bluuebunny/crossref_metadata_2025 huggingface dataset:
Response Mitigation of Floating Platform by Porous-Media Tuned Liquid Dampers
Authors: Tsao Wen-Huai , Chen Ying-Chuan , Kees Christopher E. , Manuel Lance
Published: October 2022

A porous-media tuned liquid damper (PMTLD) can serve as an eco-friendly, economical, and effective dynamic vibration absorber. Placing porous media within a water tank can improve the capacity for energy dissipation and optimize the performance by varying its material properties. The numerical simulations of the floating platform dynamics in waves coupled with the sloshing problem in PMTLD are emphasized. Two numerical methods are adopted for fluid computation. The first potential-based approach employs a mixed-type boundary value problem (BVP) solver, which is implemented by the boundary element method (BEM), coupled with a free surface particle tracker, which includes the nonlinear damping effects via a quadratic Forchheimer term for PMTLD. Another equivalent mechanical model is also used exclusively for solving the linear PMTLD. The coupling behavior between fluid and structure is solved by the Newmark method. The second viscous approach uses the finite element method (FEM) to spatially discretize the Navier-Stokes equations and handles the free surface via the volume of fluid (VOF) and the level set (LS) equations. The multiphase simulation is implemented by a computational modeling toolkit Proteus for the fluid phase and Chrono for the solid phase. The correlations between potential flow and Navier-Stokes (NS) models are presented. The PMTLD is designed for a floating platform by analogy with the tuned mass damper (TMD). Numerical results show that the PMTLD can effectively reduce the structure’s dynamic response in terms of vibration amplitude around resonance. Such damping devices have great potential for practical applications in offshore platforms and wind turbine design.
A Study on Safer New Optimal Route for Anti-Collision in Coastal Waters
Authors: Kim Won-Ouk , Kang Song-Jin , Kim Young-Rong , Kim Chang-Je
Published: October 2022

Although radar and AIS alarm functions have been used as support measures for collision prevention in many ships, they lacked the function to identify actual collision risk ships and inform the degree of risk and did not provide information on avoidance routes. This study aims to design a newly developed safer new optimal route for anti-collision based on the Collision Risk Zone assessment method, targeting mainly very small-sized ships that caused most of the collision accidents due to human errors. Designing a safer new optimal route is composed of three segments according to the ship’s characteristics. That is, empirical method for small-sized ships, collision risk zone method for larger ships and then combination method between empirical and collision risk method. In addition, this study analyzed the collision risk of various scenarios according to the navigation relationships and speed conditions between the two meeting ships. As a result, the model proposed in this study numerically calculated the risk of collision according to the navigation situation and could provide a safe optimal avoidance path accordingly. Therefore, this model can be applied to build the collision avoidance model of not only the current ship but remote-controlled ship, which is under compliance with COLREG regulations and involves the possibility of human error in an operation.
Analysis of Interference Characteristics of a Boat in Chasing a Large Ship
Authors: Deng Weihua , Yu Jiawei , Feng Dakui , Xiang Han , Yao Chaobang
Published: October 2022

Recovery of Unmanned Surface Vehicles (USV) is a typical multibody dynamics problem. When boat (that is USV) chases the large ship, the flow field around it will be affected by the wake of large ship, which will cause many difficulties for the maneuver of boat. In this paper, the model 4667-1 of the US series 62 planning craft is taken as the boat, and the 10x larger model of DTMB 5512 is taken as the large ship (named as 5512-MS). Numerical analysis on the performance of the boat affected by the wake field of the large ship in calm water is studied utilizing in-house CFD solver, coupled with multi-moving domain method and dynamic overset grid technology. The 2-DOF simulation is conducted to solve the resistance and attitude of the boat and DTMB 5512, and the simulation results are compared with the experimental data to verify the reliability of the numerical method. Numerical simulations of boat chasing the large ship along different paths are performed to analyze the interference characteristics in the chasing process. The study shows that along different paths, there are obvious differences in the motion and forces of the boat. Finally, the suggested route for recovery of USV is presented.
Assessment of the Power Obtained by a Multi Wind Turbine Floating Platform
Authors: Martín-San-Román Raquel , Azcona-Armendáriz José , Iribas-Latour Mikel , Cuerva-Tejero Alvaro
Published: October 2022

In order to reduce the cost of floating wind energy, several multi wind turbine floating platform designs have been proposed and are currently under development. Multi wind turbine configurations in onshore sites have been found to produce a combined blockage effect on the incoming flow that leads to a greater extraction of power compared to isolated rotors. The main objective of this study is to assess the power obtained by a multi wind turbine configuration with respect to a single turbine, both on a floating platform under wind and wave loading. In this study, the NREL 5MW OC4 semi-submersible floating wind turbine has been taken as reference. With this wind turbine model, three different configurations, in two operational cases, have been simulated using CENER’s in-house MUST (Multi wind tUrbine Simulation Tool), coupled to the aerodynamic module AeroVIEW (Aerodynamic Vortex fIlamEnt Wake). The configurations that have been analysed are: first, the single floating wind turbine; second, forced platform movements on a bi-wind turbine and finally a bi-wind turbine freely floating platform. The results of the comparisons show a positive effect of having two nearby side by side rotors on the same floating platform, with an increase in the generated power.
Experimental Investigation of Flow Around a Single Circular Cylinder Freely Vibrating in Two Degrees-of-Freedom
Authors: el Sheshtawy Hasan , el Moctar Ould , Tödter Simon , Schellin Thomas E.
Published: October 2022

