bluuebunny/crossref_metadata_2025 huggingface dataset:
Broadband Electrostatic Waves Behind Dipolarization Front: Observations and Analyses
Authors: Guo Z. Z. , Fu H. S. , Cao J. B. , Yu Y. , Chen Z. Z. , Xu Y. , Liu Y. Y. , Wang Z. , Chen G. , Xiong X.
Published: December 2021

Using high‐resolution MMS data, we report the observations of broadband electrostatic waves associated with parallel electron temperature anisotropy () behind a dipolarization front (DF). These electrostatic waves include electrostatic solitary waves and electron cyclotron waves. To quantify electron anisotropy, we define the parallel flux anisotropy parameter , where is phase space densities at each energy. By performing correlation analyses between parallel flux anisotropies () and power spectral densities (PSDs) of these waves, we find that: (a) in 0.8–20 keV are positively correlated with the parallel electric field fluctuations in 50–3,000 Hz; (b) in 0.8–20 keV are positively correlated with perpendicular electric field fluctuations in all frequency ranges; (c) the correlation between parallel flux anisotropies and perpendicular electric field fluctuations is more significant in this case. We also discuss the possibility of electron firehose instability and wave–particle interactions. Our study promotes the understanding of the properties and dynamics of DFs.
Progressive p-channel vertical transistors fabricated using electrodeposited copper oxide designed with grain boundary tunability
Authors: Jung Sung Hyeon , Yang Ji Sook , Kim Young Been , Deshpande Nishad G. , Kim Dong Su , Choi Ji Hoon , Suh Hee Won , Lee Hak Hyeon , Cho Hyung Koun
Published: December 2021

In this study, we designed a new transistor structure without spacers using an electrodeposition method for the active layer. We strategically utilized grain boundary tunability for the fabrication of spacer-free p-type vertical transistors.
Individualised Homoeopathy in the Treatment of Onycholysis: An Evidence-Based Clinical Case Report
Authors: Debnath Dhiraj , Banerjee Abhiram , Rahaman Md Mostafijur , Choubey Gurudev
Published: December 2021

Introduction Onycholysis is a chronic nail disorder characterised by the progressive separation of the nail plate from the underlying nail bed. Apart from causing pain and discomfort, it affects the quality of life of an individual due to its visualised cosmetic appearance.

Case Summary A 45-year-old female presented with complete loss of nail plate of the left middle finger for 1 month. At the first visit, homoeopathic medicine Tuberculinum bovinum was prescribed and the patient was followed up periodically for 4 months. A series of photographs captured at the first visit and in subsequent visits objectively document the gradual regrowth of her nail plate. Various aspects of her subjective improvement were documented by three validated outcome measurement scales. The patient herself assessed that, after 4 months of follow-up, she is ‘back to normal’ for her main complaint as well as for the overall well-being, which is documented as a +4 score in ‘Outcome in Relation to Impact on Daily Living’ (ORIDL) scale. The Dermatology Life Quality Index (DLQI) score was reduced from 20 at the first visit to 1 after 4 months of treatment. Modified Naranjo Criteria for Homeopathy (MONARCH) score recorded at the final visit (+8 in ‘-6 to +13’ scale) is suggestive of a high likelihood that the improvement in the patient can be attributed to the homoeopathic treatment provided.

Conclusion This clinical case report is presented here to critically document the effect of individualised homoeopathic treatment in onycholysis within a plausible timeframe.
Homeopathic Treatment of Subclinical Hypothyroidism—A Series of 19 Cases
Authors: Grelle Luiz Carlos Esteves , Camacho Luiz Antonio Bastos
Published: December 2021

Background Subclinical hypothyroidism (SCH) is a common clinical problem. Controversy surrounds the definition, clinical importance, and need for prompt diagnosis and treatment of the mild form of SCH.

Aim The aim of the study was to analyze the evolution of serum thyroid stimulating hormone (TSH) levels after a therapeutic homeopathic intervention in women older than 40 years with SCH.

Methods This study is a retrospective series of 19 cases of SCH, with serum TSH levels between 5 and 10 mIU/L, treated exclusively with homeopathic medicines prescribed on an individualized basis.

Results Nineteen patients were included according to the inclusion and exclusion criteria. Their mean age was 56 years, they were followed for a mean duration of 69 months, the mean number of serum TSH level measurements was 18, and the intervention was successful for 13 patients.

Conclusion The homeopathic therapeutic intervention was successful in 68% of the patients, with serum TSH levels back within the normal range (0.5–5.0 mIU/L).
A Randomised Placebo-Controlled Trial to Assess the Efficacy of Osteoarthritic nosode in the Treatment of Knee Osteoarthritis
Authors: Sexena Reteka , Jain Tarkeshwar
Published: December 2021

Background Knee osteoarthritis (OA) is the most common musculoskeletal disease that affects the ability for sitting on the chair, standing, walking and climbing stairs and various other daily living activities of an affected individual.

Objective The primary objective of the study was to assess the efficacy of Osteoarthritic nosode in the treatment of knee OA on the symptomatic and functional domains in comparison to control group with knee-specific exercises as co-intervention in both the groups.

