bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of an Integrated Approach for Analysis and Design of Turbocharged Internal Combustion Engine
Authors: Ebel Thiago , Anderson Mark , Pandya Parth , Perchanok Mat , Tiney Nick , Gravante Steve P.
Published: September 2021

When developing a turbocharged internal combustion engine, the choice of turbocharger is usually based on designer experience and existing hardware. However, proper turbocharger design relies on matching the compressor and turbine performance to the engine requirements so that parameters such as boost and back pressure, compressor pressure ratio, and turbine inlet temperatures meet the needs of the engine without exceeding its allowable operating envelope. Therefore, the ultimate measure of a successful turbocharger design is how well it is matched to an engine across various operating conditions. This, in turn, determines whether a new turbocharger is required, or an existing solution can be used.

When existing turbocharger solutions are not viable, the engine designer is at a loss on how to define a new turbocharger that meets the desired performance requirements. A common approach in industry has been to scale the performance of an existing turbocharger (compressor and turbine maps) and take these requirements for Original Equipment Manufacturers to possibly match it with a real machine. However, the assumptions made in a basic scaling process are quite simplistic and generally not satisfactory in this situation. A better approach would be to use a validated meanline model for a compressor and turbine instead, allowing to perform an actual preliminary design of such components. Such approach allows to link the engine performance requirements in a very early stage of te component design project and it guides the designer for the design decisions, such as rotor size, variable geometry nozzles, diameter, or shroud trims and others. Therefore, a feasible solution is more likely with design less iterations.

This paper describes a methodology for an integrated approach to design and analyze a turbocharged internal combustion engine using commercially available state-of-the-art 1D gas dynamics simulation tool linked to two powerful turbomachinery meanline programs. The outputs of this analysis are detailed performance data of the engine and turbocharger at different engine operating conditions.

Two case studies are then presented for a 10-liter diesel truck engine. The first study demonstrates how the programs are used to evaluate an existing engine and reverse engineer an existing turbocharger based only on the available performance maps. Then a second study is done using a similar approach but redesigning a new turbocharger (based on the reverse engineered one) for an increased torque output of the same engine.
Oxy-Fuel Combustor Injector
Authors: Etemad Shahrokh , Baird Benjamin D. , Alavandi Sandeep
Published: September 2021

Oxygen-fuel-diluent mixing is important for oxy-combustion as it impacts emissions, efficiency (oxygen slippage) and pattern factor. In this work, rapid mixing validation testing was conducted. Combustion testing was performed with natural gas and syngas from atmospheric pressure (1 atm.) to high pressure (10 atm.) to demonstrate stable operation. Oxy-natural gas testing demonstrated stable operation and low CO emissions over a wide range of test conditions. Syngas testing showed low CO emissions and a wider operability range with high dilution/low oxygen levels. Complete oxygen burnout was accomplished, indicating no oxygen slippage occurred at stoichiometric conditions and hence improved cycle efficiency.
Improving Fuel Efficiency Using Various Configurations of a Hydrogen Ejector in a Fuel Cell
Authors: Yun Seok-Beom , Kim Youn-Jea
Published: September 2021

Renewable energy such as hydrogen or solar energy is promising due to issues surrounding environmental pollution. In particular, hydrogen only produces water and generates electric energy in a fuel cell when reacting electrochemically with air. A fuel cell consists of many parts such as a cell stack, an ejector, a hydrogen tank, and a regulator, and so on. In this study, the ejector, a device that supplies hydrogen to proton exchange membrane fuel cell (PEMFC), is studied. The ejector recirculates unreacted hydrogen in proton exchange membrane fuel cells by the Venturi effect. Since the ejector is related to energy efficiency, many researchers have conducted research to improve the performance of the ejector. Therefore, it is most desirable that hydrogen recirculation in the ejector is increased. The present research investigates how the configuration of the ejector affects the hydrogen recirculation. A concave configuration of the ejector is considered. This concave having a helical pattern is dependent on a pitch ratio and the number of grooves. The results are compared with numerical analysis data from existing publications using computational fluid dynamics (CFD). The influence of the configuration was analyzed by performing numerical simulations with three-dimensional grid systems. A poly-hex-core mesh type was applied to reduce errors caused by convection and diffusion in the computational domain. Considering the configurations of the ejector, turbulence dissipation rate, static pressure, and tangential velocity inflow were analyzed graphically. Consequently, it was determined that the model displays a 7% increase in recirculation ratio over the reference model.
Multi-Physics Topology Optimization for Thermal-Flow Problems Applied to Additively Manufactured Heat Exchangers
Authors: Tang Tsz Ling Elaine , Xia Songtao , Rop Peter , de Wispelaere Steven , Subramanian Ramesh , Koos Bernd
Published: September 2021

