bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Coupling Misalignment on the Vibration Characteristics of a Two Stage Turbine Rotor
Authors: Arumugam P. , Swarnamani S. , Prabhu B. S.
Published: March 2021

Misalignment between driving and driven machines is unavoidable. Flexible couplings are used to accommodate the misalignment. The flexible mechanisms in the coupling impose moments on the rotors connected. The reaction forces developed due to the imposed moments act as periodic excitation forces on the rotating shafts. In the present work the effect of these reaction forces on the vibration characteristics of a two-stage turbine rotor-bearing system has been studied considering flexible element coupling.
Magnetic Bearing Models With Flexible Supports in Rotor Stability Analyses
Authors: Brockett Theodore S. , Barrett Lloyd E.
Published: March 2021

A method is presented that enables collocated and noncollocated magnetic bearing models on flexible supports to be included into the transfer matrix method for rotor stability analyses. The linear magnetic bearing model is represented as an open-loop stiffness, an actuator gain, and a frequency-dependent transfer function relating the sensed rotor displacement to the perturbation currents in the coils of the bearing actuator. The open-loop stiffness is handled in the same way that an ordinary hydrodynamic bearing is handled, while the bearing actuator gain and transfer function combination is treated as a complex-valued frequency-dependent stiffness that acts between the actuator location and the sensor position. The flexible support is modeled as a lumped mass with linear principal and cross-coupled stiffness and damping coefficients. The singularities introduced into the eigenvalue search surface from representing degrees of freedom from the main line of the rotor as transfer functions are canceled. This enables eigenvalues to be found in the vicinity of singular points. The stability of a specific rotor-bearing system is studied as a function of support flexibility and damping thus demonstrating the proposed method.
Influence of Geometric Parameters on Annular Fluid Seal Characteristics
Authors: Bonneau Olivier , Lucas Victor , Frene Jean
Published: March 2021

The numerical prediction of the dynamical behavior of turbopumps is very important. The space technology and the field of energy products are in constant development and it is necessary to quantify the influence of each component. The dynamical characteristics of annular seals must be calculated with accuracy.

The aim of this work is to quantify the influence of geometric parameters on the dynamical behavior of the shaft.

Three parameters will be studied: the duct loss parameter (at the seal entrance), a conical seal, and a misaligned seal. The two last geometrical defects have a direct influence on the film thickness.

It is important to insist on the influence of the entrance duct loss which governs, in large part, the stiffness calculus (and then the stability). The most difficult problem is to evaluate this duct loss which depends on the seal geometry, Reynolds number and fluid characteristics...

This study shows the important rôle played by geometrical parameter of a seal. The conicity and the misalignment modify the dynamical behavior of the shaft. These effects are essentially due to the axial flow which generates a pressure field due to axial film geometry. It should be noted that in the case of predominant circumferential flow these conclusions are totally different.
Pseudo Static Excitation of Turbine Blades Under Acceleration
Authors: Vyas Nalinaksh S.
Published: March 2021

Coriolis forces, on a blade mounted on a disc rotating with angular acceleration, give rise to a pseudo static excitation to the blade. The resulting vibrations are simultaneously influenced by the changing stiffness of the blade under acceleration. The occurrence of this shock phenomenon has been reported in earlier studies for uniform beams. In this paper the phenomenon is investigated for a typical tapered, pretwisted, turbine lade with an asymmetric aerofoil cross section and mounted on the disc at a stagger angle. The governing equations of motion, for uniform rates of acceleration are derived employing Lagrangian equations. The vibration response patterns of the blade, obtained numerically, for typical acceleration rates are illustrated.
On the Active-Passive Hybrid Vibration Control Actions of Structures With Active Constrained Layer Treatments
Authors: Liao W. H. , Wang K. W.
Published: March 2021

This paper is concerned with the analysis of active and passive hybrid actions in structures with active constrained damping layers (ACL). A system model is derived via Hamilton’s Principle, based on the constitutive equations of the elastic, viscoelastic, and piezoelectric materials. The model converges to a fully-active piezotronic system as the thickness of the viscoelastic material (VEM) layer approaches zero. A mixed Galerkin-GHM method is employed to discretize and analyze the model in time domain. With an LQR optimal control formulation, the effects of the active constrained layer configuration on the system vibration suppression performance and control effort requirements are investigated. Analysis illustrate that the active piezoelectric action with proper feedback controls will always enhance the damping ability of the passive constrained layer. On the other hand, the viscoelastic layer will reduce the direct control authorities from the active source to the host structure. The significance of this effect depends very much on the viscoelastic layer thickness and material properties. Therefore, with some parameter combinations, the ACL configuration could require more control effort while achieving less vibration reductions compared to a fully-active system. Through analyzing the performance and control effort indices, the conditions where this active-passive hybrid approach can outperform both the passive and active systems are quantified. Based on this study, design guidelines can be set up to effectively integrate the host structure with the piezoelectric and viscoelastic materials, such that a true active-passive hybrid control system can be achieved.
Passive Control of Structural Vibration in Base-Isolated Shear Structures
Authors: Hussein R.
Published: March 2021

This paper presents three analytic models for predictions or structural response of oscillating systems with Coulomb and viscous friction. Numeric results were obtained from the models and compared to demonstrate the effects of friction on vibration amplification.
Robustness of Natural Controls of Distributed-Parameter Systems
Authors: Hwang Jai Hyuk , Kim Doo Man , Lim Kyoung Ho
Published: March 2021

