bluuebunny/crossref_metadata_2025 huggingface dataset:
Cotrimoxazole-induced hyperkalaemia in a patient with known hypoaldosteronism
Authors: Montebello Annalisa , Gruppetta Mark
Published: March 2021

A70-year-old man, with established hypoadrenalism due to a previous bilateral adrenalectomy, was admitted with recurrent episodes of postural dizziness and presyncope. He had been discharged from hospital 3 weeks earlier on a 1-month course of cotrimoxazole following a diagnosis of prostatitis. His electrolytes on admission showed new onset hyponatraemia and hyperkalaemia.

His usual glucocorticoid replacement dose was doubled in view of a presumed diagnosis of hypocortisolaemia. However, the hyperkalaemia persisted. On rereviewing his treatment, we suspected a possible diagnosis of cotrimoxazole-induced hyperkalaemia. Cotrimoxazole was stopped and ciprofloxacin started instead. His fludrocortisone replacement was doubled for 3 days after stopping treatment to decrease his postural symptoms. His postural symptoms improved, his serum potassium decreased to normal levels and he was safely discharged.

It is essential to remember that cotrimoxazole, a commonly used antibiotic, can induce a potentially fatal hyperkalaemia especially in patients with known hypoadrenalism.
Possible COVID-19 reinfection in a patient with X-linked agammaglobulinaemia
Authors: Loh Sook Yin , Bassett John , Hoodless Emily Jayne , Walshaw Martin
Published: March 2021

This report highlights the case of a patient with X-linked agammaglobulinaemia (XLA) and resultant bronchiectasis who was discharged from hospital after recovering from real-time reverse transcriptase-PCR positive COVID-19 infection having had a subsequent negative swab and resolution of symptoms, but was readmitted 3 weeks later with recrudescent symptoms and a further positive swab. Although there are reports of COVID-19 infection in XLA, for the first time we report a case of possible reinfection. Lessons learnt from this case include the potential for reinfection of COVID-19 in a patient with a weakened immune system and the importance of repeating COVID-19 swabs in inpatients. Extra caution needs to be taken when providing care in groups of patients who have a weakened or absent immune system.
Plasma lipidomics profile in pregnancy and gestational diabetes risk: a prospective study in a multiracial/ethnic cohort
Authors: Rahman Mohammad L , Feng Yen-Chen A , Fiehn Oliver , Albert Paul S , Tsai Michael Y , Zhu Yeyi , Wang Xiaobin , Tekola-Ayele Fasil , Liang Liming , Zhang Cuilin
Published: March 2021

Introduction

Disruption of lipid metabolism is implicated in gestational diabetes (GDM). However, prospective studies on lipidomics and GDM risk in race/ethnically diverse populations are sparse. Here, we aimed to (1) identify lipid networks in early pregnancy to mid-pregnancy that are associated with subsequent GDM risk and (2) examine the associations of lipid networks with glycemic biomarkers to understand the underlying mechanisms.

Research design and methods

This study included 107 GDM cases confirmed using the Carpenter and Coustan criteria and 214 non-GDM matched controls from the National Institute of Child Health and Human Development Fetal Growth Studies-Singleton cohort, untargeted lipidomics data of 420 metabolites (328 annotated and 92 unannotated), and information on glycemic biomarkers in maternal plasma at visit 0 (10–14 weeks) and visit 1 (15–26 weeks). We constructed lipid networks using weighted correlation network analysis technique. We examined prospective associations of lipid networks and individual lipids with GDM risk using linear mixed effect models. Furthermore, we calculated Pearson’s partial correlation for GDM-related lipid networks and individual lipids with plasma glucose, insulin, C-peptide and glycated hemoglobin at both study visits.

Results

Lipid networks primarily characterized by elevated plasma diglycerides and short, saturated/low unsaturated triglycerides and lower plasma cholesteryl esters, sphingomyelins and phosphatidylcholines were associated with higher risk of developing GDM (false discovery rate (FDR) <0.05). Among individual lipids, 58 metabolites at visit 0 and 96 metabolites at visit 1 (40 metabolites at both time points) significantly differed between women who developed GDM and who did not (FDR <0.05). Furthermore, GDM-related lipid networks and individual lipids showed consistent correlations with maternal glycemic markers particularly in early pregnancy at visit 0.

Conclusions

Plasma lipid metabolites in early pregnancy both individually and interactively in distinct networks were associated with subsequent GDM risk in race/ethnically diverse US women. Future research is warranted to assess lipid metabolites as etiologic markers of GDM.
Is there a role for an advanced practitioner in UK military prehospital care?
Authors: Paxman Elizabeth , Lamb D , Findlay S
Published: March 2021

Recruitment and retention of doctors have been highlighted as some of the leading causes of the current perceived crisis within civilian emergency care. Indeed, the NHS recognises the contribution made by other healthcare professionals by supporting accreditation in advanced practice to mitigate the risks associated with these capability gaps. Consequently, roles such as the advanced clinical practitioner are now well established. Previous research and clinical experience in the civilian sector suggest that the advanced practitioner (AP) role could be used within Defence. Operationally, the role could be advantageous for the Defence Medical Services in the delivery of deployed healthcare. However, there is no available research that defines the role of UK military APs and, more specifically, their potential to support deployed prehospital care. Further work is required to determine how an AP might be effectively used within the military prehospital patient care pathway.
Patient-reported burden of dry eye disease in the UK: a cross-sectional web-based survey
Authors: Hossain Parwez , Siffel Csaba , Joseph Corey , Meunier Juliette , Markowitz Jessica T. , Dana Reza
Published: March 2021

Objectives

To compare sociodemographics and vision-related quality of life (QoL) of individuals with or without dry eye disease (DED); and to explore the impact of DED symptom severity on visual function, activity limitations and work productivity.

