bluuebunny/crossref_metadata_2025 huggingface dataset:
A Priori Denoising Strategies for Sparse Identification of Nonlinear Dynamical Systems: A Comparative Study
Authors: Cortiella Alexandre , Park K. C. , Doostan Alireza
Published: May 2022

In recent years, identification of nonlinear dynamical systems from data has become increasingly popular. Sparse regression approaches, such as Sparse Identification of Nonlinear Dynamics (SINDy), fostered the development of novel governing equation identification algorithms assuming the state variables are known {\it a priori} and the governing equations lend themselves to sparse, linear expansions in a (nonlinear) basis of the state variables. In the context of the identification of governing equations of nonlinear dynamical systems, one faces the problem of identifiability of model parameters when state measurements are corrupted by noise. Measurement noise affects the stability of the recovery process yielding incorrect sparsity patterns and inaccurate estimation of coefficients of the governing equations. In this work, we investigate and compare the performance of several local and global smoothing techniques to {\it a priori} denoise the state measurements and numerically estimate the state time-derivatives to improve the accuracy and robustness of two sparse regression methods to recover governing equations: Sequentially Thresholded Least Squares (STLS) and Weighted Basis Pursuit Denoising (WBPDN) algorithms. We empirically show that, in general, global methods, which use the entire measurement data set, outperform local methods, which employ a neighboring data subset around a local point. We additionally compare Generalized Cross Validation (GCV) and Pareto curve criteria as model selection techniques to automatically estimate near optimal tuning parameters, and conclude that Pareto curves yield better results. The performance of the denoising strategies and sparse regression methods is empirically evaluated through well-known benchmark problems of nonlinear dynamical systems.
Poincaré Plot Features and Statistical Features From Current and Vibration Signals for Fault Severity Classification of Helical Gear Tooth Breaks
Authors: Peña Mario , Cerrada Mariela , Medina Rubén , Cabrera Diego , Sánchez René Vinicio
Published: May 2022

Most of the approaches of feature extraction for data-driven rotating machinery fault diagnosis assume characteristics of periodicity and seasonality typically inherent to linear signals obtained from different sensors. Nevertheless, the behavior of rotating machinery is not necessarily linear when a failure occurs. Thus, new techniques based on the theory of chaos and nonlinear systems are needed to extract proper features of signals. This article introduces the use of features extracted from the Poincaré plot (PP), which are computed over vibration and current signals measured on a gearbox powered by an induction motor. A comparison between the performance of classic statistical features and PP features is developed by applying feature analysis based on analysis of varaince (ANOVA) and cluster validity assessment to rank and select the subset of best features. K-nearest-neighbor (KNN) algorithm is used to test the performance of the selected feature set for fault severity classification. The use of PP for the analysis of nonlinear, nonperiodic signals is not new; however, its application in mechanical systems is not widely extended. Our contribution aims at highlighting the use of the PP features, supported by data collected from a test bed under real conditions of speed and load, to proof the potential application of this approach. The results show that PP features extracted from the current signal yields 96% of classification accuracy when using at least 11 features.
Design of Curved Annular Diffusers II: Using Splitter Blades
Authors: Kuchana Vinayender , Balakrishnan N. , Srinivasan Balamurugan
Published: May 2022

The use of splitter blade as a passive flow control mechanism in the design of separation free aggressive annular diffuser is explored through computational fluid dynamics simulations. The fundamental working principle of a splitter blade in case of a two-dimensional rectangular diffuser and an annular diffuser is discussed. The effects of splitter blade configuration on the end-wall adverse pressure gradients are discussed. An aggressive diffuser design space is identified with ducts of maximum slope of 50 deg and maximum divergence angle between the outer and inner walls of 10 deg for axial-length to inlet height ratio ranging from 1.25 to 2.5. One or more splitter blades are employed in the duct to eliminate flow separation for all the ducts in the aggressive design space considered. Requirement of number of splitter blades in the aggressive design space is demarcated. Performance charts for the ducts in this aggressive design space are also established.
A Novel Approach for Computational Fluid Dynamics Analysis of Mean Wind Loads on Heliostats
Authors: Durán R.L. , Hinojosa J.F. , Sosa-Flores P.
Published: May 2022

A computational fluid dynamics study about the aerodynamic loads over a heliostat due to an atmospheric boundary layer flow using a modified k–ɛ turbulence model is presented. A new formulation is used, in which the model quantities vary with the velocity field. Modified wall functions for roughness were used at the bottom of the computational domain to achieve horizontal homogeneity of the airflow. Good horizontal homogeneity for the streamwise and spanwise velocity and turbulence intensity profiles were found. The incident profiles were compared with the inlet ones. The average percentage differences were 0.22% for velocity and 0.43% for turbulent intensity. Good agreement was found between the numerical data and theoretical values of the streamwise and spanwise shear stress at the bottom of the domain. The aerodynamic coefficients of the heliostat at different elevation angles were obtained, and a good agreement was found between the numerical data concerning the wind tunnel experimental values. An average percentage difference of 3.1% was found for drag, 6.5% for lift, and 6.0% for overturning. A significant improvement was obtained by using this new formulation with respect to a non-modified k–ɛ turbulence model. The average differences of the aerodynamic coefficients were 6.6% for drag, 12.4% for lift, and 10.1% for overturning. The velocity, turbulent kinetic energy, and pressure fields at different elevation angles were analyzed. It was found that at an elevation of 60 deg, the stagnation point of the flow occurs at the superior edge of the heliostat, causing the maximum lift force over the structure.
Effect on Wear Performance of ZrO2 Amount of 316L Stainless Steel Matrix Composites Produced by a Mechanical Alloying Method
Authors: Simsek Dogan
Published: May 2022

