which had localized surface “fuzz.” Although scanning electron microscopic observations revealed an almost random distribution of cocci along the filament surface, transmission electron microscopy revealed that the streptococci were attached to the
Bacterionema
by the surface fuzz. No differences in corncob formation were observed in sodium phosphate buffer, pH 6 to 8, at phosphate concentrations ranging from 0.005 to 0.05 M. Concentrations of NaCl or KCl up to 0.25 M did not affect corncob formation, and low concentrations of CaCl
2
increased corncob formation slightly, whereas MgCl
2
, ethylenediaminetetraacetic acid, and citrate buffers reduced the number of streptococci binding to the filaments. These results suggest that divalent cations may play a role in this process.
Some Characteristics of the Outer Membrane Material Released by Growing Enterotoxigenic
Escherichia coli
Authors: Gankema Henk , Wensink Jan , Guinée Pieter A. M. , Jansen Wim H. , Witholt Bernard
Published: June 2021

The high-molecular-weight material released into the medium by
Escherichia coli
AP1, an enterotoxigenic strain of porcine origin, has been isolated and resolved into two clearly distinct fractions, based on sucrose density gradient and differential centrifugation, chemical analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and freeze-fracture electron microscopy. These two fractions, referred to as “medium vesicles” and “medium lipopolysaccharides”, were compared with the cellular outer and cytoplasmic membranes, the periplasmic fraction, and the cytoplasmic fraction. The medium vesicles closely resembled outer membrane and accounted for 3 to 5% of the total cellular outer membrane. They contained most of the heat-labile enterotoxin (LT) activity released into the medium by
E. coli
AP1. The medium lipopolysaccharide consisted mostly of lipopolysaccharide and a small amount of outer membrane and contained relatively little LT activity. Based on experiments with
E. coli
K-12 strains, in which about 5% of the newly synthesized outer membrane is lost from areas of outer membrane synthesis, it is proposed that enterotoxigenic
E. coli
strains release LT as part of such newly synthesized outer membrane fragments and that released outer membrane fragments may function as physiologically significant LT carriers.
Neurovirulence Mutant of Vesicular Stomatitis Virus with an Altered Target Cell Tropism In Vivo
Authors: Preble Olivia T. , Costello Lauren E. , Huang Diana D. , Barmada Mamdouha A.
Published: June 2021

Intracerebral infection of weanling Swiss mice with a temperature-sensitive (
ts
) mutant of vesicular stomatitis virus (VSV),
ts
pi364, resulted in a unique neuropathological syndrome not previously described with other VSV mutants. Mice infected with wild-type VSV died from an acute encephalitis characterized by neuronal necrosis and efficient virus replication in both brain and spinal cord. In contrast, with VSV
ts
pi364, the most prominent histopathological feature was destruction of the ependyma of the lateral ventricles. Virus antigen was also limited to the leptomeninges and the lateral ventricles. Infected mice survived and developed hydrocephalus. Replication of
ts
pi364 in the brain was 10- to 100- fold less than that of wild-type VSV, and appearance of virus in the spinal cord was delayed. VSV
ts
pi364 was isolated from mouse cells persistently infected with VSV. Another VSV
ts
pi mutant, isolated from the same persistent infection, behaved in vivo like wild-type VSV, even though both mutants were very similar in plaque size, reversion frequency, cut-off temperature, and synthesis of virus-specific proteins at semipermissive temperature. These results strongly suggest that VSV
ts
pi364 has a second, non-
ts
mutation which results in a restricted target cell range in vivo; wild-type VSV can infect both neurons and ependymal cells, whereas
ts
pi364 does not replicate in neurons.
In Vitro Studies of Rickettsia-Host Cell Interactions: Ultrastructural Study of
Rickettsia prowazekii
-Infected Chicken Embryo Fibroblasts
Authors: Silverman David J. , Wisseman Charles L. , Waddell Anna
Published: June 2021