In this paper, the effect of parameter and spatial discretization errors on the closed-loop behavior of distributed-parameter systems is analyzed for natural controls. If the control force designed on the basis of the postulated system with the parameter and discretization errors is applied to control the actual system, the closed-loop performance of the actual system will be degraded depending on the degree of the errors. The extent of deviation of the closed-loop performance from the expected one is derived and evaluated using operator techniques. It has been found that the extent of the deviation is proportional to the magnitude of the parameter and discretization errors, and that the proportional coefficient depends on the structures of the natural controls.
Vibration Control of the Piping System: A Method Using Feedback-Error-Learning
Authors: Takita Yoshihiro
Published: March 2021

This paper presents a vibration control method for piping systems using a feedback control system constructed with LQ-control and a neural network featuring feedback-error learning. The piping system is normally flexible, therefore, natural frequencies of the system fluctuate variably when the density of the content. This paper shows that the piping system changes dynamics according to increases or decreases of the mass effects. In order to reduce the first vibration mode of the piping system without spillover instability, the control system is designed using LQ-control with feedback-error-learning applied to an adapted nonlinear feedback controller. The effectiveness of this control method is confirmed by the neural network simulation program named NeuroLab and is experimented using data measured by the control system constructed with the digital signal processing unit.
H∞ Structural Controller Design Based on Absolute Acceleration Measurement
Authors: Yamada Nariyasu , Nishitani Akira
Published: March 2021

This paper discusses the H∞ structural control system design procedure for a building structure on the basis of the measurement of the top floor absolute acceleration response. The discussion covers the design procedure from its basic concept to its details. The validity of the presented H∞ controller design is experimentally demonstrated.
Updating Substructure Models With Dynamic Boundary Conditions
Authors: Link Michael , Qian Zheng
Published: March 2021

In recent years procedures for updating analytical model parameters have been developed by minimizing differences between analytical and preferably experimental modal analysis results. Provided that the initial analysis model contains parameters capable of describing possible damage these techniques could also be used for damage detection. In this case the parameters are updated using test data before and after the damage.

Looking at complex structures with hundreds of parameters one generally has to measure the modal data at many locations and try to reduce the number of unknown parameters by some kind of localization technique because the measurement information is generally not sufficient to identify all the parameters equally distributed all over the structure.

Another way of reducing the number of parameters shall be presented here. This method is based on the idea of measuring only a part of the structure and replacing the residual structure by dynamic boundary conditions which describe the dynamic stiffness at the interfaces between the measured main structure and the remaining unmeasured residual structure. This approach has some advantage since testing could be concentrated on critical areas where structural modifications are expected either due to damage or due to intended design changes.

The dynamic boundary conditions are expressed in Craig-Bampton (CB) format by transforming the mass and stiffness matrices of the unmeasured residual structure to the interface degrees of freedom (DOF) and to the modal DOFs of the residual structure fixed at the interface. The dynamic boundary stiffness concentrates all physical parameters of the residual structure in only a few parameters which are open for updating. In this approach damage or modelling errors within the unmeasured residual structure are taken into account only in a global sense whereas the measured main structure is parametrized locally as usual by factoring mass and stiffness submatrices defining the type and the location of the physical parameters to be identified. The procedure was applied to identify the design parameters of a beam type frame structure with bolted joints using experimental modal data.
Evaluating Primary Care Management of Acute Sport-Related Concussion
Authors: Cools Michael J. , Northam Weston T. , Boyd Michael , Alexander Andrew , Mihalik Jason P. , Guskiewicz Kevin M. , Carneiro Kevin A.
Published: March 2021

Primary care providers (PCPs) are evaluating increasing numbers of concussions, but it is unknown how often they are documenting concussion-specific history and physical examination findings vital for this process. This study reviews clinical documentation to determine how PCPs are evaluating concussed patients. PCPs often did not document important aspects of concussion history, including dizziness (48%), nausea (48%), vision changes (54%), cognitive complaints (54%), emotional changes (83%), sleep difficulties (84%), and neck pain (87%). Additionally, they often did not document important aspects of a concussion physical examination, including detailed neurologic examination (73%), clinical cognitive assessment (87%), balance testing (59%), and neck evaluation (54%). Omitting these parts of the history and physical examination could result in a premature return to play.
Higher Physical Activity Is Related to Lower Neck Adiposity in Young Men, but to Higher Neck Adiposity in Young Women: An Exploratory Study
Authors: Arias-Tellez Maria Jose , Acosta Francisco M. , Migueles Jairo H. , Pascual-Gamarra Jose M. , Merchan-Ramirez Elisa , de Lucena Martins Clarice M. , Llamas-Elvira Jose M. , Martinez-Tellez Borja , Ruiz Jonatan R.
Published: March 2021

