bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the effects of Liuzijue Qigong on the lung function of COVID-19 patients during disease recovery
Authors: Wang Jilin , Cui Yanru , Liu Shuang , Zhou Jiangxue , Sun Yingxia
Published: August 2021

Background:

The coronavirus disease 2019 (COVID-19) outbreak began in late 2019 and spread rapidly throughout China and then the rest of the world. COVID-19 is a serious respiratory disease and many patients’ exhibit varying levels of persistent parenchymal lung damage. However, there is currently a lack of effective rehabilitation treatments for COVID-19 patients with lung damage. Several clinical trials have shown that Liuzijue Qigong (LQG) can enhance the strength of respiratory muscles and overall quality of life. In this study, a meta-analysis approach was used to assess the effects of LQG on the lung function of COVID-19 patients during disease recovery.

Methods:

Eight databases will be explored for relevant investigations including China National Knowledge Infrastructure, Wanfang, VIP, China Biology Medicine, EMBASE, PubMed, Web of Science, and the Cochrane Library. All databases will be explored for articles published from inception through July 2021. Data will be extracted independently by 2 researchers according to the eligibility criteria. Finally, RevMan 5.3.0 will be implemented for statistical analyses.

Results:

The results of this study will show the effects of LQG on the lung function of COVID-19 patients during disease recovery and will be submitted to a peer-reviewed journal for publication.

Conclusions:

This study will provide reliable evidence based on the effects of LQG on the lung function of COVID-19 patients during disease recovery.

Trial registration number:

CRD42021268102
A comparison between the effects of drug costs and share of family income on drug costs in determining drug price
Authors: Dong Xiaobei , Tsang Chi Chun Steve , Kotian Anoop , Zeng Jason , Tran Michael , Wang Junling
Published: August 2021

High health care and medication expenditures pose a financial burden on Americans seeking care. It is imperative to determine the role of affordability in influencing access to health care and medications.

To investigate the association between financial burden and health care access by comparing the effects of absolute and relative financial burdens, measured by total health care/medication expenditure (Expenditure) and health care/medication expenditure as a share of annual family income (Expenditure Share), respectively.

Delay in receiving health care services and delay in obtaining prescription medications.

A cross-sectional analysis of the 2017 Medical Expenditure Panel Survey using multivariate logistic regressions with Expenditure and Expenditure Share variables standardized to facilitate comparison.

While both absolute and relative financial burdens were found to be positively associated with the outcomes, the relative measure had a significantly higher association that was about twice as much as the absolute one. For the outcome of delay in getting health care, the standardized odds ratios (OR) for health care expenditure and health care expenditure as a share of family income were 1.13 (95% confidence interval [CI] = 1.09–1.18) and 1.25 (95% CI = 1.20–1.32), respectively. For the outcome of delay in getting medications, the standardized OR for medication expenditure and medication expenditure as a share of family income were 1.11 (95% CI = 1.08–1.15) and 1.23 (95% CI = 1.18–1.29), respectively.

The study illustrated the importance of including income in policy considerations intended to balance value, access, and affordability. Specifically, income should be included in measures assessing the value of medications.
Real-world oral anticoagulants for Asian patients with non-valvular atrial fibrillation
Authors: Kim Seung Min , Jeon Eun-Tae , Jung Jin-Man , Lee Ji-Sung
Published: August 2021

Background and Purpose:

This study aimed to evaluate the comparative efficacy and safety of 4 non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in Asians with non-valvular atrial fibrillation in real-world practice through a network meta-analysis of observational studies.

Methods:

We searched multiple comprehensive databases (PubMed, Embase, and Cochrane library) for studies published until August 2020. Hazard ratios and 95% confidence intervals were used for the pooled estimates. Efficacy outcomes included ischemic stroke (IS), stroke/systemic embolism (SSE), myocardial infarction (MI), and all-cause mortality, and safety outcomes included major bleeding, gastrointestinal (GI) bleeding, and intracerebral hemorrhage (ICH). The P score was calculated for ranking probabilities. Subgroup analyses were separately performed in accordance with the dosage range of NOACs (“standard-” and “low-dose”).

Results:

A total of 11, 6, and 8 studies were allocated to the total population, standard-dose group, and low-dose group, respectively. In the total study population, edoxaban ranked the best in terms of IS and ICH prevention and apixaban ranked the best for SSE, major bleeding, and GI bleeding. In the standard-dose regimen, apixaban ranked the best in terms of IS and SSE prevention. For major bleeding, GI bleeding, and ICH, edoxaban ranked the best. In the low-dose regimen, edoxaban ranked the best for IS, SSE, GI bleeding, and ICH prevention. For major bleeding prevention, apixaban ranked best.