Experimental investigations were performed for a single circular cantilevered cylinder located in a circulating water channel. The cylinder of mass ratio 1.78 and aspect ratio 17.8, vertically fixed at one end, was freely oscillating in the streamwise and lateral directions. Tests were performed at three reduced velocities of 1.29, 1.93, and 5.83, corresponding to Reynolds numbers 1.26 × 104, 1.88 × 104, and 5.65 × 104, respectively. At the inlet of the water channel, a Laser doppler velocimetry system measured mean velocities and turbulence intensities. Vortex shedding frequencies were compared with cylinder response frequencies in the streamwise and lateral directions. A particle image velocimetry technique analyzed the wake’s flow topology, and a triaxial accelerometer measured the cylinder response. Wake patterns of shed vortices caused by the flow around the cylinder were experimentally investigated. The main objective was to investigate wake patterns obtained for the stationary cylinder and for the cylinder oscillating with an elliptic trajectory and with a Lissajous trajectory. The PIV technique was used to capture vortex patterns on the mid plane along the cylinder’s length at three different time steps. The experiments provided reliable benchmark data suitable for numerical validation of vortex-induced vibration for circular cylinders oscillating in two degrees-of-freedom.
A Comparison of Different Numerical Methods to Simulate Forced Roll Oscillations of Floating Structures in Grid-Based Schemes
Authors: Meyer Jannik , Neufeldt Henrik , Hildebrandt Arndt
Published: October 2022

To accurately describe the motion of floating structures in waves using low-fidelity methods (Boundary Element Method, analytic methods), roll damping has to be determined with higher fidelity due to the influence of viscous effects. In these higher-fidelity estimations, either existing models like Ikeda’s model, which was validated using model test results, or Computational Fluid Dynamics simulations are frequently used. Forced roll tests are the main method to estimate the hydrodynamic properties (damping & added mass). In this study, three different numerical approaches to simulate structures in roll motions in grid based Finite Volume Method schemes are compared regarding their efficiency and numerical accuracy.

The results of this study show a good agreement between all three methods. While mesh morphing and Arbitrary Mesh Interface show similar results, the runtime of the Arbitrary Mesh Interface is increased by factor three. The most computationally challenging method is the overset method, which has its benefits in more complex motion environments and need further improvement to be a feasible alternative to the established methods mesh morphing and Arbitrary Mesh Interface.
Reconstruction of Fish Farm Model Tests in CFD for Detailed Analysis of Internal Sloshing and Wave Loading in Extreme Sea States
Authors: van der Plas P. , Serraris J. W. , Helder J. A. , Hanssen F.-C. W. , Bjar L. F. , Krogenes K. O.
Published: October 2022

In recent years fish-farming is gradually moving towards more exposed offshore environments. This makes the study of loading conditions in extreme sea states increasingly relevant. Sea farms often involve light and slender structures which typically include flexible components such as nets and other farming equipment. This poses a significant challenge in model tests when it comes to the installation of measurement equipment such as pressure inducers and force panels. Reconstruction in CFD provides a meaningful tool to complement model test data and to investigate design variations when model testing is unfeasible or financially unattractive. Combined model tests and CFD form a hybrid approach resulting in synergy for both methods.

The model tests are performed to determine the overall motion behavior of the fish cage and to produce a large amount of wave impact events. However, the overall pressure distribution and resulting loads on the supporting semi-submersible structure could not be measured.

CFD is used to reconstruct the flow in and around a fish-farm concept consisting of a fish cage supported by a circular semi-submersible ring. The CFD simulations are used to get more detailed information about the loads on the supporting semi-submersible structure during specific wave events that were observed in the model tests.

The incoming undisturbed waves from the model tests are reconstructed in CFD. Furthermore, the motions of the fish cage are included in CFD by imposing the (synchronized) motions as registered during the model tests. This paper describes the iterative wave matching procedure that was applied to reconstruct the wave events in CFD and presents a comparison of the full simulation setup with experiments.
Analysis of Structures in Very Shallow Water: CFD Analysis of Wave Propagation and Breaking Waves
Authors: Johannesen Magnus , Lande Øystein
Published: October 2022

Structures installed in very shallow water are experiencing forces from a very disturbed flow field, including rapidly changing gradients and breaking waves. Estimating loads on these structures usually involves running full 3D CFD analyses to predict the flow field and calculate the forces.

This paper is comparing a full 3D CFD simulation using OpenFOAM to a novel method of wave propagation with a multilayer solver based on Basilisk in order to establish the applicability of such a method in estimating loads on structures in shallow water. By applying the multilayer method the analysis time is reduced so much that one can estimate kinematics with a statistical approach where one analyses a wide range of sea states to estimate loading on the structure. This approach is common in deep water where much of the kinematics are simplified.
Structural Load Estimation of Downstream Wind Turbines in an Offshore Wind Farm
Authors: Xia Yiqing , Matsumoto Yosuke , Yousefi Iman , Oouchi Kazuyoshi , Kaneko Shunsuke , Nittouji Michio , Fujii Kenji , Machida Kaho
Published: October 2022