Design

Cross-sectional web-based survey.

Setting

General UK population.

Participants

Adults ≥18 years with (N=1002) or without (N=1003) self-reported DED recruited through email and screened.

Main outcome measures

All participants completed the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), with six additional questions (items A3–A8), and the EuroQol 5 dimensions 5 levels. DED participants also completed Impact of Dry Eye on Everyday Life questionnaire, 5-item Dry Eye Questionnaire and the Standardised Patient Evaluation of Eye Dryness questionnaire along with the Ocular Comfort Index, Work Productivity and Activity Impairment and the Eye Dryness Score (EDS), a Visual Analogue Scale.

Results

Baseline demographic and clinical characteristics were similar in participants with versus without DED (mean age, 55.2 vs 55.0 years; 61.8% vs 61.0% women, respectively) based on recruitment targets. Scores were derived from NEI VFQ-25 using the new 28-item revised VFQ (VFQ-28R) scoring. Mean (SD) VFQ-28R scores were lower in participants with versus without DED, indicating worse functioning (activity limitations, 73.3 (12.3) vs 84.4 (12.3); socioemotional functioning, 75.3 (21.5) vs 90.3 (16.2); total score, 71.6 (12.8) vs 83.6 (12.6)). Higher percentages of problems/inability to do activities were observed among those with versus without DED. The impact of DED on visual function was worse for participants with more severe DED symptoms, as assessed by EDS. In addition, a higher EDS was associated with worse symptoms on common DED scales and a worse impact on work productivity.

Conclusions

DED symptoms were associated with negative effects on visual function, activities and work productivity, whereas worse DED symptoms had a greater impact on vision-related QoL and work productivity.
Neurotrauma clinicians’ perspectives on the contextual challenges associated with long-term follow-up following traumatic brain injury in low-income and middle-income countries: a qualitative study protocol
Authors: Smith Brandon George , Whiffin Charlotte Jane , Esene Ignatius N , Karekezi Claire , Bashford Tom , Mukhtar Khan Muhammad , Fontoura Solla Davi Jorge , Indira Devi Bhagavatula , Hutchinson Peter John , Kolias Angelos G , Figaji Anthony , Rubiano Andres M
Published: March 2021

Introduction

Traumatic brain injury (TBI) is a global public health concern; however, low/middle-income countries (LMICs) face the greatest burden. The WHO recognises the significant differences between patient outcomes following injuries in high-income countries versus those in LMICs. Outcome data are not reliably recorded in LMICs and despite improved injury surveillance data, data on disability and long-term functional outcomes remain poorly recorded. Therefore, the full picture of outcome post-TBI in LMICs is largely unknown.

Methods and analysis

This is a cross-sectional pragmatic qualitative study using individual semistructured interviews with clinicians who have experience of neurotrauma in LMICs. The aim of this study is to understand the contextual challenges associated with long-term follow-up of patients following TBI in LMICs. For the purpose of the study, we define ‘long-term’ as any data collected following discharge from hospital. We aim to conduct individual semistructured interviews with 24–48 neurosurgeons, beginning February 2020. Interviews will be recorded and transcribed verbatim. A reflexive thematic analysis will be conducted supported by NVivo software.

Ethics and dissemination

The University of Cambridge Psychology Research Ethics Committee approved this study in February 2020. Ethical issues within this study include consent, confidentiality and anonymity, and data protection. Participants will provide informed consent and their contributions will be kept confidential. Participants will be free to withdraw at any time without penalty; however, their interview data can only be withdrawn up to 1 week after data collection. Findings generated from the study will be shared with relevant stakeholders such as the World Federation of Neurosurgical Societies and disseminated in conference presentations and journal publications.
Using financial incentives to increase physical activity among employees as a strategy of workplace health promotion: protocol for a systematic review
Authors: Heise Thomas Leonhard , Frense Jennifer , Christianson Lara , Seuring Till
Published: March 2021

Introduction

Shifts towards sedentary occupations in high-income countries (HIC) over the last decades and the health burden associated with physical inactivity have led to innovative strategies to promote physical activity (PA) among the working population. Financial rewards have been proposed to incentivise participation in programmes promoting PA or the achievement of PA-related goals. This review will assess (1) effects of financial incentives provided by employers to promote PA on programme adherence/compliance, PA and closely linked outcomes (eg, days of sick leave), (2) effects according to age, gender, implementation and study quality and (3) intervention costs and cost-effectiveness.