Heat exchangers are often subjected to increasing demands on their efficiency with a reduced volumetric footprint. With the advancement in additive manufacturing technologies, topology optimization can be a viable strategy to derive novel designs to improve product performance. Topology optimization has been vastly investigated in the past few decades for structural designs. In this presentation, a thermo-flow topology optimization workflow was developed for heat exchanger applications which performs a multi-physics analysis (e.g. with coupled flow dynamics and heat transfer). In the thermo-flow topology optimization workflow, thermo-flow solver in STAR-CCM+ was utilized to evaluate thermal and flow performance metrics. Adjoint sensitivity was computed with the adjoint solver based on a defined objective function. The adjoint sensitivity was then used as an input to a method of moving asymptotes (MMA) optimizer to identify new designs. This integrated workflow is demonstrated through the design optimization for application to heat exchangers with single phase fluids in a dual flow arrangement. The multi-physics topology optimization enables objectives of different physics to be evaluated in a single optimization run. The major complicating factor compared to earlier optimization work on the gas turbine components, is the dual flow character of the problem that requires optimization on both sides of the heat exchanger. Future efforts on several individual flows involved in the heat exchange problem, as well as single phase versus two-phase flow phenomena will be discussed.
A Model for Tilting Pad Thrust Bearings Operating With Reduced Flow Rate – Do Benefits Outweigh Risks?
Authors: Koosha Rasool , San Andrés Luis
Published: September 2021

The literature on tilting pad thrust bearings (TPTB) calls for flow reduction as an effective means to reduce drag power losses as well as oil pumping costs. However, the highest level of flow reduction a bearing can undergo while maintaining reliable operation is a key question that demands comprehensive analysis. This paper implements a model into an existing thermoelasto-hydrodynamic (TEHD) computational analysis tool to deliver load performance predictions for TPTBs operating with reduced flow rates. For bearings supplied with either a reduced flow or an over flow conditions, a sound model for the flow and thermal energy mixing in a feed groove determines the temperature of the lubricant entering a thrust pad. Under a reduced flow condition, the analysis reduces the effective arc length of a wetted pad until matching the available flow. Predicted discharge flow temperature rise and pad subsurface temperature rise from the present model match measurements in the archival literature for an eight-pad bearing supplied with 150% to 25% of the nominal flow rate, i.e., the minimum flow that fully lubricates the bearing pads. A supply flow above nominal rate increases the bearing drag power because the lubricant enters a pad at a lower temperature, and yet has little effect on a thrust pad peak temperature rise or its minimum film thickness. A reduced flow below nominal produces areas lubricant starvation zones, and thus the minimum film thickness substantially decreases while the film and pad’s surface temperature rapidly increase to produce significant thermal crowning of the pad surface. Compared to the bearing lubricated with a nominal rate, a starved flow bearing produces a larger axial stiffness and a lesser damping coefficient. A reduction in drag power with less lubricant supplied brings an immediate energy efficiency improvement to bearing operation. However, sustained long-term operation with overly warm pad temperatures could reduce the reliability of the mechanical element and its ultimate failure.
Analysis of Co3O4-SnO2 and Co3O4-Fe2O3 nanosystems by x-ray photoelectron spectroscopy
Authors: Maccato Chiara , Bigiani Lorenzo , Klotzsche Max , Barreca Davide , Gasparotto Alberto
Published: September 2021

In this work, x-ray photoelectron spectroscopy was employed to characterize the surface composition and elemental chemical states of supported Co3O4-SnO2 and Co3O4-Fe2O3 nanocomposites. The present materials were prepared on Si(100) substrates by the chemical vapor deposition of cobalt oxide under O2 + H2O atmospheres, followed by the tailored introduction of SnO2 or Fe2O3 by means of radio frequency-sputtering. Material structural and morphological characterization revealed the formation of nanocomposite heterostructures involving a conformal Co3O4 coverage by SnO2 or Fe2O3 overlayers. Survey spectra as well as detailed scans of C 1s, O 1s, Co 2p, Sn 3d, and Fe 2p regions are presented and critically discussed. The results provide evidence for the formation of pure and oxygen-deficient nanocomposites, and the occurrence of an electronic interplay between the single oxide constituents.
Measurements of open-water arctic ocean noise directionality and transport velocity
Authors: Thode Aaron M. , Norman Robert G. , Conrad Alexander S. , Tenorio-Hallé Ludovic , Blackwell Susanna B. , Kim Katherine H.
Published: September 2021

Measurements from bottom-mounted acoustic vector sensors, deployed seasonally between 2008 and 2014 on the shallow Beaufort Sea shelf along the Alaskan North Slope, are used to estimate the ambient sound pressure power spectral density, acoustic transport velocity of energy, and dominant azimuth between 25 and 450 Hz. Even during ice-free conditions, this region has unusual acoustic features when compared against other U.S. coastal regions. Two distinct regimes exist in the diffuse ambient noise environment: one with high pressure spectral density levels but low directionality, and another with lower spectral density levels but high directionality. The transition between the two states, which is invisible in traditional spectrograms, occurs between 73 and 79 dB re 1 μPa2/Hz at 100 Hz, with the transition region occurring at lower spectral levels at higher frequencies. Across a wide bandwidth, the high-directionality ambient noise consistently arrives from geographical azimuths between 0° and 30° from true north over multiple years and locations, with a seasonal interquartile range of 40° at low frequencies and high transport velocities. The long-term stability of this directional regime, which is believed to arise from the dominance of wind-driven sources along an east–west coastline, makes it an important feature of arctic ambient sound.
Biodynamic Responses to Whole-Body Vibration Training: A Systematic Review
Authors: Nawayseh Naser , AlBaiti Saleh
Published: September 2021