This study investigated the wear performances of ZrO2 reinforced 316L stainless steel matrix composite materials. The 316L matrix was mechanically alloyed by adding three different amounts (1 wt%, 2 wt%, and 3 wt%) of ZrO2 for 60 min. Mechanically alloyed powders were shaped through a uniaxial hydraulic press under 800 MPa pressure, and thus, green compacts in Ø12 × 6 mm dimensions were produced. The green compacts produced were sintered at 1300 °C in a vacuum environment of 10−6 mbar for 2 h. Sintered composites were characterized by hardness and density measurements and microstructure studies. The wear tests were carried out under ASTM G99-05 standards through a pin-on-disc wear test device, exerting three different loads (10 N, 20 N, and 30 N) and using four different sliding distances (500 m, 1000 m, 1500 m, and 2000 m). As a result of the studies, it was observed that the reinforcement material (ZrO2), added to the matrix, was positioned at the grain boundaries. As the amount of reinforcement within the matrix increased, the hardness of the composites increased while their densities decreased. In the wear test results, on the other hand, the increase in the amount of reinforcement decreased the weight loss. As for the wear surfaces, the abrasive wear mechanism was dominant.
High-Temperature Wear Behavior of CoCr Matrix Coatings Reinforced by Niobium Element From Room Temperature to 1000 °C
Authors: Cui Gongjun , Li Fangzhou , Bian Canxing , Gao Guijun , Kou Ziming
Published: May 2022

The high-temperature wear resistant CoCr matrix coatings reinforced by the Nb element were fabricated on the Inconel 718 alloy by using the hot-pressed sintered method. The effects of Nb on the microstructure, hardness, and high-temperature tribological performance of coatings are also investigated in detail, and Nb content was further optimized. The tribological properties were investigated by using a ball-on-disk tribo-tester at 23 °C (room temperature), 200 °C, 400 °C, 600 °C, 800 °C, and 1000 °C. The results showed that the Nb element showed the solution strengthening effect and particle strengthening effect. The Nb greatly affected the tribological performance of the coatings. With the increase of Nb content, the wear-rate and friction coefficient initially decreased and then increased. There was a critical value of Nb content for the high-temperature wear behavior of coatings. The coating with 5.0 wt% Nb kept the best tribological properties compared with other specimens, and the wear resistance was 1.4–29 times as high as that of the substrate. It was attributed to the high hardness, high load-bearing capacity of the Nb-rich phases, and oxide lubricating film on the worn surfaces. The corresponding wear mechanism was discussed.
Numerical Analysis of Transient Wheel-Rail Rolling/Slipping Contact Behaviors
Authors: Deng Xiangyun , Ni Yi-Qing , Liu Xiubo
Published: May 2022

Wheel slips often produce wheel/rail damage, threatening the operation safety, and increasing the maintenance cost of contact-type railways. To understand the characteristics of wheel slips for further development of more accurate slip protection methods, this study employs a validated explicit finite element (FE) method to evaluate the transient wheel-rail rolling/slipping contact behaviors. The contact during the traction of the wheel from both standstill status and moving status is focused. Friction and traction coefficients are the two most crucial factors affecting the wheel slips. Conditions of partial and full slips within the contact patch are determined by setting different combinations of the traction and friction coefficients. The contact behaviors including stick-slip, partial slip, full slip, surface stress, and wear are studied. It is revealed that wheel slips may occur not only in the case where the traction coefficient exceeds the limiting value, but also when being slightly smaller. As a consequence, wheel slips can produce much larger wear-rate. This study provides an insight into the wheel slipping/spinning mechanism and theoretical guidance for the development of more accurate control methods of wheel slips.
Electrical properties of p-type Zn:Ga2O3 thin films
Authors: Chikoidze Ekaterine , Sartel Corinne , Yamano Hayate , Chi Zeyu , Bouchez Guillaume , Jomard François , Sallet Vincent , Guillot Gérard , Boukheddaden Kamel , Pérez-Tomás Amador , Tchelidze Tamar , Dumont Yves
Published: May 2022

Ultra-wide bandgap gallium oxide (∼5 eV) has emerged as a novel semiconductor platform for extending the current limits of power electronics and deep ultraviolet optoelectronics at a predicted fraction of cost. Finding effective acceptor dopant for gallium oxide is a hot issue. One element that quite often is considered as a potential candidate is zinc. A number of experimental works have reported the signature of Zn-acceptor, but the direct evidence of hole conductivity was missing. In this work, p-type Zn-doped Ga2O3 thin films were grown by the metal-organic chemical vapour deposition technique on sapphire substrates. By high-temperature Hall effect measurements, Zn related acceptor level ionization energy as 0.77 eV above the valence band maximum was determined. Additionally, we have carried out the simulation study regarding the application of the Zn:Ga2O3 semi-insulating material, to be used as a guard ring for improving the high voltage performance of the Schottky diode structure.
Characterizing Lumbar Spine Kinematics and Kinetics During Simulated Low-Speed Rear Impact Collisions
Authors: Fewster Kayla M. , Zehr Jackie D. , Gooyers Chad E. , Parkinson Robert J. , Callaghan Jack P.
Published: May 2022