The role of lifestyle behaviors on neck adipose tissue (NAT), a fat depot that appears to be involved in the pathogenesis of different cardiometabolic diseases and in inflammatory status, is unknown. In this cross-sectional and exploratory study, the authors examined the relationship between sedentary time and physical activity (PA) with neck adiposity in young adults. A total of 134 subjects (69% women, 23 ± 2 years) were enrolled. The time spent in sedentary behavior and PA of different intensity were objectively measured for 7 consecutive days (24 hr/day), using a wrist (nondominant)-worn accelerometer. The NAT volume was assessed using computed tomography, and the compartmental (subcutaneous, intermuscular, and perivertebral) and total NAT volumes were determined at the level of vertebra C5. Anthropometric indicators and body composition (by dual-energy X-ray absorptiometry) were determined. The time spent in light physical activity and moderate physical activity (MPA) and the overall PA were inversely associated with the intermuscular NAT volume in men, as were the MPA and overall PA with total NAT volume (all ps ≤ .04). Sedentary time was directly related to the total NAT volume (p = .04). An opposite trend was observed in women, finding a direct relationship of MPA with the subcutaneous NAT; of light physical activity, MPA, and overall PA with the perivertebral NAT; and of light physical activity with total NAT volumes (all ps ≤ .05). The observed associations were weak, and after adjusting for multiplicity, the results became nonsignificant (p > .05). These findings suggest that the specific characteristics of PA (time and intensity) might have sex-dependent implications in the accumulation of NAT.
Fewer butterflies seen by community scientists across the warming and drying landscapes of the American West
Authors: Forister M. L. , Halsch C. A. , Nice C. C. , Fordyce J. A. , Dilts T. E. , Oliver J. C. , Prudic K. L. , Shapiro A. M. , Wilson J. K. , Glassberg J.
Published: March 2021

Warming autumns, fewer butterflies

Many recent studies have revealed sweeping declines in insects over the past few decades. Butterflies are no exception. Foristeret al.used three different datasets, collected by both experts and community scientists, and found that the number of butterflies has declined over the past 40 years. Although the drivers of decline are complex, the authors found that climate change—in particular, warmer months in the autumn—explain a large portion, even as warming summers actually lead to increases. This work shows that climate change impacts may be insidious and unexpected in their effects.

Science, this issue p.1042
Eyeless worms detect color
Authors: Neal Lauren A. , Vosshall Leslie B.
Published: March 2021

Roundworms discriminate color of toxic food despite a lack of eyes and opsin photoreceptor genes
Immunological yin-yang after pregnancy
Authors: Maltzman Jonathan S.
Published: March 2021

Pregnancy induces both humoral sensitization and T cell tolerance to paternal tissues.
Force Evolutionary Billiards and Billiard Equivalence of the Euler and Lagrange Cases
Authors: Vedyushkina V. V. , Fomenko A. T.
Published: March 2021

A class of force evolutionary billiards is discovered that realizes important integrable Hamiltonian systems on all regular isoenergy 3-surfaces simultaneously, i.e., on the phase 4-space. It is proved that the well-known Euler and Lagrange integrable systems are billiard equivalent, although the degrees of their integrals are different (two and one).
A rare cause of secondary organising pneumonia
Authors: Fernandes Ana Luisa , Ferro Ana , Santos Joana dos , Seabra Bárbara
Published: March 2021

Non-tuberculous mycobacterial pulmonary disease may have different clinical manifestations. We report a case of a 64-year-old woman presenting with persistent respiratory complaints, fever and radiological findings. Initially, she was diagnosed with community-acquired pneumonia, but after being submitted to an extensive investigation, including CT-guided transthoracic lung biopsy, a diagnosis of organising pneumonia (OP) was established. The patient was treated with corticosteroids with no favourable response. Subsequently,Mycobacterium aviumcomplex (MAC) was identified in bronchoalveolar lavage culture. The patient was diagnosed with OP secondary to MAC infection and specific antibiotic treatment was initiated. This case represents an infrequent association and illustrates how important it is to investigate primary causes of OP to obtain a satisfactory treatment response.
Late Neoproterozoic – early Paleozoic basin evolution in the Coal Creek inlier of Yukon, Canada: implications for the tectonic evolution of northwestern Laurentia
Authors: Busch James F. , Rooney Alan D. , Meyer Edward E. , Town Caleb F. , Moynihan David P. , Strauss Justin V.
Published: March 2021

The age and nature of the Neoproterozoic – early Paleozoic rift–drift transition has been interpreted differently along the length of the North American Cordillera. The Ediacaran “upper” group (herein elevated to the Rackla Group) of the Coal Creek inlier, Yukon, Canada, represents a key succession to reconstruct the sedimentation history of northwestern Laurentia across the Precambrian–Cambrian boundary and elucidate the timing of active tectonism during the protracted breakup of the supercontinent Rodinia. These previously undifferentiated late Neoproterozoic – early Paleozoic map units in the Coal Creek inlier are herein formally defined as the Lone, Cliff Creek, Mount Ina, Last Chance, Shade, and Shell Creek formations. New sedimentological and stratigraphic data from these units is used to reconstruct the depositional setting. In the Last Chance Formation, chemostratigraphic observations indicate a ca. 5‰ δ13Ccarbgradient coincident with the globally recognized ca. 574–567 Ma Shuram carbon isotope excursion. Map and stratigraphic relationships in the overlying Shell Creek Formation provide evidence for latest Ediacaran – middle Cambrian tilting and rift-related sedimentation. This provides evidence for active extension through the Cambrian Miaolingian Series in northwestern Canada, supporting arguments for a multiphase and protracted breakup of Rodinia.
Quantum system: Wave function, entanglement and the uncertainty principle
Authors: Melkikh A. V.
Published: March 2021