Methods and analysis

We will search for relevant studies in eight academic databases, two grey literature resources, two trial registers and on five organisational websites (oldest record/content to present). We will include (cluster) randomised controlled studies with a financial incentive to promote PA as intervention (≥1 months), conducted among employees in HIC and reporting data on at least one primary outcome in stages of screening (title/abstract, full text). To assess study quality and potential bias, we will use the revised Cochrane risk-of-bias tool (RoB 2). We will extract study data into prepiloted extraction sheets. Each task in screening, quality assessment and data extraction will be done by two authors independently. If a sufficient number of studies provide homogeneous data (ie, similar follow-up) for primary outcomes, meta-analyses will be carried out. We will report GRADE ratings to provide information on the certainty of the evidence.

Ethics and dissemination

For this review, no ethical approval will be required because only data of studies in which informed consent was obtained will be considered and analysed. The final review manuscript will be published in an Open Access journal. To ensure effective promotion of this review project, we will disseminate major findings through relevant communication channels.

PROSPERO registration number

CRD42020184345.
Being Your Best: protocol for a feasibility study of a codesigned approach to reduce symptoms of frailty in people aged 65 years or more after transition from hospital
Authors: Lowthian Judy A , Green Maja , Meyer Claudia , Cyarto Elizabeth , Robinson Elizabeth , Mills Amber , Sutherland Fran , Hutchinson Alison M , Smit De Villers , Boyd Leanne , Walker Katie , Newnham Harvey , Rose Michael
Published: March 2021

Introduction

The population is ageing, with increasing health and supportive care needs. For older people, complex chronic health conditions and frailty can lead to a cascade of repeated hospitalisations and further decline. Existing solutions are fragmented and not person centred. The proposedBeing Your Bestprogramme integrates care across hospital and community settings to address symptoms of frailty.

Methods and analysis

A multicentre pragmatic mixed methods study aiming to recruit 80 community-dwelling patients aged ≥65 years recently discharged from hospital.Being Your Bestis a codesigned 6-month programme that provides referral and linkage with existing services comprising four modules to prevent or mitigate symptoms of physical, nutritional, cognitive and social frailty. Feasibility will be assessed in terms of recruitment, acceptability of the intervention to participants and level of retention in the programme. Changes in frailty (Modified Reported Edmonton Frail Scale), cognition (Mini-Mental State Examination), functional ability (Barthel and Lawton), loneliness (University of California Los Angeles Loneliness Scale-3 items) and nutrition (Malnutrition Screening Tool) will also be measured at 6 and 12 months.

Ethics and dissemination

The study has received approval from Monash Health Human Research Ethics Committee (RES-19-0000904L). Results will be disseminated through peer-reviewed journals, conference and seminar presentations.

Trial registration number

ACTRN12620000533998; Pre-results.
Staying ahead of the curve: Navigating changes and maintaining gains in patient safety culture - a mixed-methods study
Authors: Titi Maher Abdelraheim , Baksh Maram Mohammed , Zubairi Beena , Abdalla Rawia Ahmad Mustafa , Alsaif Faisal Abdullah , Amer Yasser S , Jamal Diana , El-Jardali Fadi
Published: March 2021

Objectives

This study examines how the results of the Hospital Survey on Patient Safety Culture changed between 2012 and 2019 and identifies organisational factors affecting these changes.

Design

The study combined the use of quantitative surveys of staff and qualitative interviews with hospital leadership. Secondary data analysis was performed for previous surveys.

Setting

This study was conducted in a tertiary care teaching multisite hospital in Riyadh, Saudi Arabia.

Participants

One thousand hospital staff participated in the survey. Thirty-one executive board members and directors and four focus groups of frontliners were qualitatively interviewed.

Primary and secondary outcome measures

Twelve safety culture dimensions were assessed to study the patient safety culture as perceived by the healthcare professionals. An additional semi-structured interview was conducted to identify organisational factors, changes, and barriers affecting the patient safety culture. Furthermore, suggestions to improve patient safety were proposed.

Results

Comparing the results revealed a general positive trend in scores from 2012 to 2019. The areas of strength included teamwork within and across units, organisational learning, managerial support, overall perception of safety and feedback and communication about error. Non-punitive response to error, staffing and communication and openness consistently remain the lowest-scoring composites. Interview results revealed that organisational changes may have influenced the answers of the participants on some survey composites.

Conclusions

Patient safety is a moving target with areas for improvement that are continuously identified. Effective quality improvement initiatives can lead to visible changes in the patient safety culture in a hospital, and consistent leadership commitment and support can maintain these improvements.
The attitudes, perceptions and experiences of medical school applicants following the closure of schools and cancellation of public examinations in 2020 due to the COVID-19 pandemic: a cross-sectional questionnaire study of UK medical applicants
Authors: Woolf Katherine , Harrison David , McManus Chris
Published: March 2021

Objective

Describe the experiences and views of medical applicants from diverse social backgrounds following the closure of schools and universities and the cancellation of public examinations in the UK due to COVID-19.

Design

Cross-sectional questionnaire study, part of the longitudinal UK Medical Applicant Cohort Study (UKMACS).

Setting

UK medical school admissions in 2020.

Participants

2887 participants completed an online questionnaire from 8 April to 22 April 2020. Eligible participants had registered to take the University Clinical Admissions Test in 2019 and agreed to be invited to take part, or had completed a previous UKMACS questionnaire, had been seriously considering applying to medicine in the UK for entry in 2020, and were UK residents.

