bluuebunny/crossref_metadata_2025 huggingface dataset:
Stick-slip investigation of dual drilling and reaming bottom hole assembly
Authors: Al Dushaishi Mohammed F , Alsaba Mortadha T , Abbas Ahmed K , Tashtoush Tariq
Published: July 2021

Drillstring vibration is known to cause failures of drilling equipment, including the drill bit. In particular, stick-slip vibration has been known for causing premature failure of the drill bit, hence resulting in reducing the rate of penetration. With dual reaming while drilling, cutting forces are acting on the drillstring due to the simultaneous contact of the reamer and the drill bit. Field studies have shown dramatic changes in the dynamics of the bottom hole assembly due to the dual cutting actions. This paper investigates the dynamics of bottom hole assembly for dual reaming and drilling operation, with emphasis on stick-slip vibrations due to the reamer and the bit contact with the formation. A coupled vibration model representing the drillstring was created to simulate the stick-slip vibrations caused by the bit and reamer interactions using the finite element approach. The numerical analysis showed an elevated stick-slip vibration due to the dual-action of the reamer and the bit. Sensitivity analysis indicated that the cutter aggressiveness for the bit and the reamer are the most significant parameters affecting stick-slip behavior.
Numerical study of heat transfer of laminar air flow in perforated trapezoidal corrugated plate-fin ducts
Authors: Piradl Morteza , Pesteei Seyed Mehdi
Published: July 2021

A novel trapezoidal corrugated perforated fin core is proposed in this study. The porosity of the fin surface, or perforations, is indicated to promote the unusual behavior of increasing the heat transfer coefficient, while reducing the friction factor with respect to its non-perforated counterpart, primarily due to surface transpiration, which leads to better flow mixing and successive boundary layer disturbances. This allows the heat exchanger to be built much more compact with a smaller volume and a front area. To highlight this, the results of the computational simulations for velocity and temperature fields in typical trapezoidal corrugated perforated plate-fin ducts are presented. Constant property, fully or periodically developed laminar airflow [Formula: see text] with Reynolds number [Formula: see text] passing through inter-fin passages, with fins at constant wall temperature T, in which the fin walls have perforations equally spaced along the length of the duct, is considered and a parametric study of the effects of the duct geometry, including the variation of the inclination angle [Formula: see text] of the diverging plane, the aspect ratio of the channel or period length and fin density effects [Formula: see text] and the converging-diverging ratio of the plate [Formula: see text], is performed. The results of the Fanning friction factor and the Nusselt number over the wide range of the Reynolds number, which was treated in this study, show the improved performance. The improvement is assessed quantitatively by the area goodness factor ( j/ f) relative to Re, comparison with simple flat channels. It is seen that increasing ϕ to [Formula: see text] improves the core performance; As ϕ increases beyond [Formula: see text], performance starts to decrease. j/ f increases with increasing λ; and λ = 3.6 acts as an inflection point. It is better to have a large λ value for lower Re range and vice versa. As ε increases, the performance increases; so, the highest area goodness factor value occurs at [Formula: see text]. In case 11, with [Formula: see text], [Formula: see text], and [Formula: see text] at Re = 200, compared to the non-perforated channel, the friction factor decreases about 11%, and the area goodness factor increases about 72%. Thus, the area goodness factor of the perforated case reaches 0.37.
Thinking Vertically: Facilitating Transition for Students With Disabilities
Authors: Draper Ellary A.
Published: July 2021

Within special education, transition is a required part of a student’s Individualized Education Program, specifically the transition from school to postsecondary life. Recently, special educators have begun to investigate best practices of transition at all levels—early intervention into school, elementary to middle school, and middle to high school. Yet in music education transition is not widely discussed for students with and without disabilities. This article includes an overview of best practices of transition in special education and provides ideas on how to implement these practices in music education to better facilitate transition between schools to postsecondary life for students with disabilities.
Construction of piezoelectric and flexoelectric models of composites by asymptotic homogenization and application to laminates
Authors: Nasimsobhan Maryam , Ganghoffer Jean-François , Shamshirsaz Mahnaz
Published: July 2021

The effective piezoelectric and flexoelectric properties of heterogeneous solid bodies with constituents obeying a piezoelectric behavior are evaluated in full generality, based on the asymptotic expansion method. The successive situations of materials obeying a piezoelectric and flexoelectric behavior at the macroscale is envisaged in the present work. Closed-form expressions for the effective flexoelectric properties are obtained for stratified materials. A general theory for laminated piezoelectric plates is formulated on the basis of the formulated asymptotic models, and the response of the homogeneous substitution plate is evaluated for a loading consisting of a pure bending moment, triggering electric fields and strain and electric fields gradients within the plate thickness. The local mechanical and electric fields at the microscopic level within the initial heterogeneous stratified domain are evaluated by solving unit cell boundary value problems for the localization operators. An effective flexoelectric plate model for a stratified composite is constructed, showing the generation of the gradient of an electric field under application of a pure bending moment.
Hierarchal Formation of Trust on Peer-to-Peer Lodging Platforms
Authors: Luo Yi , Tang Liang (Rebecca) , Kim Eojina , Wang Xi
Published: July 2021