Materials and Methods It was a single blind randomised controlled trial study conducted at the out/inpatient department of Dr Madan Pratap Khunteta Homoeopathic Medical College, Hospital & Research Centre and Dr Girendra Pal Homoeopathic Hospital, Homoeopathy University, Saipura, Sanganer, Jaipur for a period of 1 year where cases were registered for first 9 months so that minimum of 3 months follow-up can be obtained during the course of the study. Total 50 patients who were radiographically diagnosed to be suffering from knee OA excluding Grade 4 of knee OA were allocated equally and randomly into two treatment groups. The patients in Group A received placebo and physiotherapy and patients in Group B received Osteoarthritic nosode and physiotherapy. The changes in patients' symptomatic and functional domain were evaluated by Knee Outcome Survey-Activity of Daily Living Scale (KOS- ADLS) questionnaire score assessed at the baseline and after 3 months (six follow-ups at 15 days interval) of treatment.

Results Out of 50 patients enrolled, 45 patients completed the trial. Those patients who had completed 3 months of follow-up, that is, 6 follow-ups at 15 days interval, were included in the study. The results showed that the patients with knee OA in Group B had significant improvement in both symptomatic and functional domains after treatment when compared with their initial status and when compared with Group A. Group A (placebo and physiotherapy) showed non-significant to no improvement in 72% of cases and 16% were aggravated when assessed on the symptomatic and functional domains. Group B (OA nosode and physiotherapy) showed mild to marked improvement in 80% of cases, whereas 12% showed non-significant to no improvement when assessed on the symptomatic and functional domains.

Conclusion Osteoarthritic nosode with physiotherapy is significantly effective than placebo with physiotherapy in the management of cases of knee OA.
Pyoderma Gangrenosum after Cardiac Surgery
Authors: Petrov Asen , Kappert Utz , Schmidt Torsten , Matschke Klaus Ehrhard , Wilbring Manuel
Published: December 2021

Background Pyoderma gangrenosum after cardiac surgery is a rare, noninfectious ulcerating skin disease mimicking sternal wound infection.

Methods A systematic search of literature for pyoderma gangrenosum complicating cases of cardiac surgery was conducted between September 1985 and September 2020 on PubMed and Cochrane databases. A systematic review and detailed overview of clinical presentation, diagnostic, treatment, and outcome is provided.

Results A total of 15 studies enclosing 15 patients suffering from pyoderma gangrenosum following cardiac surgery were identified. Onset of symptoms was observed after a median of 5 days. Patients were predominantly male (81.3%) with a median age of 64 years. Typical clinical presentation mimicked sternal site infection, mainly by means of mediastinitis. Specific signs were rapid progression, erythematous to violaceous color of the wound border, accompanied by unspecific symptoms including fever, malaise, and severe pain. Additionally, pathergy (development of ulcers at the sites of minor cutaneous trauma) was reported frequently. Biopsy is mandatory with a cutaneous neutrophilic inflammation confirming the diagnosis. Initial treatment mostly (75.0% of reported cases) was misled, addressing suspicion of surgical site infection. After correct diagnosis, the treatment was switched to an immunosuppressive therapy. Full sternal wound closure took between 5 weeks and 5 months. Reported case mortality was 12.5% in actually low-risk surgeries.

Conclusion Despite pyoderma gangrenosum has typical signs, it remains an exclusion diagnosis. The treatment is completely opposite to the main differential diagnosis—the typical surgical site infection. Knowledge about diagnosis and treatment is essential in the context of avoiding fatal mistreatment.
Ejection Fraction Recovery after Coronary Artery Bypass Grafting for Ischemic Cardiomyopathy
Authors: Ntinopoulos Vasileios , Papadopoulos Nestoras , Odavic Dragan , Haeussler Achim , Dzemali Omer
Published: December 2021

Background Controversy exists about left ventricular systolic function recovery after coronary artery bypass grafting in patients with ischemic cardiomyopathy. The aim of this study is to evaluate the temporal evolvement of left ventricular systolic function after coronary artery bypass surgery in patients with ischemic cardiomyopathy.

Patients and Methods A total of 50 patients with coronary artery disease and left ventricular ejection fraction (LVEF) ≤35% underwent isolated coronary artery bypass grafting in a single center in the period 2017 to 2019. We performed a retrospective analysis of the echocardiographic and clinical follow-up data at 3 months and 1 year postoperatively.

Results Median LVEF preoperatively was 25% (20–33%), mean patient age was 66 ± 8.2 years, 33 (66%) patients were operated off-pump, and 22 (44%) procedures were non-elective. There was no in-hospital myocardial infarction, stroke, and repeat revascularization. Three (6%) patients underwent re-exploration for bleeding or tamponade. In-hospital mortality was 8% and 1-year mortality was 12%. At 1 year postoperatively, there was no repeat revascularization, no myocardial infarction, 1 (2.6%) patient had a transient ischemic attack, and 10 (20%) patients required an implantable defibrillator. There was a statistically significant median ejection fraction increase at 3 months (15% [5–22%], p < 0.0001) and 1 year (23% [13–25%], p < 0.0001) postoperatively, with an absolute increase ≥10% in 32 (74.4%) and 30 (78.9%) patients at 3 months and 1 year, respectively.