A definition of entanglement based on the overlap of wave functions of identical particles is proposed. A definition of a quantum system of particles related to their entanglement with each other and the environment is proposed. It is shown that in the general case, the uncertainty principle cannot be formulated for a system of quantum particles in the form of a single inequality.
Development of a Starter with Protective Systems for a Three-Phase Induction Motor
Authors: Orovwode Hope , Matthew Simeon , Agbetuyi A. Felix , Adoghe U. Anthony , Amuta Elizabeth
Published: March 2021

Frequent burning of three-phase induction motors windings has been reported. The initial symptoms observed before the burning of the windings were an increase in operating current and a temperature rise. The induction motor protection and control system was designed, developed, and constructed to reduce the problem of burnt winding by early detection and disconnection of supply if the problem persists. It was found to be efficient, reliable, durable, and rugged. The system is a boost to Nigerian industrialists as it will reduce cases of burning of induction motors and the consequent downtime and cost. The system is cheap and easy to repair and maintain because the parts and components used in the design are available locally.
Study of the operation of the output filter of a single-phase series active power filter
Authors: Antchev Mihail , Gourgoulitsov Vanjo , Antchev Hristo
Published: March 2021

In the article is presented a single-phase series active power filter (SFSAPF) designed to compensate the total harmonic distortion (THD) factor of the supply network voltage. Particular attention is paid to the work of the output capacitor of the passive filter, and dependencies for the design of the filter at hysteresis voltage control are presented. The value of the higher harmonics of the current through the filter capacitor is determined. A mathematical relationship between the voltage ripple of the capacitor, its value and the switching frequency is derived. As a result of the advanced research a methodology for designing the output filter of a single-phase serial active power filter has been proposed. The results from computer simulation and experiment are also given.
Rotations with Crotalaria spp. do not suppress populations of Meloidogyne incognita in cotton
Authors: Khanal Churamani , Galbieri Rafael , Timper Patricia
Published: March 2021

Field studies were conducted in Mato Grosso, Brazil and Georgia, USA to evaluate the efficacy of Crotalaria spp. as a rotational cover crop for managing Meloidogyne incognita in cotton (Gossypium hirsutum). The two studies differed in how Crotalaria spp. were incorporated into the cotton production system to reflect differences in climate (tropical vs subtropical) and production systems typical for the two regions. In Mato Grosso, Crotalaria juncea and C. spectabilis were planted after soybean in late summer, grown for approximately 300 days, and incorporated into the soil 6-15 days prior to cotton planting. In Georgia, C. juncea and a nematode-resistant cowpea, Vigna ungiculata, were planted after maize in the late summer, grown until killed by frost in the early winter, and cotton was planted in the next season. Soil population densities of M. incognita and root galling in cotton were similar in cotton following either fallow, resistant cowpea, or Crotalaria spp. However, Crotalaria spp. significantly increased cotton plant height at the time of harvest relative to the other treatments. Except for one of the experiments in Brazil, incorporation of Crotalaria spp. in the rotational scheme did not increase cotton yield. Results indicate that a cover crop of Crotalaria spp. does not suppress M. incognita in cotton production system more than a fallow period or planting a resistant cover crop.
New or rare Madagascar tiger beetles—21. Physodeutera (Microlepidia) propripenis sp. nov., Ph. (M.) marginemaculata (W. Horn) and Ph. (M.) peyrierasi Rivalier (Coleoptera: Cicindelidae)
Authors: MORAVEC JIŘÍ , BRZOSKA DAVID , VYBÍRAL JAN
Published: March 2021

A new species of the Madagascan endemic genus Physodeutera Lacordaire, 1842 is described from northern Madagascar as Physodeutera (Microlepidia) propripenis sp. nov. The new species is compared to similar Physodeutera (Microlepidia) marginemaculata (W. Horn, 1934) and Physodeutera (Microlepidia) peyrierasi Rivalier, 1967. Apart from a detailed description of the new species, illustrations in colour photographs of its habitus, diagnostic characters and habitat are introduced. Differential diagnoses of the two similar species, as well as illustrations of their habitus and distinguishing characters in colour photographs are presented with references to their redescriptions and illustrations based on type and other relevant specimens in the monograph of the genus (Moravec 2002a). A revised key to the subgenus Microlepidia Rivalier, 1967 is presented in order to supplement the key previously published in the monograph. Essential maps of the distribution of the three species are also given.
New species and subspecies of Laoechinophorus from China and Thailand (Coleoptera, Cerambycidae, Lamiinae, Morimopsini)
Authors: YAMASAKO JUNSUKE , VIVES EDUARD , LIU BIN
Published: March 2021

Two new species with a new subspecies of the genus Laoechinophorus Gouverneur, 2016 are described: L. thailandicus thailandicus ssp. nov. and L. thailandicus tsuyukii ssp. nov. from Thailand, and L. yunnanus sp. nov. from China. A description of male genitalia of the type species, L. unifasciatus Gouverneur, 2016, from Laos, and a key to the species of the genus are provided.
A review of the genus Changiola (Orthoptera: Grylloidea: Pteroplistinae) and description of the first species from Borneo
Authors: TAN MING KAI , MUHAMMAD AMIRA AQILAH , ROBILLARD TONY
Published: March 2021

