bluuebunny/crossref_metadata_2025 huggingface dataset:
A Differential Stress-Strain Relation for the Hexagonal Close-Packed Array of Elastic Spheres
Authors: Duffy J.
Published: June 2021

A differential stress-strain relation is derived for a medium composed of a hexagonal close-packed array of elastic spheres in contact. The stress-strain relation is based on the theory of elastic bodies in contact, and includes the effects of both normal and tangential components of contact forces. Results of an experiment performed as a test of the differential stress-strain relation are presented.
A Mathematical Model Depicting the Stress-Strain Diagram and the Hysteresis Loop
Authors: Whiteman I. R.
Published: June 2021

A model is made up of elastoplastic elements, all of which have the same value of Young’s modulus E, but which have different values of yield stress. It is shown that the dimensionless tangent modulus graph Et/E represents the cumulative frequency distribution of those elements which are in the elastic region. From the frequency distribution, the equations for the stress-strain diagram and the hysteresis loop can be written.
Theory of Flight of the Sounding Rocket
Authors: Liu V. C.
Published: June 2021

Solutions of the equations of motion of vertically ascending rockets (both in power flight and in free flight) are given in closed form. Atmospheric density is assumed to vary exponentially with altitude, and the variation of the drag coefficient of the rocket with Mach number is assumed to follow a definite pattern. (The validity of the latter assumption is established by its close agreement with measured results.) These solutions, given in terms of special transcendental functions, can be used for the rapid estimation of sounding-rocket performance, eliminating the often-used laborious process of stepwise integration. The general rocket-performance parameters prescribed in the analysis also can be used to advantage in comparing and selecting multistage sounding rockets.
Unsteady Laminar Boundary Layers Over an Arbitrary Cylinder With Heat Transfer in an Incompressible Flow
Authors: Yang Kwang-Tzu
Published: June 2021

A method is presented for calculating the development of momentum and thermal laminar boundary layers on a heated cylinder of arbitrary shape when the cylinder moves in an incompressible fluid at rest with an unsteady velocity. This analysis is based on solutions to the unsteady momentum and energy-integral equations in conjunction with a set of universal functions, derived from exact solutions to the boundary-layer equations for a specific unsteady problem. These universal functions are given in tabulated form. Those associated with the energy-integral equation are calculated with a Prandtl number of 0.7. The reliability and limitation of these functions are indicated and discussed in the light of several simple problems of which solutions are available. A detailed calculation procedure for the general unsteady problem is given and then followed by a numerical example.
Strain-Hardening Solutions to Plate Problems
Authors: Perrone Nicholas , Hodge P. G.
Published: June 2021

Two sets of strain-hardening flow laws based on an analogy with a kinematic model are derived for circular plates made of an initially Tresca material. The two sets of flow laws, called complete and direct hardening, differ in the point at which the plane-stress assumption is introduced. The complete-hardening flow laws are more consistent since the plane-stress assumption is made at the latest possible stage in their derivation. Complete and direct-hardening solutions are obtained to each of three different plate problems. The results indicate that the direct-hardening solutions give a fair approximation to the complete-hardening ones.
Dynamic Loading Tests of an Aircraft-Type Beam
Authors: Ripperger E. A. , Barton W. R.
Published: June 2021

Experimental tests were conducted to determine the failure characteristics of simplified box-type wing structures loaded dynamically, as compared to those of similar beams loaded statically. It was found that under dynamic loading, of the type applied, failure occurred at essentially the same loads and deflections observed at failure under static loading conditions. Tip deflections and accelerations were calculated using the force-deflection relationship determined by static loading, and compared to measured values. Agreement between measured and calculated values was only fair.
Extensional Vibrations of Elastic Plates
Authors: Mindlin R. D. , Medick M. A.
Published: June 2021

A system of approximate, two-dimensional equations of extensional motion of isotropic, elastic plates is derived. The equations take into account the coupling between extensional, symmetric thickness-stretch and symmetric thickness-shear modes and also include two face-shear modes. The spectrum of frequencies for real, imaginary, and complex wave numbers in an infinite plate is explored in detail and compared with the corresponding solution of the three-dimensional equations.
Effect of Acoustic Streaming on Heat Transfer of Porous Composite Phase Change Material by Using Lattice Boltzmann Simulation
Authors: Li Xiangxuan , Li Xinyi , Cui Wei , Ma Ting , Lu Lin , Wang Qiuwang
Published: June 2021

In this paper, the lattice Boltzmann (LB) method was used to simulate the flow and heat transfer process in porous composite phase change material (PCM) with acoustic streaming, to investigate the mechanism of heat transfer enhancement caused by acoustic streaming. The study focused on the effect of acoustic streaming at different Rayleigh number, Prandtl number, amplitude and wavelength of acoustic streaming on the flow field, temperature field, liquid fraction field, and average Nusselt number at the hot wall. The results show that acoustic streaming can enhance the fluid flow in the liquid phase region, and reduce the temperature inhomogeneity and inclination of liquid–solid interface front. The natural convection and the forced convection caused by acoustic streaming both get strengthened with the increasing of Rayleigh number, thus the influence of acoustic streaming first slightly rises and then drops. The momentum diffuses slower compared to the heat diffusion with the increasing of Prandtl number, thus the influence of acoustic streaming increases. With the amplitude of acoustic streaming increasing, the effect of acoustic streaming has a more remarkable inhibiting effect on average liquid fraction, decreasing by 1.11%, 5.09%, and 20.1% at the amplitude of acoustic streaming δρ* = 0.005, 0.01, 0.02, respectively. The average temperature and average liquid fraction show no obvious differences with the increasing of the wavelength of the acoustic streaming.
Development and Processing of Thermal-Hydraulic Model for GFR 2400 Fast Reactor Design and NESTLE Coupled Transient Code
Authors: Osuský Filip , Vrban Branislav , Čerba Štefan , Lüley Jakub , Nečas Vladimír
Published: June 2021