Background: Recent work has demonstrated that low back pain is a common complaint following low-speed collisions. Despite frequent pain reporting, no studies involving human volunteers have been completed to examine the exposures in the lumbar spine during low-speed rear impact collisions. Methods: Twenty-four participants were recruited and a custom-built crash sled simulated rear impact collisions, with a change in velocity of 8 km/h. Randomized collisions were completed with and without lumbar support. Inverse dynamics analyses were conducted, and outputs were used to generate estimates of peak L4/L5 joint compression and shear. Results: Average (SD) peak L4/L5 compression and shear reaction forces were not significantly different without lumbar support (compression = 498.22 N [178.0 N]; shear = 302.2 N [98.5 N]) compared to with lumbar support (compression = 484.5 N [151.1 N]; shear = 291.3 N [176.8 N]). Lumbar flexion angle at the time of peak shear was 36° (12°) without and 33° (11°) with lumbar support. Conclusion: Overall, the estimated reaction forces were 14% and 30% of existing National Institute of Occupational Safety and Health occupational exposure limits for compression and shear during repeated lifting, respectively. Findings also demonstrate that, during a laboratory collision simulation, lumbar support does not significantly influence the total estimated L4/L5 joint reaction force.
Total Testosterone and Cortisol During Wheelchair Rugby Training in Athletes With Cervical Spinal Cord Injury
Authors: Stieler Eduardo , Costa Varley Teoldo da , Cruz Aline Ângela Silva , Rosa João Paulo Pereira , Lôbo Ingrid LudImilla Bastos , Romão Julia , Esteves Andrea Maculano , de Mello Marco Tulio , Silva Andressa
Published: May 2022

Context: Hormonal assessment in the sport context is important to monitor the physiological adaptations of athletes. However, Paralympic athletes, especially with cervical spinal cord injury (CSCI), may have different hormonal responses than nondisabled athletes. Therefore, the aim of this study was to evaluate the blood concentrations of total testosterone (TT) and cortisol (C) during acute (one training session) and chronic (1 and 2 month) training of athletes with CSCI in wheelchair rugby (WCR). Design: Longitudinal and observational study. Methods: Eight high-performance athletes with CSCI (31 [3.9] y; 75.6 [15.8] kg; 22.9 [4.2] kg/m2 body mass index; 6.2 [2] y of experience in sport) were evaluated at 3 different intervals (evaluations 1, 2, and 3 [E1, E2, and E3]) over 2 months of training. TT and C blood were evaluated before (pre) and after (post) the training sessions at each training moment, as well as the training load through the ratings of perceived exertion. Results: Athletes with CSCI had low TT concentrations. In acute training sessions, at E3, C decreases after the training session, unlike the TT/C ratio, which increased after the session. Regarding hormonal changes during chronic training at the end of the training period, unlike C, which increased. The training load (arbitrary units) decreased in E3 when compared with the other evaluation moments. Conclusion: It was concluded that in chronic training, TT concentrations decreased, while C increased at the end of the 2 months of training. These results may indicate that training volume was high throughout training and that a reduction in training volume could benefit athletes. On the other hand, in the acute training session with reduced training load, a decrease in C was observed after the training session. This indicates that athletes may be well recovered in this training session. Therefore, we suggest acute and long-term hormonal assessment for athletes with CSCI as a strategy to monitor anabolic/catabolic hormonal status during WCR training.
Characterization of the SARS-CoV-2 B.1.621 (Mu) variant
Authors: Halfmann Peter J. , Kuroda Makoto , Armbrust Tammy , Theiler James , Balaram Ariane , Moreno Gage K. , Accola Molly A. , Iwatsuki-Horimoto Kiyoko , Valdez Riccardo , Stoneman Emily , Braun Katarina , Yamayoshi Seiya , Somsen Elizabeth , Baczenas John J. , Mitamura Keiko , Hagihara Masao , Adachi Eisuke , Koga Michiko , McLaughlin Matthew , Rehrauer William , Imai Masaki , Yamamoto Shinya , Tsutsumi Takeya , Saito Makoto , Friedrich Thomas C. , O’Connor Shelby L. , O’Connor David H. , Gordon Aubree , Korber Bette , Kawaoka Yoshihiro
Published: May 2022

The SARS-CoV-2 B.1.621 (Mu) variant emerged in January 2021 and was categorized as a variant of interest by the World Health Organization in August 2021. This designation prompted us to study the sensitivity of this variant to antibody neutralization. In a live virus neutralization assay with serum samples from individuals vaccinated with the Pfizer/BioNTech or Moderna mRNA vaccines, we measured neutralization antibody titers against B.1.621, an early isolate (spike 614D), and a variant of concern (B.1.351, Beta variant). We observed reduced neutralizing antibody titers against the B.1.621 variant (3.4- to 7-fold reduction, depending on the serum sample and time after the second vaccination) compared to the early isolate and a similar reduction when compared to B.1.351. Likewise, convalescent serum from hamsters previously infected with an early isolate neutralized B.1.621 to a lower degree. Despite this antibody titer reduction, hamsters could not be efficiently rechallenged with the B.1.621 variant, suggesting that the immune response to the first infection is adequate to provide protection against a subsequent infection with the B.1.621 variant.
Transcytosis of IgA Attenuates Salmonella Invasion in Human Enteroids and Intestinal Organoids
Authors: Costello Cait M. , Willsey Graham G. , Richards Angelene F. , Kim Jaeyoon , Pizzuto Matteo S. , Jaconi Stefano , Benigni Fabio , Corti Davide , Mantis Nicholas J. , March John C.
Published: May 2022