Conclusion Patients with ischemic cardiomyopathy undergoing coronary artery bypass surgery show continuous recovery of left ventricular systolic function in the first postoperative year.
Comparative Analysis of Abrasive Materials and Polishing System on the Surface Roughness of Heat-Polymerized Acrylic Resins
Authors: Onwubu Stanley Chibuzor , Mdluli Phumlane Selby
Published: December 2021

Objective The aim of this in vitro experiment was to see how the operator's manual skills, polishing equipment, and abrasive materials affected the surface roughness of denture base resins.

Materials and Methods Forty polymethyl methacrylate (PMMA) specimens were created and polished by using two different polishing systems, namely hand and automatic polishing machines. Three operators hand-polished 30 of specimens with eggshell powder and pumice, while 10 were automatically polished (n = 5). A profilometer was used to determine the average surface roughness (Ra) after polishing. The Ra values for the specimens hand-polished were analyzed by using paired sample testing. The Ra values for all polished specimens were analyzed by using a one-way ANOVA. Differences between the two abrasive materials as well as the polishing system were determined by using the Bonferonni tests (p = 0.05).

Results and Conclusion For the PMMA specimens hand-polished, there was a strong connection in the Ra values. There were also significant variations in the Ra values across the three operators (p < 0.001). The automated technique created a substantially smoother surface than the traditional technique (p = 0.001). The greatest Ra values (0.20 µm) were found in specimens polished traditionally by using pumice, whereas the lowest Ra values (0.04 µm) were found in specimens polished mechanically with eggshell powder. The automated polishing system was the most effective polishing method when the Ra values were connected to the level of smoothness.
Converting Dissertation to Journal Article: Why and How?
Authors: Nayak Chaturbhuja
Published: December 2021

Research work embodied in a master's dissertation remains confined to a limited domain of the researcher, supervisor/co-supervisor and university library. It is desirable that the dissertation material be published in a reputed journal for various reasons including career growth of the researcher, recognition by the professional body, dissemination to a wider audience etc. Writing a research article from a dissertation does not mean just to shorten the latter mechanically or a cut-paste method. For the novice writer, it is a daunting task, but rewarding experience as well, to convert a dissertation to an article. Advice and support of the supervisor and senior colleagues having good experience in research as well as publication should be taken who can navigate the publication process, following the guidelines of the target journal. This article presents a synthesis of guidelines and practices to be followed by the researchers to see that the outcomes of their incessant and tireless efforts in preparing the dissertations be documented through publishable articles.
Impact of the National Policy on Integrative and Complementary Practices on Brazilian Public Homeopathy Services
Authors: Lemonica Renata , Patricio Karina Pavao
Published: December 2021

Background Homeopathy has been experiencing a period of expansion in Brazil due to its practical relevance in the face of new global and national health demands, culminating in the launch in 2006 of the National Policy for Integrative and Complementary Practices (NPICP) by the Ministry of Health of Brazil, which standardized and regularized the position of homeopathy within the Brazilian Unified Health System (SUS).

Aims To understand the impact of the guidelines proposed by the NPICP on homeopathy services in the SUS, specifically in the south-east region of Brazil, according to the perceptions of their managers.

Methods This is a descriptive, exploratory research study with a qualitative approach, conducted in homeopathy services in the south-east region of Brazil, through semi-structured interviews and with data processed using content analysis.

Results The data show the importance of the NPICP in regulating and offering homeopathy in the services studied. However, the NPICP's objective of promoting and fully developing integrative and complementary practices has not been achieved because it has failed to translate strategies into actions.

Conclusion Though important to the development of homeopathy services in any given location, policies stated in the NPICP were revealed to have limited impact on the implementation and development of new services. Without further legislation, training programs and appropriate budget allocation, new services will be unable to thrive and their users unable to benefit from a more comprehensive approach to healthcare.
National Survey Regarding Motivation and Conditions of Physicians Working in a Pediatric Cardiac Intensive Care Unit
Authors: Hanser Anja , Hofbeck Michael , Knies Ralf , Kumpf Matthias , Müller Nicole , Heimberg Ellen
Published: December 2021

Background The professional demands on the expertise in pediatric intensive care have continuously increased in recent years. Due to a lack of applicants, the staffing of a continuous shift service with qualified medical staff poses major challenges to the hospitals.

Methods A web-based questionnaire with 27 predominantly matrix questions on working conditions and motivation for working in this area was sent to pediatric hospitals throughout Germany.

Results 165 doctors responded to the survey. The average age of the participants was 35.2 years. The average weekend work load reported by 79% of the respondents was 2 weekends per month, 70% of the study participants performed five to seven night shifts per month. 92% of the respondents stated that they basically enjoyed working in the intensive care unit (ICU). When asked to prioritize the working conditions, an appreciative working atmosphere in the team was named as priority 1 by 57%, followed by good guidance in the independent performance of interventions (25%) and good working conditions (19%).

Discussion The survey result shows that neither aspects of work–life balance nor payments are the key issues selecting the interesting, but physically and emotionally demanding job in pediatric ICU.