Main outcome measures

Views on calculated grades, views on medical school admissions and teaching in 2020 and 2021, reported experiences of education during the national lockdown.

Results

Respondents were concerned about the calculated grades that replaced A-level examinations: female and Black Asian and Minority Ethnic applicants felt teachers would find it difficult to grade and rank students accurately, and applicants from non-selective state schools and living in deprived areas had concerns about the standardisation process. Calculated grades were generally not considered fair enough to use in selection, but were considered fair enough to use in combination with other measures including interview and aptitude test scores. Respondents from non-selective state (public) schools reported less access to educational resources compared with private/selective school pupils, less online teaching in real time and less time studying during lockdown.

Conclusions

The COVID-19 pandemic has and will have significant and long-term impacts on the selection, education and performance of our medical workforce. It is important that the views and experiences of applicants from diverse backgrounds are considered in decisions affecting their future and the future of the profession.
Abortion attempts without clinical supervision among transgender, nonbinary and gender-expansive people in the United States
Authors: Moseson Heidi , Fix Laura , Gerdts Caitlin , Ragosta Sachiko , Hastings Jen , Stoeffler Ari , Goldberg Eli A , Lunn Mitchell R , Flentje Annesa , Capriotti Matthew R , Lubensky Micah E , Obedin-Maliver Juno
Published: March 2021

Background

Transgender, nonbinary and gender-expansive (TGE) people face barriers to abortion care and may consider abortion without clinical supervision.

Methods

In 2019, we recruited participants for an online survey about sexual and reproductive health. Eligible participants were TGE people assigned female or intersex at birth, 18 years and older, from across the United States, and recruited through The PRIDE Study or via online and in-person postings.

Results

Of 1694 TGE participants, 76 people (36% of those ever pregnant) reportedconsideringtrying to end a pregnancy on their own without clinical supervision, and a subset of these (n=40; 19% of those ever pregnant) reportedattemptingto do so. Methods fell into four broad categories: herbs (n=15, 38%), physical trauma (n=10, 25%), vitamin C (n=8, 20%) and substance use (n=7, 18%). Reasons given for abortion without clinical supervision ranged from perceived efficiency and desire for privacy, to structural issues including a lack of health insurance coverage, legal restrictions, denials of or mistreatment within clinical care, and cost.

Conclusions

These data highlight a high proportion of sampled TGE people who have attempted abortion without clinical supervision. This could reflect formidable barriers to facility-based abortion care as well as a strong desire for privacy and autonomy in the abortion process. Efforts are needed to connect TGE people with information on safe and effective methods of self-managed abortion and to dismantle barriers to clinical abortion care so that TGE people may freely choose a safe, effective abortion in either setting.
Diagnostic accuracy of three-dimensional-rotational angiography and heavily T2-weighted volumetric magnetic resonance fusion imaging for the diagnosis of spinal arteriovenous shunts
Authors: Ryu Bikei , Sato Shinsuke , Takase Masayuki , Mochizuki Tatsuki , Shima Shogo , Inoue Tatsuya , Okada Yoshikazu , Niimi Yasunari
Published: March 2021

Background

Spinal arteriovenous shunts (SAVSs) are rare entities occurring in various areas, from the craniocervical junction to the sacral level. Recently, better understanding of SAVS angioarchitecture and elucidation of its pathogenesis have become possible with the advancement of imaging techniques. However, the utility of fusing different image modalities for SAVS diagnostics has not been determined. This study aimed to investigate whether three-dimensional-rotational angiography (3D-RA) and 3D-heavily T2-weighted volumetric MR (3D-MR) fusion imaging would improve the diagnostic accuracy for SAVSs.

Methods

We retrospectively reviewed 12 SAVSs in 12 patients. Assessment of 3D-RA and 3D-RA/3D-MR fusion images for SAVS was performed by seven blinded reviewers. The final diagnosis was performed by two interventional neuroradiologists with extensive experience, and the interobserver agreement between the reviewers and the final diagnosis was calculated using κ statistics. The comparison of the interobserver agreement between 3D-RA and 3D-RA/3D-MR fusion images was performed for the diagnosis of SAVS subtypes. We also statistically compared the image-quality gradings (on a 4-grade scale) to delineate the 3D relationship between vascular malformations and the surrounding anatomical landmarks.

Results

The interobserver agreement for the 3D-RA/3D-MR fusion images was substantial (κ=0.7071) and higher than that for the 3D-RA images (κ=0.3534). Significantly better image quality grades were assigned to 3D-RA/3D-MR fusion images than to 3D-RA images (p<0.0001) for the evaluation of the examined 3D relationships.

