bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring bandgap generation mechanism of phonon crystal
Authors: Wang Chiming , Xiao Wangqiang , Wu Dehui , Lin Changming , Xiao Jingjing , Yao Kaihan , Luo Yuanyi , Xu Zhanhao , Zhang Kunpeng
Published: December 2019

In this paper, based on the theoretical research of structural modal analysis, different types of phonon crystal modal structures are designed for the first time, and the characteristics and the generation mechanism of the bandgap were studied through theoretical calculations and experiments. According to the phenomenon in the experimental results, we can find that the vibration transmission characteristics of phonon crystal structure α3 are the best, and it is also superior to that of phonon crystal structure α10 (full period structure). Therefore, the comparison of theoretical analysis with experimental phenomena shows that the bandgap generation mechanism should be modal resonance instead of local resonance in the finite periodic structure. The profound reason lies in there is no separate Z direction local vibration mode of periodic structure in the vibration mode of finite structure, and the bandgap of finite structure is the mode superposition torsional resonance mechanism between scatterer and substrate mode.
Efficient quantum transport in a multi-site system combining classical noise and quantum baths
Authors: Kurt Arzu , Rossi Matteo A C , Piilo Jyrki
Published: December 2019

We study the population dynamics and quantum transport efficiency of a multi-site dissipative system driven by a random telegraph noise (RTN) by using a variational polaron master equation for both linear chain and ring configurations. By using two different environment descriptions—RTN only and a thermal bath+RTN—we show that the presence of the classical noise has a non-trivial role on quantum transport. We observe that there exist large areas of parameter space where the combined bath+RTN influence is clearly beneficial for populating the target state of the transport, and for average trapping time and transport efficiency when accounting for the presence of the reaction center via the use of the sink. This result holds for both of the considered intra-site coupling configurations including a chain and ring. In general, our formalism and achieved results provide a platform for engineering and characterizing efficient quantum transport in multi-site systems both for realistic environments and engineered systems.
The sandfish lizard’s aerodynamic filtering system
Authors: Stadler Anna T , Krieger Michael , Baumgartner Werner
Published: December 2019

Particulate air pollution has an adverse effect on cardiovascular and respiratory health. Air filtration systems are therefore essential in closed indoor environments. While mechanical filtration is described as an efficient technology, particle filters may act as a source of pollution if not correctly installed and frequently maintained. The sandfish lizard, a sand swimmer that spends nearly its whole life in fine desert sand, inspired us to rethink traditional filtering systems due to its unique ability of filtering sand from its nasal cavity. During a slow, prolonged inhalation, strong cross-flow velocities develop in a certain region of the upper respiratory tract; these cross-flows enhance gravitational settling and force inhaled sand grains towards the wall where they adhere to mucus, which covers the walls in this region. During an intense, cough-like exhalation the particles are blasted out. In this work, the sandfish’s aerodynamic filtering system was analyzed experimentally and by computational fluid dynamics simulations to study the flow profile and particle trajectories. Based on these findings, we discuss the development of a biomimetic filtering system, which could have the following advantages: due to the absence of a membrane, total pressure losses can be reduced. The mucus-covered surface would be mimicked by a specifically treated surface to trap particulate matter. Also, the device would contain a self-cleaning mechanism that simulates the lizard’s exhalation. This biomimetic filtering system would therefore have an enhanced life-time and it would be low-maintenance and therefore economical and sustainable.
Synthesis, characterization and application of acrylate-based poly ionic liquid for corrosion protection of C1020 steel In hydrochloric acid solution
Authors: Gobara Mohamed , Saleh Ahmed , Naeem Ibrahim
Published: December 2019

Poly ionic liquids (PIL) are eco-friendly in addition to being sustainable compounds that can be easily prepared and tailored according to the application. In this study, a novel PIL polymer based on acrylate was chemically synthesised via free radical polymerization method controlled by quenching the reversible reaction. The prepared 1-Butyl-3 Methylimidazolium Acrylate polymer (PAL) was characterised using FTIR as well as NMR to confirm the chemical structure. GPC was employed to determine the average molecular weight of the new polymer. PAL was applied as an effective corrosion inhibitor for C1020 steel in 1M HCl aqueous solution. Weight loss and electrochemical techniques, PDP and EIS, were applied to evaluate the corrosion inhibition performance. The electrochemical results showed that PAL acts as a mixed-type inhibitor reaches 91.8% at room temperature. The thermodynamic calculations showed that the adsorption process is exothermic. Furthermore, PAL molecules were adsorbed on the metal surface by both chemisorption and physisorption processes. SEM analysis was carried out to confirm the corrosion evaluation results. Also, quantum chemical calculations, at the B3LYP/DND level of theory, were carried out to correlate the electronic structure parameters of PAL inhibitor to its adsorption behaviour which in turn is relevant to the inhibition efficiency. Additionally, Monte Carlo simulation (MC) was conducted to investigate the adsorption modes and the interaction energies of the inhibitor on iron surface.
Comparing metal oxide thin films as transparent p-type conductive electrodes
Authors: Guillén C , Herrero J
Published: December 2019