Conclusion When evaluating vocational training in pediatric intensive care medicine, the immediate working atmosphere in the team with mutual respect and understanding and the guidance in training are more important than the general conditions.
Orbital Metastasis as Initial Clinical Presentation in a Patient of Hepatocellular Carcinoma – A Rare Case with Review of Literature
Authors: Rana Sakshi , Khosla Divya , Periasamy Kannan , Kapoor Rakesh , Bhardwaj Sunny , Madan Renu , Goyal Shikha , Rajwanshi Arvind
Published: December 2021

Orbital metastasis, as the initial clinical presentation in hepatocellular carcinoma (HCC), is a rare manifestation. A 66-year-old male patient presented with a history of protrusion of the eyeballs, double vision, and swelling over the left side of the head for 8 months. Magnetic resonance imaging of the brain with orbit revealed a heterogeneous lesion in the left frontal lobe causing its destruction with intraorbital and intracranial extension. Triphasic contrast-enhanced computed tomography was suggestive of multiple hypodense areas in both lobes of the liver. Tissue diagnosis from the liver was suggestive of HCC. A diagnosis of multifocal HCC with orbital metastasis was made. The patient was treated with palliative radiotherapy and sorafenib. Orbital metastasis in HCC is rare. Prognosis is somber in such cases. The treatment should focus on providing palliation from symptoms.
Pregnancy Outcomes among Women with Class III Obesity with Pre-diabetic Early Hemoglobin A1C
Authors: Dillon Jacquelyn , Mitchell Courtney J. , Ellett Tressa , Siegel Anne , Denoble Anna E. , Dotters-Katz Sarah K.
Published: December 2021

Objective We aimed to assess the risk of developing gestational diabetes mellitus (GDM) in women with a normal A1C (<5.7) compared with those with an A1C in the pre-diabetic range (5.7–6.4).

Study Design This study comprises of a retrospective cohort of non-anomalous singleton pregnancies with maternal body mass index (BMI) ≥40 at a single institution from 2013 to 2017. Pregnancies with multiple gestation, late entry to care, type 1 or 2 diabetes, and missing diabetes-screening information were excluded. The primary outcome was development of GDM. Secondary outcomes included fetal growth restriction, macrosomia, gestational age at delivery, large for gestational age, delivery BMI at delivery, total weight gain in pregnancy, induction of labor, shoulder dystocia, and cesarean delivery. Bivariate statistics were used to compare demographics, pregnancy complications, and delivery characteristics of women who had an early A1C < 5.7 and A1C 5.7 to 6.4. Multivariable analyses were used to estimate the odds of the primary outcome.

Results Eighty women (68%) had an early A1C <5.7 and 38 (32%) had a A1C 5.7 to 6.4. Women in the lower A1C group were less likely to be Black (45 vs. 74%, p = 0.01). No differences in other baseline demographics were observed. The median A1C was 5.3 for women with A1C < 5.7 and 5.8 for women with A1C 5.7 to 6.4 (p < 0.001). GDM was significantly more common in women with A1C 5.7 to 6.4 (3.8 vs. 24%, p = 0.002). Women with pre-diabetic range A1C had an odd ratio of 11.1 (95% CI 2.49–48.8) for GDM compared with women with a normal A1C.

Conclusion Women with class III obesity and a pre-diabetic range A1C are at an increased risk for gestational diabetes when compared with those with a normal A1C in early pregnancy.

Key Points
Preterm Singleton Birth Rate during the COVID-19 Lockdown: A Population-Based Study
Authors: Leibovitch Leah , Reichman Brian , Mimouni Francis , Zaslavsky-Paltiel Inna , Lerner-Geva Liat , Wasserteil Netanel , Sagiv Nadav , Daas Suha , Almashanu Shlomo , Strauss Tzipora
Published: December 2021

Objective The aim of the study is to evaluate the effect of the coronavirus disease 2019 (COVID-19) pandemic national lockdown period on the rate of singleton preterm births in Israel.

Study Design This is a population-based cohort study of 3,41,291 singleton infants born in the months of January to July 2017 to 2020. Multivariable logistic regression analyses were used to estimate the influence of period and year on the rates of preterm births during the lockdown period (11th March − 5th May 2020) compared with rates before (January 1st 2020 − March 10th 2020), and after the lockdown (May 6th 2020–June 30th 2020) and to the corresponding periods in 2017to 2019.

Results During the lockdown period the preterm birth rate (primary outcome) decreased by 9.7% from 5.05 to 4.56% in the pre-lockdown period (p = 0.006), an adjusted decrease of −0.52% (95% confidence interval −0.89%; −0.15%), odds ratio 0.898 (95% confidence interval 0.832; 0.970).

Conclusion The rate of singleton preterm births declined by 9.7% during the COVID-19 pandemic national lockdown period in Israel.

Key Points
Scientific Publishing Differences between Sexes in Cardiology, Cardiac, and General Surgery
Authors: Färber Gloria , Alscher Leonhard , Heyne Estelle , Doenst Torsten , Schwarzer Michael
Published: December 2021

Background Research and scientific publications are important for the advancement of science but also for the individual career development. While women have become the majority of students in medicine we do not know about female presence and scientific activity in cardiac surgery. We thus aimed to compare scientific output of women and men in German University departments of cardiac surgery with cardiology departments focusing on the same organ and surgical departments not addressing the heart (general surgery) of 34 universities in Germany.

Methods Personnel working at University departments was identified on the institutions internet homepage in 2014. Publications in 2011 to 2013 on PubMed were identified. Author and manuscript characteristics were determined.