In recent years, whole-body vibration (WBV) training has received an increasing interest in the sports and medical fields. However, there has been inconsistency among several studies regarding the effect of WBV training on the human body, which is partly due to the lack of the existence of guidelines for using WBV training machines. To understand the effect of WBV training on the human body and build the needed regulations, it is essential first to understand the biodynamic responses to vibration which represent how vibration is transmitted to and through the human body. The purpose of this study is to systematically review previous studies that measured biodynamic responses when using WBV training machines to highlight inconsistencies in their results and provide possible reasons for them. An extensive literature search was performed on the SCOPUS database to obtain relevant studies. One hundred and fifty-six potentially relevant studies were obtained but after further screening, 23 papers from 2007 to 2020 met inclusion criteria and were included in the study. The papers were analysed with respect to acceleration, transmissibility, interface force, and apparent mass during different vibration settings, body posture, age, and sex. Results and conflicts among studies were highlighted and possible explanations for the inconsistency were provided.
Epithelial memory of inflammation limits tissue damage while promoting pancreatic tumorigenesis
Authors: Del Poggetto Edoardo , Ho I-Lin , Balestrieri Chiara , Yen Er-Yen , Zhang Shaojun , Citron Francesca , Shah Rutvi , Corti Denise , Diaferia Giuseppe R. , Li Chieh-Yuan , Loponte Sara , Carbone Federica , Hayakawa Yoku , Valenti Giovanni , Jiang Shan , Sapio Luigi , Jiang Hong , Dey Prasenjit , Gao Sisi , Deem Angela K. , Rose-John Stefan , Yao Wantong , Ying Haoqiang , Rhim Andrew D. , Genovese Giannicola , Heffernan Timothy P. , Maitra Anirban , Wang Timothy C. , Wang Linghua , Draetta Giulio F. , Carugo Alessandro , Natoli Gioacchino , Viale Andrea
Published: September 2021

Defining tumor cell immune evasion

Mouse models used to study cancer often lack a full immune system, allowing implantation of human tumors into the mice. By contrast, naturally evolving tumors must contend with a fully functional immune system and its destruction of some of the cells (see the Perspective by Ho and Wood). Two groups now report studies on mouse models with a fully intact immune system. Martin
et al
. started with preexisting murine tumor cell lines and examined their continued evolution in vivo, whereas Del Poggetto
et al
. examined the development of new pancreatic tumors in the context of inflammation, as is often seen in human patients. In each study, the authors found that the immune system exerted a selective pressure on cells that would give rise to tumors, promoting the survival of those that had lost expression of tumor suppressor genes or activated a specific oncogene. The findings suggest a major role for the immune system in driving tumor evolution across multiple types of cancer. —YN
Schools begin mass testing with vexing questions
Authors: Couzin-Frankel Jennifer
Published: September 2021

Scientific uncertainties, access, and logistics are hurdles to routine screening
U.S. judge acquits researcher charged with hiding China ties
Authors: Mervis Jeffrey
Published: September 2021

Decision to free former engineering professor Anming Hu could have implications for other China Initiative cases
Draft Genome Sequence of Paraclostridium bifermentans subsp.
muricolitidis
Strain PAGU 1678
T
, Which Exacerbates Pathosis in a Mouse Model of Ulcerative Colitis
Authors: Kutsuna Ryo , Miyoshi-Akiyama Tohru , Tomida Junko , Kawamura Yoshiaki
Published: September 2021

Paraclostridium bifermentans
subsp.
muricolitidis
strain PAGU 1678
T
was isolated from rat feces and has the ability to exacerbate pathosis in a mouse model of ulcerative colitis. Here, we report the draft genome sequence of the 3,471,060-bp chromosome of strain PAGU 1678
T
.
Complete Genome Sequence of Community-Associated Methicillin-Resistant Staphylococcus aureus Sequence Type 1, SCC
mec
IV[2B], Isolated in the 1990s from Northern Western Australia
Authors: Karakatsanis Nicola M. , Mowlaboccus Shakeel , Colombi Elena , Pearson Julie C. , Ramsay Joshua P. , Coombs Geoffrey W.
Published: September 2021

Sequence type 1 (ST1) methicillin-resistant
Staphylococcus aureus
(MRSA) type IV[2B] has become one of the most common community-associated MRSA clones in Australia. We report the complete genome sequence of one of the earliest isolated Australian
S. aureus
ST1-MRSA-IV strains, WBG8287, isolated from an Indigenous Australian patient living in the remote Kimberley Region of Western Australia.
Supplemental Material: Parent crater for Australasian tektites beneath the sands of the Alashan Desert, Northwest China: Best candidate ever?
Authors: Mizera Jiří , al. et
Published: September 2021

Samples and methods, data for Figures 2 and 3
Patient-centered approach to managing factor XIII deficiency
Authors: Iyengar Varun , Montcrieff Caitlin , Pels Salley
Published: September 2021