The development of transparent and p-type conductive layers remains a challenge to achieve more efficient hole collection and to combine with the most common n-type counterparts into transparent p–n junctions. Here, several candidates based on abundant materials: Cu2O, NiO and SnO have been prepared, characterized and comparatively evaluated. Thin-film deposition methods (evaporation and sputtering) have been used along with thermal treatments (oxidation and sulfurization) to maximize the transmittance and conductivity for each material. The highest quality is achieved by Cux(S, O) layers prepared by sulfurization of Cu2O at 250 °C. Besides, the NiO films obtained by reactive sputtering at room temperature have a good quality to be applied on heat-sensitive substrates.
Enhanced photo catalytic activity of Ag2O nanostructures through strontium doping
Authors: Kiani Farwa Ahmad , Shamraiz Umair , Badshah Amin
Published: December 2019

Nanoparticles of Ag2O and varying amounts of Sr-doped Ag2O synthesized by basic co-precipitation method were practiced for purging of relentless organic dyes, after characterizing them using Powdered x-ray Diffraction (PXRD), Scanning electron microscopy (SEM), Energy dispersive x-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Photo catalytic degradation of cationic dyes such as methylene blue (MB), rhodamine B (RhB) and anionic dye methyl orange (MO) was carried out by utilizing photosensitive silver oxide nanoparticles functionalized with various concentrations of strontium under solar irradiation with the aid of UV–vis spectroscopy. Besides the rapid de colorization, Sr/Ag2O solar-driven photocatalysis was concurrently able to oxidize the dye, leading to approximate mineralization of carbon. It is proposed that prime oxidant in degradation of both kind of dyes is hydroxyl radical. Kinetic analysis reveals that photodegradation of cationic and anionic dyes follow pseudo-first order kinetics.
Fluoride effect on plasma electrolytic oxidation coating formed on Mg-Al alloy in alkaline electrolytes
Authors: Wang Lishi , Feng Tao , Yu Shanwen , Cheng Yihang , Bu Zhixiang , Hu Xinbin
Published: December 2019

Plasma electrolytic oxidation (PEO) is an effective protection technique developed for light alloys, such as aluminum, magnesium and titanium alloys. PEO electrolytes often contain fluorides, yet their functionality is not well understood during the oxide layer formation and growth. In the present work, we tracked the fluoride evolvement contained in PEO ceramic protective layer formed on AZ91 magnesium alloys. It is found that a fluoride rich layer with 1–2 μm thickness is often formed at the coating/substrate interface and nanocrystalline MgO islands with size of 20–60 nm are found to be embedded in amorphous coating substrate.
Investigation of LaAlO3 pervoskite compound for optoelectronic and thermoelectric devices under pressure
Authors: Yaseen Muhammad , Ashfaq Amna , Akhtar Anam , Asghar Rida , Ambreen Hina , Butt Mehwish Khalid , Noreen Saima , Ur Rehman Shafiq , Bibi Shamsa , Ramay Shahid M , Murtaza Adil
Published: December 2019

The electronic, optical and thermoelectric properties of LaAlO3 are studied under different pressure ranges (0–40 GPa) by using the full potential linear augmented plane wave method (FP-LAW). Calculations are done by Perdew–Burke–Ernzerhof generalized gradient approximation (PBEsol-GGA) by utilizing Wien 2k code. It was observed that with the increase of pressure band gap increased and the nature of band gap transform from indirect to direct. In Optical properties, optical conductivity, refractive index, absorption coefficient, and dielectric function are calculated at different pressures. Thermoelectric properties have been studied at temperature (150–800 K) and pressure (0–40 GPa) by using Boltz Trap code. At 800 K the values of power factor were 6.831 W K−2. cm. s and 22.13 W K−2. cm. s, respectively. Figure of merit was achieved up to 0.6. Results revealed that LaAlO3 is a suitable candidate for optoelectronic and thermoelectric devices.
CdTe:Sn thin films deposited by the simultaneous laser ablation of CdTe and Sn targets
Authors: Rivera L P , García E , Cardona D , Pérez-Centeno A , Camps E , Santana-Aranda M A , Gómez-Rosas G , de Moure-Flores F , Chávez-Chávez A , Quiñones-Galván J G
Published: December 2019