The taxonomy of the little-known cricket genus Changiola from the subfamily Pteroplistinae is reviewed here. This genus consisted of three species, two from Malay Peninsula and one from Indochina. Here, we describe a new species from Borneo, the first from the island: Changiola sarawakensis n. sp. We also provide a key to the species, although it is likely that more species will be added to this genus with more sampling in the region.
Two new species of Smicridea (Rhyacophylax) Müller 1879 (Trichoptera: Hydropsychidae) from Atlantic Forest, Brazil
Authors: SANTANA VITÓRIA , DESIDERIO GLEISON ROBSON , HAMADA NEUSA
Published: March 2021

Smicridea (Rhyacophylax) Müller 1879 contains 106 species, 41 of which occur in Brazil, mainly in the Atlantic Forest biome. Despite its diversity, it is estimated that many undescribed species are believed to be housed in scientific collections, waiting to be described. Smicridea specimens housed in two Brazilian insect collections (Coleção Entomológica Professor José Alfredo Pinheiro Dutra, Rio de Janeiro and Museu de Zoologia da Universidade de São Paulo, São Paulo) were examined and two new species of S. (Rhyacophylax) were detected. The objective of this study is to describe and illustrate these species. Smicridea (Rhyacophylax) boraceia sp. nov. and Smicridea (Rhyacophylax) dumasi sp. nov. inhabit the Atlantic forest biome and can be recognized mainly by the morphology of tergum X and the phallic apparatus. Six species groups are recognized in S. (Rhyacophylax); however, the two new species described here cannot be placed in any of these groups.
Updating the knowledge of species of the genus Astylus Laporte (Coleoptera: Melyridae) from South America
Authors: ESTRADA PATRICIA
Published: March 2021

Pic has contributed most of the descriptions of species and varieties of the genus Astylus Laporte, 1836. However, in some cases, he defined the distinction between taxa on the basis of variable characters. The study of the external morphology and genitalia of the type material of Astylus alboscutellatus Pic,1919a; A. banghaasi Pic, 1902; A. banghaasi var. reichei Pic, 1919a; A. binotatus Pic, 1940; A. elongatior Pic, 1902; A. elongatior var. disjunctus Pic, 1902; A. scalaris Pic, 1919b and A. tucumanensis Pic, 1902, as well collections material, allows to establish new diagnoses and new nomenclatural changes. Following new synonymies are proposed: A. banghaasi Pic, 1902 (= A. banghaasi var. reichei Pic, 1919a n.syn. = A. elongatior Pic, 1902 n.syn. = A. elongatior var. disjunctus Pic, 1902 n.syn.) and A. scalaris Pic, 1919b (= A. binotatus Pic, 1940 n.syn.). The valid species are redescribed.
Association between components of the delirium syndrome and outcomes in hospitalised adults: a systematic review and meta-analysis
Authors: Tieges Zoë , Quinn Terence , MacKenzie Lorn , Davis Daniel , Muniz-Terrera Graciela , MacLullich Alasdair M. J. , Shenkin Susan D.
Published: March 2021

Background

Delirium is a heterogeneous syndrome with inattention as the core feature. There is considerable variation in the presence and degree of other symptom domains such as altered arousal, psychotic features and global cognitive dysfunction. Delirium is independently associated with increased mortality, but it is unclear whether individual symptom domains of delirium have prognostic importance. We conducted a systematic review and meta-analysis of studies in hospitalised adults in general settings to identify the relationship between symptom domains of delirium and outcomes.

(PROSPERO: CRD42018093935).

Methods

We searched MEDLINE, EMBASE, PsycINFO, CINAHL,clinicaltrials.govand the Cochrane Central Register of Controlled Trials from inception to November 2019. We included studies of hospitalised adults that reported associations between symptom domains of delirium and 30-day mortality (primary outcome), and other outcomes including mortality at other time points, length of stay, and dementia. Reviewer pairs independently screened articles, extracted data, and assessed risk of bias (Risk of Bias Assessment tool for Non-randomized Studies) and quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation framework. We performed random-effects meta-analyses stratified by delirium domain where possible.

Results

From 7092 citations we included 6 studies (6002 patients, 1112 with delirium). Higher mortality (ranging from in-hospital to follow-up beyond 12 months) was associated with altered arousal (pooled Odds Ratio (OR) 2.80, 95% Confidence Interval (CI) 2.33–3.37; moderate-quality evidence), inattention (pooled OR 2.57, 95% CI 1.74–3.80; low-quality evidence), and in single studies with disorientation, memory deficits and disorganised thoughts. Risk of bias varied across studies but was moderate-to-high overall, mainly due to selection bias, lack of blinding of assessments and unclear risk of selective outcome reporting. We found no studies on the association between psychotic features, visuospatial deficits or affective disturbances in delirium and outcomes, or studies reporting non-mortality outcomes.

Conclusions

Few studies have related symptom domains of delirium to outcomes, but the available evidence suggests that altered arousal and inattention in delirium are associated with higher mortality than normal arousal and attention in people with or without delirium. Measurable symptom domains of delirium may have value in predicting survival and stratifying patients for treatment. We recommend that future delirium studies report outcomes by symptom domain.
Comparison of novel and established caries diagnostic methods: a clinical study on occlusal surfaces
Authors: Litzenburger Friederike , Schäfer Gerrit , Hickel Reinhard , Kühnisch Jan , Heck Katrin
Published: March 2021

Background

The purpose of this prospective clinical diagnostic study with validation was to compare the diagnostic accuracy of near-infrared transillumination (NIRT), laser fluorescence measurement (LF), alternating current impedance spectroscopy (ACIS) and their combinations as adjunct methods to visual examination (VE) for occlusal caries detection using a hybrid reference standard.