Results A lower proportion of women were working in cardiac surgery (25%) compared with cardiology (35%) and general (32%) surgery independent of executive function or academic degree. Scientifically active women published fewer manuscripts per capita than men both, in total and as first author. Additionally, the mean and the cumulated journal impact factor of the journals chosen was lower for women compared with men in cardiology but not in cardiac and general surgery.

Conclusion We conclude that the differences in scientific activity between women and men are more pronounced in cardiology compared with general and cardiac surgery, indicating that a higher proportion of women in a field does not result in reduced differences between sexes. The low number of women together with the lower number of manuscripts in cardiac surgery may render the appointment of women as directors challenging.
The Risk of Readmission after Early Postpartum Discharge during the COVID-19 Pandemic
Authors: Gulersen Moti , Husk Gregg , Lenchner Erez , Blitz Matthew J. , Rafael Timothy J. , Rochelson Burton , Chakravarthy Shruti , Grunebaum Amos , Chervenak Frank A. , Fruhman Gary , Jones Monique De Four , Schwartz Benjamin , Nimaroff Michael , Bornstein Eran
Published: December 2021

Objective To determine whether early postpartum discharge during the coronavirus disease 2019 (COVID-19) pandemic was associated with a change in the odds of maternal postpartum readmissions.

Study Design This is a retrospective analysis of uncomplicated postpartum low-risk women in seven obstetrical units within a large New York health system. We compared the rate of postpartum readmissions within 6 weeks of delivery between two groups: low-risk women who had early postpartum discharge as part of our protocol during the COVID-19 pandemic (April 1–June 15, 2020) and similar low-risk patients with routine postpartum discharge from the same study centers 1 year prior. Statistical analysis included the use of Wilcoxon's rank-sum and chi-squared tests, Nelson–Aalen cumulative hazard curves, and multivariate logistic regression.

Results Of the 8,206 patients included, 4,038 (49.2%) were patients who had early postpartum discharge during the COVID-19 pandemic and 4,168 (50.8%) were patients with routine postpartum discharge prior to the COVID-19 pandemic. The rates of postpartum readmissions after vaginal delivery (1.0 vs. 0.9%; adjusted odds ratio [OR]: 0.75, 95% confidence interval [CI]: 0.39–1.45) and cesarean delivery (1.5 vs. 1.9%; adjusted OR: 0.65, 95% CI: 0.29–1.45) were similar between the two groups. Demographic risk factors for postpartum readmission included Medicaid insurance and obesity.

Conclusion Early postpartum discharge during the COVID-19 pandemic was associated with no change in the odds of maternal postpartum readmissions after low-risk vaginal or cesarean deliveries. Early postpartum discharge for low-risk patients to shorten hospital length of stay should be considered in the face of public health crises.

Key Points
Left Atrial Myxoma and Antiphospholipid Syndrome—A Case Report
Authors: Meter Mijo , Meter Diana , Ceprnja Toni , Perkovic Dijana
Published: December 2021

Cardiac myxoma (CM) is the most frequent type of primary cardiac neoplasm and is responsible for 58 to 80% of primary cardiac tumors. The antiphospholipid syndrome (APS) occurs most commonly in the systemic lupus erythematosus but it can be also found in other conditions. The coexistence of CM and APS is rarely described in the literature. We report an unusual case of the left atrial myxoma and concomitant APS in a female patient who presented with right-sided hemiplegia. Although rare, we must think about the CM in patients with a newly diagnosed APS and left atrial mass. Nevertheless, we must make a distinction from other possible cardiac structures, especially atrial thrombus. Transthoracic echocardiography is the most frequently used initial imaging modality to detect CM. The aim of this case report was to emphasize that additional imaging modalities and multidisciplinary approach are mandatory in making a proper diagnosis and to choose a further treatment strategy.
A Comparison of the Flipped Classroom Model for Medical Student Education in Ophthalmology before and during the COVID-19 Pandemic
Authors: Yom Kelly H. , Diel Ryan J. , Kemp Pavlina S.
Published: December 2021

Background The coronavirus disease 2019 (COVID-19) pandemic has necessitated a shift of medical education to online learning in lieu of traditional clinic-based rotations. The flipped classroom model, which has been shown to be an effective approach to the medical student ophthalmology curriculum, shows promise as a method of learning that can be shared virtually. As such, the aim of this study was to investigate the effectiveness of a flipped classroom approach to the primary care-focused ophthalmology clerkship delivered entirely online in the face of the COVID-19 pandemic.

Methods Medical students who completed the 2-week introductory clinical ophthalmology clerkship from July 2019 to July 2020 were included in this study. The curriculum centers on a flipped classroom model and was delivered in person prior to March 2020, after which it transitioned to an online format for 5 months. A survey was administered to students completing this rotation, which utilized 6-point Likert scales to assess students' interest in the field of ophthalmology, perceptions of the flipped classroom curriculum, and confidence in evaluating ophthalmic complaints. The cohort that completed in-person learning was then compared with the cohort that completed online learning.

Results A total of 112 responding students were included in our analysis, with 68/82 students from the in-person cohort and 44/66 students in the online cohort responding to the survey. Students who participated in the online virtual clerkship were equally likely to feel comfortable evaluating eye complaints than those who participated in the in-person clerkship, and more likely to report that the course enhanced their interest in ophthalmology. However, online students were less likely to feel comfortable using the direct ophthalmoscope compared with those in the in-person cohort.