Secretory IgA (SIgA) is the most abundant antibody type in intestinal secretions where it contributes to safeguarding the epithelium from invasive pathogens like the Gram-negative bacterium,
Salmonella enterica
serovar Typhimurium (STm). For example, we recently reported that passive oral administration of the recombinant monoclonal SIgA antibody, Sal4, to mice promotes STm agglutination in the intestinal lumen and restricts bacterial invasion of Peyer’s patch tissues.
Prevalence and Characterization of the Cefazolin Inoculum Effect in North American Methicillin-Susceptible Staphylococcus aureus Isolates
Authors: Dingle Tanis C. , Gamage Dulini , Gomez-Villegas Sara , Hanson Blake M. , Reyes Jinnethe , Abbott April , Burnham Carey-Ann D. , Dien Bard Jennifer , Fritz Stephanie , Miller William R. , Westblade Lars F. , Zimmer Barbara , Arias Cesar A. , Butler-Wu Susan
Published: May 2022

Antistaphylococcal penicillins and cefazolin remain the primary treatments for infections with methicillin-susceptible
Staphylococcus aureus
(MSSA). The cefazolin inoculum effect (CzIE) causes the cefazolin MIC to be elevated in proportion to the number of bacteria in the inoculum.
Prophylactic Delivery of a Bacteriophage Cocktail in Feed Significantly Reduces Salmonella Colonization in Pigs
Authors: Thanki Anisha M. , Mignard Guillaume , Atterbury Robert J. , Barrow Paul , Millard Andrew D. , Clokie Martha R. J.
Published: May 2022

Infections caused by
Salmonella
spp. cause 93.8 million cases of human food poisoning worldwide, each year of which 11.7% are due to consumption of contaminated pork products. An increasing number of swine infections are caused by multidrug-resistant (MDR)
Salmonella
strains, many of which have entered, and continue to enter the human food chain.
Genomic Degeneration and Reduction in the Fish Pathogen
Mycobacterium shottsii
Authors: Gauthier D. T. , Doss J. H. , LaGatta M. , Gupta T. , Karls R. K. , Quinn F. D.
Published: May 2022

Morone saxatilis
(striped bass) is an ecologically and economically important finfish species on the United States east coast.
Mycobacterium shottsii
and
Mycobacterium pseudoshottsii
were originally described in the early 2000s as novel species from outbreaks of visceral and dermal mycobacteriosis in this species. Biochemical and genetic characterization place these species within the
Mycobacterium ulcerans
/
M. marinum
clade (MuMC), and
M. pseudoshottsii
has been proposed as an ecovar of
M. ulcerans
.
Increased Abundance of Achromobacter xylosoxidans and Bacillus cereus in Upper Airway Transcriptionally Active Microbiome of COVID-19 Mortality Patients Indicates Role of Co-Infections in Disease Severity and Outcome
Authors: Devi Priti , Maurya Ranjeet , Mehta Priyanka , Shamim Uzma , Yadav Aanchal , Chattopadhyay Partha , Kanakan Akshay , Khare Kriti , Vasudevan Janani Srinivasa , Sahni Shweta , Mishra Pallavi , Tyagi Akansha , Jha Sujeet , Budhiraja Sandeep , Tarai Bansidhar , Pandey Rajesh
Published: May 2022

COVID-19 is invariably a disease of diverse clinical manifestation, with multiple facets involved in modulating the progression and outcome. In this regard, we investigated the role of transcriptionally active microbial co-infections as possible modulators of disease pathology in hospital admitted SARS-CoV-2 infected patients.
The Emergence of a Multidrug-Resistant and Pathogenic ST42 Lineage of Staphylococcus haemolyticus from a Hospital in China
Authors: Qin Mingyang , Chen Ping , Deng Baoguo , He Ruowen , Wu Yiping , Yang Yanxian , Deng Wenbin , Ding Xin , Yang Fan , Xie Chuanbo , Yang Yongqiang , Tian Guo-Bao
Published: May 2022

S. haemolyticus
is an emerging opportunistic pathogen with a high burden of antimicrobial resistance. We performed molecular epidemiological analysis of
S. haemolyticus
that was isolated from a hospital, and found that the phylogenetic lineages are diverse accompanied by a dominant epidemic clonal lineage ST42.
Development of Resistance to Clarithromycin and Amoxicillin-Clavulanic Acid in
Lactiplantibacillus plantarum In Vitro
Is Followed by Genomic Rearrangements and Evolution of Virulence
Authors: Kostenko V. V. , Mouzykantov A. A. , Baranova N. B. , Boulygina E. A. , Markelova M. I. , Khusnutdinova D. R. , Trushin M. V. , Chernova O. A. , Chernov V. M.
Published: May 2022

Ensuring the safety of the use of probiotics is a top priority. We found that increased resistance to popular antimicrobial drugs in
Lactiplantibacillus plantarum
is accompanied by significant changes in the genomic profile and phenotypic sensitivity to a number of antimicrobial drugs as well as in the level of virulence of this bacterium against
Drosophila
.
Supplemental Material: Mercury isotopic composition of igneous rocks from an accretionary orogen: Implications for lithospheric recycling
Authors: Deng Changzhou , Yin Runsheng , al. et
Published: May 2022

Samples and methods, and analytical results for igneous rocks in northeast China. 
Supplemental Material: The role of flat slab subduction, ridge subduction, and tectonic inheritance in Andean deformation
Authors: Horton Brian K. , al. et
Published: May 2022

Methods and structural and topographic data for regional profiles. 
Supplemental Material: Deep-focus earthquakes: From high-temperature experiments to cold slabs
Authors: Gasc Julien , al. et
Published: May 2022