Conclusion

The 3D-RA/3D-MR fusion images provided better interobserver agreement of SAVS subtype diagnosis, allowing for detailed evaluation of the SAVS anatomical structures surrounding the shunt.
Protein Reconstitution Inside Giant Unilamellar Vesicles
Authors: Litschel Thomas , Schwille Petra
Published: March 2021

Giant unilamellar vesicles (GUVs) have gained great popularity as mimicries for cellular membranes. As their sizes are comfortably above the optical resolution limit, and their lipid composition is easily controlled, they are ideal for quantitative light microscopic investigation of dynamic processes in and on membranes. However, reconstitution of functional proteins into the lumen or the GUV membrane itself has proven technically challenging. In recent years, a selection of techniques has been introduced that tremendously improve GUV-assay development and enable the precise investigation of protein–membrane interactions under well-controlled conditions. Moreover, due to these methodological advances, GUVs are considered important candidates as protocells in bottom-up synthetic biology. In this review, we discuss the state of the art of the most important vesicle production and protein encapsulation methods and highlight some key protein systems whose functional reconstitution has advanced the field.
Study on Soil Spring Model for Pipe and Silty Clay Interaction Based on Physical Model Test
Authors: Li Liyun , Han Junyan , Wang Xiangjian
Published: March 2021

The previous soil spring model cannot describe the nonlinear characteristics of soil in elastic stage, and there are some shortcomings in the selection of soil spring parameters in some published codes. Meanwhile, the literatures about the spring model for pipe and silty clay interaction are rare. Thus, a series of pipe‐silty clay interaction tests are conducted, and some corresponding experimental results are obtained. The effects of soil properties, pipe diameter, and embedment depth on the horizontal resistance of soil are studied. Based on the experimental results, the failure modes of soil are analysed, and a formula to calculate the peak resistance of soil and the corresponding displacement to peak resistance are proposed. Finally, a method to describe the nonlinear spring stiffness coefficient of silty clay is recommended.
Nonlinear Model Predictive Control for Pumped Storage Plants Based on Online Sequential Extreme Learning Machine with Forgetting Factor
Authors: Feng Chen , Li Chaoshun , Chang Li , Mai Zijun , Wu Chunwang
Published: March 2021

With renewable energy (RE) being increasingly connected to power grids, pumped storage plants (PSPs) play a very important role in restraining the fluctuation of power grids. However, conventional control strategy could not adapt well to the different control tasks. This paper proposes an intelligent nonlinear model predictive control (NMPC) strategy, in which hydraulic‐mechanical and electrical subsystems are combined in a synchronous control framework. A newly proposed online sequential extreme learning machine algorithm with forgetting factor (named WOS‐ELM) is introduced to learn the dynamic behaviors of the coupling system. Specifically, the initial learning parameters are optimized by prior‐knowledge learning and a new self‐adaptive adjustment strategy is also put forward. Subsequently, the stair‐like control strategy and artificial sheep algorithm (ASA) are used in rolling the optimization mechanism to replace the existing complex differential geometric solutions. Comparative experiments are carried out under different working conditions based on a PSP in China. The results show that the influence from coupling factors can be considerable and the proposed MPC strategy indicates superiority in voltage and load adjustment as well as the frequency oscillation suppression.
Analysis of Influencing Factors of Teaching Effect Based on Structural Equation Model
Authors: Xu Xin
Published: March 2021

Structural equation model is a multivariate statistical analysis method. It can not only test some unpredictable abstract ideas, but also design parameters for the causal connection model between independent variables and dependent variables. Among them, the analysis of various latent variables is based on the verification factor analysis technology. The research first collects various relevant data, derives the latent variables and measurement variables, then composes the measurement model, and then verifies the adaptability of the measurement model structure mode through actual data collection. When such suitable factors are determined, a causal model based on path analysis technology for latent variables, that is, a structural model, can be used for parameter design. This article uses the structural equation model as an analysis tool, starting from the three aspects of teachers, cases, and students to evaluate the application effect of the case teaching method in the classroom teaching of intellectual property law course and construct a structural equation model of the influencing factors of the case teaching effect. To understand students’ satisfaction with case teaching effects and related influencing factors, the research results show that the effect of case teaching is jointly affected by the level of teachers, case selection, and student response. Among them, teacher factors have the greatest impact on case teaching effects, followed by case factors, and students have the least.
Impact of Particle Sizes on Flow Characteristics of Slurry Pump for Deep‐Sea Mining
Authors: Wang Runkun , Guan Yingjie , Jin Xing , Tang Zhenji , Zhu Zuchao , Su Xianghui
Published: March 2021

As the core device of the deep‐sea mining transport system, the slurry pump and its internal solid‐liquid two‐phase flow are extremely complicated; especially, the migration characteristics of particles have a great influence on the flow and wear of the pump. In order to grasp the particle motion law inside the slurry pump, this paper took into consideration the collision effects of the particles with particles and particles with walls and calculated the unsteady flow of the solid‐liquid two‐phase by CFD‐DEM coupling algorithm. Then, the focus was put on the spatial distribution and movement characteristics of different particle diameters (namely, 5 mm, 10 mm, and 15 mm, while volume concentration Cv is constant 5%). The results show that the stratification phenomenon gradually disappears with the increase of particle diameter, and the intensity and scale of the vortex in the guide vane also increase obviously. Besides, as the particle diameter increases, the velocity changes more drastically, and the intensity and scale of the vortex increase significantly. Under low concentration conditions, the presence of particles has a limited influence on the hydraulic performance of the pump. By comparing with the experimental results, the simulation results are in good agreement with it, which proves that the CFD‐DEM simulation in this paper is effective, and the conclusions can provide theoretical support for the design and analysis of the slurry pump in engineering application.
Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application
Authors: Zmuda Trzebiatowski Marcin A. , Kłosowski Paweł , Skorek Andrzej , Żerdzicki Krzysztof , Lemski Paweł , Koberda Mateusz
Published: March 2021