Conclusions:

All 4 NOACs had different efficacy and safety outcomes according to their type and dosage. Apixaban and edoxaban might be relatively better and more well-balanced treatment for Asian patients with non-valvular atrial fibrillation.
A case report of PR-3-ANCA-positive glomerulonephritis with histological features of GPA associated with infectious endocarditis
Authors: Hirata Momoko , Miyazawa Haruhisa , Morino Junki , Kaneko Shohei , Minato Saori , Katsunori Yanai , Ishii Hiroki , Kitano Taisuke , Ito Kiyonori , Hirai Keiji , Oda Takashi , Shimizu Akira , Ueda Yoshihiko , Morishita Yoshiyuki
Published: August 2021

Rationale:

Several renal diseases are associated with infectious endocarditis. However, there are few reports on patients with granulomatosis with polyangiitis (GPA) associated with infectious endocarditis, and there is no consensus for appropriate treatment.

Patients concerns:

A 35 -years-old man with congenital ventricular septal defect presented severe anemia, hematuria and proteinuria. The blood and urine examinations showed elevated white blood cells (12,900 cells/μL), C-reactive protein level (13.1 mg/dL) and proteinase 3-anti-neutrophil cytoplasmic antibody (PR3-ANCA) level (11.0 IU/mL), severe anemia (hemoglobin: 6.1 g/dL) and renal dysfunction [estimated glomerular filtration rate (eGFR): 12.7 ml/min.1.78 m2 with hematuria and proteinuria].

Diagnoses:

The patient was diagnosed with crescentic glomerulonephritis with histological features of GPA associated with infectious endocarditis by renal biopsy and transthoracic echocardiography.

Interventions:

Antibacterial drugs (ampicillin-sulbactam) were administrated. No immunomodulating agents were used because immunosuppressive drugs may worsen infectious endocarditis. Subsequently, renal function and urinary findings improved. However, infectious endocarditis was not improved. Therefore, valve replacements and ventricular septal closure surgery were conducted.

Outcomes:

Thereafter, his postoperative course was uneventful, renal function improved (eGFR: 64.3 ml/min.1.78 m2), and PR3-ANCA level normalized.

Lessons:

We reported a case report of PR3-ANCA positive glomerulonephritis with histological features of GPA associated with infectious endocarditis. Physicians might note this renal complication when they manage infectious endocarditis.
Pulmonary mucinous cystadenoma complicated with infection
Authors: Luo Zhou-Ye , Shen Xun-Ze , Liu Fang , Lin Chen
Published: August 2021

Rationale:

Mucinous cystadenoma is a benign tumor that is commonly found in the pancreas, ovaries, or appendix, but is rarely encountered in the lungs. Worldwide, only a few reported cases of these tumors originate in the lungs. Herein, we analyzed the imaging features of a case of pulmonary mucinous cystadenoma (PMCA). To the best of our knowledge, this is the first reported case of PMCA complicated by significant infection.

Patient concerns:

A 57-year-old man was admitted to our hospital with blood in sputum for more than 2 months. Serum laboratory examination showed significantly elevated leukocyte and tumor marker, carcinoembryonic antigen. Enhanced thoracic computed tomography and whole-body positron emission tomography/computed tomography showed a cystic-solid ill-defined mass in the right upper lung.

Diagnosis:

The tumor was considered malignant, both clinically and radiologically.

Interventions:

The patient underwent right upper lobe tumor resection and mediastinal lymph node dissection.

Outcomes:

Postoperative specimen pathology was diagnosed as PMCA with infection. The patient was not administered any further treatment. The patient was alive without any recurrence or metastasis of the tumor after 2 years of follow-up.

Lessons:

Preoperative diagnosis of PMCA with atypical imaging and clinical manifestations is extremely difficult. This is the first reported case of PMCA complicated by a significant infection that was misdiagnosed preoperatively as a malignancy.
Antipsychotic patterns in outpatients with schizophrenia in China
Authors: Guo Xiaobing , Yu Hongye , Wang Hu
Published: August 2021

It is essential to monitor pharmacological treatment for schizophrenic outpatients regularly in clinical practice. Especially in China, the situation of common prescribing patterns remains unclear. The objective of this study is to reveal real-world treatment prescription patterns of antipsychotics for schizophrenia patients in a representative large tertiary hospital in China.

This study is a cross-sectional observational analysis of outpatients with schizophrenia in a large tertiary psychiatric hospital in Beijing, China, from May 11th to 24th, 2019. Data on subjects’ socio-demographic and clinical characteristics, prescriptions of psychotropic drugs were collected from the electronic medical record (EMR) system with a standardized protocol. A multivariate analysis was performed to explore the potential association between antipsychotics treatments and subjects’ characteristics.

Of the 1940 patients included in this study, only 1470 (75.77%) patients were prescribed antipsychotic medications. 1228 (83.53%) patients were prescribed second-generation antipsychotics (SGAs), 202 (13.74%) patients were treated only with first-generation antipsychotics (FGAs), 40 (2.72%) were prescribed both SGAs and FGAs. The proportion of single SGAs prescriptions was significantly higher than that of single FGAs antipsychotics in each course of monotherapy group, especially among patients with the course less than 2 years (96.08%). Risperidone was most frequently prescribed antipsychotic medication during the study (29.86%, 439 out of 1470). Intermediate-acting sedative benzodiazepines were the most commonly co-prescribed psychotropic class at 23.66%. Long-acting injectable antipsychotics (LAIs) could be the prescribing trend in clinics. Disease course, self-paying cost and LAI antipsychotic use were independently associated with antipsychotics treatments.