In this study, three IEA Wind 15MW offshore reference wind turbines with monopile support structures, are placed at a distance of eight rotor diameters in the prevailing wind direction. FAST. Farm responses are simulated under different wind conditions and sea states. The outputs suggest that for downstream turbines the effect of partial wake impingement is higher on tower bending moments than on blade bending moments. The downstream wind turbines have higher energy spectra around the tower natural frequency, which may potentially affect the fatigue loads and cut down the turbine lifetime. This study provides references for structural load analysis of downstream wind turbines in large-scale fixed-bottom offshore wind farms.
Offshore Wind Turbine Support Structures Along Indian Coast - Multi Criteria Analysis
Authors: Mallela Mounika , Saha Nilanjan , Alluri Satya Kiran Raju , Ramana Murthy M. V.
Published: October 2022

The selection of a feasible support structure for the site-specific environmental conditions helps in reducing the capital cost of the offshore wind turbines. As the study location falls under shallow water depth, the bottom fixed structures such as monopile, tripile and jacket have been considered as alternatives. The analysis of the alternatives has been carried out using API and DNVGL codal provisions in a finite element based framework, accounting for hydrodynamic and soil structure interaction effects. OWTs are simultaneously subjected to aerodynamic loads from the turbine blade rotations, estimated using blade element momentum theory based software and are coupled analysis is carried out. Multi criteria decision analysis (MCDA) is adopted to aid in the decision making regarding the choice of the feasible support structure. Multi-criteria evaluation problem consists of a viable set of alternatives for a given problem. MCDA explicitly evaluates the conflicting criteria involved in the decision making. It helps analyzing a complex problem using a predefined set of variables/criteria to derive at a logical solution. Among the various methods of MCDA for evaluating the alternatives against the criteria, the Analytical Hierarchy Process (AHP) has been adopted. In this, the pairwise comparison is made for the given alternatives using predefined criterion. The criteria considered for the study are structural configuration, fabrication, transportation and installation of the structure. The criterion again are classified into different sub criteria in order to sort out the priority of all the alternatives. The support structure with the highest priority has been identified as the optimal and feasible structure for the location under study.
Dynamic Response of Local Hull Structures Under Moving Slamming Loads
Authors: Chen Yunbin , Zhu Ling
Published: October 2022

The bow of a ship is often subjected to the action of moving slamming loads, and the slamming phenomenon occurs frequently, which has significant effect on the local and global structural response. In this paper, Euler-Bernoulli beam theory and modal superposition method are adopted to study the dynamic response of a beam under the moving slamming load. The slamming pressure is characterized as pulse load that moving along the longitudinal direction at a constant speed. The problem is solved using a Fourier sine integral transformation in space and a Laplace-Carson integral transformation in time. Deflection and stress as functions of time and position for different speeds, bending stiffnesses, etc. are given. The cases that arrival of a pulse load on a beam, steady-state vibration, departure of a pulse load from a beam all have been considerated in theoretical model. Based on the proposed theoretical model, the influence of parameters such as load rising section coefficient, migration velocity on the dynamic response of beams under moving slamming load is studied and the associated results are compared with those using the finite element method. The proposed theoretical model is useful in understanding the slamming impact and evaluating the dynamic response of structural components under slamming loads.
Stochastic Response Determination of U-Oscillating Water Columns in Severe Seas by a Statistical Linearization Scheme
Authors: Scialò Andrea , Malara Giovanni , Kougioumtzoglou Ioannis A. , Arena Felice
Published: October 2022

U-Oscillating Water Columns (U-OWCs) are fixed wave energy converters that are becoming increasingly popular. Indeed, a full-scale prototype was installed recently at the port of Civitavecchia (Rome, Italy), while another U-OWC integrated breakwater is currently under construction at the port of Salerno (Italy).

The dynamics of these systems is governed by a system of nonlinear integro-differential equations with no known exact solution. Various solution methodologies have been proposed ranging from purely numerical ones to approximate semi-analytical schemes, such as those based on statistical linearization. The latter was shown to exhibit satisfactory accuracy in determining response statistics vis-à-vis Monte Carlo data. However, significant discrepancies may arise in severe sea states, because the U-OWC is exposed to frequent inlet uncovering during the crossing of large wave troughs, and thus to a discontinuous wave excitation. In general, standard approximate models do not account for this phenomenon, and therefore they exhibit in many cases a relatively low accuracy degree.

In this paper, a novel statistical linearization scheme is developed for determining approximately the response statistics of a U-OWC exposed to severe sea states. A significant novelty of the proposed scheme relates to the fact that the determined parameters of the equivalent linear system include not only the standard mass, damping and stiffness coefficients, but also an equivalent excitation coefficient that accounts for the intermittent nature of the wave excitation.