Secondary chicken embryo fibroblasts infected in suspension with the Breinl strain of
Rickettsia prowazekii
and grown in monolayer culture were examined by both transmission and scanning electron microscopy at specific intervals after infection to study the effects of prolonged intracellular growth on the fine structure of the host cell and the rickettsiae. Cytopathological changes in the infected host cells were not apparent until late in the intracellular growth cycle when the cells began to rupture as a result of a large rickettsial burden. The only recognizable changes in heavily infected cells before lysis were the condensation of the intercristal matrix of some mitochondria and the apparent dissociation of ribosomes from the rough-surfaced endoplasmic reticulum. Although the effects of intracellular growth of rickettsiae on the fine structure of the host cell were rather unremarkable when compared with those imposed by
Rickettsia rickettsii
in a similar cell system, noticeable morphological changes in the rickettsiae were recognized during the intracellular growth cycle. These changes first became apparent about 40 h postinfection and consisted primarily of an increased electron density of the rickettsiae, the appearance of numerous vacuoles in the rickettsial cytoplasm, and a slight reduction in size of the rickettsiae. Changes of this nature may reflect transitional phases of growth characteristically seen in free-living bacterial cell systems.
Experimental production of actinomycetoma in BALB/c mice
Authors: Zlotnik H , Buckley H R
Published: June 2021

Chronic actinomycetoma associated with grain production was induced in BALB/c mice by subcutaneous inoculation of live Nocardia brasiliensis in Freund incomplete adjuvant into the hind footpads. Similar inoculation of N. asteroides and N. caviae resulted in local tumor formation which healed spontaneously after 5 months, the disease disseminating into the peritoneum, where masses or organisms could be detected. Grains were recovered from superficial skin lesions of N. caviae, but not from the N. asteroides-infected mice. Mycetoma lesions, appearing as early as 1 month after inoculation of 1.2 X 10(7) colony-forming units of N. brasiliensis per ml or as late as 3 months with inoculation of 1.0 X 10(5) colony-forming units per ml, became persistent and were readily detectable even 6 months after inoculation. No spontaneous healing occurred, and grains were recovered at different stages of the disease. Saline suspensions of N. brasiliensis also produced typical mycetoma lesions, although the incubation period was ca. 6 months. Adjuvant addition appeared to accelerate the onset of the disease. Experimental production of actinomycetoma in laboratory animals allows the study of many unanswered aspects of the disease and also provides a suitable model for therapeutic trials in the search for new and more effective chemotherapeutic agents.
Replication of murine cytomegalovirus in lung macrophages: effect of phagocytosis of bacteria
Authors: Shanley J D , Pesanti E L
Published: June 2021

Murine cytomegalovirus was found to replicate in lung and peritoneal macrophages of both CF-1 and BALB/c mice in vitro. Cytopathic changes typical of cytomegalovirus infection, including intranuclear inclusions, developed within the infected cells and eventually resulted in death of infected macrophages. Viral antigens were demonstrable by indirect immunofluorescence microscopy, and morphologically typical herpesvirus particles were observed in both nuclei and cytoplasm of murine cytomegalovirus-infected macrophages. Within 24 h after infection, at which time there was expression of viral antigens but no marcophage death, murine cytomegalovirus-infected macrophages demonstrated marked inhibition of phagocytosis of Staphylococcus aureus. Direct inhibition of macrophage function by cytomegalovirus infection in vivo could impair pulmonary defenses and may account in part for the frequent association of cytomegalovirus infection with other infectious agents.
Effect of specific binding of human albumin, fibrinogen, and immunoglobulin G on surface characteristics of bacterial strains as revealed by partition experiments in polymer phase systems
Authors: Miörner H , Myhre E , Björck L , Kronvall G
Published: June 2021

Four strains of gram-positive cocci with different combinations of positive binding of human proteins were investigated with respect to changes in physicochemical surface properties after specific protein binding. Staphylococcus aureus Cowan I, two group A beta-hemolytic streptococci, and one group G streptococcal strain were studied; they represented three different combinations of reactivity for human serum albumin, human immunoglobulin G, and fibrinogen. Using single-tube partition of bacterial cells in a dextran-polyethylene glycol system of constant polymer concentration but varying ionic compositions, it was possible to detect changes in the partition of bacteria after specific protein binding. There was a correlation between the binding of radiolabled human proteins to the bacterial strains and the effect of human proteins on the partition of the bacteria in the phase systems. Thus, the specific binding of proteins to the bacteria changes their physicochemical surface properties. These types of bacteria-protein interactions may play an important role in modulating host-parasite relationships.
Release of soluble peptidoglycan from growing conococci: demonstration of anhydro-muramyl-containing fragments
Authors: Sinha R K , Rosenthal R S
Published: June 2021