The paper investigates the influence of the used thermal-hydraulic approximations on the coupled calculations of gas-cooled fast reactor design (hereby GFR 2400). The NESTLE code is used as coupled simulation tool and solves the multigroup neutron diffusion equation by the finite difference method that is internally coupled with a thermal-hydraulic subchannel code. The in-house developed tempin code and the computational fluid dynamics (CFD) code fluent (from ANSYS code system, Canonsburg, PA) are used to prepare the thermal-hydraulic data for the GFR 2400 calculations. The tempin code solves the steady-state heat balance equation with flowing coolant in triangular lattice cell together with temperature dependent thermal-hydraulic properties of the fuel, cladding, and coolant. Based on the calculated fuel bundle temperature distributions by the tempin code, the thermal-hydraulic material properties (approximations) suitable for the NESTLE coupled code are processed for the GFR 2400 design. The influence of the constant and radial heat generation term within the fuel pin is studied within the paper. The performance of the NESTLE code with thermal-hydraulic approximations processed by both (tempin and fluent) methods is compared with the findings of the GoFastR project. Moreover, both the thermal-hydraulic approximations were compared for one steady-state and one transient state, related to the rapid withdrawal of one control rod assembly from the core. Changes in thermal-hydraulic distributions are described and visualized in the paper.
Effects of Sweep, Dihedral and Skew on Aerodynamic Performance of Low-Pressure Axial Fans With Small Hub-to-Tip Diameter Ratio
Authors: Wang Jie , Kruyt Niels P.
Published: June 2021

Axial fans with a small hub-to-tip diameter ratio are used in many branches of industry. Optimization of their aerodynamic performance is important, for which using sweep, dihedral, and skew of the blades' stacking line form an important method. Investigations on axial fans with medium to high hub-to-tip diameter ratio have shown that forward sweep of blades can give an improved aerodynamic performance, especially the total-to-total efficiency. However, only a few studies for fans with a small hub-to-tip diameter ratio have been reported. For such fans, extensive regions of backflow are present behind the fan near the hub. Based on a validated computational fluid dynamics simulation method, the effects of a sweep, dihedral and skew in axial and circumferential directions (in forward and backward direction) on the aerodynamic performance of small hub-to-tip ratio fans are investigated, with a linear stacking line. Current results show that forward sweep and circumferential skew are beneficial for higher total-to-total efficiency and that higher total-to-static efficiency can be obtained by forward dihedral and axial skew. The backward shape variety generally gives negative aerodynamic effects. Forward sweep and circumferential skew shorten the radial migration path, but more flow separation is present near the hub. With forward dihedral and axial skew, the backflow region is reduced in size and axial extent, but a more significant hub corner stall region is found. The pressure reduction due to sweep and dihedral is more limited than what could be expected from wing aerodynamics.
Fractal Properties of a Falling Particle Curtain in Air
Authors: Ludwigsen Josh , Wayne Patrick , Freelong Daniel , Vigil Gregory , Shaheen Carolina , Vorobeiff Peter , Truman C. Randall
Published: June 2021

The formation of a gravity-driven falling particle curtain is important for many problems, including solar tower particle receivers and setting the correct initial conditions for modeling shock interaction with multiphase media. One important characteristic of the curtain is the time history of its fractal dimension that characterizes the evolutionary growth of perturbations along the curtain's extent. For multiphase flows, fractal dimension can be used to help predict the types of instabilities that will occur within the flow. Our experiment aimed to establish the transient and stationary-value fractal dimension of a dense particle curtain with varying thickness containing particles with a density of 1.44 gm/cm3 and nominal diameter of 40 μm. High-speed video of the curtain was captured and analyzed. This data from this experiment, besides providing insights into the relevant physical processes, will be used to validate numerical models for multiphase flows.
An Analysis of the Secondary Flow Around a Tandem Blade Under the Presence of a Tip Gap in a High-Speed Linear Compressor Cascade
Authors: Konrath Liesbeth , Peitsch Dieter , Heinrich Alexander
Published: June 2021

Tandem blades have often been under investigation, experimentally as well as numerically, but most of the studies have been about tandem blade stators without tip gap. This work analyzes the influence of a tip gap on the flow field of a tandem blade for engine core compressors. Experiments have been conducted in a high-speed linear compressor cascade on a tandem and a reference geometry. The flow is analyzed using five-hole probe measurements in the wake of the blades and oil flow visualization to show the near surface stream lines. First, the results for design conditions (tandem and conventional blades) are compared to measurements on corresponding blades without a tip gap. Similarities and differences in the flow topology due to the tip clearance are analyzed, showing that the introduction of the tip clearance has a similar influence on the loss and turning development for the tandem and the conventional blades. The tandem blade features two tip clearance vortices with a complex flow interaction and the possible formation of a third counter-rotating vortex between them. An incidence variation from 0 deg to 5 deg for both blades indicates at first a similar behavior. After a separation of the flow field into gap and non-gap half, it becomes apparent that the tandem blade shows higher losses on the gap side, while featuring a close-to-constant behavior on the non-gap side. Further investigation of the flow on the gap side shows indicators of the front blade exhibiting tip clearance vortex break down, while the rear blade seems unaffected.
Direct current and high power impulse magnetron sputtering discharges with a positively biased anode
Authors: Hippler Rainer , Cada Martin , Hubicka Zdenek
Published: June 2021