CdTe:Sn thin films were grown by pulsed laser deposition on glass substrates at room temperature. The study of the changes in the chemical, structural and optical properties of the films as a function of the density of Sn ions calculated from Langmuir planar probe measurments is presented. Four films were grown by the simultaneous ablation of CdTe and Sn targets in vacuum. The Sn ion density was modified by varying the fluence on the Sn target, while the CdTe plasma density was kept constant for all the deposits. One CdTe film was grown as control sample using the same experimental conditions as in the CdTe:Sn films. The chemical composition was analyzed by XPS, where a dependence of the Sn incorporation into the CdTe lattice, on the Sn ion plasma density was demonstrated. The crystalline structure analysis by XRD showed a hexagonal structure for all the films. When the CdTe and Sn plasmas were combined, a preferential orientation in the plane (110) was observed for the resulting films. Furthermore, as Sn plasma density increased, the intensity of the (110) peak increased as well, suggesting that crystalline re-orientation is an effect of Sn incorporated into the CdTe lattice. Vibrational behavior was analyzed by Raman spectroscopy. A vibrational mode appeared at 118 cm−1 and was related to a Sn-Te vibration, suggesting the incorporation of substitutional Sn into the CdTe lattice. The Sn-Te bonding was confirmed by XPS by the appearance of signals centered at 485 and 494 eV, which correspond to Sn2+ in SnTe. Thin films thicknesses values were between 320 and 460 nm increasing with Sn ion density. The band gap calculated using UV–vis spectrophotometry, resulted in values ranging from 1.42 to 1.46 eV. PL measurements showed a slight blue shift of the near-edge emission as Sn plasma density increased.
Bidens pilosa Extract Effects on Pine Wilt: Causal Agents and Their Natural Enemies
Authors: Taba Satoshi , Ashikaga Koichiro , Oohama Tsuyoshi , Ajitomi Atsushi , Kiyuna Chouji , Kinjo Misa , Sekine Ken-Taro
Published: December 2019

We investigated the nematicidal and insecticidal activities of the aqueous extract from Bidens pilosa var. radiata on pine-wood nematode (Bursaphelenchus xylophilus) and Japanese pine sawyer (Monochamus alternatus) larvae and adults, the causal agent and vector of pine wilt, respectively. The aqueous extract killed the pine-wood nematode, adults, and larvae of the vector in vitro at all concentrations tested, and the effect decreased significantly with increasing extract dilution. Repellent activity was observed on the nematode and the vector adults as well, although the activity decreased with time in case of the vector. Furthermore, the aqueous extract of B. pilosa effectively promoted approximately 3.0–9.0 mm of hyphal growth in Beauveria spp., when compared with the control treatment. A minor insecticidal effect was also observed on two species of click beetle (Cryptalaus larvatus pini and Paracalais berus), which are natural predators of the Japanese pine-sawyer larvae. Pesticidal and repellent activities of the aqueous extract observed on several organisms related to pine wilt suggest that a multifactorial approach may effectively control this devastating disease.
Trace finite element methods for surface vector-Laplace equations
Authors: Jankuhn Thomas , Reusken Arnold
Published: December 2019

In this paper we analyze a class of trace finite element methods for the discretization of vector-Laplace equations. A key issue in the finite element discretization of such problems is the treatment of the constraint that the unknown vector field must be tangential to the surface (‘tangent condition’). We study three different natural techniques for treating the tangent condition, namely a consistent penalty method, a simpler inconsistent penalty method and a Lagrange multiplier method. The main goal of the paper is to present an analysis that reveals important properties of these three different techniques for treating the tangent constraint. A detailed error analysis is presented that takes the approximation of both the geometry of the surface and the solution of the partial differential equation into account. Error bounds in the energy norm are derived that show how the discretization error depends on relevant parameters such as the degree of the polynomials used for the approximation of the solution, the degree of the polynomials used for the approximation of the level set function that characterizes the surface, the penalty parameter and the degree of the polynomials used for the approximation of the Lagrange multiplier.
Safety of central compartment neck dissection for transoral endoscopic thyroid surgery in papillary thyroid carcinoma
Authors: Wang Tiantian , Wu Yanping , Xie Qiuping , Yan Haichen , Zhou Xiaoming , Yu Xing , Chen Yufei , Xiang Cheng , Yan Haichao , Zhao Qunzi , Zhang Maolin , Qi Ming , Wang Ping , Wang Yong
Published: December 2019