Additional information on methods and data processing, Table S1 (experimental conditions), and supplemental figures of the starting material microstructures and of samples from experiments BR1F and TF2F. 
Classification of tic disorders based on functional MRI by machine learning: a study protocol
Authors: Wang Fang , Wen Fang , Liu Jingran , Yan Junjuan , Yu Liping , Li Ying , Cui Yonghua
Published: May 2022

Introduction

Tic disorder (TD) is a common neurodevelopmental disorder in children, and it can be categorised into three subtypes: provisional tic disorder (PTD), chronic motor or vocal TD (CMT or CVT), and Tourette syndrome (TS). An early diagnostic classification among these subtypes is not possible based on a new-onset tic symptom. Machine learning tools have been widely used for early diagnostic classification based on functional MRI (fMRI). However, few machine learning models have been built for the diagnostic classification of patients with TD. Therefore, in the present study, we will provide a study protocol that uses the machine learning model to make early classifications of the three different types of TD.

Methods and analysis

We planned to recruit 200 children aged 6–9 years with new-onset tic symptoms and 100 age-matched and sex-matched healthy controls under resting-state MRI scanning. Based on the neuroimaging data of resting-state fMRI, the support vector machine (SVM) model will be built. We planned to construct an SVM model based on functional connectivity for the early diagnosis classification of TD subtypes (including PTD, CMT/CVT, TS).

Ethics and dissemination

This study was approved by the ethics committee of Beijing Children’s Hospital. The trial results will be submitted to peer-reviewed journals for publication.

Trial registration number

ChiCTR2000033257.
A Phase II trial of Higher RadiOtherapy Dose In The Eradication of early rectal cancer (APHRODITE): protocol for a multicentre, open-label randomised controlled trial
Authors: Hudson Eleanor M , Noutch Samantha , Brown Sarah , Adapala Ravi , Bach Simon P , Burnett Carole , Burrage Alwyn , Gilbert Alexandra , Hawkins Maria , Howard Debra , Jefford Monica , Kochhar Rohit , Saunders Mark , Seligmann Jenny , Smith Alexandra , Teo Mark , Webb Edward JD , Webster Amanda , West Nicholas , Sebag-Montefiore David , Gollins Simon , Appelt Ane L
Published: May 2022

Introduction

The standard of care for patients with localised rectal cancer is radical surgery, often combined with preoperative neoadjuvant (chemo)radiotherapy. While oncologically effective, this treatment strategy is associated with operative mortality risks, significant morbidity and stoma formation. An alternative approach is chemoradiotherapy to try to achieve a sustained clinical complete response (cCR). This non-surgical management can be attractive, particularly for patients at high risk of surgical complications. Modern radiotherapy techniques allow increased treatment conformality, enabling increased radiation dose to the tumour while reducing dose to normal tissue. The objective of this trial is to assess if radiotherapy dose escalation increases the cCR rate, with acceptable toxicity, for treatment of patients with early rectal cancer unsuitable for radical surgery.

Methods and analysis

APHRODITE (A Phase II trial of Higher RadiOtherapy Dose In The Eradication of early rectal cancer) is a multicentre, open-label randomised controlled phase II trial aiming to recruit 104 participants from 10 to 12 UK sites. Participants will be allocated with a 2:1 ratio of intervention:control. The intervention is escalated dose radiotherapy (62 Gy to primary tumour, 50.4 Gy to surrounding mesorectum in 28 fractions) using simultaneous integrated boost. The control arm will receive 50.4 Gy to the primary tumour and surrounding mesorectum. Both arms will use intensity-modulated radiotherapy and daily image guidance, combined with concurrent chemotherapy (capecitabine, 5-fluorouracil/leucovorin or omitted). The primary endpoint is the proportion of participants with cCR at 6 months after start of treatment. Secondary outcomes include early and late toxicities, time to stoma formation, overall survival and patient-reported outcomes (European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaires QLQ-C30 and QLQ-CR29, low anterior resection syndrome (LARS) questionnaire).

Ethics and dissemination

The trial obtained ethical approval from North West Greater Manchester East Research Ethics Committee (reference number 19/NW/0565) and is funded by Yorkshire Cancer Research. The final trial results will be published in peer-reviewed journals and adhere to International Committee of Medical Journal Editors guidelines.

Trial registration number

ISRCTN16158514.
Randomised controlled trials on prevention, diagnosis and treatment of diabetes in African countries: a systematic review
Authors: Sandholzer-Yilmaz Angelika Sabine , Kroeber Eric Sven , Ayele Wondimu , Frese T , Kantelhardt Eva Johanna , Unverzagt Susanne
Published: May 2022

Objectives

The epidemiological transition from infectious to chronic diseases leads to novel challenges in African health systems. The prevalence of diabetes mellitus (DM) is increasing dramatically. Undiagnosed and undertreated DM leads to numerous complications including end-organ damage and death. Our objectives were to collect the best locally generated evidence on DM interventions, identify knowledge gaps and determine underexplored research areas.

Design

A systematic review and meta-analysis of randomised controlled trials.

Participants and setting

African patients in primary, secondary and tertiary prevention, diagnosis and treatment DM type 1 (DM1), type 2 (DM2) and gestational DM (GDM).

Outcome

All-cause mortality, glycaemic control, complications, quality of life, hospital admission, treatment adherence and costs.

Data sources

Articles published in MEDLINE Ovid, CENTRAL, CINAHL, African Journals Online and African Index Medicus and the International Clinical Trials Registry Platform in English language without time restrictions. The systematic search was last updated in October 2020.