A magnetron sputtering discharge with a positively biased anode in argon gas is investigated by Langmuir probe diagnostics and by energy-resolved mass spectrometry. The discharge is operated in continuous (direct current) and in pulsed (high power impulse magnetron sputtering, Hi) mode with a Ti target and in Ar gas. Singly-charged Ar+, Ti+, and Ar2+ and doubly-charged Ar2+ and Ti2+ ions are observed. A novel approach is to bias the magnetron anode. Application of a positive anode voltage shifts the kinetic energies of plasma ions by qe0Va, where Va is the anode voltage and qe0 is the ion charge. It allows for an effective control of plasma ion energies.
Novel enzymatic cross-linking–based hydrogel nanofilm caging system on pancreatic β cell spheroid for long-term blood glucose regulation
Authors: Kim Minji , Kim Hyunbum , Lee Young-sun , Lee Sangjun , Kim Seong-Eun , Lee Uk-Jae , Jung Sungwon , Park Chung-Gyu , Hong Jinkee , Doh Junsang , Lee Dong Yun , Kim Byung-Gee , Hwang Nathaniel S.
Published: June 2021

A multilayer hydrogel nanofilm on the cell surface via enzymatic reactions provides a new platform for β cell–based therapy.
Chemogenetic dissection of the primate prefronto-subcortical pathways for working memory and decision-making
Authors: Oyama Kei , Hori Yukiko , Nagai Yuji , Miyakawa Naohisa , Mimura Koki , Hirabayashi Toshiyuki , Inoue Ken-ichi , Suhara Tetsuya , Takada Masahiko , Higuchi Makoto , Minamimoto Takafumi
Published: June 2021

Imaging-guided selective silencing of the prefronto-caudate/thalamus pathways reveals their distinct roles in cognitive functions.
Hepatocyte TLR4 triggers inter-hepatocyte Jagged1/Notch signaling to determine NASH-induced fibrosis
Authors: Yu Junjie , Zhu Changyu , Wang Xiaobo , Kim KyeongJin , Bartolome Alberto , Dongiovanni Paola , Yates Katherine P. , Valenti Luca , Carrer Michele , Sadowski Thorsten , Qiang Li , Tabas Ira , Lavine Joel E. , Pajvani Utpal B.
Published: June 2021

Increased Jagged1 in pericentral hepatocytes causes liver fibrosis in response to hepatocyte TLR4–NF-κB pathway activation in NASH.
Functional human IgA targets a conserved site on malaria sporozoites
Authors: Tan Joshua , Cho Hyeseon , Pholcharee Tossapol , Pereira Lais S. , Doumbo Safiatou , Doumtabe Didier , Flynn Barbara J. , Schön Arne , Kanatani Sachie , Aylor Samantha O. , Oyen David , Vistein Rachel , Wang Lawrence , Dillon Marlon , Skinner Jeff , Peterson Mary , Li Shanping , Idris Azza H. , Molina-Cruz Alvaro , Zhao Ming , Olano Lisa Renee , Lee Patricia J. , Roth Alison , Sinnis Photini , Barillas-Mury Carolina , Kayentao Kassoum , Ongoiba Aissata , Francica Joseph R. , Traore Boubacar , Wilson Ian A. , Seder Robert A. , Crompton Peter D.
Published: June 2021

A functional human IgA response to malaria targets a conserved epitope in the N terminus of the
Plasmodium falciparum
circumsporozoite protein.
The Copper Chaperone CcsA, Coupled with Superoxide Dismutase SodA, Mediates the Oxidative Stress Response in Aspergillus fumigatus
Authors: Du Wenlong , Zhai Pengfei , Liu Shuai , Zhang Yuanwei , Lu Ling
Published: June 2021

Reactive oxygen species (ROS) produced by phagocytes have been reported to participate in the killing of fungal pathogens. Superoxide dismutases (SODs) are considered to be the first defense line against superoxide anions.
Replication Kinetics, Cell Tropism, and Associated Immune Responses in SARS-CoV-2- and H5N1 Virus-Infected Human Induced Pluripotent Stem Cell-Derived Neural Models
Authors: Bauer Lisa , Lendemeijer Bas , Leijten Lonneke , Embregts Carmen W. E. , Rockx Barry , Kushner Steven A. , de Vrij Femke M. S. , van Riel Debby
Published: June 2021

Infections with the recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are often associated with neurological complications. Evidence suggests that SARS-CoV-2 enters the brain via the olfactory nerve; however, SARS-CoV-2 is only rarely detected in the central nervous system of COVID-19 patients.
Measurement of Klebsiella Intestinal Colonization Density To Assess Infection Risk
Authors: Sun Yuang , Patel Alieysa , SantaLucia John , Roberts Emily , Zhao Lili , Kaye Keith , Rao Krishna , Bachman Michael A.
Published: June 2021