Based on the concept of trust from a hierarchical approach and with the support of processing fluency theory, the current study investigates customer trust, and its relationships with flow experience, satisfaction, and repatronage intention on peer-to-peer (P2P) lodging platforms. Customer flow experience on the Airbnb platform is verified to be an antecedent of economy-based trust. The hierarchical organization of trust is also proved applicable in the context of sharing economy websites (economy-based trust → information-based trust → identification-based trust). The results provide marketers and hosts of P2P lodging platforms effective strategies to assist customers form trust in sequential steps and in multiple perspectives. The present study is a pioneer which in depth examined trust formation in the emerging sharing economy platforms.
Experimental study on the effect of surface texture on tribological properties of nanodiamond films under water lubrication
Authors: Yan Ying , Lei Xuelin , He Yun
Published: July 2021

The effect of nanoscale surface texture on the frictional and wear performances of nanocrystalline diamond films under water-lubricating conditions were comparatively investigated using a reciprocating ball-on-flat tribometer. Although the untreated nanocrystalline diamond film shows a stable frictional state with an average friction coefficient of 0.26, the subsequent textured films show a beneficial effect on rapidly reducing the friction coefficient, which decreased to a stable value of 0.1. Furthermore, compared with the nanocrystalline diamond coating, the textured films showed a large decreasing rate of the corresponding ball wear rate from 4.16 × 10−3 to 1.15 × 10−3 mm3/N/m. This is due to the fact that the hydrodynamic fluid film composed of water and debris can provide a good lubrication environment, so the entire friction process has reached the state of fluid lubrication. Meanwhile, the surface texture can greatly improve the hydrophilicity of the diamond films, and as the texture density increases, the water contact angle decreases from 94.75° of the nanocrystalline diamond film to 78.5° of the textured films. The proper textured diamond film (NCD90) exhibits superior tribological properties among all tested diamond films, such as short run-in period, low coefficient of friction, and wear rate.
Sibling rivalry: Voters for radical left parties and their competitors in Germany, Sweden, and the Netherlands
Authors: Hansen Michael A. , Olsen Jonathan
Published: July 2021

This article analyzes voters for Radical Left Parties (RLPs) in three countries—Germany, the Netherlands, and Sweden. Belonging to the democratic socialist subtype of RLPs, parties in these countries find themselves in an intense “sibling rivalry” with social democratic and green parties for voters on the left side of the political spectrum. There is little existing scholarly analysis of the demand-side of RLPs in competition with their competitors. We fill this gap using the European Social Survey (ESS), testing various demographic and attitudinal variables to disentangle the vote on the left. We conclude that what distinguishes the RLP voter from the social democratic or green voter in these countries is not socio-demographic characteristics but rather three attitudinal variables - satisfaction with democracy, attitudes toward immigrants, and the role of government in reducing income disparities. Furthermore, we find that given these three attitudinal variables, the probability to vote for an RLP compared to a social democratic or green party increases dramatically the farther the voter places him/herself to the left.
Anthropology and the politics of alterity: A Latin American dialectic and its relevance for ontological anthropologies
Authors: Lazar Sian
Published: July 2021

Recent anglophone ontological anthropologies have an important Latin American intellectual and political history that is rarely fully acknowledged. This article outlines some of that history, arguing that debates about the politics of this ‘ontological turn’ should be read in the context of a tension between political economy and cosmological approaches that have been a feature of Latin American anthropology in some form since the early 20th century, and that are deeply implicated in histories of conquest and colonialism, including internal colonialism. This conceptual history helps to explain both the desire of some scholars to avoid a certain kind of politicisation and the argument that methodological and theoretical innovation within anthropology is political in itself. But it also means that ontological anthropology encounters some of the same challenges faced by indigenous movements confronted with similar choices.
Fabulous: Remarks on scenarism, simulations, and scenarios
Authors: Faubion James D
Published: July 2021

In “Governing the Future,” Limor Samimian-Darash does much to illuminate scenarism and the divergence between the simulations and the scenarios that constitute the chief apparatuses of anticipatory governance. She renders both of them fabulations, drawing the concept as well as the divergence between simulations and scenarios from the epistemological and ontological precedents that Henri Bergson and Gilles Deleuze have set. Her renderings are compelling, but leave many epistemological and ontological issues unresolved. I address three of these issues. First, it has to do with what sort of concept scenarism might be. Second, it has to do with the poetics of simulations and scenarios. Third, it has to do with the virtuality or actuality of simulations and scenarios, in their planning as in their enactments.
Reasons to Pretend Orgasm, Mate Retention, and Relationship Satisfaction in Brazilian Women
Authors: Biermann Mariana C. , Farias Mariana G. , Meneses Glysa O. , Lopes Guilherme S. , Shackelford Todd K.
Published: July 2021