Background

Remote access and endoscopic thyroid surgery has been gaining popularity because it allows patients to avoid a visible scar in the neck. There is limited data on transoral endoscopic thyroidectomy when it relates to patients with papillary thyroid carcinoma. We aim to evaluate the safety of ipsilateral central compartment dissection for patients who undergo transoral thyroidectomy (thyroidectomy vestibular approach–compartment lymph node dissection).

Patients and Methods

A total of 80 patients who underwent thyroidectomy vestibular approach–compartment lymph node dissection for papillary thyroid carcinoma from June 2015 to September 2016 were identified. Over the same period, a matched cohort of 80 patients who underwent open thyroidectomy with routine ipsilateral central compartment dissection was also identified (Open-compartment lymph node dissection). The two groups were analyzed in terms of patient characteristics, perioperative clinical results and post-operative outcomes.

Results

All patients were female with a mean age of 32-year. There was no difference in mean maximum tumor size and number of lymph nodes dissected. Moreover, there was no difference in average positive lymph nodes between thyroidectomy vestibular approach–compartment lymph node dissection and Open-compartment lymph node dissection (1.48 vs 1.08, P = 0.647). Operative time was longer in the thyroidectomy vestibular approach–compartment lymph node dissection group (193 vs 102 min, P < 0.001). Thyroidectomy specific complications were similar with rates of temporary recurrent laryngeal nerve palsy of 6.3 vs 8.8% and temporary hypocalcemia rates of 2.5 vs 5% in the thyroidectomy vestibular approach–compartment lymph node dissection and Open-compartment lymph node dissection groups, respectively.

Conclusions

Thyroidectomy vestibular approach–compartment lymph node dissection is a feasible and safe option for select patients with papillary thyroid carcinoma who require central node dissection compared with Open-compartment lymph node dissection, and can be a viable alternative for patients wishing to avoid a visible scar.
Extreme Downregulation of Chromosome Y and Cancer Risk in Men
Authors: Cáceres Alejandro , Jene Aina , Esko Tonu , Pérez-Jurado Luis A , González Juan R
Published: December 2019

Background

Understanding the biological differences between sexes in cancer is essential for personalized treatment and prevention. We hypothesized that the extreme downregulation of chromosome Y gene expression (EDY) is a signature of cancer risk in men and the functional mediator of the reported association between the mosaic loss of chromosome Y (LOY) and cancer.

Methods

We advanced a method to measure EDY from transcriptomic data. We studied EDY across 47 nondiseased tissues from the Genotype Tissue-Expression Project (n = 371) and its association with cancer status across 12 cancer studies from The Cancer Genome Atlas (n = 1774) and seven other studies (n = 7562). Associations of EDY with cancer status and presence of loss-off function mutations in chromosome X were tested with logistic regression models, and a Fisher’s test was used to assess genome-wide association of EDY with the proportion of copy number gains. All statistical tests were two-sided.

Results

EDY was likely to occur in multiple nondiseased tissues (P < .001) and was statistically significantly associated with the EGFR tyrosine kinase inhibitor resistance pathway (false discovery rate = 0.028). EDY strongly associated with cancer risk in men (odds ratio [OR] = 3.66, 95% confidence interval [CI] = 1.58 to 8.46, P = .002), adjusted by LOY and age, and its variability was largely explained by several genes of the nonrecombinant region whose chromosome X homologs showed loss-of-function mutations that co-occurred with EDY during cancer (OR = 2.82, 95% CI = 1.32 to 6.01, P = .007). EDY associated with a high proportion of EGFR amplifications (OR = 5.64, 95% CI = 3.70 to 8.59, false discovery rate < 0.001) and EGFR overexpression along with SRY hypomethylation and nonrecombinant region hypermethylation, indicating alternative causes of EDY in cancer other than LOY. EDY associations were independently validated for different cancers and exposure to smoking, and its status was accurately predicted from individual methylation patterns.