Conclusion Regardless of its mode of delivery, the flipped classroom model is able to impart confidence in evaluating ophthalmic complaints and interest in the field of ophthalmology to medical students. While online learning can never serve as a full replacement for learning physical examination skills and other important clinical experiences, there are aspects of the virtual flipped classroom that do not compromise student's learning and engagement and may be implemented into curricula even after clinical activities are allowed to resume.
ECO-spotting: looking for extremely compact objects with bosonic fields
Authors: Cardoso Vitor , Macedo Caio F B , Maeda Kei-ichi , Okawa Hirotada
Published: December 2021

Black holes are thought to describe the geometry of massive, dark compact objects in the Universe. To further support and quantify this long-held belief requires knowledge of possible, if exotic alternatives. Here, we wish to understand how compact can self-gravitating solutions be. We discuss theories with a well-posed initial value problem, consisting in either a single self-interacting scalar, vector or both. We focus on spherically symmetric solutions, investigating the influence of self-interacting potentials into the compactness of the solutions, in particular those that allow for flat-spacetime solutions. We are able to connect such stars to hairy black hole solutions, which emerge as a zero-mass black hole. We show that such stars can have light rings, but their compactness is never parametrically close to that of black holes. The challenge of finding black hole mimickers to investigate full numerical-relativity binary setups remains open.
Adaptive surface geometry determination in multi-material x-ray computed tomography using fringe projection
Authors: Großeheide Jonas , Geiger Kilian , Schmidt Ânderson , Bütow Calvin , Montavon Benjamin , Schmitt Robert H
Published: December 2021

One of the main challenges during digital post-processing of x-ray computed tomography (XCT) measurement data is the reconstruction of the surface geometry of the measured objects. Conventionally, the surface geometry is defined as an isosurface with identical greyscale values or via gradient-based surface geometry determination. However, these approaches are susceptible to measurement artefacts. Due to the complex surface geometry and rough surface, XCT measurements of additively manufactured (AM) parts are particularly prone to measurement artefacts caused by various physical effects when the x-rays penetrate the material. The irregular greyscale values at the measured surface geometry render commonly used single threshold greyscale value based isosurfaces as insufficient for representing the external and internal surface of the measured objects. This issue becomes particularly apparent when measuring multi-material objects, such as additively manufactured polymer objects with integrated radio-frequency identification tags. To address this challenge, this study presents a methodology for reliable surface geometry determination of XCT data based on previously acquired fringe projection (FP) data. For this purpose, the conventionally acquired surfaces geometries from the XCT and FP measurements are extracted, pre-processed and registered to each other before being merged into a single mesh. This merged data set is subsequently used as a starting point or reference for a locally adaptive threshold surface geometry determination algorithm, which is able to capture the surface geometry at a sub-voxel resolution. In order to validate the methodology and confirm the envisaged benefits, selected geometry elements of the resulting surface geometry from measurements samples manufactured by additive manufacturing with integrated RIFD tags are compared to coordinate measurement machine reference measurements. The results indicate a more robust surface geometry detection against artefacts especially for multi-material applications where the x-ray absorbance of the inner material is higher than the absorbance of the outer material. In summary, the main result is a systematic approach to merge FP and XCT data, in order to combine the advantages of both techniques, which leads to an artefact-reduced surface geometry determination for multi-material applications and a reduction of deviations from reference measurements compared to conventional methods by nearly 35%.
On the combined flow and structural measurements via robotic volumetric PTV
Authors: M A Mitrotta Francesco , Sodja Jurij , Sciacchitano Andrea
Published: December 2021

This study describes a novel measurement approach for combined flow and structural measurements in wind tunnels using robotic volumetric particle tracking velocimetry (PTV). The measurement approach is based on the application of a particle tracking algorithm on images including flow or structure tracers, where the latter are implemented by means of fiducial markers. The main steps of the measurement procedure comprise the simultaneous acquisition of flow and structure tracers in the same images, the distinction of the tracers leading to separate flow and structure image sets, the application of Lagrangian particle tracking and the further post-processing, and recombination of the obtained data. The approach is applied to the fluid-structure interaction between a flexible plate with a span of 1.2 m and a periodic gust. The total measurement volume amounts approximately to 150 liters. A phase-averaged description of the FSI problem is presented, with the focus on the effects of the spatio-temporal averaging of the flow information. The structural displacements obtained from the PTV system are validated against a scanning vibrometer. The phase-averaged displacement of the markers is also analyzed, assessing both the validity of the phase-averaged approach and the physical coherence of their motion with respect to a structural model of the plate. It is found that robotic volumetric PTV is suitable for the measurement of large-scale structural displacements, while it should not be used to measure small-scale vibrations. Finally, a visualization of the combined measurement is presented, together with an analysis of the consistency between the measured structure and flow field.
Ultrasound-based sensors for respiratory motion assessment in multimodality PET imaging
Authors: Madore Bruno , Belsley Gabriela , Cheng Cheng-Chieh , Preiswerk Frank , Kijewski Marie Foley , Wu Pei-Hsin , Martell Laurel B , Pluim Josien P W , Di Carli Marcelo , Moore Stephen C
Published: December 2021