Factor XIII (FXIII) is a thrombin-activated protransglutaminase that plays a key role in blood clot formation. Congenital FXIII A-subunit deficiency represents a rare bleeding disorder that affects one in 2–3 million individuals worldwide and is treated with recombinant FXIII (rFXIII). However, due to the rarity of the disease, clinicians are often left to weigh individual variation in FXIII activity and/or symptoms to optimally guide dosing. Cases often become further complicated when patients experience refractory bleeding, which can be difficult to treat. This report describes an approach to rFXIII dosing in two patients who required deviation from standard protocols to maintain therapeutic FXIII troughs. We highlight limitations in our understanding of FXIII deficiency management, while also providing an example of the application of pharmacokinetic data to individualise therapy for improved outcomes. Finally, the case reminds us of the importance of patient-centered, cost-conscious care and multidisplinary teamwork in complex cases.
Canalicular adenoma: palatal presentation of an uncommon lesion
Authors: Nair Priya K , Varma Beena R , Veeraraghavan Ravi , Janardhanan Mahija
Published: September 2021

Canalicular adenoma is a unique, rare, benign salivary gland neoplasm whose reported prevalence varies in different studies. According to literature, this neoplasm has a marked predilection to occur in the upper lip of elderly women. Histological features are usually distinctive and diagnostic. This neoplasm has good prognosis after conservative surgical management but the propensity of multifocal nature and recurrence of this lesion mandates regular follow-up. This case report illustrates the case of a canalicular adenoma in the palate in a 71-year-old male patient. Here, we discuss the differential diagnosis with a brief review of literature.
Fungal central skull-base osteomyelitis: atypical presentation and management issues
Authors: Yadav Sanjeev , Kumar Rajeev , Kumar Rakesh , Sagar Prem
Published: September 2021

Mucormycosis is a very commonly encountered disease in the sinonasal region in patients with diabetes and immunocompromised status specially in the northern part of the Indian continent. Due to its fulminant nature and involvement in the rhino-orbital-cerebral region, prognosis is poor even after extensive debridement and amphotericin-B therapy. We present a case with diagnosis of sarcoidosis being treated with systemic steroids who developed sudden-onset ptosis and left lateral rectus palsy. On radiological evaluation with MRI, a heterogenously peripherally enhancing lesion was seen in the nasopharynx suggestive of nasopharyngeal abscess. The patient was taken up for emergency surgery; a necrotic lesion with destruction of sphenoid bone, pterygoids and clivus was seen originating in the nasopharynx. The lesion on fungal staining came out to be broad aseptate hyphae suggestive of mucormycosis.
Successful management of a pregnant woman with COVID-19 and multiple severe complications
Authors: Aldika Akbar Muhammad Ilham , Gumilar Khanisyah Erza , Tjokroprawiro Brahmana Askandar , Ulhaq Renata Alya
Published: September 2021

We report a case of a 36-year-old gravida 2 para 1 woman at 38 weeks of gestation. A caesarean section was performed for severe pre-eclampsia, intrauterine growth restriction and oligohydramnios. The patient suffered postoperative bleeding, and exploratory laparotomy was performed. Uterine atonia, Couvelaire uterus and left adnexal haematoma were found, requiring a supracervical hysterectomy. As COVID-19 pneumonia and superimposed bacterial infection developed, the patient was mechanically ventilated in the intensive care unit. Remdesivir and meropenem were initially administered, but were changed to levofloxacin and ciprofloxacin following antibiotic sensitivity tests. Blood culture grewEnterococcus galinarum. Meanwhile, bleeding of the incisional wound occurred, which was controlled by the cessation of heparin therapy and regular wound care. With intensive monitoring and multidisciplinary management, the patient’s condition improved, and she was discharged from the hospital on day 25 from admission.
Confabulation, amnesia and motor memory loss as a presentation of apparent ITPR1 antibody autoimmune encephalitis
Authors: Schiff Julia R , Fiorillo Benjamin P , Sadjadi Raha , Henry Tracey L , Gruen Judah K , Gensler Lauren M
Published: September 2021

A 59-year-old woman presented to the hospital with acute, hypoactive altered mental status. Her symptoms had begun 3 days prior when she developed hallucinations, urinary and faecal incontinence, and somnolence. She also exhibited confabulations, amnesia, motor memory loss and a wide-based gait. Medical, psychiatric and neurological evaluations including imaging and laboratory workup were unrevealing. Treatment for possible Wernicke encephalopathy and psychosis with high-dose intravenous thiamine and antipsychotic medications did not lead to improvement. After discharge, a send-out cerebrospinal fluid autoimmune encephalitis panel resulted positive for the newly identified neuronal inositol triphosphate receptor one (ITPR1) antibody. This prompted readmission for intravenous steroids, plasmapheresis and intravenous immunoglobulin, which yielded mild clinical improvement. Here, we describe confabulations and psychiatric symptoms as novel manifestations of the primary presentation of anti-ITPR1 encephalitis in an effort to promote faster recognition of this disease and early initiation of treatment in suspected cases.
Multidisciplinary management of temporomandibular joint ankylosis in an adult: journey from arthroplasty to oral rehabilitation
Authors: Kothari Kamlesh , Jayakumar Naveenkumar , Razzaque Aayesha
Published: September 2021