Second-generation antipsychotics showed domination in prescriptions. More concerns should be paid with concomitant psychiatric medications in clinics.
Iron therapy in iron-deficiency patients with heart failure with preserved ejection fraction
Authors: Fukuta Hidekatsu , Hagiwara Hiromi , Kamiya Takeshi
Published: August 2021

Background:

Nearly half of patients with heart failure (HF) have preserved ejection fraction (EF) and the mortality and morbidity of patients with HF with preserved EF (HFpEF) are high. However, there is no established therapy to improve survival in these patients. HFpEF patients are often elderly and their primary chronic symptom is severe exercise intolerance. Thus, improvement of exercise capacity presents another important clinical outcome in HFpEF patients. Iron deficiency is common in HF patients, and the presence of iron deficiency, regardless of concomitant anemia, is associated with worse symptoms, impaired exercise capacity, and higher mortality and hospitalization in these patients. Several meta-analyses of randomized controlled trials reported that iron administration improved HF symptoms, exercise capacity, and clinical outcomes in iron-deficiency patients with HF with reduced EF. However, there is insufficient evidence as to the effect of iron administration in iron-deficiency HFpEF patients.

Methods and Results:

This meta-analysis will include randomized controlled trials on the effects of iron administration on HF symptoms, exercise capacity, and health-related quality of life in iron-deficiency HFpEF patients. Information of studies will be collected from PubMed, Web of Science, Cochrane Library, and ClinicalTrials.gov. The primary outcome will be exercise capacity (6-minute walking distance). The secondary outcomes will be HF symptoms, health-related quality of life, and mortality and hospitalization rates.

Conclusion:

This meta-analysis will evaluate the effect of iron therapy in iron-deficiency HFpEF patients, providing evidence as to the iron administration in these patients.

Systematic review registration:

PROSPERO CRD42020205297.
Association of pre-percutaneous coronary flow grade and clinical outcomes in patients with non-ST-segment elevation myocardial infarction
Authors: Kim Yong Hoon , Her Ae-Young , Jeong Myung Ho , Kim Byeong-Keuk , Hong Sung-Jin , Kim Seunghwan , Ahn Chul-Min , Kim Jung-Sun , Ko Young-Guk , Choi Donghoon , Hong Myeong-Ki , Jang Yangsoo
Published: August 2021

Because of a paucity of published data, we compared the 2-year major clinical outcomes between pre-percutaneous coronary intervention (pre-PCI) thrombolysis in myocardial infarction (TIMI) flow grade 0/1 (pre-TIMI flow grade [pre-TIMI] 0/1) group and pre-PCI TIMI flow grade 2/3 (pre-TIMI 2/3) group in patients with non-ST-segment elevation myocardial infarction (NSTEMI) who underwent successful implantation of newer-generation drug-eluting stent.

A total of 7506 NSTEMI patients were divided into 2 groups: pre-TIMI 0/1 group (n = 3157) and pre-TIMI 2/3 group (n = 4349). The primary outcome was major adverse cardiac events defined as all-cause death, recurrent myocardial infarction, or any repeat revascularization. The secondary outcome was stent thrombosis (ST).

After propensity score-matched (PSM) analysis, 2 PSM groups (2473 pairs, n = 4946, C-statistic = 0.684) were generated. Major adverse cardiac events (hazard ration [HR], 1.294; 95% confidence interval [CI]: 1.065–1.572; P = .009), all-cause death (HR, 1.559, P = .003), cardiac death (HR: 1.641, P = .005), and all-cause death or MI (HR: 1.531, P = .001) rates were significantly higher in the pre-TIMI 0/1 group than in the pre-TIMI 2/3 group. Moreover, these differences were more prominent during the first 1 month after the index PCI. However, the cumulative incidences of recurrent myocardial infarction, any revascularization, and ST were similar between the 2 groups.

Among a contemporary cohort of NSTEMI, these data suggest that the presence of a pre-PCI patency of the infarct-related artery showed better mortality reduction capacity than those with a lack of patency.
Management of Toddler's Fracture
Authors: Boutin Ariane , Misir Amita , Boutis Kathy
Published: August 2021

Objectives

In studies that included children diagnosed with toddler's fractures (TFs), we determined the fracture-related adverse outcomes in those treated with immobilization versus no immobilization. Furthermore, we compared health services utilization between these 2 immobilization strategies.

Methods

A search was done on Ovid MEDLINE(R), Embase Classic + Embase, and Cochrane Central Register of Controlled Trials along with reference lists as conference proceedings and abstracts. No language or publication status or location restrictions were used. All study steps, including the methodological quality assessment, were conducted independently and in duplicate by 2 authors.