We investigated the relationship between Brazilian women’s reported reasons for pretending orgasm, their performance of mate retention behaviors, and their relationship satisfaction. Additionally, we secured evidence of the validity and reliability of a Brazilian-Portuguese adaptation of the Reasons to Pretend Orgasm Inventory (RPOI). Participants were 295 Brazilian women in a heterosexual relationship ( Mage = 24.9 years, SDage = 5.4 years). Participants completed a Brazilian-Portuguese adaptation of the Mate Retention Inventory-Short Form, and the translated RPOI (the Escala de Razões para Fingir Orgasmo; ERFO). The resulting 47-item ERFO represents well the original 63-item RPOI. The frequency with which Brazilian women pretend orgasm was negatively associated with their relationship satisfaction. Our sample size may not be sufficient to detect small effects. In addition, due to the exploratory nature of the study, the results should be interpreted with caution and future research may attempt to replicate these findings with larger samples and in other countries.
Partisanship Versus Democracy: Voting in Turkey’s Competitive Authoritarian Elections
Authors: Demirel-Pegg Tijen , Dusso Aaron
Published: July 2021

Do voters care about anti-democratic behavior by their leaders? While political pundits and academics often hope that they do, there has been little research that tests the effects that specific anti-democratic actions have on voters during elections. This is because there are few clear instances where violations of democratic norms are so visible to the average voter that one would expect it to have an effect, above and beyond traditional predictors of the vote. However, the recent elections in Turkey offer a unique opportunity to test the effect that nullifying an entire election (an unequivocal violation of democratic norms) has on voters. We do exactly that with a survey of voters following the election re-do. We find that even in such an extraordinary circumstance, voters rely on standard voting drivers like partisanship, rather than concern for the functioning of democracy itself. Ultimately, our findings have important implications for voting in competitive authoritarian regimes, as they fail to show that anti-democratic behavior is punished.
A quinoxaline-based compound ameliorates bone loss in ovariectomized mice
Authors: Zhou Ying , Xue Xiaoyan , Guo Yanyan , Liu Huan , Hou Zheng , Chen Zhou , Wang Ning , Li Fen , Wang Yang
Published: July 2021

DMB (6,7-dichloro-2-methylsulfonyl-3-Ntert-butylaminoquinoxaline) is a quinoxaline-based compound that has been investigated as a glucagon-like peptide-1 receptor (GLP-1R) agonist. To clarify anti-osteoporosis effect of DMB, an osteoporotic mice model was established by ovariectomy (OVX) operation. The OVX mice were given intraperitoneally DMB, exendin-4 (EX-4), or 17β-estradiol (E2) for two months. Then bone mass and structure, and bone morphometric parameters were examined by micro-CT. Weight gain and food consumption, bone turnover markers, and biomechanical strength of the femur were tested, and bone histomorphometry was analyzed. The food intake and weight gain was obviously reduced by E2 or EX-4, but not DMB. However, DMB or EX-4 treatment obviously inhibited skeletal deterioration and enhanced bone strength. The improvement involved in the increased osteoblast number and level of bone formation markers, and reduced osteoclasts number and level of bone resorption markers. In addition, DMB was found to stimulate osteoblastogenesis-related marker gene expression. These results demonstrated that DMB ameliorated bone loss mainly via induction of bone formation, which suggests that the small molecule compound might be applied to the management of postmenopausal osteoporosis.
The Role of Team–Member Exchange in Proactive Personality and Employees’ Proactive Behaviors: The Moderating Effect of Transformational Leadership
Authors: Lai Fong-Yi , Lin Cheng-Chen , Lu Szu-Chi , Chen Hsiao-Ling
Published: July 2021

This study conceptualizes team–member exchange as a mediator and transformational leadership as a moderator to understand the role of proactive personality in two types of proactive behaviors (affiliative and challenging). Considering the issue of common method variance, data were collected following a multitemporal and multisource research design, and the hypotheses were tested on a sample of 210 participants. The results showed that after controlling leader–member exchange, team–member exchange mediated the relationship between proactive personality and employees’ proactive behaviors. In addition, transformational leadership strengthened the positive relationship between the team–member exchange and challenging proactive behavior. Moreover, transformational leadership had a stronger moderating effect on challenging proactive behavior than affiliative proactive behavior. Strengths, limitations, practical implications, and directions for future research are discussed.
Survey on the Research Misconduct and Questionable Research Practices of Medical Students, PhD Students, and Supervisors at the Zagreb School of Medicine in Croatia
Authors: Ljubenković Ana Marija , Borovečki Ana , Ćurković Marko , Hofmann Bjørn , Holm Søren
Published: July 2021

This cross-sectional study evaluates the knowledge, attitudes, experiences, and behavior of final year medical students, PhD students, and supervisors at the School of Medicine of the University of Zagreb in relation to research misconduct, questionable research practices, and the research environment. The overall response rate was 36.4% (68%–100% for the paper survey and 8%–15% for the online surveys). The analysis reveals statistically significant differences in attitude scores between PhD students and supervisors, the latter having attitudes more in concordance with accepted norms. The results overall show a nonnegligible incidence of self-reported misconduct and questionable research practices, as well as some problematic attitudes towards misconduct and questionable research practices. The incidence of problematic authorship practices was particularly high. The research environment was evaluated as being mostly supportive of research integrity.
Unplanned Office Visits Following Outpatient Hand Surgery
Authors: Townsend Clay B. , Henry Tyler W. , Lutsky Kevin F. , Beredjiklian Pedro K.
Published: July 2021

Background

Returning to the office for an unplanned visit postoperatively can be burdensome to both the patient and provider. The purpose of this study was to quantify the rate of unplanned office visits after common soft tissue hand surgeries and assess the reasons for these unplanned visits.