Results

Out of 3736 identified publications, we included 60 eligible studies conducted in 15 countries, 75% were conducted in urban healthcare settings, including 10 112 participants. We included 8 studies on DM1, 6 on GDM, 2 on pre-DM, 37 on mainly DM2 including 7 on DM-related complications. The design of the studied intervention was heterogeneous with a focus on educational strategies. The other studies investigated the efficacy of nutritional strategies including food supplementations, pharmacological strategies and strategies to enhance physical activity. Seven studies included interventions on DM-related complications.

Conclusions

Research activities increased in recent years, but available evidence is still not representative for all African countries. There is a big lack of evidence in primary healthcare and rural settings, implementation research, pharmacological interventions, especially in poorer countries. Nevertheless, the identified studies offer a variety of effective interventions that can inform medical care and future research.

PROSPERO registration number

CRD42019122785.
Long-term quality of integrated community case management care for children in Bugoye Subcounty, Uganda: a retrospective observational study
Authors: Miller James S , Mulogo Edgar Mugema , Wesuta Andrew Christopher , Mumbere Nobert , Mbaju Jackson , Matte Michael , Ntaro Moses , Guiles Daniel A , Patel Palka R , Bwambale Shem , Kenney Jessica , Reyes Raquel , Stone Geren S
Published: May 2022

Objective

Integrated community case management (iCCM) of childhood illness in Uganda involves protocol-based care of malaria, pneumonia and diarrhoea for children under 5 years old. This study assessed volunteer village health workers’ (VHW) ability to provide correct iCCM care according to the national protocol and change in their performance over time since initial training.

Setting

VHWs affiliated with the Ugandan national programme provide community-based care in eight villages in Bugoye Subcounty, a rural area in Kasese District. The first cohort of VHWs began providing iCCM care in March 2013, the second cohort in July 2016.

Participants

All children receiving iCCM care in 18 430 clinical encounters occurring between April 2014 and December 2018.

Primary and secondary outcome measures

The descriptive primary outcome measure was the proportion of patients receiving overall correct care, defined as adherence to the iCCM protocol for the presenting condition (hereafter quality of care). The analytic primary outcome was change in the odds of receiving correct care over time, assessed using logistic regression models with generalised estimating equations. Secondary outcome measures included a set of binary measures of adherence to specific elements of the iCCM protocol. Preplanned and final measures were the same.

Results

Overall, VHWs provided correct care in 74% of clinical encounters. For the first cohort of VHWs, regression modelling demonstrated a modest increase in quality of care until approximately 3 years after their initial iCCM training (OR 1.022 per month elapsed, 95% CI 1.005 to 1.038), followed by a modest decrease thereafter (OR 0.978 per month, 95% CI 0.970 to 0.986). For the second cohort, quality of care was essentially constant over time (OR 1.007 per month, 95% CI 0.989 to 1.025).

Conclusion

Quality of care was relatively constant over time, though the trend towards decreasing quality of care after 3 years of providing iCCM care requires further monitoring.
Treatment outcomes of blastocysts thaw cycles, comparing the presence and absence of a corpus luteum: a systematic review and meta-analysis
Authors: Gan Joscelyn , Rozen Genia , Polyakov Alex
Published: May 2022

Purpose

This study aims to review the literature and perform a meta-analysis to determine if the presence of a corpus luteum has an impact on treatment outcomes in thaw cycles, where blastocyst embryos are transferred.

Method

PUBMED, EMBASE, CENTRAL and CINAHL were searched for papers published between January 2017 and 27 July 2020. Additional articles were selected from the reference list of the results and previous reviews. Three reviewers independently reviewed and extracted data. The meta-analysis was conducted though RevMan V.5.4.1. Studies were quality assessed with the Cochrane risk of bias tool and the Newcastle-Ottawa Scale.

Results

Nine publications were included for data extraction and subsequent meta-analysis. Two studies were randomised controlled trials, and seven were cohort studies. Subgroup analysis of the different study designs was performed. While the rates of positive human chorionic gonadotropin results (relative risk, RR 1.0, 95% CI 0.95 to 1.05) and clinical pregnancies (RR 1.06, 95% CI 0.96 to 1.18) were comparable between the two groups, the rates of live births were higher in thaw cycles with a corpus luteum (RR 1.14, 95% CI 1.06 to 1.22). Analysis of pregnancy losses demonstrated that both biochemical pregnancy (early miscarriage) (RR 0.71, 95% CI 0.62 to 0.82) and miscarriages (RR 0.72, 95% CI 0.62 to 0.83) were increased in cycles without a corpus luteum.

Conclusion

Where clinically appropriate, the use of cycle types that have a functional corpus luteum should be favoured. There were several limitations to this study, including the quality of studies and the inherent bias of retrospective cohort studies. Further, high-quality research, particularly randomised controlled trials with blastocysts embryos, is required to further explore these findings.

PROSPERO registration number

CRD42020209583.
Does scoring patient complexity using COMPRI predict the length of hospital stay? A multicentre case–control study in Japan
Authors: Yokokawa Daiki , Shikino Kiyoshi , Kishi Yasuhiro , Ban Toshiaki , Miyahara Shigeyoshi , Ohira Yoshiyuki , Yanagita Yasutaka , Yamauchi Yosuke , Hayashi Yasushi , Ishizuka Kosuke , Hirose Yuta , Tsukamoto Tomoko , Noda Kazutaka , Uehara Takanori , Ikusaka Masatomi
Published: May 2022

Objective

To clarify the factors associated with prolonged hospital stays, focusing on the COMplexity PRediction Instrument (COMPRI) score’s accuracy in predicting the length of stay of newly hospitalised patients in general internal medicine wards.