Ankylosis of the temporomandibular joint is a debilitating condition resulting in progressive trismus and facial disfigurement. Common trigger factors include paediatric mandibular trauma, middle ear infection or traumatic childbirth. Although diminishing in incidence among urban population, it is still prevalent in the underprivileged world. Substandard child safety norms, delayed presentation, lack of access to specialties like maxillofacial surgery in rural areas and absence of follow-up contribute to ankylosis. Afflictions in ankylosis are multipronged, involving aesthetic, functional, psychological and nutritional implications to name a few. The damage this pathology causes to the young mind and their morale is humongous. Although well documented, a complete presentation of cases with follow-up till oral and myofascial rehabilitation is seldom reported. This paper describes multidisciplinary management of a young female patient with temporomandibular joint ankylosis. Staged management commencing from interpositional arthroplasty until dental restoration with a 2-year follow-up is presented in this paper.
Normative data and percentile curves for axial length and axial length/corneal curvature in Chinese children and adolescents aged 4–18 years
Authors: He Xiangui , Sankaridurg Padmaja , Naduvilath Thomas , Wang Jingjing , Xiong Shuyu , Weng Rebecca , Du Linlin , Chen Jun , Zou Haidong , Xu Xun
Published: September 2021

Purpose

To develop age-specific and gender-specific reference percentile charts for axial length (AL) and AL/corneal radius of curvature (AL/CR) and, to use percentiles to determine probability of myopia and estimate refractive error (RE).

Methods

Analysis of AL, cycloplegic RE and CR of 14 127 Chinese participants aged 4–18 years from 3 studies. AL and AL/CR percentiles estimated using Lambda-Mu-Sigma method and compared for agreement using intraclass correlation (ICC). Logistic regression was used to model risk of myopia based on age, gender, AL and AL/CR percentiles. Accuracy of AL progression and RE estimated using percentiles was validated using an independent sample of 5742 eyes of children aged 7–10 years.

Results

Age-specific and gender-specific AL and AL/CR (3rd, 5th, 10th, 25th, 50th, 75th, 90th and 95th) percentiles are presented. Concordance between AL and AL/CR percentiles improved with age (0.13 at 4 years to >0.75 from 13 years) and a year-to-year change was observed for all except <10th percentile from 15 years. Increasing age, AL and AL/CR was associated with a more myopic RE (r2=0.45,0.70 and 0.83, respectively). The sensitivity and specificity of the model to estimate probability of myopia was 86.0% and 84.5%, respectively. Estimation of 1-year change in AL using percentiles correlated highly with actual AL (ICC=0.98). Concordance of estimated to actual RE was high (ICC=0.80) and within ±0.50D and ±1.0D of actual RE for 47.4% and 78.9% of eyes, respectively.

Conclusion

Age-specific and gender-specific AL and AL/CR percentiles provide reference data, aid in identifying and monitoring individuals at risk of myopia and have utility in screening for myopia. AL/CR percentiles were more accurate in estimating probability of myopia in younger children.
Spectral domain optical coherence tomography-based retinochoroidal cystine crystal score: a window into infantile nephropathic cystinosis
Authors: Keidel Leonie , Hohenfellner Katharina , Schworm Benedikt , Priglinger Siegfried , Luft Nikolaus , Priglinger Claudia
Published: September 2021

Précis

Cystinosis is a lysosomal storage disease leading to an accumulation of cystine crystals in several organs. We aim to comprehensively describe chorioretinal cystine crystals via spectral domain optical coherence tomography (SD-OCT) and elaborate a new biomarker for systemic disease control.

Background/aims

Cystinosis is a rare lysosomal storage disease leading to an accumulation of cystine crystals in several organs. This study aims to describe the deposition of retinochoroidal crystals in infantile nephropathic cystinosis and to elucidate their potential value as an objective biomarker for systemic disease control.

Methods

This cross-sectional study was carried out by the University Eye Hospital of the Ludwig-Maximilian University (Munich, Germany) in collaboration with the German Cystinosis Study Group. A complete ophthalmologic examination was performed, along with posterior segment SD-OCT (Spectralis; Heidelberg Engineering GmbH, Heidelberg, Germany). Retinochoroidal crystals were graded by employing a novel semiquantitative grading system—the retinochoroidal cystine crystal score (RCCCS). To quantify quality of vision, patients completed a specific questionnaire. A total of 85 eyes of 43 patients with cystinosis were included (mean age 22.3±8.8 years, range 6–39; male:female ratio=23:20).

Results

Cystine crystals were detectable in all neuroretinal layers and the choroid, most frequently in the choriocapillaris. The RCCCS was negatively correlated with cysteamine intake (r=0.533, p=0.001) and positively with cystatin C, a stable parameter of renal function (r=0.496, p=0.016). Moreover, the value of the RCCCS affected subjective quality of vision. Genetic analysis indicated pronounced crystal deposition in patients with heterozygous mutations containing the 57-kb-deletion allele of theCTNSgene.