The more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model of the orbit were performed. The intraorbital hydraulic pressure was introduced as a face load applied directly to the orbit in the first variant, while in the second one the load was applied to the orbit indirectly as a set of nodal forces transferred from the external surface of the eyeball via the intraorbital tissues to the orbital walls within the contact problem. Such an approach is aimed at a better understanding of the pattern for the formation of blowout fractures during the indirect load applied to the orbital bones. The nonlinear dynamic analysis of both numerical models showed that the potential fracture was observed in the second variant only, embracing a relatively large area: both medial and lower wall of the orbit. Interestingly, the pressure generated by the intraorbital entities transferred the energy of the impact to the orbital sidewalls mainly; thus, the nature of the mechanism known as the hydraulic was far from the expected hydraulic pressure. According to the eyeball’s deformation as well as the areas of the greatest Huber-Mises-Hencky (H-M-H) stress within the orbit, a new term of strut mechanism was proposed instead of the hydraulic mechanism as more realistic regarding the investigated phenomenon. The results of the current research may strongly influence the development of modern implantology as well as affect forensic medicine.
Antimicrobial Resistance among Pregnant Women with Urinary Tract Infections Attending Antenatal Clinic at Levy Mwanawasa University Teaching Hospital (LMUTH), Lusaka, Zambia
Authors: Yeta Kekelwa Inyambo , Michelo Charles , Jacobs Choolwe
Published: March 2021

Introduction. Globally, there is a growing concern over antimicrobial resistance (AMR) which is currently estimated to account for more than 700,000 deaths per year worldwide. AMR undermines the management of infectious diseases in general especially in pregnancy where significant bacteriuria continues to be a serious cause of maternal and perinatal morbidity and mortality. We therefore aimed to determine the prevalence of AMR and the associated factors among pregnant women with urinary tract infections (UTIs) attending antenatal clinic at a selected hospital in Lusaka, Zambia. Methods. This was a hospital-based, cross-sectional study conducted between November 2018 and May 2019. Interviewer-administered questionnaire was used to assess the sociodemographic characteristics and behavioural characteristics. Laboratory tests were also conducted. Descriptive statistics of study participants were used to describe the characteristics of the respondents. Chi-square was used to assess the association between categorical variables. The logistic regression analysis was carried out to generate the adjusted odds ratio with 95% confidence interval. Results. Overall (n = 203), the prevalence of UTI was 60% (95% CI: 53.3%–66.7%). The most isolated bacteria were E. coli (59%) and Klebsiella (21%). The prevalence of AMR was found to be 53% (95% CI: 46.1%–59.8%). The drugs highly resistant to antimicrobials were nalidixic acid (88.3%), ampicillin (77.8%), and norfloxacin (58.5%), while the least resistant drug was chloramphenicol (20%). There were no important significant predictors to AMR among pregnant women observed in this study. Conclusion. We found high burden of AMR closely linked to observe high prevalence of UTI suggested in this small population. This suggests a need to develop integrated surveillance systems that aim for early and regular screening of pregnant women for UTI as well as concurrent determination of antibiotic susceptibility patterns. This is important to prevent complications that may endanger maternal and fetal health outcomes. Furthermore, further research is needed to explore reasons for this high prevalence of AMR including examining possible attribution to the misuse of drugs so as to inform, enforce, or adjust the prescription-only policies and enforce antimicrobial stewardship programs.
Reducing Racial Disparities in Surviving Gastrointestinal Cancer Will Require Looking Beyond the Fact That African-Americans Have Low Rates of Surgery
Authors: Hébert James R.
Published: March 2021

This article by Bliton and colleagues in this issue of the journal concludes that disproportionately low surgery rates among Black patients contribute to the known survival disparity between Blacks and Whites. Using data from the National Cancer Database (NCDB), they were able to address the implicit hypothesis that the measured outcome disparities are partly attributable to failure to deliver surgical care equitably. As with most good research on difficult and complex topics, it also raises interesting and provocative questions about the role of race in poor survival among African-American patients with gastrointestinal cancer. The main limitation of the NCDB is its inability to account for individual-level factors. Those things related to health behaviors, such as diet, physical activity, and tobacco use, but that also include characteristics of the built environment, comprehensive access to care measures, clinical decision-making, racial discrimination and other forms of psychosocial stress, and environmental contamination, would influence both the likelihood of getting cancer and the probability of having aggressive disease with poor prognosis. These factors also may be related to clinical decision-making. Suggestions are made to design studies and collect data that would help to inform future investigations to deepen our understanding of racial disparities in cancer survival.

See related article by Bliton et al., p. 529
Integrative Genomic Analysis of Gemcitabine Resistance in Pancreatic Cancer by Patient-derived Xenograft Models
Authors: Yang Gang , Guan Wenfang , Cao Zhe , Guo Wenbo , Xiong Guangbing , Zhao Fangyu , Feng Mengyu , Qiu Jiangdong , Liu Yueze , Zhang Michael Q. , You Lei , Zhang Taiping , Zhao Yupei , Gu Jin
Published: March 2021

Purpose:

Gemcitabine is most commonly used for pancreatic cancer. However, the molecular features and mechanisms of the frequently occurring resistance remain unclear. This work aims at exploring the molecular features of gemcitabine resistance and identifying candidate biomarkers and combinatorial targets for the treatment.