Design

A case–control study.

Setting

Three general internal medicine wards in Chiba Prefecture, Japan.

Participants

Thirty-four newly hospitalised patients were recruited between November 2017 and December 2019, with a final analytic sample of 33 patients. We included hospitals in different cities with general medicine outpatient and ward facilities, who agreed to participate. We excluded any patients who were re-hospitalised within 2 weeks of a prior discharge.

Primary and secondary outcome measures

Patients’ COMPRI scores and their consequent lengths of hospital stay.

Results

The 17 patients (52%) allocated to the long-term hospitalisation group (those hospitalised ≥14 days) had a significantly higher average age, COMPRI score and percentage of participants with comorbid chronic illnesses than the short-term hospitalisation group (<14 days). A logistic regression model (model A, comprising only the COMPRI score as the explanatory variable) and a multiple logistic regression model (model B, comprising variables other than the COMPRI score as explanatory variables) were created as prediction models for the long-term hospitalisation group. When age ≥75 years, a COMPRI score ≥6 and a physician with 10 years’ experience were set as explanatory variables, model A showed better predictive accuracy compared with model B (fivefold cross-validation, area under curve of 0.87 vs 0.78). The OR of a patient with a COMPRI score of ≥6 joining the long-term hospitalisation group was 4.25 (95% CI=1.43 to 12.63).

Conclusions

Clinicians can use the COMPRI score when screening for complexity assessment to identify hospitalised patients at high risk of prolonged hospitalisation. Providing such patients with multifaceted and intensive care may shorten hospital stays.
Ventilatory weaning strategies for predicting extubation success in children following cardiac surgery for congenital heart disease: a protocol for a systematic review and meta-analysis
Authors: Garcia Amanda Alves Assis , Vieira Alexia Gabriela da Silva , Kuramoto Danielle Akemi Bergara , Leite Ilana Gomes , Freitas Thais Rodrigues de , Reicher Marcello Erich , Trevisani Virginia Fernandes Moca , Guedes Neto Henrique Jorge , Flumignan Ronald Luiz Gomes , Amorim Jorge Eduardo de , Nakano Luis Carlos Uta
Published: May 2022

Introduction

Congenital heart disease (CHD) comprises the anatomic malformations that jeopardise the structure and function of the heart. It can be extremely complex and serious, corresponding to 30% of all deaths in the first month of life. The surgical approach for adequate treatment requires postoperative mechanical ventilation. The most critical decision related to the postoperative management of patients submitted to cardiac surgery is the right time for extubation, especially because not only abrupt or inadequate discontinuation of ventilatory support can lead to clinical decline and necessity of reintubation but also extended time of mechanical ventilation, which can lead to complications, such as pneumonia, atelectasis, diaphragm hypertrophy, and increasing morbidity and mortality.

Methods and analysis

This systematic review plans to include individual parallel, cross-over and cluster randomised controlled trials regarding any breathing trial test to predict extubation success in children submitted to cardiac surgery due to CHD. Studies with paediatric patients submitted to cardiac surgery for congenital cardiopathy repair, attended at a critical care unit, and under mechanical ventilatory support will be included. The main outcomes analysed will be success of extubation, reduction of pulmonary complications and time reduction of mechanical ventilation.

Ethics and dissemination

We will not treat patients directly; therefore, ethics committee approval was not necessary because it is not a primary study. We expect that this study may improve healthcare and medical assistance, helping healthcare professionals with routine daily decisions regarding the correct time for extubation.

PROSPERO registration number

CRD42021223999.
Identifying and addressing conflicting results across multiple discordant systematic reviews on the same question: protocol for a replication study of the Jadad algorithm
Authors: Lunny Carole , Thirugnanasampanthar Sai Surabi , Kanji Salmaan , Ferri Nicola , Thabet Pierre , Pieper Dawid , Tasnim Sara , Nelson Harrison , Reid Emma , Zhang Jia He (Janet) , Kalkat Banveer , Chi Yuan , Thompson Jacqueline , Abdoulrezzak Reema , Zheng Di Wen (Wendy) , Pangka Lindy , Wang Dian (Xin Ran) , Safavi Parisa , Sooch Anmol , Kang Kevin , Whitelaw Sera , Tricco Andrea C
Published: May 2022

Introduction

An increasing growth of systematic reviews (SRs) presents notable challenges for decision-makers seeking to answer clinical questions. In 1997, an algorithm was created by Jadad to assess discordance in results across SRs on the same question. Our study aims to (1) replicate assessments done in a sample of studies using the Jadad algorithm to determine if the same SR would have been chosen, (2) evaluate the Jadad algorithm in terms of utility, efficiency and comprehensiveness, and (3) describe how authors address discordance in results across multiple SRs.

Methods and analysis

We will use a database of 1218 overviews (2000–2020) created from a bibliometric study as the basis of our search for studies assessing discordance (called discordant reviews). This bibliometric study searched MEDLINE (Ovid), Epistemonikos and Cochrane Database of Systematic Reviews for overviews. We will include any study using Jadad (1997) or another method to assess discordance. The first 30 studies screened at the full-text stage by two independent reviewers will be included. We will replicate the authors’ Jadad assessments. We will compare our outcomes qualitatively and evaluate the differences between our Jadad assessment of discordance and the authors’ assessment.