Colonization by bacterial pathogens often precedes infection and offers a window of opportunity to prevent these infections in the first place.
Klebsiella
colonization is significantly and reproducibly associated with subsequent infection; however, factors that enhance or mitigate this risk in individual patients are unclear. This study developed an assay to measure the density of
Klebsiella
colonization, relative to total fecal bacteria, in rectal swabs from hospitalized patients.
A tale of two Tweefonteins: What physical correlation, geochronology, magnetic polarity stratigraphy, and palynology reveal about the end-Permian terrestrial extinction paradigm in South Africa
Authors: Gastaldo Robert A. , Neveling Johann , Geissman John W. , Kamo Sandra L. , Looy Cindy V.
Published: June 2021

The contact between the Daptocephalus to Lystrosaurus declivis (previously Lystrosaurus) Assemblage Zones (AZs) described from continental deposits of the Karoo Basin was commonly interpreted to represent an extinction crisis associated with the end-Permian mass-extinction event at ca. 251.901 ± 0.024 Ma. This terrestrial extinction model is based on several sections in the Eastern Cape and Free State Provinces of South Africa. Here, new stratigraphic and paleontologic data are presented for the Eastern Cape Province, in geochronologic and magnetostratigraphic context, wherein lithologic and biologic changes are assessed over a physically correlated stratigraphy exceeding 4.5 km in distance. Spatial variation in lithofacies demonstrates the gradational nature of lithostratigraphic boundaries and depositional trends. This pattern is mimicked by the distribution of vertebrates assigned to the Daptocephalus and L. declivis AZs where diagnostic taxa of each co-occur as lateral equivalents in landscapes dominated by a Glossopteris flora. High-precision U-Pb zircon (chemical abrasion-isotope dilution-thermal ionization mass spectrometry) age results indicate maximum Changhsingian depositional dates that can be used as approximate tie points in our stratigraphic framework, which is supported by a magnetic polarity stratigraphy. The coeval nature of diagnostic pre- and post-extinction vertebrate taxa demonstrates that the L. declivis AZ did not replace the Daptocephalus AZ stratigraphically, that a biotic crisis and turnover likely is absent, and a reevaluation is required for the utilization of these biozones here and globally. Based on our data set, we propose a multidisciplinary approach to correlate the classic Upper Permian localities of the Eastern Cape Province with the Free State Province localities, which demonstrates their time-transgressive nature.
Supplemental Material: Evaluating the role of topographic inversion in the formation of the Stanislaus Table Mountains in the Sierra Nevada (California, USA)
Authors: Gabet Emmanuel
Published: June 2021

The profile lines and lithological maps.
Femtochemistry of Rhodopsins
Authors: Ostrovsky M. A. , Nadtochenko V. A.
Published: June 2021

The review considers the spectral kinetic data obtained by us by femtosecond absorption laser spectroscopy for the photochromic reaction of retinal isomerization in animal rhodopsin (type II), namely, bovine visual rhodopsin and microbial rhodopsins (type I), such as Exiguobacterium sibiricum rhodopsin and Halobacterium salinarum bacteriorhodopsin. It is shown that the elementary act of the photoreaction of retinal isomerization in type I and type II rhodopsins can be interpreted as a transition through a conical intersection with retention of the coherence of the vibrational wave packets generated during excitation. The coherent nature of the reaction is most pronounced in visual rhodopsin as a result of the barrier-free movement along the excited surface of potential energy, which also leads to an extremely high rate of retinal isomerization compared to microbial rhodopsins. Differences in the dynamics of photochemical reactions of type I and type II rhodopsins can be related to both differences in the initial isomeric forms of their chromophores (all-trans and 11-cis retinal, respectively), as well as with the effect of the protein environment on the chromophore. Despite the practically identical values of the quantum yields of the direct photoreaction of visual rhodopsin and bacteriorhodopsin, the reverse photoreaction of visual rhodopsin is much less effective (φ = 0.15) than in the case of bacteriorhodopsin (φ = 0.81). It can be assumed that the photobiological mechanism for converting light into an information process in the evolutionarily younger visual rhodopsins (type II rhodopsins) should be more reliable than the mechanism for converting light into a photoenergetic process in the evolutionarily more ancient microbial rhodopsins (type I rhodopsins). The low value of the quantum yield of the reverse reaction of visual rhodopsin can be considered as an increase in the reliability of the forward reaction, which triggers the process of phototransduction.
Parent-reported health status of preterm survivors in a Canadian cohort
Authors: Ghotra Satvinder , Feeny David , Barr Ronald , Yang Junmin , Saigal Saroj , Vincer Michael , Afifi Jehier , Shah Prakeshkumar S , Lee Shoo K , Synnes Anne R
Published: June 2021

Objectives

Health status (HS)/ health-related quality of life measures, completed by self or proxy, are important outcome indicators. Most HS literature on children born preterm includes adolescents and adults with limited data at preschool age. This study aimed to describe parent-reported HS in a large national cohort of extreme preterm children at preschool age and to identify clinical and sociodemographic variables associated with HS.

Methods

Infants born before 29 weeks’ gestation between 2009 and 2011 were enrolled in a prospective longitudinal national cohort study through the Canadian Neonatal Network (CNN) and the Canadian Neonatal Follow-Up Network (CNFUN). HS, at 36 months’ corrected age (CA), was measured with the Health Status Classification System for Pre-School Children tool completed by parents. Information about HS predictors was extracted from the CNN and CNFUN databases.