Methods

Patients who underwent common soft tissue hand surgeries over a 6-month time period were queried from an electronic medical record database. Manual chart review was performed to record patient demographics, unplanned visits within 3 months postoperatively, and specific reasons for unplanned visits. A total of 1648 postoperative follow-up visits in 1224 patients were included in analysis.

Results

Within 3 months of surgery, 6.3% (103/1648) of postoperative visits were found to be unplanned. There was no difference in the rate of unplanned visits among the included surgeries ( P = .46). The most common reasons for an unplanned office visit overall were wound problems (34%), pain (23.3%), and stiffness (17.5%). The trigger finger release group had significantly more patients return to the office for stiffness ( P = .01), the De Quervain release group had significantly more patients return for pain ( P = .02), and the carpal tunnel release group had significantly more patients return for persistent symptoms ( P < .05).

Conclusions

Unplanned office visits represented about 1 of 16 postoperative visits. Orthopedic surgeons should be aware of the most common reasons for these visits and be prepared to address these problems promptly. Preoperative patient education on these potential problems may help decrease the frequency of unplanned follow-up visits.
Treatment of Pyogenic Flexor Tenosynovitis in the Emergency Department Setting With WALANT Technique
Authors: Braza Matthew E. , Kelley Joshua P. , Kelpin John P. , Fahrenkopf Matthew P. , Do Viet H.
Published: July 2021

Background

The standard of care for treatment of pyogenic flexor tenosynovitis (PFT) involves antibiotic therapy and prompt irrigation of the flexor tendon sheath, traditionally performed in the operating room. With the acceptance of wide-awake local anesthesia no tourniquet (WALANT) hand surgery and its potential ability to minimize time to flexor tendon sheath irrigation, we sought to determine whether closed irrigation of the flexor tendon sheath could be safely and effectively performed in the emergency department setting with WALANT technique.

Methods

A retrospective review was conducted of the senior author’s hand surgery consultations over a 12-month period. Six patients were identified who were diagnosed with PFT and subsequently underwent irrigation of the flexor tendon sheath using WALANT technique. Patient outcomes such as length of hospital stay, need for reoperation, infectious etiology, perioperative complications, and postprocedure range of motion (ROM) were identified.

Results

Six patients with diagnosis of PFT underwent irrigation of the flexor tendon sheath in the emergency department with local anesthesia only. The irrigation procedures were all well-tolerated. One patient required reoperation due to lack of appropriate clinical improvement following initial irrigation. Four of 6 patients regained their preinjury ROM while the remaining 2 patients had mild proximal interphalangeal joint extension lag. There were no complications associated with the procedures.

Conclusions

Surgical treatment of PFT with closed irrigation of the flexor tendon sheath in the emergency department utilizing WALANT technique was safe, effective, and well-tolerated. Local anesthesia alone can be used effectively for irrigation procedures of the flexor tendon sheath.
Amenorrhea
Authors: Munjal Pooja , Nair Manju
Published: July 2021

Amenorrhoea is defined as absence of menstruation in women of reproductive age. Primary amenorrhoea is a failure to start menstruation by the age of 13 years without secondary sexual characteristics or by the age of 15 years with normal secondary sexual characteristics. Secondary amenorrhoea is the absence of menstruation for 6 months in a woman with normal prior menstruation. Secondary amenorrhea is more common type, with a prevalence of between 3 and 4%. This compares with a prevalence of 0.3% for those with primary amenorrhea.
Predictors of health-related quality of life in musculoskeletal disease patients: a longitudinal analysis
Authors: Madrid-García Alfredo , León-Mateos Leticia , Pato Esperanza , Jover Juan A , Fernández-Gutiérrez Benjamín , Abasolo Lydia , Menasalvas Ernestina , Rodríguez-Rodríguez Luis
Published: July 2021

Introduction:

Rheumatic and musculoskeletal diseases (RMDs) have a significant impact on patients’ health-related quality of life (HRQoL) exacerbating disability, reducing independence and work capacity, among others. Predictors’ identification affecting HRQoL could help to place efforts that minimize the deleterious impact of these conditions on patients’ wellbeing. This study evaluates the influence of demographic and clinical predictors on the HRQoL of a cohort of RMD patients, measured using the Rosser classification index (RCI).

Methods:

We included patients attending the Hospital Clínico San Carlos (HCSC) rheumatology outpatient clinic from 1 April 2007 to 30 November 2017. The primary outcome was the HRQoL assessed in each of the patient’s visits using the RCI. Demographic and clinical variables extracted from a departmental electronic health record (EHR) were used as predictors: RMD diagnoses, treatments, comorbidities, and averaged HRQoL values from previous periods (for this last variable, values were imputed if no information was available). Association between predictors and HRQoL was analyzed using penalized generalized estimating equations (PGEEs). To account for imputation bias, the PGEE model was repeated excluding averaged HRQoL predictors, and common predictors were considered.