Experimental Design:

In this study, we established 66 patient-derived xenografts (PDXs) on the basis of clinical pancreatic cancer specimens and treated them with gemcitabine. We generated multiomics data (including whole-exome sequencing, RNA sequencing, miRNA sequencing, and DNA methylation array) of 15 drug-sensitive and 13 -resistant PDXs before and after the gemcitabine treatment. We performed integrative computational analysis to identify the molecular networks related to gemcitabine intrinsic and acquired resistance. Then, short hairpin RNA–based high-content screening was implemented to validate the function of the deregulated genes.

Results:

The comprehensive multiomics analysis and functional experiment revealed that MRPS5 and GSPT1 had strong effects on cell proliferation, and CD55 and DHTKD1 contributed to gemcitabine resistance in pancreatic cancer cells. Moreover, we found miR-135a-5p was significantly associated with the prognosis of patients with pancreatic cancer and could be a candidate biomarker to predict gemcitabine response. Comparing the molecular features before and after the treatment, we found that PI3K-Akt, p53, and hypoxia-inducible factor-1 pathways were significantly altered in multiple patients, providing candidate target pathways for reducing the acquired resistance.

Conclusions:

This integrative genomic study systematically investigated the predictive markers and molecular mechanisms of chemoresistance in pancreatic cancer and provides potential therapy targets for overcoming gemcitabine resistance.
Discovery of a Novel CIP2A Variant (NOCIVA) with Clinical Relevance in Predicting TKI Resistance in Myeloid Leukemias
Authors: Mäkelä Eleonora , Pavic Karolina , Varila Taru , Salmenniemi Urpu , Löyttyniemi Eliisa , Nagelli Srikar G. , Ammunét Tea , Kähäri Veli-Matti , Clark Richard E. , Elo Laura L. , Bachanaboyina Venkata Kumari , Lucas Claire M. , Itälä-Remes Maija , Westermarck Jukka
Published: March 2021

Purpose:

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncoprotein that inhibits the tumor suppressor PP2A-B56α. However, CIP2A mRNA variants remain uncharacterized. Here, we report the discovery of a CIP2A splicing variant, novel CIP2A variant (NOCIVA).

Experimental Design:

Characterization of CIP2A variants was performed by both 3′ and 5′ rapid amplification of cDNA ends from cancer cells. The function of NOCIVA was assessed by structural and molecular biology approaches. Its clinical relevance was studied in an acute myeloid leukemia (AML) patient cohort and two independent chronic myeloid leukemia (CML) cohorts.

Results:

NOCIVA contains CIP2A exons 1 to 13 fused to 349 nucleotides from CIP2A intron 13. Intriguingly, the first 39 nucleotides of the NOCIVA-specific sequence are in the coding frame with exon 13 of CIP2A and code for a 13-amino acid peptide tail nonhomologous to any known human protein sequence. Therefore, NOCIVA translates to a unique human protein. NOCIVA retains the capacity to bind to B56α, but, whereas CIP2A is predominantly a cytoplasmic protein, NOCIVA translocates to the nucleus. Indicative of prevalent alternative splicing from CIP2A to NOCIVA in myeloid malignancies, AML and CML patient samples overexpress NOCIVA, but not CIP2A mRNA. In AML, a high NOCIVA/CIP2A mRNA expression ratio is a marker for adverse overall survival. In CML, high NOCIVA expression is associated with inferior event-free survival among imatinib-treated patients, but not among patients treated with dasatinib or nilotinib.

Conclusions:

We discovered a novel variant of the oncoprotein CIP2A and its clinical relevance in predicting tyrosine kinase inhibitor therapy resistance in myeloid leukemias.
The Lung Immune Prognostic Index May Predict the Efficacy of Different Treatments in Patients with Advanced NSCLC: A Meta-Analysis
Authors: Xie Jianhua , Zang Yuqin , Liu Miaomiao , Peng Lili , Zhang Hongzhen
Published: March 2021