Results

Of 811 children included, there were 79, 309 and 423 participants in 23–24, 25–26 and 27–28 weeks’ gestational age groups, respectively. At 36 months’ CA, 78% had a parent-reported health concern, mild in >50% and severe in 7%. Most affected HS attributes were speech (52.1%) and self-care (41.4%). Independent predictors of HS included substance use during pregnancy, infant male sex, Score for Neonatal Acute Physiology-II, bronchopulmonary dysplasia, severe retinopathy of prematurity, caregiver employment and single caregiver.

Conclusion

Most parents expressed no or mild health concerns for their children at 36 months’ CA. Factors associated with health concerns included initial severity of illness, complications of prematurity and social factors.
Extubation generates lung volume inhomogeneity in preterm infants
Authors: Bhatia Risha , Carlisle Hazel R , Armstrong Ruth K , Kamlin C Omar Farouk , Davis Peter G , Tingay David G
Published: June 2021

Objective

To evaluate the feasibility of electrical impedance tomography (EIT) to describe the regional tidal ventilation (VT) and change in end-expiratory lung volume (EELV) patterns in preterm infants during the process of extubation from invasive to non-invasive respiratory support.

Design

Prospective observational study.

Setting

Single-centre tertiary neonatal intensive care unit.

Patients

Preterm infants born <32 weeks’ gestation who were being extubated to nasal continuous positive airway pressure as per clinician discretion.

Interventions

EIT measurements were taken in supine infants during elective extubation from synchronised positive pressure ventilation (SIPPV) before extubation, during and then at 2 and 20 min after commencing nasal continuous positive applied pressure (nCPAP). Extubation and pressure settings were determined by clinicians.

Main outcome measures

Global and regional ΔEELV and ΔVT, heart rate, respiratory rate and oxygen saturation were measured throughout.

Results

Thirty infants of median (range) 2 (1, 21) days were extubated to a median (range) CPAP 7 (6, 8) cm H2O. SpO2/FiO2 ratio was a mean (95% CI) 50 (35, 65) lower 20 min after nCPAP compared with SIPPV. EELV was lower at all points after extubation compared with SIPPV, and EELV loss was primarily in the ventral lung (p=0.04). VT was increased immediately after extubation, especially in the central and ventral regions of the lung, but the application of nCPAP returned VT to pre-extubation patterns.

Conclusions

EIT was able to describe the complex lung conditions occurring during extubation to nCPAP, specifically lung volume loss and greater use of the dorsal lung. EIT may have a role in guiding peri-extubation respiratory support.
Laryngeal mask combined with bronchial tube achieves one-lung ventilation for transthoracic oesophagectomy
Authors: Kang Fang , Li Juan , Zhou Gary
Published: June 2021

Laryngeal mask combined with bronchial blocker provides an alternative for lung isolation but lacks adequate access to the non-dependent lung. Substituting the blocker with a bronchial tube may overcome this limitation. In this report, a #4.5 cuffed bronchial tube was introduced into the non-dependent lung through a second-generation laryngeal mask for transthoracic oesophagectomy. During the 2.5-hour thoracotomy, one-lung ventilation was achieved by isolating the left lung with the bronchial tube and ventilating the right lung via the laryngeal mask, using volume-control mode (7 mL/kg × 12/min) with PIP21–23 cm H2O, pH 7.36 and PaCO238.3. Prior to thoracotomy closure, suction and reinflation of the left lung were performed through the bronchial tube. Bronchoscopy via the laryngeal mask revealed no injury to the airway after removal of the bronchial tube. The case shows that laryngeal mask combined with bronchial intubation provides one-lung ventilation with access to the isolated lung.
Laparoscopic management of gastric volvulus, diaphragmatic eventration and wandering spleen in a child
Authors: Kataria Riya , Sundaram Jegadeesh , Agarwal Prakash , Lal Tusharindra
Published: June 2021

Gastric volvulus (GV) and wandering spleen (WS) associated with eventration of diaphragm share a common pathological cause of absence or laxity of intraperitoneal ligaments. We herein report a rare case of a 13-year-old child presenting with an acute GV, WS, diaphragmatic eventration and an ectopic ascended kidney managed with a laparoscopic approach.
Case of eustachian valve endocarditis and the importance of synergistic antibiotic therapy
Authors: Kumar Dilpat , Boyer James , Fnu Warsha , Boamah Harry
Published: June 2021

A 46-year-old woman with a history of end-stage renal disease on chronic haemodialysis presented with 1 week of fever, chills, altered mental status and hand pain. She was febrile and ill-appearing on presentation with a pulse rate of 102 beats per minute. She had a tunnelled dialysis catheter in her right neck. Hand examination demonstrated a swollen, erythematous and tender wrist. Cardiovascular examination demonstrated no murmurs. CT of the hand showed abscesses involving the left forearm. Blood and abscess cultures grew methicillin-resistantStaphylococcus aureus(MRSA). Transesophageal echocardiography (TEE) showed a 1.0×1.0 cm mobile vegetation involving the eustachian valve (EV), confirming EV endocarditis. She remained bacteraemic for 18 days despite being on vancomycin with appropriate blood levels. Vancomycin was switched to daptomycin andceftaroline,which cleared her cultures. Repeat TEE showed improved vegetation size. Our case highlights the rarity and management of EV endocarditis and the importance of synergy for treatment of persistent MRSA bacteraemia.
Post PCI severe gastrointestinal bleeding in the setting of idiopathic thrombocytopenic purpura: a treatment dilemma
Authors: Ghafoor Hafiz , Sharma Nitish Kumar , Alampoondi Venkataramanan Sai Vikram , Hadley Michelle
Published: June 2021