Results

Of the 490 references identified, 4 retrospective studies of low quality met inclusion criteria and collectively included 355 study participants. With respect to fracture-related adverse outcomes, there was no risk difference [0; 95% confidence interval (CI), −0.09 to 0.09] between the immobilization and no immobilization treatment strategies. Furthermore, in the immobilization versus no immobilization groups, there was a higher mean difference in the number of radiographs (0.69; 95% CI, 0.15–1.23) and scheduled outpatient orthopedic visits (0.96; 95% CI, 0.24–1.68), but a decreased relative risk (0.41; 95% CI, 0.05–3.19) of repeat emergency department visits. No data were reported on patient pain or caregiver satisfaction.

Conclusions

In children with TF, this study suggests that no immobilization may be a safe alternative to immobilization for this minor fracture; however, high-quality evidence is needed to optimally inform clinical decision making. Future work should include validated measures of patient recovery, pain, and caregiver perspectives when comparing treatment strategies for this injury.
The Biology of Chronic Lymphocytic Leukemia
Authors: Moia Riccardo , Patriarca Andrea , Schipani Mattia , Gaidano Gianluca
Published: August 2021

The high degree of clinical heterogeneity of chronic lymphocytic leukemia (CLL) is influenced by the disease molecular complexity. Genetic studies have allowed to better understand CLL biology and to identify molecular biomarkers of clinical relevance. TP53 disruption represents the strongest prognosticator of chemorefractoriness and indicates the use of Bruton tyrosine kinase inhibitors (BTKis) and BCL2 inhibitors. Unmutated IGHV (immunoglobulin heavy variable) genes also predict refractoriness to chemoimmunotherapy; importantly, when treated with B-cell receptor inhibitors or BCL2 inhibitors, IGHV unmutated patients display an outcome similar to that of IGHV mutated CLL. Before choosing treatment, a comprehensive assessment of TP53 and IGHV status is recommended by all guidelines for CLL clinical management. In case of fixed-duration therapeutic strategies, monitoring of minimal residual disease may provide a tool to decide treatment duration. The current precision medicine management of CLL patients might be further improved by the adoption of novel biomarkers that are emerging as clinically meaningful for this disease.
Robotic DIEP Flap Harvest through a Totally Extraperitoneal Approach Using a Single-Port Surgical Robotic System
Authors: Choi Jae Hyeok , Song Seung Yong , Park Hyung Seok , Kim Choong Hyeon , Kim Jee Ye , Lew Dae Hyun , Roh Tai Suk , Lee Dong Won
Published: August 2021

Deep inferior epigastric artery perforator (DIEP) flap surgery is one of the most common techniques for breast reconstruction using abdominal tissue. Although the DIEP flap reduces donor-site morbidity when compared with the conventional free transverse rectus abdominis musculocutaneous flap, violation of the anterior rectus sheath, rectus muscle, and motor nerves cannot be avoided. To further minimize tissue damage in the donor site, the use of a surgical robotic system for DIEP flap harvest with a totally extraperitoneal approach has been suggested. This totally extraperitoneal approach has a long learning curve because of the narrow preperitoneal space and the difficulty of converting a potential space to an actual space. Thus, the authors suggest a single-port robotic system optimized for narrow surgical spaces as a feasible option for DIEP flap harvest by a totally extraperitoneal approach, which has a shorter learning curve.
Premature Fusion of the Sagittal Suture as an Incidental Radiographic Finding in Young Children
Authors: Manrique Monica , Mantilla-Rivas Esperanza , Porras Perez Antonio R. , Bryant Justin R. , Rana Md Sohel , Tu Liyun , Keating Robert F. , Oh Albert K. , Linguraru Marius G. , Rogers Gary F.
Published: August 2021

Background:

Craniosynostosis typically develops prenatally and creates characteristic changes in craniofacial form. Nevertheless, postnatal forms of craniosynostosis have been described. The purpose of this study was to determine the prevalence of incidentally identified, but temporally premature, cranial suture fusion in normocephalic children.

Methods:

Computed tomographic scans obtained from children aged 1 to 5 years evaluated in the authors’ emergency department between 2005 and 2016 were reviewed for evidence of craniosynostosis. Patients with prior ventriculoperitoneal shunt, brain or cranial abnormality, or known syndromes were excluded. The presence of craniosynostosis and cranial index was assessed by a panel of three craniofacial surgeons and one pediatric neurosurgeon. Demographic information, fusion type, reason for the computed tomographic scan, and medical history were recorded as covariates. Cranial shape and intracranial volume were calculated using a previously validated automated system.

Results:

Three hundred thirty-one patients met the inclusion criteria. The mean age was 2.4 ± 1.3 years. Eleven patients (3.3 percent) were found to have a complete (n = 9) or partial (n = 2) fusion of the sagittal suture. All patients had a normal cranial index (0.80; range, 0.72 to 0.87) and a grossly normal head shape. Only two fusions (18.2 percent) were documented by the radiologist. Cranial shape analysis performed in five of the 11 patients showed subtle phenotypic changes along the scaphocephaly spectrum in four patients, with a normal shape in the remaining case.