Conclusion

Ocular cystinosis leads to retinochoroidal crystal accumulation in every stage of the disease. Crystal deposition may be markedly influenced by oral cysteamine therapy. Therefore, the presented SD-OCT based grading system might serve as an objective biomarker for systemic disease control.
Femoroacetabular impingement syndrome and labral injuries: grading the evidence on diagnosis and non-operative treatment—a statement paper commissioned by the Danish Society of Sports Physical Therapy (DSSF)
Authors: Ishøi Lasse , Nielsen Mathias Fabricius , Krommes Kasper , Husted Rasmus Skov , Hölmich Per , Pedersen Lisbeth Lund , Thorborg Kristian
Published: September 2021

This statement summarises and appraises the evidence on diagnostic tests and clinical information, and non-operative treatment of femoroacetabular impingement (FAI) syndrome and labral injuries. We included studies based on the highest available level of evidence as judged by study design. We evaluated the certainty of evidence using the Grading of Recommendations Assessment Development and Evaluation framework. We found 29 studies reporting 23 clinical tests and 14 different forms of clinical information, respectively. Restricted internal hip rotation in 0° hip flexion with or without pain was best to rule in FAI syndrome (low diagnostic effectiveness; low quality of evidence; interpretation of evidence: may increase post-test probability slightly), whereas no pain in Flexion Adduction Internal Rotation test or no restricted range of motion in Flexion Abduction External Rotation test compared with the unaffected side were best to rule out (very low to high diagnostic effectiveness; very low to moderate quality of evidence; interpretation of evidence: very uncertain, but may reduce post-test probability slightly). No forms of clinical information were found useful for diagnosis. For treatment of FAI syndrome, 14 randomised controlled trials were found. Prescribed physiotherapy, consisting of hip strengthening, hip joint manual therapy techniques, functional activity-specific retraining and education showed a small to medium effect size compared with a combination of passive modalities, stretching and advice (very low to low quality of evidence; interpretation of evidence: very uncertain, but may slightly improve outcomes). Prescribed physiotherapy was, however, inferior to hip arthroscopy (small effect size; moderate quality of evidence; interpretation of evidence: hip arthroscopy probably increases outcome slightly). For both domains, the overall quality of evidence ranged from very low to moderate indicating that future research on diagnosis and treatment may alter the conclusions from this review.
Ross for Valve replacement In AduLts (REVIVAL) pilot trial: rationale and design of a randomised controlled trial
Authors: Whitlock Richard , Belley-Cote Emilie , Rega Filip , Chu Michael W.A. , McClure Graham R , Hronyecz Hanna , Verbrugghe Peter , Devereaux PJ , Bangdiwala Shrikant , Eikelboom John , Brady Katheryn , Sharifulin Ravil , Bogachev-Prokophiev Alexander , Stoica Serban
Published: September 2021

Introduction

In non-elderly adults, aortic valve replacement (AVR) with conventional prostheses yield poor long-term outcomes. Recent publications suggest a benefit of the Ross procedure over conventional AVR and highlight the need for high-quality randomised controlled trial (RCTs) on the optimal AVR. We have initiated a pilot trial assess two feasibility criteria and one assumption: (1) evaluate the capacity to enrol six patients per centre per year in at least five international centre, (2) validate greater than 90% compliance with allocation and (3) to validate the proportion of mechanical (≥65%) vs biological (≤35%) valves in the conventional arm.

Methods and analysis

Ross for Valve replacement In AduLts (REVIVAL) is a multinational, expertise-based RCT in adults aged 18–60 years undergoing AVR, comparing the Ross procedure versus one of the alternative approaches (mechanical vs stented or stentless bioprosthesis). The feasibility objectives will be assessed after randomising 60 patients; we will then make a decision regarding whether to expand the trial with the current protocol. We will ultimately examine the impact of the Ross procedure as compared with conventional AVR in non-elderly adults on survival free of valve-related life-threatening complications (major bleeding, systemic thromboembolism, valve thrombosis and valve reoperation) over the duration of follow-up. The objectives of the pilot trial will be analysed using descriptive statistics. In the full trial, the intention-to-treat principle will guide all primary analyses. A time-to-event analysis will be performed and Kaplan-Meier survival curves with comparison between groups using a log rank test will be presented.

Ethics and dissemination

REVIVAL will answer whether non-elderly adults benefit from the Ross procedure over conventional valve replacement. The final results at major meetings, journals, regional seminars, hospital rounds and via the Reducing Global Perioperative Risk Multimedia Resource Centre.

Trial registration number

ClinicalTrials.gov Identifier:NCT03798782

Protocol version

January 29, 2019 (Final Version 1.0)
Health service utilisation among African migrants in China: a nationwide cross-sectional study
Authors: Xiong Ming Zhou , Zhao Peizhen , Zou Xia , Hall Brian , Cao Honghua , Wang Cheng
Published: September 2021

Objectives

To assess the health utilisation status and associated factors among African migrants in China.

Design

A national cross-sectional study was conducted among African migrants in China in 2019.

Setting

Participants were recruited online and offline to participate in a self-report survey. Online participants were recruited through WeChat across China, and offline participants were recruited in Guangzhou.

Participants

We recruited participants who were from an African country; had spent at least 1 month cumulatively in China; were at least 18 years old; were willing to provide informed consent. A total of 1025 participants were recruited online and offline, 19 of them were excluded due to invalid response and 1006 people were finally included in the analysis.

Outcome measures

The primary outcome was health service utilisation and associated factors among African migrants during their stay in China in the past 12 months. The potential factors include the predisposing factors (demographic characteristics and social structure variables), enabling factors (annual income, health insurance in China) and need factors (non-communicable chronic and infectious diseases, depression) which determined by Anderson framework were measured.