Discussion:

A total of 18,187 outpatients with 95,960 visits were included. From 410 initial predictors, 19 were independently associated with patients’ HRQoL in both PGEE models. Chronic kidney disease (CKD), an episode of prescription of third level analgesics, monoarthritis, and fibromyalgia diagnoses were associated with worse HRQoL. Conversely, the prescription in the previous visit of acid-lowering medication, colchicine, and third level analgesics was associated with better HRQoL.

Conclusion:

We have identified several diagnoses, treatments, and comorbidities independently associated with HRQoL in a cohort of outpatients attending a rheumatology clinic.
Explaining Individual Differences in Advantageous Inequity Aversion by Social-Affective Trait Dimensions and Family Environment
Authors: Yu Hongbo , Lu Chunlei , Gao Xiaoxue , Shen Bo , Liu Kui , Li Weijian , Xiao Yuqin , Yang Bo , Zhao Xudong , Crockett Molly. J. , Zhou Xiaolin
Published: July 2021

Humans are averse to both having less (i.e., disadvantageous inequity aversion [IA]) and having more than others (i.e., advantageous IA). However, the social-affective traits that drive individual differences in IA are not well understood. Here, by combining a modified dictator game and a computational model, we found in a sample of incarcerated adolescents ( N = 67) that callous-unemotional traits were specifically associated with low advantageous but not disadvantageous IA. We replicated and extended the finding in a large-scale university student sample ( N = 2,250) by adopting a dimensional approach to social-affective trait measures. We showed that advantageous IA was strongly and negatively associated with a trait dimension characterized by callousness and lack of social emotions (e.g., guilt and compassion). A supportive family environment negatively correlated with this trait dimension and positively with advantageous IA. These results identify a core set of social-affective dimensions specifically associated with advantageous IA.
Isolated Penile Calciphylaxis Diagnosed by Ultrasound Imaging in a New Dialysis Patient: A Case Report
Authors: Helmeczi Wryan , Pitre Tyler , Hudson Emma , Mondhe Suhas , Burns Kevin
Published: July 2021

Rationale:

The recognition of calciphylaxis often eludes practitioners because of its multiple ambiguous presentations. It classically targets areas of the body dense with adipose tissue. A heightened suspicion for the disorder is therefore required in the case of penile calciphylaxis, given its unconventional location. The diagnosis of calciphylaxis is also challenging as the gold standard for diagnosis is biopsy which can often yield equivocal results. Unfortunately, in penile calciphylaxis, the utility of biopsies is further debated due to their potential to precipitate new lesions and their decreased sensitivity due to the limited depth of tissue that can be sampled. For these reasons, it is important that practitioners recognize other accessible and accurate investigative tools which can aid in their diagnosis.

Presenting concerns of the patient:

We present the case of a 49-year-old man who presented to the emergency room with penile pain in the context of known chronic kidney disease secondary to diabetic nephropathy. The pain had been present for about a week, was exquisitely tender, and was initially associated with a faint violaceous lesion. This gentleman had just recently initiated peritoneal dialysis and had no other lesions on his body.

Diagnosis:

His pain was determined by ultrasound and plain radiograph to be secondary to calciphylaxis after two biopsies were nondiagnostic.

Interventions:

The patient had already made changes to his diet to reduce phosphate and calcium intake, and had been on phosphate-lowering therapy with both calcium and phosphate being within their respective target range. Following his diagnosis, this patient was promptly converted from peritoneal dialysis to hemodialysis with sodium thiosulphate and initiated hyperbaric oxygen therapy. This patient continues to be followed by nephrology and urology specialists.
Endocarditis Caused by Candida parapsilosis Presenting With Severe Thrombocytopenia in a Patient With Tetralogy of Fallot
Authors: Freddo Andrew M. , Mathur Swati , Dunlevy Hillary , Jaggers James , Khanna Amber
Published: July 2021

Infective endocarditis (IE) occurs more frequently in individuals living with congenital heart disease, often with high morbidity and mortality. Although gram-positive bacterial infections commonly cause IE, prosthetic valves are a known risk factor for fungal IE. We report a case of prosthetic pulmonary valve Candida parapsilosis IE in a 58-year-old male with repaired tetralogy of Fallot. He presented with fatigue, petechiae, and hematochezia. He had severe thrombocytopenia from idiopathic/immune thrombocytopenia purpura, which resolved with steroids and immunoglobulin. Treatment with antifungals as well as a surgical pulmonary valve replacement resulted in recovery without relapse at greater than a year.
A phase 2 study of nilotinib in pediatric patients with CML: long-term update on growth retardation and safety
Authors: Hijiya Nobuko , Maschan Alexey , Rizzari Carmelo , Shimada Hiroyuki , Dufour Carlo , Goto Hiroaki , Kang Hyoung Jin , Guinipero Terri , Karakas Zeynep , Bautista Francisco , Ducassou Stéphane , Yoo Keon Hee , Zwaan Christian Michel , Millot Frédéric , Patterson Briana , Samis Jill , Aimone Paola , Allepuz Alex , Titorenko Ksenia , Sosothikul Darintr
Published: July 2021