Background: Our purpose was to evaluate the predictive value of the lung immune prognostic index (LIPI) in patients with advanced non-small cell lung cancer (NSCLC) receiving different treatments. Methods: A systemic literature search of major databases of medicine was performed to explore the association of LIPI with different therapeutic effects in patients with advanced NSCLC, with overall survival (OS) as the surrogate marker. As such, HR and 95% CI were simultaneously selected to evaluate such an association. Results: A total of 4 studies involving 7,373 patients reported an association of the LIPI score with OS in advanced NSCLC patients. Further sorted by therapeutic regimen, the numbers of patients receiving immune checkpoint inhibitors (ICI), targeted therapy (TT), and chemotherapy (CT) were 3,651, 1,241, and 2,481, respectively. Overall, the good and intermediate LIPI groups (HR = 1.61; 95% CI 1.48–1.75; p < 0.01) showed no heterogeneity (I2 = 0%; p = 0.521), whereas the good and poor LIPI groups (HR = 2.74; 95% CI 2.26–3.33; p < 0.01) had a high heterogeneity (I2 = 67.9%; p = 0.019). For ICI, CT, and TT, the good and intermediate LIPI groups exhibited an HR of 1.70 (95% CI 1.49–1.93; p < 0.01) with I2 = 0% (p = 0.521), an HR 1.49 (95% CI 1.32–1.67; p < 0.01) with I2 = 0% (p = 0.437), and an HR of 1.85 (95% CI 1.45–2.36; p < 0.01) with I2 = 0% (p = 0.382), respectively. The good and poor LIPI groups had an HR of 3.46 (95% CI 2.72–4.39; p < 0.01) with I2 = 51.7% (p = 0.126), an HR of 2.22 (95% CI 1.85–2.66; p < 0.01) with I2 = 20.3% (p = 0.286), and an HR of 3.32 (95% CI 2.53–4.36; p < 0.01) with I2 = 0% (p = 0.703), for ICI, CT, and TT, respectively. Conclusions: In addition to being a possible prognostic indicator for advanced NSCLC patients receiving ICI, CT or TT, the LIPI may be used to stratify patients in randomized studies. These findings are of great help in deciding on the therapeutic strategy, and more well-designed studies are warranted to further verify them.
The cascade methods of doubly-fed induction machine for generator system
Authors: Nguyen Diep-Dung , Than Ngoc-Hoan , Hoang Duc-Tuan
Published: March 2021

This paper presents two solutions to cascade the doubly-fed induction machines in the power generator systems. The first solution is a traditional one with the power control circuit located on the stator-side. The second solution is a new one with the power control circuit located on the rotor-side. After analysis and evaluation, it is shown that the solution with the power control circuit located on the rotor side has advantages over the solution with the power control circuit located on the stator-side. Therefore, the authors chose the solution which is a power control circuit located on the rotor side to study, analyze in-depth and run the simulation. The results show that the proposed solution has a very good quality, the output voltage of the generator always follows the grid-voltage even when changing the gird-voltage or changing the speed of the generator.
Design and performance evaluation of a PV interface system based on inductive power transfer
Authors: Ragab Ahmed , Marei Mostafa I. , Mokhtar Mohamed , Abdelsattar Ahmed
Published: March 2021

This paper presents a photovoltaic (PV) based battery charger utilizing a wireless power transfer (WPT) interface system. The double-sided inductor-capacitor-capacitor (LCC) compensation network is utilized for the inductive power transfer (IPT) system. Because of nonlinear characteristics of the PV, the maximum power point tracking (MPPT) is achieved by controlling the phase displacement angle or the pulse width of the quasi-square pulse inverter connected to the transmitting coil of the IPT system. As a result, the power transferred to the secondary-side, which is connected to a battery bank, is regulated. The IPT-based PV interface system is designed to achieve zero voltage switching (ZVS) in the primary side at rated conditions to minimize the switching loss. Extensive simulation studies are carried out using EMTDC/PSCAD software to investigate the dynamic performance of the proposed IPT-based PV interface system.
A high efficiency and high speed charge of Li-Ion battery charger interface using switching-based technique in 180 nm CMOS technology
Authors: El Alaoui Mustapha , Farah Fouad , El khadiri Karim , Tahiri Ahmed , El Alami Rachid , Qjidaa Hassan
Published: March 2021

In this work, the design and analysis of new Li-Ion battery charger interface using the switching-based technique is proposed for high efficiency, high speed charge and low area. The high efficiency, the lower size area and the fast charge are the more important norms of the proposed Li-Ion battery charger interface. The battery charging is completed passes to each charging mode: The first mode is the trickle charge mode (TC), the second mode is the constant current mode (CC) and the last mode is the constant voltage mode (CV), in thirty three minutes. The new Li-Ion battery charger interface is designed, simulated and layouted in Cadence software using TSCM 180 nm CMOS technology. With an input voltage VIN = 4.5 V, the output battery voltage (VBAT) may range from 2.7 V to 4.2 V and the maximum charging battery current (IBAT) is 1.7 A. The peak efficiency reaches 97% and the total area is only 0.03mm2 .
Effect of partial shading in grid connected solar PV system with FL controller
Authors: Shenoy K Latha , Nayak C. Gurudas , Mandi Rajashekar P.
Published: March 2021

As conventional fossil fuel reserves shrink and the danger of climate change prevailing, the need for alternative energy sources is unparalleled. A smart approach to compensate the dependence on electricity generated by burning fossil fuels is through the power generation using grid connected PV system. Partial shading on PV array affects the quantity of the output power in photovoltaic (PV) systems. To extract maximum power from PV under variable irradiance, variable temperature and partial shading condition, various MPPT algorithms are used. Incremental conductance and fuzzy based MPPT techniques are used for maximum power extraction from PV array. Basically 11 kW Solar PV system comprising of PV array coupled with an Inverter through a dc-dc converter is considered for the analysis and output of the inverter is supplied to the load through the LCL filter. An Intelligent controller for maximum power point tracking of PV power is designed. Also, a fuzzy controller for VSC is developed to improve the system performance. The above proposed design has been simulated in the MATLAB/Simulink and analyzed the system performance under various operating conditions. Finally, the performance is evaluated with IEEE 1547 standard for showing the effectiveness of the system.