Gastrointestinal (GI) bleeding is a serious complication encountered commonly in patients on chronic anticoagulation and/or antiplatelet agents. There is a lack of guidelines on how to manage antiplatelet/anticoagulant therapy in patients with thrombocytopenia and GI bleeding. This poses a clinical dilemma when a clinician encounters serious GI bleeding in clinical practice. We present a patient with paroxysmal atrial fibrillation and chronic thrombocytopenia who suffered severe GI bleeding less than 2 weeks after a percutaneous coronary intervention while being treated with dual antiplatelet therapy and oral anticoagulation.
Postoperative complications in glaucoma surgery: literature review-based recommendations to improve reporting consistency
Authors: Stringa Francesco , Kastner Alan , Heuer Dale , Barton Keith , King Anthony J
Published: June 2021

Aims

To recommend a list of complications of glaucoma surgery to be used in future glaucoma surgery research and reporting by exploring the spectrum of complications’ names, the variety of definitions and time frames used for reporting them in glaucoma surgical trials.

Methods

Complications’ names, definitions and time frames identified from a previously conducted systematic review of glaucoma surgery trials (registration number: CRD42019121226) were reviewed. Only postoperative complications were considered. Surgical techniques described in the papers from the previous systematic review were retrieved and grouped according their mechanism of action.

Reviewers independently recommended each complication’s inclusion or exclusion in a list to be proposed as a potential standard for reporting in glaucoma interventions. A literature-based definition of a ‘surgical complication’ was used to inform these decisions. Recorded complication’s details were used to inform the development of clinically relevant definitions, a consensus-driven exercise between reviewers resolved disagreements.

Results

We identified 48/111 (43.2%) of the reported complications as suitable for inclusion, of which 17 were merged into other included complications having a broader meaning making up a final table of 32 postoperative complications. For 25 of them, the authors kept ‘names’ that were previously used in the systematic review, but provided a definition that was not mentioned in these papers. Five included complications were given both ‘names’ and definitions not previously mentioned. The authors maintained the name and definition for one complication. There were 16 complications that were in common to all the procedures retrieved from the previous review.

Conclusions

We propose a table of revised names and comprehensive definitions of postoperative complications, to simplify the process of reporting complications after glaucoma surgery and to improve consistency among surgical trials.
Predicting new major depression symptoms from long working hours, psychosocial safety climate and work engagement: a population-based cohort study
Authors: Zadow Amy Jane , Dollard Maureen F , Dormann Christian , Landsbergis Paul
Published: June 2021

Objectives

This study sought to assess the association between long working hours, psychosocial safety climate (PSC), work engagement (WE) and new major depression symptoms emerging over the next 12 months. PSC is the work climate supporting workplace psychological health.

Setting

Australian prospective cohort population data from the states of New South Wales, Western Australia and South Australia.

Participants

At Time 1, there were 3921 respondents in the sample. Self-employed, casual temporary, unclassified, those with working hours <35 (37% of 2850) and participants with major depression symptoms at Time 1 (6.7% of 1782) were removed. The final sample was a population-based cohort of 1084 full-time Australian employees.

Primary and secondary outcome measures

The planned and measured outcomes were new cases of major depression symptoms.

Results

Long working hours were not significantly related to new cases of major depression symptoms; however, when mild cases were removed, the 41–48 and ≥55 long working hour categories were positively related to major depression symptoms. Low PSC was associated with a threefold increase in risk for new major depression symptoms. PSC was not related to long working hours, and long working hours did not mediate the relationship between PSC and new cases of major depression symptoms. The inverse relationship between PSC and major depression symptoms was stronger for males than females. Additional analyses identified that WE was positively related to long working hours. Long working hours (41–48 and ≥55 hours) mediated a positive relationship between WE and major depression symptoms when mild cases of major depression were removed.

Conclusion

The results suggest that low workplace PSC and potentially long working hours (41–48; ≥55 hours/week) increase the risk of new major depression symptoms. Furthermore, high WE may increase long working hours and subsequent major depression symptoms.
Birth defects surveillance after assisted reproductive technology in Beijing: a whole of population-based cohort study
Authors: Zhang Lu , Zhang Wen , Xu Hongyan , Liu Kaibo
Published: June 2021

Objectives

To compare the differences in the prevalence of birth defects among offspring conceived by assisted reproductive technology (ART) and conceived spontaneously (non-ART), and assess the contribution of ART to birth defects.

Design

A population-based retrospective cohort study.

Setting

Beijing.

Participants

Pregnant women whose expected date of childbirth was verified as occurring between October 2014 and September 2015, and were registered on the Beijing Maternal and Child Health Information Network System, were the recorded pregnancy outcomes. 2699 ART offspring and 191 368 non-ART offspring (live births, stillbirths and medical terminations) were included in our study.

Interventions

None.

Outcome measures

Risk ratios (RR) for birth defects were calculated among ART conceptions and non-ART conceptions with confounding factors by using logistic regression models.