The phase 2, open-label study (DIALOG) of nilotinib in pediatric patients with Philadelphia chromosome-positive chronic myelogenous leukemia (CML) met its coprimary end points, showing sustained nilotinib efficacy in patients with newly diagnosed (ND) or imatinib/dasatinib resistant/intolerant (R/I) CML. This update assessed growth and safety profiles in patients who had completed ≥48, 28-day treatment cycles of nilotinib 230 mg/m2 twice daily, or previously discontinued the study. Height was assessed regularly and reported using standard deviation scores (SDSs) based on World Health Organization growth charts. All data were summarized descriptively (cutoff, 6 March 2019). Overall, 33 patients in the R/I cohort and 25 patients in the ND cohort received nilotinib. Each cohort showed a negative slope in height SDS over the course of the study, indicating attenuated growth rates during nilotinib treatment: overall median change from baseline in height SDS after 48 cycles was −0.54 SDS (range, − 1.6 to 0.4) and −0.91 SDS (−1.4 to −0.1) in R/I and ND cohorts, respectively. Patients in the R/I cohort were shorter at baseline than those in the ND cohort, and remained so throughout the study. The most common all-cause adverse events were increased blood bilirubin (53.4%), headache (46.6%), pyrexia (37.9%), and increased alanine transferase (36.2%). Apart from the impact on growth, the safety profile of nilotinib was generally consistent with previous reports. This study was registered on www.clinicaltrials.gov at #NCT01844765.
Associations between elevated kidney and liver biomarker ratios, metabolic syndrome and all-cause and coronary heart disease (CHD) mortality: analysis of the U.S. National Health and Nutrition Examination Survey (NHANES)
Authors: Oye-Somefun Akinkunle , Kuk Jennifer L. , Ardern Chris I.
Published: July 2021

Background

We examined the relationship between ratios of select biomarkers of kidney and liver function on all-cause and coronary heart disease (CHD) mortality, both in isolation, and in combination with metabolic syndrome (MetS), among adults (20 + years, n = 10,604).

Methods

Data was derived from the U.S. National Health and Nutrition Examination Survey (1999–2016) including public-use linked mortality follow-up files through December 31, 2015.

Results

Select biomarker ratios of kidney (UACR or albuminuria and BUN-CR) and liver (AST-ALT and GGT-ALP) function in isolation and in combination with MetS were associated with all-cause and CHD mortality. Compared to individuals with neither elevated biomarker ratios nor MetS (HR = 1.00, referent), increased risk of all-cause mortality was observed in the following groups: MetS with elevated UACR (HR, 95% CI = 2.57, 1.99–3.33), MetS with elevated AST-ALT (HR = 2.22, 1.61–3.07), elevated UACR without MetS (HR = 2.12, 1.65–2.72), and elevated AST-ALT without MetS (HR = 1.71, 1.35–2.18); no other biomarker ratios were associated with all-cause mortality. For cause-specific deaths, elevated risk of CHD mortality was associated with MetS with elevated UACR (HR = 1.67, 1.05–2.67), MetS with elevated AST-ALT (HR = 2.80, 1.62–4.86), and elevated BUN-CR without MetS (HR = 2.12, 1.12–4.04); no other biomarker ratios were associated with CHD mortality.

Conclusion

Future longitudinal studies are necessary to examine the utility of these biomarker ratios in risk stratification for chronic disease management.
Physicians’ decreased tendency to choose palliative care for patients with advanced dementia between 1999 and 2015
Authors: Haapasalmi Saila , Piili Reetta P. , Metsänoja Riina , Kellokumpu-Lehtinen Pirkko-Liisa I. , Lehto Juho T.
Published: July 2021

Background

Physicians’ decision-making for seriously ill patients with advanced dementia is of high importance, especially as the prevalence of dementia is rising rapidly, and includes many challenging ethical, medical and juridical aspects. We assessed the change in this decision-making over 16 years (from 1999 to 2015) and several background factors influencing physicians’ decision.

Methods

A postal survey including a hypothetical patient-scenario representing a patient with an advanced dementia and a life-threatening gastrointestinal bleeding was sent to 1182 and 1258 Finnish physicians in 1999 and 2015, respectively. The target groups were general practitioners (GPs), surgeons, internists and oncologists. The respondents were asked to choose between several life-prolonging and palliative care approaches. The influence of physicians’ background factors and attitudes on their decision were assessed.

Results

The response rate was 56%. A palliative care approach was chosen by 57 and 50% of the physicians in 1999 and 2015, respectively (p = 0.01). This change was statistically significant among GPs (50 vs 40%,p = 0.018) and oncologists (77 vs 56%,p = 0.011). GPs chose a palliative care approach less often than other responders in both years (50 vs. 63% in 1999 and 40 vs. 56% in 2015,p < 0.001). In logistic regression analysis, responding in 2015 and being a GP remained explanatory factors for a lower tendency to choose palliative care. The impact of family’s benefit on the decision-making decreased, whereas the influence of the patient’s benefit and ethical values as well as the patient’s or physician’s legal protection increased from 1999 to 2015.