Results

Eight hundred and seven online and 218 offline participants completed the survey, including 624 males and 382 females, with an average age of 26.4±8.9 years. Around 28.5% reported health utilization in the past 12 months. Results showed that longer duration in China, migration to China for business (aOR=2.23, 95% CI:1.13-4.40) and study (aOR=5.00, 95% CI:2.74-9.11), living in apartment (aOR=2.59, 95% CI:1.62-4.14) or dormitory (aOR=3.22, 95% CI:2.17-4.80) in China, suffering from chronic diseases, communicable diseases, and greater depressive symptoms (aOR=1.91, 95% CI:1.42-2.56) facilitated health service utilization.

Conclusions

The healthcare service that African migrants received in China is low. The existing public health policies and intervention measures need to be improved to make health utilisation more accessible and feasible for African migrants.
Relationship between cerebral aneurysms and variations in cerebral basal arterial network: a morphometric cross-sectional study in Computed Tomography Angiograms from a neurointerventional unit
Authors: Burlakoti Arjun , Kumaratilake Jaliya , Taylor Jamie , Henneberg Maciej
Published: September 2021

Objective

Segments of cerebral basal arterial network (CBAN) dampen the peak pressure in blood flowing through these arteries, thus minimising the chances of development of cerebral aneurysms. The objective of this research was to find the relationship of occurrence of intracranial aneurysms to variations of the components of the CBAN.

Design and setting

This is an observational, quantitative and retrospective research, which used cerebral CT angiography (CCTA) images.

Participants

Cerebral CTA of 145 adult patients of both sexes were studied.

Main outcome measures

Diameters of segments of CBAN were measured in CCTA images and the relative size of each vessel was calculated to standardise for differences in overall arterial sizes among patients. Relationships among sizes of CBAN components were analysed. Presence of aneurysms in different parts of the CBAN was recorded.

Results

Forty-six aneurysms in right internal carotid artery (ICA) and middle cerebral artery (MCA) and 32 aneurysms in left ICA and MCA segments were noted in 42 and 30 patients, respectively. Aneurysms in anterior communicating artery complex and vertebral-basilar arterial segments were seen in 27 and 8 patients, respectively, while they were not detected in parts of posterior cerebral artery (PCA). The significant (p<0.001) inverse relationships between sizes of posterior communicating artery and the first segment of PCA on both sides indicated that blood inputs to the second part of PCA were similar. Difference in means of the index of arterial size variation for people with aneurysms (mean 0.96, SD 0.23) and without aneurysms (mean 0.86, SD 0.22) was significant (p=0.015).

Conclusion

Variation in segments of CBAN was quantified. The peak pressure dampening mechanism in such arterial segments reduces the chances of development of aneurysms.
Thyroid diagnostic modalities (fine needle aspiration and core needle biopsy) with histology correlation: a tertiary centre experience
Authors: Appukutty Sona J , Paterson Anna , Patel Nishant S , Duckworth Adam , Chan James , O'Donovan Maria , Marker Alison J
Published: September 2021

Aims

To determine the proportion of thyroid fine needle aspiration (FNA) and core needle biopsy (CNB) cases reported at a single institute into each UK Royal College of Pathologists (RCPath) Thy1-5 and local T category, respectively. Where subsequent histology was available, malignancy rates, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were compared for both procedures.

Methods

1591 FNAs (2010–2018) and 514 CNBs (2013–2018) cases were identified, together with paired histology excision specimens.

Results

The FNA samples were classified as: Thy1: 45.3%, Thy2/Thy2c: 22.1%, Thy3a/Thy3f: 28%, Thy4: 1.6% and Thy5: 3%; while the CNB were classified as: T1: 7.2%, T2: 22.4%, T3 59.3%, T4: 1% and T5: 10.1%. Comparison of FNA and CNB classified as Thy5/T5 showed a 100% risk of malignancy (ROM), sensitivity (98% vs 100%), specificity (14.1% vs 12.1%), PPV (29.4% vs 29.4%), NPV (94.9% vs 100%) and accuracy (36.5% vs 35.6%), respectively, for a diagnosis of malignancy. ROMs for other categories were: Thy1/T1 (9% vs 6.7%), Thy2/T2 (5.1% vs 0%), Thy3/T3 (17.5% vs 18.4%) and Thy4/T4 (73.3% vs 100%).

Conclusions

The proportion of cases in each RCPath Thy category has remained relatively stable during the 9-year study period, with the exception of the Thy3a category, which has increased over time. This finding is in line with other more recent reports in the literature and the proportion of T3 cases in the CNB group. The proportion of Thy2/Thy2c cases has also reduced over time, reflecting a local change in the triaging protocol for probable benign lesions. Both FNA and CNB showed comparable performance in our study.
Leading by virtual interaction: an application of cultural-historical activity theory
Authors: Sjaus Ana , Ritchie Krista Corinne
Published: September 2021

IntroductionThe pandemic spread of SARS-CoV-2, a novel, highly contagious and easily transmissible pathogen, has profoundly affected all aspects of human interaction. Guided by the need to reduce face-to-face contacts, medical organisations have rapidly shifted group activities to virtual platforms. Over 1 year into the pandemic, the necessity to maintain public health restrictions ensures that virtual meetings will be the norm for the foreseeable future.