Results

194 067 offspring were included in the present study, and 2699 (1.4%) were conceived using ART. Among all the births, the prevalence of any birth defect in the ART offspring (5.5%) was significantly higher than in the non-ART offspring (3.8%) (crude RR, 1.49, 95% CI 1.26 to 1.76). After adjusting for confounding factors, ART use was still associated with an increased risk of any birth defect (5.4% vs 3.5% in ART and non-ART group, adjusted RR (aRR), 1.43, 95% CI 1.08 to 1.90), especially for chromosomal abnormalities (0.5% vs 0.2% in ART and non-ART group, aRR, 3.11, 95% CI 1.28 to 7.58), in singleton births to mothers <35 years. Circulatory system malformations and musculoskeletal system malformations were observed to have a non-significant increase in offspring conceived by ART. However, the associations between ART and birth defects were not detected in multiple births or mothers ≥35 years.

Conclusions

This study confirmed a small but significant association between ART and birth defects. However, the risk tends to be non-significant under the conditions of advanced maternal age or multiple pregnancies.
Role of social deprivation on asthma care quality among a cohort of children in US community health centres
Authors: Lucas Jennifer A , Marino Miguel , Fankhauser Katie , Bazemore Andrew , Giebultowicz Sophia , Cowburn Stuart , Kaufmann Jorge , Ezekiel-Herrera David , Heintzman John
Published: June 2021

Objective

Social deprivation is associated with worse asthma outcomes. The Social Deprivation Index is a composite measure of social determinants of health used to identify neighbourhood-level disadvantage in healthcare. Our objective was to determine if higher neighbourhood-level social deprivation is associated with documented asthma care quality measures among children treated at community health centres (CHCs).

Methods (setting, participants, outcome measures)

We used data from CHCs in 15 states in the Accelerating Data Value Across a National Community Health Center Network (ADVANCE). The sample included 34 266 children with asthma from 2008 to 2017, aged 3–17 living in neighbourhoods with differing levels of social deprivation measured using quartiles of the Social Deprivation Index score. We conducted logistic regression to examine the odds of problem list documentation of asthma and asthma severity, and negative binomial regression for rates of albuterol, inhaled steroid and oral steroid prescription adjusted for patient-level covariates.

Results

Children from the most deprived neighbourhoods had increased rates of albuterol (rate ratio (RR)=1.22, 95% CI 1.13 to 1.32) compared with those in the least deprived neighbourhoods, while the point estimate for inhaled steroids was higher, but fell just short of significance at the alpha=0.05 level (RR=1.16, 95% CI 0.99 to 1.34). We did not observe community-level differences in problem list documentation of asthma or asthma severity.

Conclusions

Higher neighbourhood-level social deprivation was associated with more albuterol and inhaled steroid prescriptions among children with asthma, while problem list documentation of asthma and asthma severity varied little across neighbourhoods with differing deprivation scores. While the homogeneity of the CHC safety net setting studied may mitigate variation in diagnosis and documentation of asthma, enhanced clinician awareness of differences in community risk could help target paediatric patients at risk of lower quality asthma care.
Comparison of predicted psychological distress among workers between artificial intelligence and psychiatrists: a cross-sectional study in Tsukuba Science City, Japan
Authors: Doki Shotaro , Sasahara Shinichiro , Hori Daisuke , Oi Yuichi , Takahashi Tsukasa , Shiraki Nagisa , Ikeda Yu , Ikeda Tomohiko , Arai Yo , Muroi Kei , Matsuzaki Ichiyo
Published: June 2021

Objectives

Psychological distress is a worldwide problem and a serious problem that needs to be addressed in the field of occupational health. This study aimed to use artificial intelligence (AI) to predict psychological distress among workers using sociodemographic, lifestyle and sleep factors, not subjective information such as mood and emotion, and to examine the performance of the AI models through a comparison with psychiatrists.

Design

Cross-sectional study.

Setting

We conducted a survey on psychological distress and living conditions among workers. An AI model for predicting psychological distress was created and then the results were compared in terms of accuracy with predictions made by psychiatrists.

Participants

An AI model of the neural network and six psychiatrists.

Primary outcome

The accuracies of the AI model and psychiatrists for predicting psychological distress.

Methods

In total, data from 7251 workers were analysed to predict moderate and severe psychological distress. An AI model of the neural network was created and accuracy, sensitivity and specificity were calculated. Six psychiatrists used the same data as the AI model to predict psychological distress and conduct a comparison with the AI model.

Results

The accuracies of the AI model and psychiatrists for predicting moderate psychological distress were 65.2% and 64.4%, respectively, showing no significant difference. The accuracies of the AI model and psychiatrists for predicting severe psychological distress were 89.9% and 85.5%, respectively, indicating that the AI model had significantly higher accuracy.

Conclusions

A machine learning model was successfully developed to screen workers with depressed mood. The explanatory variables used for the predictions did not directly ask about mood. Therefore, this newly developed model appears to be able to predict psychological distress among workers easily, regardless of their subjective views.
Knowledge, training and willingness to perform bystander cardiopulmonary resuscitation among university students in Chongqing, China: a cross-sectional study
Authors: Mao Jiani , Chen Feng , Xing Dianguo , Zhou Huixian , Jia Ling , Zhang Yan
Published: June 2021

Objective

To evaluate knowledge of cardiopulmonary resuscitation (CPR) among Chinese college students and their attitude towards participating in CPR training and willingness to perform bystander CPR.

Design

A cross-sectional study.

Participants

A total of 1128 college students were selected through a multistage stratified random sampling method from 12 universities in Chongqing, China.