Conclusions

Physicians chose a palliative care approach for a patient with advanced dementia and life-threatening bleeding less often in 2015 than in 1999. Specialty, attitudes and other background factors influenced significantly physician decision-making. Education on the identification and palliative care of the patients with late-stage dementia are needed to make these decisions more consistent.
Distance education perception scale for medical students: a validity and reliability study
Authors: Özkaya Güven , Aydin Mevlüt Okan , Alper Züleyha
Published: July 2021

Background

There are major changes in education strategies as higher education institutions urgently need to adopt distance education tools and practices due to the Covid-19 pandemic. Medical education is also trying to get out of this emergency using distance education. In this study, we aimed to develop a reliable and valid scale in order to evaluate the perceptions of medical students towards distance education.

Methods

The students taking part in the study were in the first five academic years of the medical faculty in Bursa in Turkey. At first, 57 items were determined to evaluate students’ perceptions. Content validity was examined according to the assessment of the expert team. Construct validity of these items was examined by exploratory and confirmatory factor analysis. Also, Cronbach’s alpha coefficients were calculated for reliability analysis. The medical students’ responses were scored using a five-point Likert scale.

Results

When the content validity was examined, the number of items was determined to be 38 items. Construct validity of these items was examined by exploratory and confirmatory factor analysis. Because of the exploratory factor analysis performed on the responses of 429 medical students, 22 items were included in four factors. This four-factor model was applied to 286 medical students and validated by confirmatory factor analysis. Also, Cronbach’s alpha coefficients were calculated for reliability analysis and values were between 0.713 and 0.930.

Conclusions

This study demonstrated validation and reliability of perceptions of distance education for medical students. We suggest a 22-item model with a four-factorial scale.
Health economic evidence in clinical guidelines in South Africa: a mixed-methods study
Authors: Wilkinson Maryke , Hofman Karen J. , Young Taryn , Schmidt Bey-Marrié , Kredo Tamara
Published: July 2021

Background

Evidence-informed clinical practice guidelines (CPGs) are useful tools to inform transparent healthcare decision-making. Consideration of health economic evidence (HEE) during CPG development in a structured manner remains a challenge globally and locally. This study explored the views, current practice, training needs and challenges faced by CPG developers in the production and use of HEE for CPGs in South Africa.

Methods

This mixed-methods study comprised an online survey and a focus group discussion. The survey was piloted and subsequently sent to CPG role players - evidence reviewers, CPG panellists, academics involved with training in relevant disciplines like health economics and public health, implementers and funders. The focus group participants hold strategic roles in CPG development and health economic activities nationally. The survey evaluated mean values, measures of variability, and percentages for Likert scales, while narrative components were thematically analysed. Focus group data were manually coded, thematically analysed and verified.

Results

The survey (n = 55 respondents to 245 surveys distributed) and one focus group (n = 5 participants from 10 people invited) occurred between October 2018 and February 2019. We found the most consistent reason why HEE should inform CPG decisions was ‘making more efficient use of limited financial resources’. This was explained by numerous context and methodological barriers. Focus groups participants noted that consideration of complex HEE are not achievable without bolstering skills in applying evidence-based medicine principles. Further concerns include lack of clarity of standard methods; inequitable and opaque topic selection across private and public sectors; inadequate skills of CPG panel members to use HEE; and the ability of health economists to communicate results in accessible ways. Overall, in the absence of clarity about process and methods, politics and interests may drive CPG decisions about which interventions to implement.

Conclusions

HEE should ideally be considered in CPG decisions in South Africa. However, this will remain hampered until the CPG community agree on methods and processes for using HEE in CPGs. Focused investment by national government to address the challenges identified by the study is imperative for a better return on investment as National Health Insurance moves forward.
Self-supervised deep learning model for COVID-19 lung CT image segmentation highlighting putative causal relationship among age, underlying disease and COVID-19
Authors: Fung Daryl L. X. , Liu Qian , Zammit Judah , Leung Carson Kai-Sang , Hu Pingzhao
Published: July 2021

Background

Coronavirus disease 2019 (COVID-19) is very contagious. Cases appear faster than the available Polymerase Chain Reaction test kits in many countries. Recently, lung computerized tomography (CT) has been used as an auxiliary COVID-19 testing approach. Automatic analysis of the lung CT images is needed to increase the diagnostic efficiency and release the human participant. Deep learning is successful in automatically solving computer vision problems. Thus, it can be introduced to the automatic and rapid COVID-19 CT diagnosis. Many advanced deep learning-based computer vison techniques were developed to increase the model performance but have not been introduced to medical image analysis.

Methods

In this study, we propose a self-supervised two-stage deep learning model to segment COVID-19 lesions (ground-glass opacity and consolidation) from chest CT images to support rapid COVID-19 diagnosis. The proposed deep learning model integrates several advanced computer vision techniques such as generative adversarial image inpainting, focal loss, and lookahead optimizer. Two real-life datasets were used to evaluate the model’s performance compared to the previous related works. To explore the clinical and biological mechanism of the predicted lesion segments, we extract some engineered features from the predicted lung lesions. We evaluate their mediation effects on the relationship of age with COVID-19 severity, as well as the relationship of underlying diseases with COVID-19 severity using statistic mediation analysis.

Results

The best overall F1 score is observed in the proposed self-supervised two-stage segmentation model (0.63) compared to the two related baseline models (0.55, 0.49). We also identified several CT image phenotypes that mediate the potential causal relationship between underlying diseases with COVID-19 severity as well as the potential causal relationship between age with COVID-19 severity.