Previous analysis of soluble peptidoglycan (PG) fragments released by exponentially growing gonococci implicated the combined action of both hexosaminidase and amidase activities in PG turnover. Current studies further characterized PG fragments which were labeled in the glycan with D-glucosamine and in the peptide moiety with meso-diaminopimelic acid of L- and D-alanine. Labeled PG fragments were isolated by gel filtration and characterized on the bases of (i) KD values, (ii) free amino group analysis using fluorodinitrobenzene, (iii) borohydride reduction, (iv) alkali-catalyzed beta-elimination, (v) paper chromatography in various solvents, (vi) electrophoretic mobility at various pH values, (vii) digestibility by Charonia lampas glycosidases, and (viii) content of labeled D- and L-alanine. A set of well-characterized PG fragments was used as standards. The monomer fraction (the major extracellular product) was found to contain two components. Most (about 80%) appeared to be N-acetylglucosaminyl-beta-1 leads to 4-1,6-anhydro-N-acetylmuramyl-L-ala-D-glu-meso-diaminopimelic acid; the remainder was the corresponding disaccharide tetrapeptide containing a C-terminal D-alanine. An unusual feature of these products was the presence of the anhydro-muramyl (non-reducing) ends, reflecting the activity of a gonococcal transglycosylase, and the near absence of products containing detectable reducing ends. Otherwise, the structures of the monomer fragments were typical of those expected for a gram-negative bacterium (chemotype I). The corresponding peptide-cross-linked dimer and the free disaccharide also contained nonreducing ends, exclusively. Free peptides (products of amidase activity) consisted of both tripeptide and tetrapeptide. In summary, all gonococci examined appear to possess an unusual transglycosylase activity which contributes to the release of soluble PG fragments containing nonreducing, anhydro-muramyl ends. The release of these fragments in vivo might be a unique aspect of gonococci-host interactions.
CX3CR1 Is a Receptor for Human Respiratory Syncytial Virus in Cotton Rats
Authors: Green Gia , Johnson Sara M. , Costello Heather , Brakel Kelsey , Harder Olivia , Oomens Antonius G. , Peeples Mark E. , Moulton Hong M. , Niewiesk Stefan
Published: June 2021

The knowledge about a virus receptor is useful to better understand the uptake of a virus into a cell and potentially develop antivirals directed against either the receptor molecule on the cell or the receptor-binding protein of the virus. Among a number of potential receptor proteins, human CX3CR1 has been demonstrated to act as a receptor for respiratory syncytial virus (RSV) on human epithelial cells in tissue culture.
Multiple primary malignancies: synchronous lymphoma, pancreatic neuroendocrine tumour and colorectal cancer
Authors: Dayer Nicolas , Fasquelle François , Salati Emanuela , Dietrich Gilles
Published: June 2021

A 67-year-old woman underwent a medical check-up by her general practitioner after complaining of atypical pain in the shoulder girdle. Due to the important inflammatory syndrome noticed on blood testing, a polymyalgia rheumatica was suspected and she was started on corticosteroid treatment with good clinical response, but no impact on inflammation. She underwent extensive imaging with a thoraco-abdominal CT scanner that demonstrated a pancreatic mass, then later a PET-CT showed 3 different hyperactive lesions. Biopsies then revealed simultaneous diffuse large B-cell lymphoma (DLBCL), colorectal adenocarcinoma and pancreatic neuroendocrine tumour. She benefited from low rectal endoscopic excision of the colorectal tumour, R-CHOP chemotherapy for DLBCL and laparoscopic left pancreatectomy. Successful treatment required a good multidisciplinary collaboration between the different specialists. The patient made a good recovery and achieved complete remission at 1 year. This an unusual presentation of multiple primary malignancies.
Utility of endoscopic transpapillary pancreatic cyst drainage for intraductal papillary mucinous neoplasm infection
Authors: Watanabe Shunsuke , Toki Masao , Shibahara Junji , Hisamatsu Tadakazu
Published: June 2021