Primary and secondary outcomes

Primary outcomes included CPR knowledge and willingness to participate in training and perform bystander CPR; secondary outcomes included CPR training experience and obstacles to training and performing CPR.

Results

The average score on CPR knowledge was 2.078 (±1.342). Only 45.5% of the respondents were willing to participate in CPR training. Women, respondents who were postgraduate or above, with liberal arts as major and with high CPR knowledge level were more willing to participate in CPR training. A total of 47.2% of the respondents were willing to provide simple assistance, such as checking the consciousness and breathing of the patient and dialling 120 (medical emergency call). Only 34.1% indicated their willingness to perform bystander CPR on strangers. Perceived behavioural control, behavioural attitudes and subjective norms are positive predictors of willingness to provide bystander CPR.

Conclusions

CPR knowledge and training rate were low among Chongqing college students. Willingness to participate in training and perform bystander CPR was also low. Improving legislation, strengthening training programmes, incorporating CPR training into the school curriculum and reshaping the social and public culture of offering timely help to those in need are recommended strategies to improve bystander CPR performance.
Functional results of total-knee arthroplasty versus medial unicompartmental arthroplasty: two-year results of a randomised, assessor-blinded multicentre trial
Authors: Knifsund Jani , Niinimaki Tuukka , Nurmi Heikki , Toom Alar , Keemu Hannes , Laaksonen Inari , Seppänen Matti , Liukas Antti , Pamilo Konsta , Vahlberg T , Äärimaa Ville , Mäkelä KT
Published: June 2021

Objective

The primary objective of the trial was to assess the clinical effectiveness of medial unicompartmental knee arthroplasty versus total knee arthroplasty in patients with isolated medial osteoarthritis of the knee.

Design

Prospective, randomised, 2 years, assessor-blind, multicentre, superiority trial.

Setting

The patients were enrolled between December 2015 and May 2018 from the outpatient clinics of three public high-volume arthroplasty hospitals (Finland).

Participants

We recruited 143 patients with symptomatic-isolated medial osteoarthritis of the knee needing an arthroplasty procedure. All the patients were suitable for both unicompartmental and total knee arthroplasties. Population was selected as the end-stage-isolated medial osteoarthritis.

Interventions

All patients, randomized 1:1, received a medial unicompartmental arthroplasty or a total knee arthroplasty through a similar midline skin incision. Patients were blinded to the type of arthroplasty for the whole 2 years of follow-up.

Main outcome measures

Primary outcome measure was between-group differences in the Oxford Knee Score (OKS) and secondary outcome Knee injury and Osteoarthritis Score (KOOS) at 2 years postoperatively. The changes within and between the groups were analysed with analysis of variance for repeated measurements.

Results

The primary outcome was comparable for medial unicompartmental arthroplasty and total knee arthroplasty at 2 years. The mean difference in the OKS between the groups was 1.6 points (95% CI −0.7 to 3.9). In the KOOS subscales, the mean difference between the groups was 0.1 points (95% CI −4.8 to 5.0) for pain, 7.8 points (95% CI 1.5 to 14.0) for symptoms, 4.3 points (95% CI −0.6 to 9.2) for function in daily living, 4.3 points (95% CI −3.0 to 11.6) for function in sports, and 2.1 points (95% CI −4.8 to 9.1) for knee-related quality of life.

Conclusions

The recovery after unicompartmental knee arthroplasty was faster compared with total knee arthroplasty, but unicompartmental arthroplasty did not provide a better patient-reported outcome at 2 years.

Trial registration number

NCT02481427.
Children with neurodisability and feeding difficulties: a UK survey of parent-delivered interventions
Authors: Taylor Helen , Pennington Lindsay , Craig Dawn , Morris Christopher , McConachie Helen , Cadwgan Jill , Sellers Diane , Andrew Morag , Smith Johanna , Garland Deborah , McColl Elaine , Buswell Charlotte , Thomas Julian , Colver Allan , Parr Jeremy
Published: June 2021

Background

Eating, drinking and swallowing difficulties (EDSD) are common in children with neurodisability, and have physical and non-physical causes. EDSD have substantial impacts on the child and family. Little is currently documented about what advice is usually given by professionals, including the interventions commonly used, and what informally constitutes ‘best clinical practice’. We aimed to identify current UK practice of parent-delivered interventions for EDSD for children with neurodisability, and the outcomes valued by professionals and parents.

Methods

Two populations were sampled: health professionals working with children and young people (aged 0–18 years) with neurodisability who experience EDSD (n=421); parents of children with neurodisability aged up to 12 years who experience EDSD (n=359). Questionnaires were developed based on the findings from updates of three systematic reviews, a mapping review of interventions used with this population, and in consultation with health professionals and parents. The questionnaires were distributed through UK health professional and parent networks and mainstream and specialist schools.

Results

Diverse professional groups, including speech and language therapists, occupational therapists, paediatricians and dietitians, support children with EDSD and neurodisability. A range of parent-delivered interventions, such as food and drink modification, positioning and modification of mealtime environment, were recommended by health professionals and are used by and acceptable to parents. Health professionals thought the interventions were effective but parents’ views were less consistent. Both health professionals and parents rated better general health and improved nutrition as the most important outcomes.

Conclusions

These survey findings outline current UK practice of parent-delivered interventions for EDSD in young children with neurodisability. The survey suggests key outcomes to measure in assessing the effectiveness of interventions. Further research is now needed to fully evaluate the effectiveness of interventions and move towards an evidence-based approach to best practice.