Conclusions

This work contributes a promising COVID-19 lung CT image segmentation model and provides predicted lesion segments with potential clinical interpretability. The model could automatically segment the COVID-19 lesions from the raw CT images with higher accuracy than related works. The features of these lesions are associated with COVID-19 severity through mediating the known causal of the COVID-19 severity (age and underlying diseases).
VMP1, a novel prognostic biomarker, contributes to glioma development by regulating autophagy
Authors: Lin Wanzun , Sun Yun , Qiu Xianxin , Huang Qingting , Kong Lin , Lu Jiade J.
Published: July 2021

Background

Malignant glioma, especially glioblastoma, is a highly aggressive disease with a dismal prognosis. Vacuole membrane protein 1 (VMP1) is a critical autophagy-associated protein with roles in oncogenesis and tumor progression. However, the contribution of VMP1 to glioma development as well as its prognostic value has not been established.

Methods

The expression of VMP1 and clinicopathologic data for 1996 glioma samples were collected from authoritative public databases to explore its prognostic value. Lentiviral CRISPR-Cas9 gene editing system was performed to deplete VMP1 expression. Apoptosis assays, cell cycle assays, colony formation assays, and EdU incorporation analysis were conducted to validate the biological function of VMP1. Transmission electron microscopy was used to determine the role of VMP1 in regulating autophagy.

Results

VMP1 overexpression was associated with advanced disease and had a poor prognosis in patients with glioma. The depletion of VMP1 by CRISPR-Cas9 gene editing significantly inhibited cell proliferation, increased cell death, and induced cell cycle arrest. Mechanistically, VMP1 knockout blocked autophagic flux and thus sensitized glioma cells to radiotherapy and chemotherapy. Moreover, a nomogram model showed that VMP1 expression has high prognostic value for determining survival in glioma.

Conclusions

Our results provide insights into the pathological and biological functions of VMP1, including its roles in promoting tumor growth and progression, and support its value as a new diagnostic and prognostic biomarker for glioma.
The COVID-19 pandemic: doom to international medical electives? Results from two German elective databases
Authors: Egiz Abdullah , Storz Maximilian Andreas
Published: July 2021

Objective

International medical electives are an essential part of medical education and popular among medical students. During the COVID-19 pandemic, however, many students had assistantship placements postponed and electives cancelled. Educational institutions switched face-to-face campus-based teaching to virtual platforms. Although it is conceivable that international medical electives were particularly affected by this development, numerical data on this phenomenon is yet scarce. To investigate how the COVID-19 pandemic influenced the clinical elective behavior of German-speaking medical students, we systematically analyzed two large German online databases (Famulatur-Ranking and PJ-Ranking) cataloging medical elective experience testimonies.

Results

The COVID-19 pandemic substantially reduced the number of German medical students undertaking abroad medical electives. Between 2018 and 2020, a total of 10,976 reports were uploaded to both databases. We observed a notable decline in abroad elective reports in 2020. Prior to the COVID-19 pandemic, almost 5% of reports uploaded to “PJ-ranking” covered an international medical elective. This number dropped to 1.68% in 2020. Analyzing “Famulaturranking”, we observed a comparable phenomenon. While 4.74% of reports in 2019 covered an international elective, the number dropped to 2.02% in 2020. The long-term consequences of this phenomenon will be subject to future research.
Attention based multi-component spatiotemporal cross-domain neural network model for wireless cellular network traffic prediction
Authors: Zeng Qingtian , Sun Qiang , Chen Geng , Duan Hua
Published: July 2021

Wireless cellular traffic prediction is a critical issue for researchers and practitioners in the 5G/B5G field. However, it is very challenging since the wireless cellular traffic usually shows high nonlinearities and complex patterns. Most existing wireless cellular traffic prediction methods lack the abilities of modeling the dynamic spatial–temporal correlations of wireless cellular traffic data, thus cannot yield satisfactory prediction results. In order to improve the accuracy of 5G/B5G cellular network traffic prediction, an attention-based multi-component spatiotemporal cross-domain neural network model (att-MCSTCNet) is proposed, which uses Conv-LSTM or Conv-GRU for neighbor data, daily cycle data, and weekly cycle data modeling, and then assigns different weights to the three kinds of feature data through the attention layer, improves their feature extraction ability, and suppresses the feature information that interferes with the prediction time. Finally, the model is combined with timestamp feature embedding, multiple cross-domain data fusion, and jointly with other models to assist the model in traffic prediction. Experimental results show that compared with the existing models, the prediction performance of the proposed model is better. Among them, the RMSE performance of the att-MCSTCNet (Conv-LSTM) model on Sms, Call, and Internet datasets is improved by 13.70 ~ 54.96%, 10.50 ~ 28.15%, and 35.85 ~ 100.23%, respectively, compared with other existing models. The RMSE performance of the att-MCSTCNet (Conv-GRU) model on Sms, Call, and Internet datasets is about 14.56 ~ 55.82%, 12.24 ~ 29.89%, and 38.79 ~ 103.17% higher than other existing models, respectively.