Breathing motion can displace internal organs by up to several cm; as such, it is a primary factor limiting image quality in medical imaging. Motion can also complicate matters when trying to fuse images from different modalities, acquired at different locations and/or on different days. Currently available devices for monitoring breathing motion often do so indirectly, by detecting changes in the outline of the torso rather than the internal motion itself, and these devices are often fixed to floors, ceilings or walls, and thus cannot accompany patients from one location to another. We have developed small ultrasound-based sensors, referred to as ‘organ configuration motion’ (OCM) sensors, that attach to the skin and provide rich motion-sensitive information. In the present work we tested the ability of OCM sensors to enable respiratory gating during in vivo PET imaging. A motion phantom involving an FDG solution was assembled, and two cancer patients scheduled for a clinical PET/CT exam were recruited for this study. OCM signals were used to help reconstruct phantom and in vivo data into time series of motion-resolved images. As expected, the motion-resolved images captured the underlying motion. In Patient #1, a single large lesion proved to be mostly stationary through the breathing cycle. However, in Patient #2, several small lesions were mobile during breathing, and our proposed new approach captured their breathing-related displacements. In summary, a relatively inexpensive hardware solution was developed here for respiration monitoring. Because the proposed sensors attach to the skin, as opposed to walls or ceilings, they can accompany patients from one procedure to the next, potentially allowing data gathered in different places and at different times to be combined and compared in ways that account for breathing motion.
Design of JL-CFET (junctionless complementary field effect transistor)-based inverter for low power applications
Authors: Lee Sumi , Choi Yejoo , Won Sang Min , Son Donghee , Baac Hyoung Won , Shin Changhwan
Published: December 2021

Junctionless complementary field effect transistor (JL-CFET) is an emerging device that needs a small layout area and low fabrication cost. However, in order for the JL-CFET to be adopted for low power applications, two main constraints need to be overcome: (a) a high work function of metal gate and (b) a low drain current. In this work, an optimal device design is proposed to overcome those problems, by analyzing various performance metrics, such as on-state drive current, subthreshold swing, drain induced barrier lowering, propagation delay time, and ring oscillator’s oscillation frequency, which are extracted from various structures of JL-CFET. In addition, the negative capacitance effect in JL-CFET is examined to address the limit from device structures.
Impact of the gamma and neutron attenuation behaviors on the functionally graded composite materials
Authors: Gökmen Uğur , Özkan Zübeyde , Bilge Ocak Sema
Published: December 2021

Gamma-ray and neutron shielding properties of the AA6082 + TiO2 (0–50 wt%) functionally graded composite materials (FGCMs) were investigated using the PSD software. The values of the mean free path (MFP), half-value layer (HVL), linear attenuation coefficients (LAC), mass attenuation coefficient (MAC), tenth-value layer (TVL), exposure buildup factors (EBF), effective atomic number (Z

eff
), effective conductivity (C

eff
), and fast neutron removal cross-sections (FNRC) were found for the energy range between 0.015–15 MeV. The increase in the TiO2 content in the AA6082 composite material has raised the values of MAC and LAC. The calculations for the EBFs were carried out using the G-P fitting method for the energy range between 0.015–15 MeV and penetration depth of up to 40 mfp. The results revealed that HVL values ranged between 0.01–0.116 cm, TVL values ranged between 0.01–0.385 cm, FNRC values ranged between 7.918–10.017 cm−1, and C

eff
values ranged between 5.67 × 1010 and 9.85 × 1010 S m−1. The AA6082 + TiO2 (50%) composite material was observed to provide the maximum photon and neutron shielding capacity since it offered the highest Z

eff
, MAC, and FNRC values, and the lowest HVL value. In terms of several aspects, the research is considered original. Besides contributing to several technologies including nanotechnology and space technologies, present research’s results may contribute to nuclear technology.
Determine the Physical Mechanism and Source Region of Beat Wave Modulation by Changing the Frequency of HF Waves
Authors: Guo Zhe , Fang Hanxian , Honary Farideh
Published: December 2021

This paper introduces a new approach for the determination of the source region of BW (beat wave) modulation. This type of modulation is achieved by transmitting HF continuous waves with a frequency difference of f, where f is the frequency of modulated ELF/VLF (extremely low frequency/very low frequency) waves from two sub-arrays of a high power HF transmitter. Despite the advantages of BW modulation in terms of generating more stable ELF/VLF signal and high modulation efficiency, there exists a controversy on the physical mechanism of BW and its source region. In this paper, the two controversial theories, i.e. BW based on D-E region thermal nonlinearity and BW based on F region ponderomotive nonlinearity are examined for cases where each of these two theories exists exclusively or both of them exist simultaneously. According to the analysis and the simulation results presented in this paper, it is found that the generated VLF signal amplitude exhibits significant variation as a function of HF frequency in different source regions. Therefore, this characteristic can be utilised as a potential new approach to determine the physical mechanism and source location of BW.
Exploration of structural, optical, and photoluminescent properties of (1 – x)NiCo2O4/xPbS nanocomposites for optoelectronic applications
Authors: Heiba Zein K , Mohamed Mohamed Bakr , Farag Noura M , Badawi Ali
Published: December 2021