Conclusions:

Sagittal fusion is present in 3.3 percent of otherwise phenotypically normal children aged 1 to 5 years. The clinical significance of this result is unclear, but routine screening of affected patients is paramount.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Risk, IV.
Locally Advanced Scalp Tumors
Authors: Sleiwah Aseel , Mughal Maleeha , Thomas Nicholas , Roblin Paul , Townley William , Jeannon Jean-Pierre
Published: August 2021

Introduction

Locally advanced nonmelanoma skin cancers of the head and neck are well described in the current literature. However, data about clinical and survival outcomes are lacking. We present survival data from a tertiary head and neck cancer unit in London.

Methods

A retrospective analysis of data collected from a single institution was conducted. All patients with locally advanced cutaneous scalp carcinomas invading the skull between 2011 and 2019 were included. Data included patient demographics, tumor, comorbidities, interventions, flap survival, and metal work exposure. Survival outcomes were examined using Kaplan-Meier analysis.

Results

Twenty-three patients were identified. The mean age was 72 years. Eighteen patients were male, and 5 were female. Five patients were immunosuppressed. Nineteen patients underwent outer cortex drill-down/full-thickness calvarial resection, followed by reconstruction with free tissue transfer. Six patients had titanium mesh reconstruction after segmental skull resections. Three patients underwent further surgery because of exposed metalwork. Disease-free survival at 3 years after surgery was 60%.

Conclusions

Locally advanced nonmelanoma skin cancers invading the bone are sporadic. There are little published data on clinical and survival outcomes in this group. Despite the nature of these skin lesions, a high degree of local control can be obtained by extensive surgical resection, outer table drill-down, and calvarial resection. We conclude that aggressive management of the bony invasion improves disease-free survival and improves local control.
Pure autonomic failure and the differential diagnosis of autonomic peripheral neuropathies
Authors: González-Duarte Alejandra , Varma-Doyle Aditi , Freeman Roy
Published: August 2021

Purpose of review

Pure autonomic failure (PAF) is a peripheral autonomic neurodegenerative disease caused by alpha-synuclein deposition that is predominantly confined to peripheral autonomic neurons. Patients present with insidious features of autonomic failure that have a chronic course.

In this review, we highlight the features of PAF, the differentiating features from other autonomic neuropathies, the diagnostic tests, and the predictors for conversion to a central synucleinopathy.

Recent findings

Natural history studies have defined the predictors for and rate of conversion to a central alpha-synucleinopathy. Skin immunohistochemistry techniques and demonstration of length-dependent neuronal loss of both somatic and autonomic small fiber nerves, and intraneural phosphorylated synuclein deposition provide diagnostic biomarkers. In the future, diagnosis maybe supported by measuring cerebrospinal fluid alpha-synuclein oligomers using techniques, such as protein misfolding cyclic amplification assay and real-time quaking-induced conversion.

PAF is a sporadic peripheral autonomic neurodegenerative disease that belongs to the group of disorders known as alpha-synucleinopathies. Peripheral autonomic manifestations are similar to those seen in other autonomic neuropathies, particularly, diabetic autonomic neuropathy, amyloid polyneuropathy, and autoimmune autonomic neuropathies. Novel diagnostic procedures like skin immunohistochemistry for alpha-synuclein, and protein amplification techniques are being investigated to provide an earlier and more specific diagnosis. A substantial number of PAF patients’ phenoconvert to a central alpha-synucleinopathy.
Optimization of Non-Coding Regions Improves Protective Efficacy of an mRNA SARS-CoV-2 Vaccine in Nonhuman Primates
Authors: Gebre Makda S. , Rauch Susanne , Roth Nicole , Yu Jingyou , Chandrashekar Abishek , Mercado Noe B. , He Xuan , Liu Jinyan , McMahan Katherine , Martinot Amanda , Giffin Tori , Hope David , Patel Shivani , Sellers Daniel , Sanborn Owen , Barrett Julia , Liu Xiaowen , Cole Andrew C. , Pessaint Laurent , Valentin Daniel , Flinchbaugh Zack , Yalley-Ogunro Jake , Muench Jeanne , Brown Renita , Cook Anthony , Teow Elyse , Andersen Hanne , Lewis Mark G. , Mueller Stefan O. , Petsch Benjamin , Barouch Dan H.
Published: August 2021