The reliability of the scheme is demonstrated by comparisons with relevant Monte Carlo simulation data.
Code and Solution Verification of Sliding and Overset Grid Methods on Wind Turbine Flows
Authors: Gomes Tiago , Lemaire Sébastien , Vaz Guilherme
Published: October 2022

Sliding Grids (SG) and Overset Grids (OG) are two CFD methods for discretizing the domain with several sub-grids, with the potential of enabling complex body motion in unsteady simulations. Their fundamental difference lies on the sub-grid placement, fitted into each other (SG) or overlapped (OG), which ends up impacting the information transfer mechanism that couples them. In the present work Verification procedures are applied to a novel wind turbine flow manufactured solution, followed by the aerodynamic analysis of the rotor of the NREL 5MW wind turbine. The studies aim at assessing the impact of these methods on the simulation errors, namely in terms of interpolation schemes and resulting mass imbalance, and to compare them directly performing the same task, to fulfill a gap perceived in the literature. The results suggest that SG tend to be more convenient to be used in meshes incorporating the rotor geometry, while potentially being similar to OG in terms of accuracy. This convenience consderation also derives from convergence issues with OG, which are thought to be linked with the rotating domain’s interface being too close to the turbine’s geometry. Moreover, higher than second order interpolation schemes are found to minimize the mass imbalance introduced by these methods and consequent pressure fluctuations.
Supplemental Material: Fault permeability from stochastic modeling of clay smears
Authors: Saló-Salgado Lluís , Juanes Ruben , al. et
Published: October 2022

Detailed description of the PREDICT methodology. 
Supplemental Material: Trends and rhythms in carbonatites and kimberlites reflect thermo-tectonic evolution of Earth
Authors: Liu Shuang-Liang , Fan Hong-Rui , al. et
Published: October 2022

 Figures S1–S7, Table S1, and references. 
Supplemental Material: Preferential preservation of low-elevation biotas in the nonmarine fossil record
Authors: Holland Steven M. , al. et
Published: October 2022

Data files of elevations and their coordinates for modern sedimentary basins. 
Supplemental Material: Provenance of eolian deposits in the Xorkol Basin: Implications for Eocene dust-transport pattern in western China
Authors: Pan Feng , Li Jianxing , al. et
Published: October 2022

Description of geochemical provenance proxies, the additional figure and data tables.
Obesity alone should not rule out knee replacement surgery
Authors: Saul Helen , Gursul Deniz , Evans Jonathan
Published: October 2022

The study

Evans JT, Mouchti S, Blom AW, et al. Obesity and revision surgery, mortality, and patient-reported outcomes after primary knee replacement surgery in the National Joint Registry: a UK cohort study.PLoS Med2021;18:7.
Neighbourhood material deprivation and severe maternal morbidity: a population-based cohort study in Ontario, Canada
Authors: Snelgrove John W , Lam Melody , Watson Tristan , Richard Lucie , Fell Deshayne B , Murphy Kellie E , Rosella Laura C
Published: October 2022

Objectives

Rates of age-associated severe maternal morbidity (SMM) have increased in Canada, and an association with neighbourhood income is well established. Our aim was to examine SMM trends according to neighbourhood material deprivation quintile, and to assess whether neighbourhood deprivation effects are moderated by maternal age.

Design, setting and participants

A population-based retrospective cohort study using linked administrative databases in Ontario, Canada. We included primiparous women with a live birth or stillbirth at ≥20 weeks’ gestational age.

Primary outcome

SMM from pregnancy onset to 42 days postpartum. We calculated SMM rate differences (RD) and rate ratios (RR) by neighbourhood material deprivation quintile for each of four 4-year cohorts from 1 April 2002 to 31 March 2018. Log-binomial multivariable regression adjusted for maternal age, demographic and pregnancy-related variables.

Results

There were 1 048 845 primiparous births during the study period. The overall rate of SMM was 18.0 per 1000 births. SMM rates were elevated for women living in areas with high material deprivation. In the final 4-year cohort, the RD between women living in high vs low deprivation neighbourhoods was 3.91 SMM cases per 1000 births (95% CI: 2.12 to 5.70). This was higher than the difference observed during the first 4-year cohort (RD 2.09, 95% CI: 0.62 to 3.56). SMM remained associated with neighbourhood material deprivation following multivariable adjustment in the pooled sample (RR 1.16, 95% CI: 1.11 to 1.21). There was no evidence of interaction with maternal age.

Conclusion

SMM rate increases were more pronounced for primiparous women living in neighbourhoods with high material deprivation compared with those living in low deprivation areas. This raises concerns of a widening social gap in maternal health disparities and highlights an opportunity to focus risk reduction efforts toward disadvantaged women during pregnancy and postpartum.
Effectiveness of combined exercise in people with type 2 diabetes and concurrent overweight/obesity: a systematic review and meta-analysis
Authors: Zhao Xiaoyan , He Qianyu , Zeng Yongmei , Cheng Li
Published: October 2022

Objective

To synthesise the available scientific evidence on the effects of combined exercise on glycaemic control, weight loss, insulin sensitivity, blood pressure and serum lipids among patients with type 2 diabetes (T2D) and concurrent overweight/obesity.

Design and sample

PubMed, EMBASE, Web of Science, the Cochrane library, WANFANG, CNKI, SinoMed, OpenGrey and ClinicalTrials.gov were searched from inception through April 2020 to identify randomised controlled trials (RCTs) that reported the effects of combined exercise in individuals with T2D and concurrent overweight/obesity.

Methods

Quality assessment was performed using the Cochrane Collaboration’s risk of bias tool. The mean difference (MD) with its corresponding 95% CI was used to estimate the effect size. Meta-analysis was performed using Review Manager V.5.3.

Results

A total of 10 RCTs with 978 participants were included in the meta-analysis. Pooled results demonstrated that combined exercise significantly reduced haemoglobin A1c (MD=−0.16%, 95% CI: −0.28 to −0.05, p=0.006); body mass index (MD=−0.98 kg/m2, 95% CI: −1.41 to −0.56, p<0.001); homeostasis model assessment of insulin resistance (MD=−1.19, 95% CI: −1.93 to −0.46, p=0.001); serum insulin (MD=−2.18 μIU/mL, 95% CI: −2.99 to −1.37, p<0.001) and diastolic blood pressure (MD=−3.24 mm Hg, 95% CI: −5.32 to −1.16, p=0.002).