A 61-year-old woman with intraductal papillary mucinous neoplasm (IPMN) infection, who was treated with antibiotics, developed IPMN reinfection with febrile epigastric pain and was febrile. CT showed that the diameter of the IPMN had grown and hardened, with thickening of the cyst wall. Endoscopic retrograde pancreatography was then performed and a nasopancreatic cyst drainage tube was placed into the cyst. Symptoms and inflammatory findings improved considerably 17 days after endoscopic drainage. Few reports and evidence have been found regarding IPMN infections, and the frequency of onset, route of infection and optimal drainage method remain unknown. This study indicated that endoscopic transpapillary pancreatic cyst drainage was effective and is highly recommended for IPMN infection.
Randomised trial of first-line bronchial artery embolisation for non-severe haemoptysis of mild abundance
Authors: Fartoukh Muriel , Demoule Alexandre , Sanchez Olivier , Tuffet Sophie , Bergot Emmanuel , Godet Cendrine , Andrejak Claire , Pontier-Marchandise Sandrine , Parrot Antoine , Mayaux Julien , Meyer Guy , Cluzel Philippe , Sapoval Marc , Le Pennec Vincent , Carette Marie-France , Cadranel Jacques , Rousseau Alexandra , Khalil Antoine , Simon Tabassome
Published: June 2021

Background

Whereas first-line bronchial artery embolisation (BAE) is considered standard of care for the management of severe haemoptysis, it is unknown whether this approach is warranted for non-severe haemoptysis.

Research question

To assess the efficacy on bleeding control and the safety of first-line BAE in non-severe haemoptysis of mild abundance.

Study design and methods

This multicentre, randomised controlled open-label trial enrolled adult patients without major comorbid condition and having mild haemoptysis (onset <72 hours, 100–200 mL estimated bleeding amount), related to a systemic arterial mechanism. Patients were randomly assigned (1:1) to BAE associated with medical therapy or to medical therapy alone.

Results

Bleeding recurrence at day 30 after randomisation (primary outcome) occurred in 4 (11.8%) of 34 patients in the BAE strategy and 17 (44.7%) of 38 patients in the medical strategy (difference −33%; 95% CI −13.8% to −52.1%, p=0.002). The 90-day bleeding recurrence-free survival rates were 91.2% (95% CI 75.1% to 97.1%) and 60.2% (95% CI 42.9% to 73.8%), respectively (HR=0.19, 95% CI 0.05 to 0.67, p=0.01). No death occurred during follow-up and no bleeding recurrence needed surgery.

Four adverse events (one major with systemic emboli) occurred during hospitalisation, all in the BAE strategy (11.8% vs 0%; difference 11.8%, 95% CI 0.9 to 22.6, p=0.045); all eventually resolved.

Conclusion

In non-severe haemoptysis of mild abundance, BAE associated with medical therapy had a superior efficacy for preventing bleeding recurrences at 30 and 90 days, as compared with medical therapy alone. However, it was associated with a higher rate of adverse events.

Trial registration number

NCT01278199
Ambient PM2.5exposure and hospital cost and length of hospital stay for respiratory diseases in 11 cities in Shanxi Province, China
Authors: Cao Dawei , Li Dongyan , Wu Yinglin , Qian Zhengmin (Min) , Liu Yi , Liu Qiyong , Sun Jimin , Guo Yuming , Zhang Shiyu , Jiao Guangyuan , Yang Xiaoran , Wang Chongjian , McMillin Stephen Edward , Zhang Xinri , Lin Hualiang
Published: June 2021

Background

Few studies have examined the effects of ambient particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) on hospital cost and length of hospital stay for respiratory diseases in China.

Methods

We estimated ambient air pollution exposure for respiratory cases through inverse distance-weighted averages of air monitoring stations based on their residential address and averaged at the city level. We used generalised additive models to quantify city-specific associations in 11 cities in Shanxi and a meta-analysis to estimate the overall effects. We further estimated respiratory burden attributable to PM2.5using the standards of WHO (25 µg/m3) and China (75 µg/m3) as reference.