The CVnCoV (CureVac) mRNA vaccine for SARS-CoV-2 has recently been evaluated in a phase 2b/3 efficacy trial in humans. CV2CoV is a second-generation mRNA vaccine with optimized non-coding regions and enhanced antigen expression. Here we report a head-to-head study of the immunogenicity and protective efficacy of CVnCoV and CV2CoV in nonhuman primates. We immunized 18 cynomolgus macaques with two doses of 12 ug of lipid nanoparticle formulated CVnCoV, CV2CoV, or sham (N=6/group). CV2CoV induced substantially higher binding and neutralizing antibodies, memory B cell responses, and T cell responses as compared with CVnCoV. CV2CoV also induced more potent neutralizing antibody responses against SARS-CoV-2 variants, including B.1.351 (beta), B.1.617.2 (delta), and C.37 (lambda). While CVnCoV provided partial protection against SARS-CoV-2 challenge, CV2CoV afforded robust protection with markedly lower viral loads in the upper and lower respiratory tract. Antibody responses correlated with protective efficacy. These data demonstrate that optimization of non-coding regions can greatly improve the immunogenicity and protective efficacy of an mRNA SARS-CoV-2 vaccine in nonhuman primates.
Quantitative 4D X-ray microtomography under extreme conditions: a case study on magma migration
Authors: Giovenco Elena , Perrillat Jean-Philippe , Boulard Eglantine , King Andrew , Guignot Nicolas , Le Godec Yann
Published: August 2021

X-ray computed tomography (XCT) is a well known method for three-dimensional characterization of materials that is established as a powerful tool in high-pressure/high-temperature research. The optimization of synchrotron beamlines and the development of fast high-efficiency detectors now allow the addition of a temporal dimension to tomography studies under extreme conditions. Presented here is the experimental setup developed on the PSICHE beamline at SOLEIL to perform high-speed XCT in the Ultra-fast Tomography Paris–Edinburgh cell (UToPEc). The UToPEc is a compact panoramic (165° angular aperture) press optimized for fast tomography that can access 10 GPa and 1700°C. It is installed on a high-speed rotation stage (up to 360° s−1) and allows the acquisition of a full computed tomography (CT) image with micrometre spatial resolution within a second. This marks a major technical breakthrough for time-lapse XCT and the real-time visualization of evolving dynamic systems. In this paper, a practical step-by-step guide to the use of the technique is provided, from the collection of CT images and their reconstruction to performing quantitative analysis, while accounting for the constraints imposed by high-pressure and high-temperature experimentation. The tomographic series allows the tracking of key topological parameters such as phase fractions from 3D volumetric data, and also the evolution of morphological properties (e.g. volume, flatness, dip) of each selected entity. The potential of this 4D tomography is illustrated by percolation experiments of carbonate melts within solid silicates, relevant for magma transfers in the Earth's mantle.
Observer-based robust actuator fault isolation and identification for microsatellite attitude control systems
Authors: Li Huayi , Jia Qingxian , Ma Rui , Chen Xueqin
Published: August 2021

Purpose

The purpose of this paper is to accomplish robust actuator fault isolation and identification for microsatellite attitude control systems (ACSs) subject to a series of space disturbance torques and gyro drifts.

Design/methodology/approach

For the satellite attitude dynamics with Lipschitz constraint, a multi-objective nonlinear unknown input observer (NUIO) is explored to accomplish robust actuator fault isolation based on a synthesis of Hinf techniques and regional pole assignment technique. Subsequently, a novel disturbance-decoupling learning observer (D2LO) is proposed to identify the isolated actuator fault accurately. Additionally, the design of the NUIO and the D2LO are reformulated into convex optimization problems involving linear matrix inequalities (LMIs), which can be readily solved using standard LMI tools.

Findings

The simulation studies on a microsatellite example are performed to prove the effectiveness and applicability of the proposed robust actuator fault isolation and identification methodologies.

Practical implications

This research includes implications for the enhancement of reliability and safety of on-orbit microsatellites.

Originality/value

This study proposes novel NUIO-based robust fault isolation and D2LO-based robust fault identification methodologies for spacecraft ACSs subject to a series of space disturbance torques and gyro drifts.
China’s bilateral trade in Africa: is institutional structure a determinant?
Authors: Gold Kafilah , Rasiah Rajah
Published: August 2021

Purpose

The purpose of this paper is to empirically examine the institutional structures and other predictors that determine bilateral trade between Africa and China from 1995 to 2017.

Design/methodology/approach

In line with the gravity model of trade, institutional, geographical and socio-economic determinants of China’s bilateral trade with 18 African oil/minerals exporting countries are examined by deploying Poisson pseudo-maximum likelihood and dynamic bias-corrected least squares dummy variable econometric techniques.

Findings

The results indicate that China’s oil/minerals imports from Africa are higher than imports of manufacturing and agricultural goods, and institutional structures indicate that a weak politically stable region with less control of corruption has a discernible effect on trade.

Research limitations/implications

Further insight can be gained if the type of manufactured goods being exported to China is examined; this is necessary given that China crowds out Africa’s manufactured goods. Therefore, this study recommends the need for Africa to continually strengthen its institutional structures to stimulate trade from other regions.