Conclusions

Combined exercise exerted significant effects in improving glycaemic control, influencing weight loss and enhancing insulin sensitivity among patients with T2D and concurrent overweight/obesity.
Codesigning patient experience measures for and with children and young people with intellectual disability: a study protocol
Authors: Mimmo Laurel , Woolfenden Susan , Travaglia Joanne , Strnadová Iva , Phillips Maya Tokutake and Karen , van Hoek Matthew and Debbie , Harrison Reema
Published: October 2022

Introduction

Children and young people with intellectual disability represent one of the most vulnerable groups in healthcare, yet they remain under-represented in projects to design, develop and/or improve healthcare service delivery. Increasingly, healthcare services are using various codesign and coproduction methodologies to engage children and young people in service delivery improvements.

Methods and analysis

This study employs an inclusive approach to the study design and execution, including two co-researchers who are young people with intellectual disability on the project team. We will follow an adapted experience-based co-design methodology to enable children and young people with intellectual disability to participate fully in the co-design of a prototype tool for eliciting patient experience data from children and young people with intellectual disability in hospital.

Ethics and dissemination

This study was granted ethical approval on 1 February 2021 by the Sydney Children’s Hospitals Network Human Research Ethics Committee, reference number 2020/ETH02898. Dissemination plan includes publications, doctoral thesis chapter, educational videos. A summary of findings will be shared with all participants and presented at the organisation quality and safety committee.
Study protocol for a 10-year prospective observational study, examining lymphoedema and patient-reported outcome after breast reconstruction
Authors: Laustsen-Kiel Cecilie Mullerup , Lauritzen Elisabeth , Langhans Linnea , Engberg Damsgaard Tine
Published: October 2022

Introduction

Over the last decades, treatment of breast cancer has become increasingly more effective. Consequently, an increasing number of women are living with late effects of breast cancer treatment, including disfiguring scars, deformity or asymmetry of the breast, secondary lymphoedema and other physical and psychosocial late effects. Data from this study will provide knowledge on how to guide breast reconstruction in the future towards outcomes with fewer complications, higher long-term quality of life (QoL) and satisfaction with the aesthetic outcome. The development of secondary lymphoedema, for which the effect of breast reconstruction has yet to be established, will be thoroughly examined.

Methods and analysis

Women receiving breast reconstruction (autologous and implant based) at the Department of Plastic Surgery and Burns Treatment, Rigshospitalet, will be invited to participate. The patients will be followed for 10 years postoperatively. Demographic, health-related, oncological characteristics and treatment data will be registered. Validated assessment tools, such as the BREAST-Q and Beck Depression Inventory, will be used to measure an extensive range of clinical outcomes, including QoL, life and aesthetic satisfaction and depression. Arm range of motion will be measured with a goniometer and lymphoedema by bioimpedance spectroscopy, compared with circular arm measurements.

Ethics and dissemination

This study will be conducted according to the 5th version of the Helsinki Declaration. The regional ethical committee for Capital Region Denmark did not find the study notifiable, according to the law of the committee § 1, part 4. All data will be anonymised before its publication. This study will be conducted according to the Danish data protection regulation and is catalogued and approved by the Capital Region Head of Knowledge Centre. According to the Danish health law § 46, part 2, this study does not need the Danish Patient Safety Authority’s approval. The findings of this study will be submitted to international peer-reviewed journals.
Causes of infective endocarditis in the Western Cape, South Africa: a prospective cohort study using a set protocol for organism detection and central decision making by an endocarditis team
Authors: Pecoraro Alfonso Jan Kemp , Pienaar Colette , Herbst Philippus George , Poerstamper Simon , Joubert Lloyd , Taljaard Jantjie , Prozesky Hans , Janson Jacques , Newton-Foot Mae , Doubell Anton Frans
Published: October 2022

Background

Blood culture negative infective endocarditis (BCNIE) poses both a diagnostic and therapeutic challenge. High rates of BCNIE reported in South Africa have been attributed to antibiotic use prior to blood culture sampling.

Objectives

To assess the impact of a systematic approach to organism detection and identify the causes of infective endocarditis (IE), in particular causes of BCNIE.

Design

Prospective cohort study.

Methods

The Tygerberg Endocarditis Cohort study prospectively enrolled patients with IE between November 2019 and February 2021. A set protocol for organism detection with management of patients by an endocarditis team was employed. This prospective cohort was compared with a retrospective cohort of patients with IE admitted between January 2017 and December 2018.

Results

One hundred and forty patients with IE were included, with 75 and 65 patients in the retrospective and prospective cohorts, respectively. Baseline demographic characteristics were similar with a mean age of 39.6 years and male predominance (male sex=67.1%). The rate of BCNIE was lower in the prospective group (28/65 or 43.1%) compared with the retrospective group (47/75 or 62.7%; p=0.039). The BCNIE in-hospital mortality rate in the retrospective cohort was 23.4% compared with 14.2% in the prospective cohort (p=0.35). A cause was identified (including non-culture techniques) in 86.2% of patients in the prospective cohort, withStaphylococcus aureus(26.2%),Bartonellaspecies (20%) and the viridans streptococci (15.3%) being most common.