Results

Each 10 µg/m3increase in lag03PM2.5corresponded to 0.53% (95% CI: 0.33% to 0.73%) increase in respiratory hospitalisation, an increment of 3.75 thousand RMB (95% CI: 1.84 to 5.670) in hospital cost and 4.13 days (95% CI: 2.51 to 5.75) in length of hospital stay. About 9.7 thousand respiratory hospitalisations, 132 million RMB in hospital cost and 145 thousand days of hospital stay could be attributable to PM2.5exposures using WHO’s guideline as reference. We estimated that 193 RMB (95% CI: 95 to 292) in hospital cost and 0.21 days (95% CI: 0.13 to 0.30) in hospital stay could be potentially avoidable for an average respiratory case.

Conclusion

Significant respiratory burden could be attributable to PM2.5exposures in Shanxi Province, China. The results need to be factored into impact assessment of air pollution policies to provide a more complete indication of the burden addressed by the policies.
Untargeted Molecular Analysis of Exhaled Breath as a Diagnostic Test for Ventilator-Associated Lower Respiratory Tract Infections (BreathDx)
Authors: van Oort Pouline MP , Nijsen Tamara M , White Iain R , Knobel Hugo H , Felton Timothy , Rattray Nicholas , Lawal Oluwasola , Bulut Murtaza , Ahmed Waqar , Artigas Antonio , Povoa Pedro R , Martin-Loeches Ignacio , Weda Hans , Goodacre Royston , Schultz Marcus J , Dark Paul M , Fowler Stephen J , Bos Lieuwe D
Published: June 2021

Patients suspected of ventilator-associated lower respiratory tract infections (VA-LRTIs) commonly receive broad-spectrum antimicrobial therapy unnecessarily. We tested whether exhaled breath analysis can discriminate between patients suspected of VA-LRTI with confirmed infection, from patients with negative cultures. Breath from 108 patients suspected of VA-LRTI was analysed by gas chromatography-mass spectrometry. The breath test had a sensitivity of 98% at a specificity of 49%, confirmed with a second analytical method. The breath test had a negative predictive value of 96% and excluded pneumonia in half of the patients with negative cultures. Trial registration number: UKCRN ID number 19086, registered May 2015.
Implementation of a comprehensive flavoured tobacco product sales restriction and retail tobacco sales
Authors: Gammon Doris G , Rogers Todd , Gaber Jennifer , Nonnemaker James M , Feld Ashley L , Henriksen Lisa , Johnson Trent O , Kelley Terence , Andersen-Rodgers Elizabeth
Published: June 2021

Objective

San Francisco’s comprehensive restriction on flavoured tobacco sales applies to all flavours (including menthol), all products and all retailers (without exemptions). This study evaluates associations of policy implementation with changes in tobacco sales in San Francisco and in two California cities without any sales restriction.

Methods

Using weekly retail sales data (July 2015 through December 2019), we computed sales volume in equivalent units within product categories and the proportion of flavoured tobacco. An interrupted time series analysis estimated within-city changes associated with the policy’s effective and enforcement dates, separately by product category for San Francisco and comparison cities, San Jose and San Diego.

Results

Predicted average weekly flavoured tobacco sales decreased by 96% from before the policy to after enforcement (p<0.05), and to very low levels across all products, including cigars with concept-flavour names (eg, Jazz). Average weekly flavoured tobacco sales did not change in San Jose and decreased by 10% in San Diego (p<0.05). Total tobacco sales decreased by 25% in San Francisco, 8% in San Jose and 17% in San Diego (each, p<0.05).

Conclusions

San Francisco’s comprehensive restriction virtually eliminated flavoured tobacco sales and decreased total tobacco sales in mainstream retailers. Unlike other US flavoured tobacco policy evaluations, there was no evidence of substitution to concept–flavour named products. Results may be attributed to San Francisco Department of Health’s self-education and rigorous retailer education, as well as the law’s rebuttable presumption of a product as flavoured based on manufacturer communication.
Prevalence of vitamin-mineral supplement use and associated factors among Canadians: results from the 2015 Canadian Community Health Survey
Authors: Keshavarz Pardis , Shafiee Mojtaba , Islam Naorin , Whiting Susan J. , Vatanparast Hassan
Published: June 2021