It has yet to be understood how virtual technologies shape healthcare and academic cultures, affect interactions, or influence strategic decisions and policies within these systems.

ConclusionIn this article, the authors reflect on the move from historically situated activity systems of team leadership in healthcare to ones that now exist in virtual formats. Cultural-historical activity theory (CHAT) is a framework that explains complex human actions, and how they unfold over time through interaction with mediational tools (eg, technology) and various people representing their own communities, roles and perceived divisions of labour. The authors use the lens of CHAT as a framework to understand the shifting dynamics at play and offer strategies for leaders to co-establish activity systems with team members to make goals of group activities explicit and to deliberately work toward them. Five specific strategies proposed are: (1) use software platforms that fit your needs and give voice to all attendees with technical support present in meetings; (2) converse explicitly about roles and emerging role fluidity during times of change and pandemic response; (3) co-construct something new intentionally; (4) engage in implementation science at this time; and (5) lead intentionally while honouring cultural norms and values. It is imperative that any changes, even the ones that are a part of the pandemic response, are made consistent with the core shared values of the medical community as this necessary new way of coming together is embraced with collective wisdom.
Arguments used by proponents and opponents in Brazil’s regulatory discussions of e-cigarettes and heated tobacco products
Authors: Nunes-Rubinstein Mônica , Leão Teresa
Published: September 2021

Objectives

To identify proponents and opponents of the commercialisation and marketing of e-cigarettes and heated tobacco products (HTPs), identify the arguments used on both sides and compare how the arguments have changed over time, we analysed three policy discussions occurring in 2009, 2018 and 2019.

Methods

We conducted a content analysis of one document and six videos from these discussions, provided on the Brazilian Health Regulatory Agency website, or upon request.

Results

The arguments most used by tobacco companies were related to claims that the use of e-cigarettes and HTPs is less harmful than conventional tobacco. Unions that support its commercialisation also argued that lifting the ban would prevent smuggling and guarantee their quality. On the other side, universities, medical and anti-tobacco institutions argued that such devices may have health risks, including the risk of inducing cigarette smoking. In 2009, most arguments belonged to the ‘health’ theme, while in 2018 and 2019 economic arguments and those related to morals and ethics were frequently used.

Conclusions

Those that supported the commercialisation and marketing of e-cigarettes and HTPs first focused on arguments of harm reduction, while 10 years later the right to access and potential economic consequences also became common. Public health agents and academics must gather evidence to effectively respond to these arguments and discuss these policies, and must prepare themselves to use and respond to arguments related to moral and economic themes.
A systematic conservation planning approach to maintaining ecosystem service provision in working landscapes
Authors: Cimon-Morin Jérôme , Goyette Jean-Olivier , Mendes Poliana , Pellerin Stéphanie , Poulin Monique
Published: September 2021

Balancing human well-being with the maintenance of ecosystem services (ES) for future generations has become one of the central sustainability challenges of the 21st century. In working landscapes, past and ongoing production-centered objectives have resulted in the conversion of ecosystems into simple land-use types, which has also altered the provision of most ES. These inevitable trade-offs between the efficient production of individual provisioning ES and the maintenance of regulating and cultural ES call for the development of a land-use strategy based on the multifunctional use of the landscape. Due to the heterogeneous nature of working landscapes, both protection and restoration actions are needed to improve their multifunctionality. Systematic conservation planning (SCP) offers a decision support framework that can support landscape multifunctionality by indicating where ES management efforts should be implemented. We describe an approach that we developed to include ES provision protection and restoration objectives in SCP with the goal of providing ongoing benefits to society. We explain the general framework of this approach and discuss concepts, challenges, innovations, and prospects for the further development of a comprehensive decision support tool. We illustrate our approach with two case studies implemented in the pan-Canadian project ResNet.
AN EFFICIENT APPROACH FOR SOLVING FRACTIONAL VARIABLE ORDER REACTION SUB-DIFFUSION BASED ON HERMITE FORMULA
Authors: ADEL MOHAMED , ELSAID MOHAMED
Published: September 2021

Anomalous Reaction-Sub-diffusion equations play an important role transferred in a lot of our daily applications in our life, especially in applied chemistry. In the presented work, a modified type of these models is considered which is the Reaction-Sub-diffusion equation of variable order, the linear and nonlinear models and we will refer to it by VORSDE. An accurate technique depends on a mix of the finite difference methods (FDM) together with Hermite formula is introduced to study these important types of anomalous equations. Regarding the analysis of the stability for the mentioned, it is done using the variable Von-Neumann technique; also the convergent analysis is introduced. As a result of the previous steps, we derived a stability condition which will be held for many discretization schemes of the variable order derivative and some other parameters and we checked it numerically.
Extended Ideals in MV-Algebras
Authors: Forouzesh F.
Published: September 2021

In this paper, we introduce the notion of extended of an ideal associated to a subset of an [Formula: see text]-algebra [Formula: see text] and investigate the related properties. A characterization of this extended ideal is given. We show that [Formula: see text] is stable ideal relative to [Formula: see text] such that [Formula: see text] if and only if [Formula: see text] is chain [Formula: see text]-algebra. Finally, the class [Formula: see text] of all stable ideals relative to [Formula: see text] is also a complete Heyting algebra, for an [Formula: see text]-algebra [Formula: see text].