Methods

Ninety-six first and second non-cavitated permanent molars from 76 individuals (mean age 24.2) were investigated using (VE) (ICDAS) and bitewing radiography (BWR), as well as NIRT, LF and ACIS. The findings of BWR and NIRT were evaluated by two examiners while the other examinations were conducted by one calibrated dentist. The hybrid reference standard consisted of non-operative validation based on the results of VE and BWR and operative validation. Statistical analysis included cross-tabulations, calculation of sensitivity, specificity and area under the receiver operating characteristic curve at three diagnostic thresholds: caries in general, enamel caries and dentin caries.

Results

NIRT, LF and ACIS exhibited high sensitivity for caries in general [1.00 (1.00–1.00), 0.77 (0.65–0.88), 0.75 (0.63–0.87)) and for dentin caries (0.97 (0.91–1.03), 0.76 (0.76–0.90), 0.64 (0.47–0.80)]. Sensitivity values for enamel caries were weak (0.21, 0.11, 0.37). Specificity values did not fall below 0.65 (NIRT) for all categories and methods, except for NIRT at the caries detection threshold (0.27). A combination of LF and ACIS with VE improved the diagnostic performance at the overall and the enamel caries threshold. The other methods showed fair to excellent discrimination at the overall caries threshold (NIRT 0.64, LF 0.89 and ACIS 0.86) and acceptable discrimination at the dentin caries threshold (NIRT 0.82, LF 0.81 and ACIS 0.79). AUROC for enamel caries exhibited the weakest discrimination. Accuracy was 65.6% for VE, 69.8% for BWR, 50.0% for NIRT, 53.1% for LF and 74.0% for ACIS. Reliability assessment for BWR and NIRT showed at least substantial agreements for all analyses.

Conclusions

The methods, NIRT, LF and ACIS, revealed different potential but no impeccable performance for occlusal caries detection. All are suitable instruments to detect hidden carious lesion in dentin. As auxiliaries to VE, LF and ACIS showed an increase in diagnostic performance.
Job preferences of medical and nursing students seeking employment in rural China: a discrete choice experiment
Authors: Bao Meiling , Huang Cunrui
Published: March 2021

Background

China has a shortage of health workers in rural areas, but little research exists on policies that attract qualified medical and nursing students to rural locations. We conducted a discrete choice experiment to determine how specific incentives would be valued by final–year students in a medical university in Guizhou Province, China.

Methods

Attributes of potential jobs were developed through the literature review, semi–structured interviews, and a pilot survey. Forty choice sets were developed using a fractional factorial design. A mixed logit model was used to estimate the relative strength of the attributes. Willingness to pay and uptake rates for a defined job were also calculated based on the mixed logit estimates.

Results

The final sample comprised 787 medical and nursing students. The statistically significant results indicated “Bianzhi” (the number of personnel allocated to each employer by the government) and physical conflicts between doctors and patients were two of the most important non-monetary job characteristics that incentivized both medical and nursing students. Policy simulation suggested that respondents were most sensitive to a salary increase, and the effect of incentive packages was stronger for students with a rural family background.

Conclusions

Strategies for patient–doctor relationships, Bianzhi and salary should be considered to attract final–year medical and nursing students to work in rural China. In addition, specific recruitment policy designs tailored for students with different majors and backgrounds should be taken into account.
Student nurses in the primary care network: a pilot
Authors: Heath Shaun , Wilcox Rebecca , Leonelli Silvia
Published: March 2021

Shaun Heath, Rebecca Wilcox and Silvia Leonelli discuss how South East London developed a hub and spoke placement pilot to place students in primary care networks, rather than with individual practices

With support from Capital Nurse, primary care in South East London developed a hub and spoke placement pilot to support student nurses in a primary care network (PCN). Two groups of students were placed in two PCN's, one in an inner London borough (PCN 1) and another in an outer London borough (PCN 2). Our pilot had substantial benefits for the students, the assessors/supervisors, the PCN and, ultimately, the future development of the primary care workforce. We advocate developing strong nurse leadership within the PCN to support and grow the educational unit, and we recommend that recurrent funding be made available to support this and the preceptorship programmes within the Sustainability and Transformation Partnerships (STP)/Integrated Care System (ICS).
RESEARCH ROUNDUP
Authors: Winter George
Published: March 2021

George Winter provides an overview of recently published articles that are of interest to practice nurses. Should you wish to look at any of the papers in more detail, a full reference is provided.
Large distal ureteric stone with high burden urothelial cancer of the entire ureter and renal pelvis: a dual pathology
Authors: Aggarwal D , Parmar K , Yadav AK , Kumar S , Naik B , Banerjee N
Published: March 2021