Ethics and dissemination

No ethics approval was required as no human subjects were involved. In addition to publishing in an open-access journal, we will disseminate evidence summaries through formal and informal conferences, academic websites, and across social media platforms. This is the first study to comprehensively evaluate and replicate Jadad algorithm assessments of discordance across multiple SRs.
Association of plasma apolipoproteins and levels of inflammation-related factors with different stages of Alzheimer’s disease: a cross-sectional study
Authors: Wang Ting , Wang Xiaoni , Yao Yunxia , Zhao Chunsong , Yang Caixia , Han Ying , Cai Yanning
Published: May 2022

Objective

Blood-based biomarkers for the early diagnosis of Alzheimer’s disease (AD) are a ‘Holy Grail’ of AD research. Growing evidence shows that levels of apolipoproteins and various inflammation-related factors are altered in the peripheral blood of patients with AD. The purpose of this study was to clear and definite whether these biomarkers are differentially expressed at the early stages of AD, and could be a biomarker as an early diagnosis of the disease.

Design

Observation study.

Setting

This study was a part of the Sino Longitudinal Study on Cognitive Decline, an ongoing prospective cohort study (ClinicalTrials.gov identifier:NCT03370744) that centres on Xuanwu Hospital (Beijing, China) in cooperation with an alliance of 94 hospitals from 50 cities across China.

Participants

In the present study, 416 right-handed Chinese Han subjects were recruited through standardised public advertisements from 2014 to 2019.

Outcome measures

Concentrations of plasma apolipoprotein A1, apolipoprotein CIII (ApoCIII), apolipoprotein E (ApoE), A-2-macroglobulin (A2M), complement C3 (C3) and complement factor H (FH) were determined using a commercial multiplex Luminex-based panel in normal controls (NC), subjective cognitive decline (SCD), mild cognitive impairment and AD groups.

Results

For individual analysis, pairwise comparisons showed that: (1) For SCD versus NC, no biomarker showed significant difference; (2) For amnestic mild cognitive impairment (aMCI) versus NC, levels of ApoCIII, ApoE, A2M, C3 and FH increased significantly; and (3) For AD versus NC, amounts of C3 increased. For models differentiating clinical groups, discriminant analysis was performed by including all protein markers, age, sex, genotype and education level in the model. This approach could distinguish between patients with aMCI (area under the curve (AUC): 0.743) and AD (AUC: 0.837) from NC.

Conclusion

Our results suggest that concentrations of certain apolipoproteins and inflammation-related factors are altered at the early stage of AD, and could be useful biomarkers for early diagnosis.

Trial registration number

NCT03370744.
The Capacity Note: a communication facilitator in the sick leave process of patients with common mental disorders – a qualitative study of user perceptions
Authors: Nordling Paula , Jakobsson Annika , Hensing Gunnel
Published: May 2022

Objectives

To describe the development of a communication facilitator, the Capacity Note, for the sick leave process of patients with common mental disorders (CMDs) in primary care, and to explore users’ perceptions of it.

Design

Qualitive study.

Setting

Primary healthcare in Region Västra Götaland, Sweden.

Participants and methods

The Capacity Note was developed inductively based on data from six qualitative studies of work capacity and CMD and was introduced at primary healthcare centres during 2018–2019. Individual semistructured interviews were performed with 13 informants (8 patients, 2 general practitioners and 3 managers) who had used the Capacity Note at least once. Interviews were audiorecorded and transcribed verbatim and inductive manifest qualitative content analysis was used to analyse the data.

Results

The Capacity Note comprised questions about work situation, work capacity limitations and possible work adjustments. Based on the interviews, four categories relating to its role as a facilitator for communication about work and health were identified: content and format, understanding, legitimacy and action, openness and timing, and time and efficiency. The participants considered the Capacity Note relevant and easy to use, and as having the potential to improve communication about and understanding of the patient’s situation. The increased understanding was perceived as contributing to a sense of legitimacy and agency. Achieving these benefits required, according to the participants, openness, an investment of time and using the Capacity Note at the right time in the sick leave process.

Conclusion

The Capacity Note was found to be relevant and as having, under the right conditions, the potential to improve communication and facilitate the sick leave process.
Gender differences in bodyweight change following COVID-19 lockdown measures in the Netherlands: a prospective longitudinal study
Authors: van den Broek Thijs , Fleischmann Maria
Published: May 2022

Background

The current study aimed to prospectively assess bodyweight change following the implementation of lockdown measures to contain the COVID-19 pandemic in the Netherlands and to explore the potentially moderating role of gender in this association.

Design

Using Dutch DNB Household Survey panel data collected between 1993 and 2020, we estimated fixed-effects regression models of bodyweight change. Models were stratified by gender and formal tests of gender differences in coefficient estimates were performed.

Participants

4365 women and 4583 men aged 18–65 were included in the study. The total number of observations was 41 330.

Outcome measures

The outcome of interest was self-reported bodyweight in kilograms. Additional analyses were performed using body mass index (self-reported weight in kilograms divided by self-reported height in metres squared) as the outcome.

Results

The implementation of Dutch lockdown measures in 2020 was associated with bodyweight gain of approximately 800 g in working-age women compared with the 3 prior years. Bodyweight gain in 2020 relative to the prior years was significantly stronger for women than for men (F(4, 8947)=3.9, p<0.01). No evidence of bodyweight gain in working-age men was found.

Conclusion

Results indicate that bodyweight gain following COVID-19 lockdown measures in the Netherlands was more pronounced among women than among men. Although necessary to contain the COVID-19 pandemic, lockdown measures may contribute to a different public health challenge in the rising prevalence of overweight and obesity.