The (1 – x)NiCo2O4/xPbS (0 ≤ x ≤ 0.2) nanocomposite samples are synthesized using the hydrothermal and thermolysis procedures. The different phases developed in the obtained nanocomposite samples are accurately determined using the x-ray diffraction technique equipped with a line-detector. The percentage of the formed phases (NiCo2O4 (NCO), PbS, PbSO4), structural and microstructure parameters are determined using Rietveld quantitative phase analysis. The transmission electron microscope (TEM) images and Rietveld analysis reveal almost isotropic particle size in the nano range with a very narrow size distribution. The obtained phase percentage of PbS and PbSO4 are smaller than nominated values (x) suggesting dissolving of some Pb and S ions into NCO which is then confirmed by the analysis of Fourier-transform infrared (FTIR) spectra of nanocomposite samples. The absorption spectra are modified upon doping NCO with PbS. The optical band gaps of the nanocomposites increase as the amount of PbS augments. The effect of alloying on extinction coefficient, refractive index, dielectric constant, optical conductivity, the intensity, and emitted color from the photoluminescence of the nanocomposite samples are also studied. The refractive index value of NCO and NCO–PbS nanocomposite samples exhibit normal dispersions. The photoluminescent measurements reveal that the NCO–PbS nanocomposites can emit a violet color. The improvement in the values of the nonlinear optical (NLO) parameters of pristine NCO at high frequencies or the nanocomposite samples at low frequencies, are made them used in NLO photonic devices.
Physical aspects of magnetized Jeffrey nanomaterial flow with irreversibility analysis
Authors: Haq Fazal , Khan Muhammad Ijaz , Khan Sami Ullah , Abualnaja Khadijah M , El-Shorbagy M A
Published: December 2021

This research presents the applications of entropy generation phenomenon in incompressible flow of Jeffrey nanofluid in the presence of distinct thermal features. The novel aspects of various features, such as Joule heating, porous medium, dissipation features, and radiative mechanism are addressed. In order to improve thermal transportation systems based on nanomaterials, convective boundary conditions are introduced. The thermal viscoelastic nanofluid model is expressed in terms of differential equations. The problem is presented via nonlinear differential equations for which analytical expressions are obtained by using the homotopy analysis method (HAM). The accuracy of solution is ensured. The effective outcomes of all physical parameters associated with the flow model are carefully examined and underlined through various curves. The observations summarized from current analysis reveal that the presence of a permeability parameter offers resistance to the flow. A monotonic decrement in local Nusselt number is noted with Hartmann number and Prandtl number. Moreover, entropy generation and Bejan number increases with radiation parameter and fluid parameter.
Lifetime measurement of a particular deep crack failure on a flat-type divertor mockup under cyclic high heat flux loading conditions
Authors: Huang Shenghong , Pan Zhiwei , Jiang Menglai , Zhao Kai , Su Yong
Published: December 2021

Plasma facing components are key to enduring high heat flux (HHF) loading from high-temperature plasma in nuclear fusion reactors. Understanding their thermal-mechanical behavior and cracking failure mechanisms related to structural designs and fabrication technologies during HHF loading is of great significance for improving their servicing performance and R&D (research and development) levels. In this study, a particular deep cracking failure process on the tungsten layer of a flat-type divertor mockup during 1800 cycles of 10 MW m−2 HHF loadings is completely monitored and measured with a special improved digital image correlation (DIC) technique. It is found that the DIC measurement under the HHF loading environment is improved successfully to capture fine deformation and strain fields with a spatial resolution less than 0.35 mm so that field strain on a 1 mm thick copper interlayer and deep crack initiation at several microns scale on the tungsten layer are measured out. Based on both full field and local strain and displacement measurements of the target divertor mockup, the thermal mechanical behaviors from deformation to crack initiation and propagation are successfully measured and traced. It is revealed that for the baseline copper interlayer design of a flat-type divertor mockup, the accumulation of plastic strain in the copper interlayer during ratcheting damage induces enough tensile stress on the tungsten layer during HHF cycles, leading to cracking and fracture failures even in its elastic state earlier than the copper LCF lifetime. Current Structural Design Criteria for ITER In-Vessel Components rules fail to cover this kind of ratcheting cracking failure mode in the design stage. New design models or mechanical validation rules to resolve this design blind spot should be established in the future.
Direct cross-section measurement of 13C(α,n)16O in the s-process Gamow peak
Authors: Balibrea-Correa J. , Ciani G. F. , Csedreki L. , Best A. , Formicola A. , Imbriani G. , Leva A. Di , Junker M.
Published: December 2021

The main neutron source for the slow neutron capture process in low mass Asymptotic Giant Branch stars is the 13C(α,n)16O reaction. This reaction is responsible for the production of half of the natural heavy elements in the Universe. Up to now, no direct measurements have reached the energy region of interest for astrophysics, the so called Gamow window, which lies between 140 and 230 keV in the center of mass. In this paper we describe the experiment carried out at the LUNA experiment at the Laboratori Nazionali del Gran Sasso and present first preliminary results.
Study of Ξ−-atom based on the ΞN interaction from QCD on lattice
Authors: Inoue Takashi
Published: December 2021

We report our preliminary theoretical study on Ξ−-atom based on a ΞN interaction extracted from QCD on lattice. First, we study ΞN interaction in nuclear matter. Then, we make a Ξ-nucleus potential in a simple folding procedure. We study Ξ−-60Ni system as an example, and find that energy levels of the atom are shifted downward due to the ΞN interaction.