Vitamin/mineral supplements are used for improving micronutrient intake and preventing deficiencies, particularly for shortfall nutrients. We assessed the prevalence of vitamin/mineral supplement use and associated factors among a representative sample of Canadians aged ≥1 years. We used nationally representative data from the 2015 Canadian Community Health Survey (CCHS)-Nutrition. The prevalence of vitamin/mineral supplement use containing shortfall nutrients (vitamins: A, C, D, B6, B12 and folate; minerals: calcium, magnesium, and zinc) was examined in this study. Logistic regression models were performed to determine factors associated with vitamin/mineral supplement use among Canadian children (1–18 years) and adults (>19 years). The overall prevalence of vitamin/mineral supplement use was 38% among men and 53% among women. Males aged 14–18 years had the lowest prevalence (26.5%; 95% confidence interval (CI) = 21.9–31.0) and females aged ≥71 years had the highest prevalence (67.8%; 95% CI = 64.1–71.5) of vitamin/mineral supplement use. Female gender, older age, higher education level, higher income, living in urban areas, having chronic conditions, having a normal body mass index (BMI), and being non-smoker were independent positive predictors of vitamin/mineral supplement use among adults. Independent positive predictors of vitamin/mineral supplement use among Canadian children included younger age, having a normal BMI, and being food secure.

Novelty: The overall prevalence of vitamin/mineral supplement use among Canadian men and women was 38% and 53%, respectively. Sociodemographic and lifestyle variables were associated with vitamin/mineral supplement use, especially among Canadian adults.
Subsurface settlements of shield tunneling predicted by 2D and 3D constitutive models considering non-coaxiality and soil anisotropy: a case study
Authors: Fang Yong , Cui Jian , Wanatowski Dariusz , Nikitas Nikolaos , Yuan Ran , He Yi
Published: June 2021

Appropriate constitutive models and reliable excavation and support sequences are believed to be the major concern in using finite element (FE) analysis to simulate shield tunnel excavation. This paper presents systematic two-dimensional (2D) and three-dimensional (3D) FE analyses employing a number of constitutive models accounting for initial soil anisotropy and non-coaxial plasticity, as evidenced within site investigations from the Tsinghuayuan Tunnel of the Jing-Zhang high-speed railway in China. The aim is to assess the effects of both the initial soil anisotropy and non-coaxiality on longitudinal and transverse tunneling-induced surface settlements. It is shown that the excavation procedures combined with the degree of cross-anisotropy are key towards the accurate prediction of maximum vertical displacements from tunneling, matching field data. Knowledge of the initial soil strength anisotropy can further improve the shape prediction of the transverse tunneling-induced surface settlement troughs. When considering n = 0.6 and β = 0° in simulations, the transverse surface settlement trough obtained is almost coincident with monitored field data. Initial stiffness anisotropy used in the prediction of shield tunnel-induced surface settlements in sandy pebble soils does improve realism of results significantly. The maximum longitudinal settlement predicted by considering cross-anisotropy is larger than that predicted by its isotropic counterpart.
Evaluation of sainfoin (Onobrychis viciifolia) for forage yield and persistence in sainfoin–alfalfa (Medicago sativa) mixtures and under different harvest frequencies
Authors: Biligetu Bill , Jefferson Paul G. , Lardner Herbert A. , Acharya Surya N.
Published: June 2021

Condensed tannins in sainfoin (Onobrychis viciifolia) improve forage digestion and reduce the risk of ruminant bloat caused by grazing alfalfa (Medicago sativa). The objectives of this study were to evaluate the forage dry matter yield (DMY) and persistence of newer sainfoin cultivars in mixtures with alfalfa, and to determine the impact of harvest frequency on the persistence of sainfoin. Sainfoin cultivars ‘AAC Mountainview’, ‘AAC Glenview’, ‘Delaney’, ‘Shoshone’, and six experimental populations were compared with ‘Nova’ and ‘Melrose’ at Lanigan, SK, from 2016 to 2018. Field plots were seeded in either monocultures of sainfoin at 33 kg·ha−1 or sainfoin–‘AC Grazeland’ alfalfa mixtures at 16:9 kg·ha−1 in alternate rows. Forage DMY was greater (P = 0.001) in mixtures than in sainfoin monocultures in all harvests. The proportion of sainfoin in mixtures at Cut 1 declined from 4.1% to 1.3% of total DMY from 2016 to 2018, and 19.0% to 4.8% in Cut 2, which was less than the recommended level to eliminate ruminant bloat risk. A second field trial was established in 2017 to compare responses of ‘AAC Mountainview’, ‘Nova’, and ‘Shoshone’ sainfoin under one-, two- or three-harvest frequencies in 2018 and 2019. The increase of harvest frequency did not reduce sainfoin stand (%). Stand percentage of ‘AAC Mountainview’ (91%) was greater (P = 0.01) than ‘Nova’ sainfoin (62%). Further agronomic studies focusing on weed control in sainfoin stands and the optimum seeding ratios of sainfoin–alfalfa within the Parkland region of Saskatchewan are needed.
Double peaks of gravitational wave spectrum induced from inflection point inflation
Authors: Gao Tie-Jun , Yang Xiu-Yi
Published: June 2021