Conclusion

The introduction of a set protocol for organism detection, managed by an endocarditis team, has identifiedStaphylococcusaureusas the most common cause of IE and identified non-culturable organisms, in particularBartonella quintana, as an important cause of BCNIE. A reduction in in-hospital mortality in patients with BCNIE was observed, but did not reach statistical significance.
SchedGuard++: Protecting against Schedule Leaks Using Linux Containers on Multi-Core Processors
Authors: Chen Jiyang , Kloda Tomasz , Tabish Rohan , Bansal Ayoosh , Chen Chien-Ying , Liu Bo , Mohan Sibin , Caccamo Marco , Sha Lui
Published: October 2022

Timing correctness is crucial in a multi-criticality real-time system, such as an autonomous driving system. It has been recently shown that these systems can be vulnerable to timing inference attacks, mainly due to their predictable behavioral patterns. Existing solutions like schedule randomization cannot protect against such attacks, often limited by the system’s real-time nature. This article presents “
SchedGuard++
”: a temporal protection framework for Linux-based real-time systems that protects against posterior schedule-based attacks by preventing untrusted tasks from executing during specific time intervals.
SchedGuard++
supports multi-core platforms and is implemented using Linux containers and a customized Linux kernel real-time scheduler. We provide schedulability analysis assuming the Logical Execution Time (LET) paradigm, which enforces I/O predictability. The proposed response time analysis takes into account the interference from trusted and untrusted tasks and the impact of the protection mechanism. We demonstrate the effectiveness of our system using a realistic radio-controlled rover platform. Not only is “
SchedGuard++
” able to protect against the posterior schedule-based attacks, but it also ensures that the real-time tasks/containers meet their temporal requirements.
Hyperbaric Oxygen Therapy Promotes Hearing Gain with Increases in Serum IGF-1 and HSP70 in Patients with Idiopathic Sudden Sensorineural Hearing Loss
Authors: Zhang Yi , Jia Xingyuan , Liu Xuehua , Zhao Lin , Zhou Yan , Liang Fang , Gao Yu , Yang Jing
Published: October 2022

Objective. Hyperbaric oxygen therapy (HBOT) has been recommended for the initial and salvage treatment of patients with idiopathic sudden sensorineural hearing loss (ISSHL), but its underlying mechanisms remain unclear. In this study, we investigated whether HBOT alters serum levels of insulin-like growth factor 1 (IGF-1) and heat shock protein 70 (HSP70) in patients with ISSHL. Then, we identified the relationship between hearing recovery and changes in serum IGF-1 and HSP70 levels. Methods. Moderately severe to profound unilateral ISSHL patients (n = 70) and healthy control participants (n = 30) were enrolled. The ISSHL patients were randomly assigned to receive medical therapy alone (MT group, n = 35) or both HBOT and medical therapy (HBOT + MT group, n = 35). Audiometric testing was performed before and after treatment. Serum IGF-1 and HSP70 levels were assessed by ELISA in ISSHL patients pre-and posttreatment and healthy controls. Results. Before treatment, compared with the healthy controls, serum IGF-1 and HSP70 were lower in ISSHL patients. After treatment, serum IGF-1 and HSP70 increased in both the HBOT + MT and MT groups, although they were significantly higher in the HBOT + MT group (

p
<
0.01

). In the HBOT + MT group, these increases were associated with hearing gains. In addition, IGF-1 was strongly associated with HSP70 (r = 0.621,

p
=
0.001

). No such association was found in the MT group (

p
=
0.757

). Conclusion. Administering HBOT in addition to medical therapy can improve the hearing of patients with moderately severe to profound unilateral ISSHL. The improvement is related to the upregulation of IGF-1 and HSP70.
COVID-19 Pandemic Experiences in Pediatric Intensive Care Unit: An Iranian Referral Hospital-Based Study
Authors: Mohammadpour Masoud , Hassani Seyed Abbas , Sharifzadeh Meisam , Tahernia Leila , Mamishi Setareh , Yaghmaie Bahareh , Najafi Zeinab , Beirami Farzaneh , Afsharipour Mehrnoush , Minuyeefar Maryam , Dolatzadeh Mina , Pak Neda , Majmaa Anahita , Zamani Zahra , Mahmoudi Shima
Published: October 2022

Introduction. In late February 2020, after we had informed about the presence of some cases of COVID-19 in Iran and its rapid spread throughout the country, we decided to make the necessary arrangements for patients with critical conditions in Pediatric Intensive Care Unit (PICU) at Children's Medical Center. There are a little data on critically ill children with COVID-19 infection with ICU requirements. The aim of this study was to describe clinical characteristics, laboratory parameters, treatment, and outcomes of the pediatrics population infected by SARS-CoV-2 admitted to PICU. Materials and Methods. This study was performed between February 2020 and May 2020 in the COVID PICU of the Children’s Medical Center Hospital in Tehran, Iran. Patients were evaluated in terms of demographic categories, primary symptoms and signs at presentation, underlying disease, SARS-CoV-2 RT-PCR test result, laboratory findings at PICU admission, chest X-ray (CXR) and lung CT findings, and treatment. Moreover, the need to noninvasive ventilation (NIV) or mechanical ventilation, the length of hospital stay in the PICU, and outcomes were assessed. Results. In total, 99 patients were admitted to COVID PICU, 42.4% (42 patients) were males, and 66 patients had positive SARS-CoV-2 real-time reverse transcriptase-polymerase chain reaction (RT-PCR). There was no statistically significant difference in the frequency of clinical signs and symptoms (except for fever) among patients with positive SARS-CoV-2 RT-PCR and negative ones. Among all admitted patients, the presence of underlying diseases was noticed in 81 (82%) patients. Of 99 patients, 34 patients were treated with NIV during their admission. Furthermore, 35 patients were intubated and treated with mechanical ventilation. Unfortunately, 11 out of 35 mechanically ventilated patients (31%) passed away. Conclusion. No laboratory and radiological findings in children infected with COVID-19 were diagnostic in cases with COVID-19 admitted to PICU. There are higher risks of severe COVID-19, PICU admission, and mortality in children with comorbidities.
Factors Associated with Nursing Student Satisfaction with Their Clinical Learning Environment at Wolkite University in Southwest Ethiopia
Authors: Benti Terefe Ayana , Gemeda Gudeta Tolesa
Published: October 2022