Originality/value

This study examines the quality of the institutional structures (political stability and corruption) in African oil/minerals exporting countries, considering that China has been alleged for capitalising on Africa’s weak institutional structures to trade with the resource-endowed region. For the first time, the UN COMTRADE HS product-country-partner-year trade data is used to examine on bilateral sector trade China–Africa links rather than proxies used in the studies of Biggeri and Sanfilippo (2009), De Grauwe et al. (2012) and Foad (2011) that did not capture the real trade value.
Stability control of permanent magnet and electromagnetic hybrid Halbach array electrodynamic suspension system
Authors: Luo Cheng , Zhang Kunlun , Liang Da , Jing Yongzhi
Published: August 2021

Purpose

The purpose of the paper is to study the stability control of permanent magnet (PM) and electromagnetic hybrid Halbach array electrodynamic suspension (EDS) system because of the poor suspension stability caused by the well-known under-damped nature of PM EDS system. The adjustment control is realized by PM and electromagnetic hybrid Halbach array, which is composed by winding active normal conductor coils on PM surface.

Design/methodology/approach

The three-dimensional (3-D) electromagnetic force analytical expression of PM and electromagnetic hybrid Halbach array EDS system for a nonmagnetic conductive plate is derived. And the accuracy of the derived equations is verified by a 3-D finite-element model (FEM). Basing on the 3-D levitation force expression, an acceleration feedback suspension controller is designed to suppress the vibration of PM EDS system, and the suspension stability of the system under the track and load disturbance was simulated and analyzed.

Findings

The 3-D electromagnetic force comparison of analytical model and FEM are in good agreement, which verifies the correctness of the analytical expression. The simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance. So it proved that the PM and electromagnetic hybrid Halbach array EDS system can overcome the poor suspension stability caused by the under-damped nature of PM EDS system through the designed acceleration feedback suspension controller.

Originality/value

This paper designed an acceleration feedback suspension controller to suppress the vibration of PM and electromagnetic hybrid Halbach array EDS system under external disturbance, basing on the derived levitation force analytical expression. And the simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance.
Extended hybrid cross-switched multilevel inverter circuit topology
Authors: Alizadeh Saeed , Farhadi-Kangarlu Mohammad , Tousi Behrouz
Published: August 2021

Purpose

Multilevel inverters (MLIs) have been studied widely over the past two decades because of their inherent advantages and interesting features. However, most of the newly introduced structures suffer from the increased standing voltage of the switches, which is defined as the maximum off-state voltage on the switches, losing modularity and increased number of direct current (DC) voltage sources. The purpose of this study is to propose a new hybrid MLI topology to alleviate the mentioned problems.

Design/methodology/approach

The proposed approach in this study includes using the advantage of two different topologies and combine them in a way that the advantages of both of the topologies are achieved. Therefore, the approach is to design a hybrid topology from two existing topologies so that a new topology has resulted.

Findings

This paper proposes a new hybrid MLI with lower power electronic switches and lowers DC voltage sources in comparison with the classic structures. The proposed MLIs maintain a balance between the number of switches, the standing voltage on the switches and the number of DC sources. The topology description, modulation method and comparative study have been presented. Also, another more reduced structure is presented for higher power factor operation. The MATLAB simulation and experimental results of a nine-level inverter have been presented to verify its operation.

Originality/value

The hybrid topology has a new structure that has not been presented before. It is important to emphasize that the topology combination and achieving the hybrid topology is wisely accomplished to improve some features of the MLI.
SME learning: leave it as a mess or solve it like a maze
Authors: Tam Steven
Published: August 2021

Purpose

This paper gives executives new perspective on how well employee learning is being managed in their small and medium-sized enterprises (SMEs).

Design/methodology/approach

The study adopted a rigorous mixed-method approach through questionnaires and semi-structured interviews, from categorizing a sample of Hong Kong SMEs into appropriate growth stages (inception, high-growth or maturity) to exploring their respective learning practices in their workplaces.

Findings

The most popular learning practices in SMEs at each growth stage are compared accordingly with the most/least important learning practices perceived by their employees from another set of results (Tam and Gray, 2021). Differences or mismatches are noted for reporting.

Research limitations/implications

Additional samples of SMEs, including those in other countries, are encouraged to broaden the horizon.

Practical implications

The findings help SME executives understand the dynamics of employee learning in their workplaces across growth stages. Knowing what learning practices are offered by the firm and what learning practices are valued by the employee will practically improve the firm’s training/learning strategies to benefit organizational development.

Originality/value

It is among the first studies examining SME learning with firm growth as well as sorting the learning practices into some traceable patterns for managerial convenience.
Easter eggs and semiotic cues: embedded meaning as early adolescents engage in programming-as-writing
Authors: Hagge Julia
Published: August 2021

Purpose

The purpose of this paper is to examine the ways in which early adolescent programmers embed meaning in their digital media created within an online programming community called Scratch.

Design/methodology/approach

The author completed an 18-month descriptive case study with 5 early adolescent participants. The research design included a multimodal analytic analysis of participant artifacts and inductive analysis of semi-structured interviews and transcription frames.

Findings

Participants embedded meaning to achieve four primary purposes, namely, to guide visitors through exhibits, to story, to engage in conversation and to game. To achieve each goal, the participants embedded unique semantic cues within specific Scratch structures.

Research limitations/implications

Questions for how researchers in literacy and learning can further explore meaning-making within programming-as-writing are suggested.