We investigate the possibility of inducing the gravitational waves (GWs) with double peak energy spectrum from primordial scalar perturbations in inflationary models with three inflection points. Here the inflection points can be generated from a polynomial potential or generated from a Higgs-like $$\phi ^4$$

ϕ
4

potential with the running of quartic coupling. In such models, the inflection point at large scales predicts the scalar spectral index and tensor-to-scalar ratio to be consistent with current CMB constraints, and the other two inflection points generate two large peaks in the scalar power spectrum at small scales, which can induce GWs with a double peak energy spectrum. We find that for some choices of the parameters the double peak spectrum can be detected by future GW detectors, and one of the peaks around $$f\simeq 10^{-9}{-}10^{-8}$$

f
≃

10

-
9

-

10

-
8

 Hz can also explain the recent NANOGrav signal. Moreover, the peaks of the power spectrum allow for the generation of primordial black holes, which accounts for a significant fraction of dark matter.
RETINAL IMAGING AND ANALYSIS USING MACHINE LEARNING WITH INFORMATION FUSION OF THE FUNCTIONAL AND STRUCTURAL FEATURES BASED ON A DUAL-MODAL FUNDUS CAMERA
Authors: DOU PENG , ZHANG YANG , ZHENG RUI , YE YU , MAO JIANBO , LIU LEI , WU MING , SUN MINGZHAI
Published: June 2021

Retinal diseases and systemic diseases, such as diabetic retinopathy (DR) and Alzheimer’s disease, may manifest themselves in the retina, changing the retinal oxygen saturation ([Formula: see text]) level or the retinal vascular structures. Recent studies explored the correlation of diseases with either retina vascular structures or [Formula: see text] level, but not both due to the lack of proper instrument or methodology. In this study, we applied a dual-modal fundus camera and developed a deep learning-based analysis method to simultaneously acquire and quantify the [Formula: see text] and vascular structures. Deep learning was used to automatically locate the optic discs and segment arterioles and venules of the blood vessels. We then sought to apply machine learning methods, such as random forest (RF) and support vector machine (SVM), to fuse the [Formula: see text] level and retinal vessel parameters as different features to discriminate against the disease from the healthy controls. We showed that the fusion of the functional (oxygen saturation) and structural (vascular parameters) features offers better performance to classify diseased and healthy subjects. For example, we gained a 13.8% and 2.0% increase in the accuracy with fusion using the RF and SVM to classify the nonproliferative DR and the healthy controls.
A SYSTEM-LEVEL VIEW OF INSTITUTIONS: CONSIDERATIONS FOR ENTREPRENEURSHIP AND POVERTY
Authors: WEBB JUSTIN W.
Published: June 2021

Poverty levels represent an important indicator of economic development. A widely-held view among scholars is that formal institutions provide the foundation to support entrepreneurial activity that, when robust, can support economic development. Scholars typically examine the influence of specific formal institutions, such as property rights, tax policies, infrastructures, or otherwise. Herein, I seek to complement and build upon this extant research by elaborating a system-level view of institutions. Interfaces, tradeoffs and externalities are discussed as three key characteristics of institutional systems alongside system-level considerations for each of these characteristics (i.e., institutional coordination, cooperation and direction that can take place at interfaces; institutional imbalances that can occur with tradeoffs; and institutional ambiguities and territoriality that can exist because of externalities). I then describe how these system-level considerations influence entrepreneurial activities and the implications for poverty in two illustrative contexts: base-of-the-pyramid markets and entrepreneurial ecosystems. I conclude with a discussion of the intended contributions and implications of this work.