Background. The clinical learning environment has been defined as “an interactive network of strengths within the clinical environment that influence the clinical learning outcomes of students. Understanding students’ level of satisfaction with their clinical learning environment is crucial to ensuring the required teaching and learning process. Therefore, this study was designed to assess the level of satisfaction with the CLE among nursing students at the Wolkite University of Ethiopia. Methods. A cross-sectional study was conducted at Wolkite University. This study was carried out in March 2022 on 208 student nurses selected by purposive and convenient sampling techniques. This study used the English version of the Clinical Learning Environment and Supervision + Nurse Teacher (CLES + T) evaluation scale. The collected data were cleaned, coded, and entered into Epi data 3.1, and then, statistical analyses were performed using SPSS version 26. Bivariate and multivariable logistic regression models were used to identify factors associated with the satisfaction level of nursing students towards CLE. Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were calculated, and

p

values < 0.05 were considered to indicate statistical significance. Results. More than half of the study participants were females, and nearly half (50.5%) of the participants were in year three of the nursing program. The study found that 39.9% (95%CI: 32.2%, 46.6%) of students were satisfied with their CLE. Factors that had a significant association with the satisfaction level of nursing students towards CLE were gender (female students) (AOR = 16.053 (6.397, 40.286)), year of study (4th year) (AOR = 6.296 (2.679, 14.796)), and the type of the hospital in which their last clinical placement was held (at a primary hospital) (AOR = 2.961 (1.122, 7.815)). Conclusion. Effective nursing education programs need to be developed to increase satisfaction with clinical practice and to promote positive emotional regulation in nursing students. Nurse practitioners and managers should be aware of their important role in the professional development of students and their satisfaction with clinical placements.
Effects of Teriparatide on Bone Mineral Density and Prevention of Fragility Fractures in Saudi Arabian Subjects with Osteoporosis: A Two-Year Clinical Study from a Single Center
Authors: Sadat-Ali Mir , Al-Omran Abdallah , AlTabash Khalid , AlDakheel Dakheel A. , Elansassy Salma , Hegazi Tarek , Al Muhaish Mona
Published: October 2022

Background and Objective. This prospective study was conducted to evaluate changes in BMD and prevention of fragility fractures in osteoporosis patients after 24 months use of teriparatide. Design. A prospective study was conducted. Setting. This study took place at King Fahd Hospital of the University, Imam AbdulRahman Bin Faisal University, Dammam, Saudi Arabia. Primary and Secondary Outcomes. The study aimed to evaluate changes in BMD and prevention of fragility fractures. Materials and Methods. We followed up 439 patients who were prescribed teriparatide at the King Fahd Hospital of the University, AlKhobar, and 415 (94.5%) patients completed a 24-month teriparatide course. The data gathered before starting medication were age, sex, previous therapy, history of fractures, and other diseases like diabetes mellitus, hypertension, and cardiac disease. At the time of the final assessment after 24 months, a history of fractures if any during the treatment was collected and a DXA scan was done. Results. A total of 415 patients were followed up for 2 years. Three hundred and sixty-five patients (87.9%) were females, and the rest were males. The average age was 68.21 ± 17.6 years. Two hundred and forty-eight patients (59.8%) were treatment naïve, and 167 (40.2%) were on treatment for osteoporosis. Twenty patients (4.8%) sustained fracture on treatment. The pretreatment DXA showed that the mean hip T-score was −3.1 ± 0.79, and after completion of the treatment, it was −1.5 ± 0.62

P
<
0.001

, while the T-score of the lumbar spine was 4.4 ± 0.86 versus −3.2 ± 0.87

P
<
0.001

. Seventeen (4.09%) had fractures while on teriparatide treatment. The mean significant gain (MSG) for BMD for the hip was 0.095 g/cm2, and for the lumbar spine, it was was 0.109 g/cm2 with

P
<
0.001

at 95% CI. Conclusions. Our study shows that 94.5% completed the treatment duration, and there was an increase in the BMD. The decrease in T-scores of the lumbar spine and hip was significant so was the reduction in the number of fractures.
Secure Medical Data Model Using Integrated Transformed Paillier and KLEIN Algorithm Encryption Technique with Elephant Herd Optimization for Healthcare Applications
Authors: Alluhaidan Ala Saleh
Published: October 2022