Upper-tract urothelial cancer comprises only 3% of all urothelial cancers. Risk factors include tobacco smoking, recurrent urinary infection, urolithiasis and analgesic abuse. Urolithiasis-induced chronic inflammation leads to urothelial proliferation and eventual malignant transformation. The most common association is reported with squamous cell cancer. A 54-year man under evaluation for right flank pain was diagnosed with a large distal ureteric stone and urothelial cancer of the entire right ureter and renal pelvis. The patient underwent right nephroureterectomy and stone retrieval, with urinary bladder cuff excision and pelvic lymph node dissection. On follow-up, the patient succumbed to disease recurrence with widespread metastasis. Urothelial cancer associated with stone disease is atypical. Long-standing inflammation causing metaplastic and dysplastic changes is a possible hypothesis. Careful assessment of the malignancy should be looked for in patients with long-standing obstruction due to stone disease.
La lectura fàcil a Catalunya (2018-2019)
Authors: Serra Elisabet , Vidal Laia
Published: March 2021

Durant els anys 2018 i 2019 la lectura fàcil s’està consolidant al nostre territori. L’accessibilitat als continguts, és a dir, fer la informació més accessible pensant en les persones amb dificultats lectores, s’està obrint pas en molts sectors que fins ara no ho tenien com a prioritat. És el cas d’administracions, biblioteques, museus, teatres i la cultura en general. Però en d’altres àmbits, com ara el judicial, continua faltant un impuls per fer arribar els seus continguts de manera planera a tota la ciutadania. En tots els àmbits, però, manca una institució que inclogui l’accessibilitat cognitiva com a eix transversal en tota la seva comunicació.
A survival of the fittest strategy for the selection of genotypes by which drug responders and non-responders can be predicted in small groups
Authors: Höhle Daniël , van Rooij Kim , Bloemers Jos , Pfaus James G. , Michiels Frits , Janssen Paddy , Claassen Eric , Tuiten Adriaan
Published: March 2021

Phenotype Prediction Scores (PPS) might be powerful tools to predict traits or the efficacy of treatments based on combinations of Single-Nucleotide Polymorphism (SNPs) in large samples. We developed a novel method to produce PPS models for small samples sizes. The set of SNPs is first filtered on those known to be relevant in biological pathways involved in a clinical condition, and then further filtered repeatedly in a survival strategy to select stabile positive/negative risk alleles. This method is applied on Female Sexual Interest/Arousal Disorder (FSIAD), for which two subtypes has been proposed: 1) a relatively insensitive excitatory system in the brain for sexual cues, and 2) a dysfunctional activation of brain mechanisms for sexual inhibition. A double-blind, randomized, placebo-controlled cross-over experiment was conducted on 129 women with FSIAD. The women received three different on-demand drug-combination treatments during 3 two-week periods: testosterone (0.5 mg) + sildenafil (50 mg), testosterone (0.5 mg) + buspirone (10 mg), or matching placebos. The resulted PPS were independently validated on patient-level and group-level. The AUC scores for T+S of the derivation set was 0.867 (95% CI = 0.796–0.939; p<0.001) and was 0.890 (95% CI = 0.778–1.000; p<0.001) on the validation set. For T+B the AUC of the derivation set was 0.957 (95% CI = 0.921–0.992; p<0.001) and 0.869 (95% CI = 0.746–0.992; p<0.001) for the validation set. Both formulas could reliably predict for each drug who benefit from the on-demand drugs and could therefore be useful in clinical practice.
Advance care planning in older hospitalised patients following an emergency admission: A mixed methods study
Authors: Bielinska Anna-Maria , Archer Stephanie , Obanobi Adetokunbo , Soosipillai Gehan , Darzi Lord Ara , Riley Julia , Urch Catherine
Published: March 2021

Introduction

Although advance care planning may be beneficial for older adults in the last year of life, its relevance following an emergency hospitalisation requires further investigation. This study quantifies the one-year mortality outcomes of all emergency admissions for patients aged 70+ years and explores patient views on the value of advance care planning following acute hospitalisation.

Method

This mixed methods study used a two-stage approach: firstly, a quantitative longitudinal cohort study exploring the one-year mortality of patients aged 70+ admitted as an emergency to a large multi-centre hospital cohort; secondly, a qualitative semi-structured interview study gathering information on patient views of advance care planning.

Results

There were 14,260 emergency admissions for 70+-year olds over a 12-month period. One-year mortality for admissions across all conditions was 22.6%. The majority of these deaths (59.3%) were within 3 months of admission. Binary logistic regression analysis indicated higher one-year mortality with increasing age and male sex. Interviews with 20 patients resulted in one superordinate theme, “Planning for health and wellbeing in the spectrum of illness”. Sub-themes entitled (1) Advance care planning benefitting healthcare for physical and psycho-social health, (2) Contemplation of physical deterioration death and dying and 3) Collaborating with healthcare professionals to undertake advance care planning, suggest that views of advance care planning are shaped by experiences of acute hospitalisation.

Conclusion

Since approximately 1 in 5 patients aged 70+ admitted to hospital as an emergency are in the last year of life, acute hospitalisation can act as a trigger for tailored ACP. Older hospitalised patients believe that advance care planning can benefit physical and psychosocial health and that discussions should consider a spectrum of possibilities, from future health to the potential of chronic illness, disability and death. In this context, patients may look for expertise from healthcare professionals for planning their future care.
Genetic ablation of fibroblast activation protein alpha attenuates left ventricular dilation after myocardial infarction
Authors: Hoffmann Daniel B. , Fraccarollo Daniela , Galuppo Paolo , Frantz Stefan , Bauersachs Johann , Tillmanns Jochen
Published: March 2021

Introduction

Regulating excessive activation of fibroblasts may be a promising target to optimize extracellular matrix deposition and myocardial stiffness. Fibroblast activation protein alpha (FAP) is upregulated in activated fibroblasts after myocardial infarction (MI), and alters fibroblast migration in vitro. We hypothesized that FAP depletion may have a protective effect on left ventricular (LV) remodeling after MI.