Practical implications

Connections to the supportive structures within Scratch are discussed in the context of programming-as-writing. Considerations regarding the use of Scratch to promote programming-as-writing are provided for educators.

Originality/value

The findings in this study provide an introductory step toward an enhanced understanding of the ways in which youth embed meaning into digital media as they engage in programming-as-writing. Although coding has been researched within the context of computer science, the use of coding in multimodal composition should be explored as it relates to literacy practices.
Social media as a platform for information and support for coronavirus: analysis ofCOVID-19 Facebook groups
Authors: Motahari-Nezhad Hossein , Shekofteh Maryam , Andalib-Kondori Maryam
Published: August 2021

Purpose

This study aims to investigate the characteristics, as well as the purpose and posts of the COVID-19 Facebook groups.

Design/methodology/approach

A systematic search for COVID-19 Facebook groups was conducted on June 1, 2020. Characteristics of the groups were examined using descriptive statistics. Mann-Whitney test was used to study the differences between groups. The study of the most popular groups’ posts was also carried out using the content analysis method.

Findings

The groups had a combined membership of 2,729,061 users. A total of 147,885 posts were received. There were about approximately 60% public groups. A high percentage of the groups (86.5%) had descriptions. The results showed a significant relationship between the groups’ description status and the number of members (p-value = 0.016). The majority of COVID-19 Facebook groups (56%) were created to meet their members’ information needs. The highest number of studied posts were related to vaccination (35.2%), followed by curfew rules (19.6%) and symptoms (10.6%).

Originality/value

Translating these insights into policies and practices will put policymakers and health-care providers in a stronger position to make better use of Facebook groups to support and enhance public knowledge about COVID-19.
Process mining and lean six sigma: a novel approach to analyze the supply chain quality of a hospital
Authors: Ramires Francisco , Sampaio Paulo
Published: August 2021

Purpose

This paper aims to depict the practical execution of the problem-solving structure provided by the define, measure, analyze, improve and control (DMAIC) framework in combination with the analytical power provided by process mining capabilities, to improve the supply chain quality of a health-care provider.

Design/methodology/approach

Prior to the study, a literature review was conducted to identify existing frameworks combining six sigma with process mining. The authors use a descriptive case study approach to explain how the two methodologies blend across the different phases of DMAIC in a health-care setting.

Findings

This case study describes how analyzing data extracted from core information systems has significant value to improvement initiatives when complemented by traditional quality methods. By intersecting process mining techniques with lean six sigma tools, the researchers found 65% of orders not complying with the target ordering time and 200 redundant purchases with high operational costs.

Research limitations/implications

By depicting how the two methodologies can be intertwined, this paper complements existing research by presenting it as a viable quality improvement approach.

Practical implications

This paper provides insights for six sigma and process mining practitioners on the benefits of combining both methodologies within the DMAIC structure. Implementing this blended approach can bring visibility to operations and accelerate process improvement initiatives.

Originality/value

The prime value of this paper lies in the integration of traditional six sigma methods with process mining as a technological approach in a health-care context, going beyond existing research, which, to the best of the knowledge, lacks descriptive case studies.
Black Americans report greater resilience to suicide unless its interpersonally motivated and are more accepting of others right to die
Authors: Schuler Kaitlyn R. , Basu Natasha , Burcak Anja , Smith Phillip N.
Published: August 2021

Purpose

Suicide is a public health crisis that differentially affects racial and ethnic groups. Suicide is a public health crisis that differentially affects racial and ethnic groups. American Indians had the highest per capita suicide rates (11.1 for females and 33.4 for males) followed by White Americans (8.0 for females and 29.8 for males; Centers for Disease Control, 2019). There is an emerging focus on racial/ethnic disparities in suicide prevention research. Prior studies suggest that more accepting attitudes toward suicide are associated with elevated suicide risk status. As such, this study aims to examine the association between racial/ethnic identity and three attitude domains: the right to die, interpersonal gestures and resilience.

Design/methodology/approach

General linear models were used to compare racial/ethnic groups in right to die, interpersonal gestures and resilience attitudes.

Findings

Participants who identified as Native American or Black were more likely than participants who identified as White, Bi/Multi-racial and Hispanic to hold attitudes supporting interpersonal motivations for suicide. Participants who identified as Black were more likely than participants who identified as White to hold right to die attitudes. Participants who identified as Black were more likely than White participants to report not viewing suicide as an option. These results suggest that racial/ethnic identity impacts attitudes toward suicide. People who identify as Native American or Black may be more likely to see suicide as acceptable for interpersonal reasons despite those who identify as Black being less likely to see suicide as an option. This study has implications for suicide prevention programs and interventions within racial/ethnic communities. Focusing interventions on attitudes supporting interpersonal motivations for suicide may increase effectiveness within Native American and Black communities.

Originality/value

This study aimed to fill a gap in suicide prevention research by examining associations between racial/ethnic identity and responses to a multidimensional attitude toward suicide measure. No prior study has compared attitudes across multiple domains and racial/ethnic groups.