In the healthcare industry, where concerns are frequently and appropriately focused on saving someone’s life, access to interfaces and computer systems storing sensitive data, such as medical records, is crucial to take into account. Medical information has to be secretive and protected by the laws of privacy with restrictions on its access. E-health security is a holistic notion that encompasses available medical data’s integrities and confidentiality which ensures that data are not accessed by unauthorized people and allow doctors to offer proper treatment. The patients’ data need to be secured on servers holding medical data. This work adds new features for ensuring storage and access safety through ITPKLEIN-EHO (integrated transformed Paillier and KLEIN algorithms) that use EHOs (elephant herd optimizations) to provide lightweight features. The key space affects lightweight encryption techniques in general. The EHOs (elephant herd optimizations) optimize key spaces by adjusting iteration rounds. The main goal is to encrypt EEGs (electroencephalographic signals) in healthcare and send it to end users using the proposed ITPKLEIN-EHO approach. This suggested technique utilizes MATLAB for its tests on various EEG data sets for implementation. The simulations of the proposed IRPKLEIN-EHO technique are evaluated with other existing techniques in terms of MSEs, PSNRs, SSIMs, PRDs, and encryption/decryption times.
Updates on Pharmacologic Management of Microvascular Angina
Authors: Soleymani Mosayeb , Masoudkabir Farzad , Shabani Mahsima , Vasheghani-Farahani Ali , Behnoush Amir Hossein , Khalaji Amirmohammad
Published: October 2022

Microvascular angina (MVA), historically called cardiac syndrome X, refers to angina with nonobstructive coronary artery disease. This female-predominant cardiovascular disorder adds considerable health-related costs due to repeated diagnostic angiography and frequent hospital admissions. Despite the high prevalence of this diagnosis in patients undergoing coronary angiography, it is still a therapeutic challenge for cardiologists. Unlike obstructive coronary artery disease, with multiple evidence-based therapies and management guidelines, little is known regarding the management of MVA. During the last decade, many therapeutic interventions have been suggested for the treatment of MVA. However, there is a lack of summarization tab and update of current knowledge about pharmacologic management of MVA, mostly due to unclear pathophysiology. In this article, we have reviewed the underlying mechanisms of MVA and the outcomes of various medications in patients with this disease. Contrary to vasospastic angina in which normal angiogram is observed as well, nitrates are not effective in the treatment of MVA. Beta-blockers and calcium channel blockers have the strongest evidence of improving the symptoms. Moreover, the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, statins, estrogen, and novel antianginal drugs has had promising outcomes. Investigations are still ongoing for vitamin D, omega-3, incretins, and n-acetyl cysteine, which have resulted in beneficial initial outcomes. We believe that the employment of the available results and results of the future large-scale trials into cardiac care guidelines would help reduce the global cost of cardiac care tremendously.
Assessing the Mechanism of Action of “Fructus Ligustri Lucidi-Cuscutae Semen” in Prostate Cancer Treatment Using Network Pharmacology and Molecular Docking
Authors: Lu Dongdong , Shang Jianwei , Guo Xiping , Zhang Yaosheng
Published: October 2022

Objective. To explore the mechanism of action of “Fructus Ligustri Lucidi-Cuscutae Semen” in the treatment of prostate cancer using network pharmacology and molecular docking. Methods. The active ingredients and targets of “Fructus Ligustri Lucidi-Cuscutae Semen” were obtained by searching the TCMSP and DrugBank databases. These were matched and corrected using the UniProt platform. A drug “active ingredient-target” network map was constructed using Cytoscape 3.8.0. Prostate cancer-related targets were acquired from GeneCards, Disgenet, DrugBank, and other databases. The protein-protein interaction (PPI) network between the drug and prostate cancer was constructed with BioGenet; the crossover network of the two targets was extracted derive the key targets of “Fructus Ligustri Lucidi-Cuscutae Semen” for prostate cancer treatment. We used the Metascape platform for GO and KEGG enrichment analysis of the key targets. AutoDockTools1.5.6 and PyMOL software were used to perform molecular docking. Results. We obtained 13 active ingredients, 221 drug targets, 1511 prostate cancer targets (including 221 key targets), and 305 KEGG pathways from “Fructus Ligustri Lucidi-Cuscutae Semen.” Paclitaxel, quercetin, kaempferol, TP53, β-sitosterol, EGFR, and ESR1 in “Fructus Ligustri Lucidi-Cuscutae Semen” showed good docking activity. Conclusion. “Fructus Ligustri Lucidi-Cuscutae Semen” is a valuable clinical guide for the treatment of prostate cancer with multicomponent, multitarget, and multipathway characteristics.
May-Thurner Syndrome—a Rare Cause of Extensive Pelvic DVT, but Is there More to Know?
Authors: Kumar Vikash , Koifman Michelle , Vachhani Bhavyakumar , Gala Dhir , Bahl Sumeet
Published: October 2022

May-Thurner Syndrome (MTS) is a rare anatomical variant characterized by the compression of the left common iliac artery by the right common iliac artery against the fifth lumbar vertebrae. It can present as acute or chronic deep vein thrombosis (DVT), leg pain, varicosities, skin ulceration, and hyperpigmentation. In this case report, we present an interesting case of a young male with no obvious risk factors, who presented with back and left lower extremity pain later diagnosed with MTS on computed tomography angiography (CTA) and venogram. The patient was treated with venoplasty and pharmacomechanical thrombolysis and was discharged on apixaban.