Materials and methods

We used the model of chronic MI in homozygous FAP deficient mice (FAP-KO, n = 51) and wild type mice (WT, n = 55) to analyze wound healing by monocyte and myofibroblast infiltration. Heart function and remodeling was studied by echocardiography, morphometric analyses including capillary density and myocyte size, collagen content and in vivo cell-proliferation. In non-operated healthy mice up to 6 months of age, morphometric analyses and collagen content was assessed (WT n = 10, FAP-KO n = 19).

Results

Healthy FAP-deficient mice did not show changes in LV structure or differences in collagen content or cardiac morphology. Infarct size, survival and cardiac function were not different between FAP-KO and wildtype mice. FAP-KO animals showed less LV-dilation and a thicker scar, accompanied by a trend towards lower collagen content. Wound healing, assessed by infiltration with inflammatory cells and myofibroblasts were not different between groups.

Conclusion

We show that genetic ablation of FAP does not impair cardiac wound healing, and attenuates LV dilation after MI in mice. FAP seems dispensable for normal cardiac function and homeostasis.
Aqueous humor monocyte chemoattractant protein-1 predicted long-term visual outcome of proliferative diabetic retinopathy undergone intravitreal injection of bevacizumab and vitrectomy
Authors: Lei Jianqin , Ding Guolong , Xie Anming , Hu Yaguang , Gao Ning , Fan Xiaojuan
Published: March 2021

Purpose

We aim to investigate the risk factors associated with the prognosis of proliferative diabetic retinopathy (PDR) after a sequential treatment of intravitreal injection of bevacizumab (IVB) and pars plana vitrectomy (PPV).

Methods

In this cohort study, 63 eyes from 55 patients (21 females) diagnosed with PDR, who needed PPV for non-clearing vitreous hemorrhage or fibrovascular membrane proliferation were enrolled. All the eyes underwent IVB followed by PPV. Anterior chamber tap was performed at the beginning of both procedures to evaluate the concentration of vascular endothelial growth factor (VEGF), interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1.

Results

Forty-seven patients (54 eyes) were followed over six months, averaging 12±5 (6–19) months. The concentration of VEGF significantly decreased after IVB (P<0.001), while other cytokines did not change significantly. The aqueous humor level of IL-8 after IVB (R = 0.378, P = 0.033), MCP-1 before (R = 0.368, P = 0.021) and after (R = 0.368, P = 0.038) IVB, and combined phacoemulsification (R = 0.293, P = 0.032) was correlated with the logMAR visual acuity at the last follow-up. Multivariate analysis showed that MCP-1 was the predictor for a worse visual outcome (B = 0.108, 95% CI 0.013–0.202; P = 0.027).

Conclusions

MCP-1 was a predictor for the unfavorable visual outcome of PDR after IVB pretreatment and PPV.
Experiences of oral pre-exposure prophylaxis (PrEP) use disclosure among South African adolescent girls and young women and its perceived impact on adherence
Authors: Giovenco Danielle , Gill Katherine , Fynn Lauren , Duyver Menna , O’Rourke Shannon , van der Straten Ariane , Morton Jennifer F. , Celum Connie L. , Bekker Linda-Gail
Published: March 2021

Introduction

There is limited understanding of how social dynamics impact pre-exposure prophylaxis (PrEP) adherence among adolescent girls and young women (AGYW) in generalized HIV-epidemic settings. We examined experiences of oral PrEP use disclosure to various social groups with the goal of identifying supportive relationships that can be leveraged to promote adherence.

Methods

We used qualitative methods to explore experiences disclosing PrEP use and the perceived impact of disclosure on adherence among 22 South African AGYW (16–25 years) taking daily oral PrEP. Serial in-depth-interviews (IDIs) were conducted 1-, 3-, and 12-months post-PrEP initiation. Respondents also self-reported their disclosures separately for various social groups and adherence was assessed using intracellular tenofovir-diphosphate levels.

Results

Qualitative respondents had a median age of 20.5 years and reported disclosing their PrEP use to friends (n = 36 total disclosures), partners, siblings, other family members (n = 24 disclosures each), and parents (n = 19 disclosures). IDI data revealed that parents and partners provided the most support to respondents and a lack of support from these groups was most often perceived as negatively affecting PrEP use. AGYW described difficulties explaining PrEP to their mothers, who believed PrEP was HIV treatment or would lead to HIV infection. Disclosure to household members was notably meaningful for AGYW (both positively and negatively). Respondents reported leveraging supportive relationships for pill reminders. For respondents who perceived a household member would be unsupportive, however, non-disclosure was less feasible and PrEP use was often stigmatized. To avoid stigma, several respondents hid or discontinued PrEP.

Conclusions

While supportive relationships may facilitate PrEP use, disclosure can also lead to stigma. Counselors should support AGYW in disclosing to key people in their social networks and provide AGYW with materials that lend credibility to explanations of PrEP. Community education is necessary to alleviate PrEP-related stigma and facilitate disclosure.