Conclusions

EDY is a male-specific signature of cancer susceptibility that supports the escape from X-inactivation tumor suppressor hypothesis for genes that protect women compared with men from cancer risk.
Evolution of Cancer Care Delivery Research in the NCI Community Oncology Research Program
Authors: Geiger Ann M , O’Mara Ann M , McCaskill-Stevens Worta J , Adjei Brenda , Tuovenin Priyanga , Castro Kathleen M
Published: December 2019

Research seeking to improve patient engagement with decision-making, use of evidence-based guidelines, and coordination of multi-specialty care has made important contributions to the decades-long effort to improve cancer care. The National Cancer Institute expanded support for these efforts by including cancer care delivery research in the 2014 formation of the National Cancer Institute Community Oncology Research Program (NCORP). Cancer care delivery research is a multi-disciplinary effort to generate evidence-based practice change that improves clinical outcomes and patient well-being. NCORP scientists and community-based clinicians and organizations rapidly embraced the addition of this type of research into the network, resulting in a robust portfolio of observational studies and intervention studies within the first 5 years of funding. This commentary describes the initial considerations in conducting this type of research in a network previously focused on cancer prevention, control, and treatment studies; characterizes the protocols developed to date; and outlines future directions for cancer care delivery research in the second round of NCORP funding.
Measuring Without a Ruler: Assessing Compliance with Calculative International Norms
Authors: Traven David , Holmes Marcus
Published: December 2019

Measuring compliance with international norms is usually taken to be a relatively straightforward exercise. To determine whether a state is compliant, scholars typically measure the level of conformity between their behavior and “the letter of the law.” IR theorists often disagree over whether compliance tells us anything meaningful about the causal effects of international norms, but most believe that it can at least be measured. We argue that, for certain norms and laws, this claim is too optimistic. We draw on recent insights from moral philosophy and moral psychology to distinguish between two types of international norms: (1) proscriptive norms that govern state practices by providing fairly specific rules of appropriateness for how states or other actors are expected to behave and (2) calculative norms, which do not stipulate any particular rules of appropriateness, but rather require that states take efforts to maximize or minimize a specific value. The laws of war, for example, hold that states cannot target civilians (proscriptive), but they do allow for tactics that generate collateral damage, as long as it is minimized (calculative). Because assessments of conformity between state practices and calculative norms require evaluation of intentions—which can be difficult at best to obtain, particularly in instances where actors have incentives to mislead or dissemble—measuring compliance by assessing behavior and its consequences can be very misleading and lead to false negatives. Using US bombing policy in Vietnam as an illustrative case, we show that failing to observe the differences between norm types can lead to confusion when evaluating the effects of international law.
Serum Folate of Less than 7.0 ng/mL is a Marker of Malnutrition
Authors: Kozman Diana , Mattox Samantha , Singh Gurmukh
Published: December 2019

Objective

To identify clinical/laboratory factors associated with folate deficiency in tertiary care patients.

Methods

We reviewed the medical records of 1019 patients with serum folate <7.0 ng/mL, 301 patients with serum folate of 15 ng/mL, and 300 patients with serum folate > 23 ng/mL.

Results

Serum prealbumin levels were subnormal in 54.8% of patients with serum folate <7.0 ng/mL. Vitamin B12, hemoglobin, and serum albumin levels were significantly lower in the <7.0 ng/mL folate group. In 62.4% of patients with serum folate <7.0 ng/mL, 1 or more markers of malnutrition were present. The low-folate group had a significantly higher prevalence of gastrointestinal (GI) disorders, sepsis, and abnormal serum creatinine level. There were no significant differences in the 2 groups regarding diabetes; behavioral/neurological disorders, including drug and alcohol abuse; bariatric surgery; or a diagnosis of malnutrition. The average body mass index (BMI) for the <7.0 ng/mL and 15 ng/mL folate groups was significantly different (28.89 and 28.31, respectively), although the difference does not appear to be clinically meaningful.

Conclusions

The prevalence of folate deficiency depends on what is considered a normal serum folate level. Approximately 10% of tertiary-care patients have levels <7.0 ng/mL and exhibit other markers of malnutrition. It is recommended that patients with GI disorders, chronic kidney disease, and sepsis be routinely tested for serum folate levels, before administration of vitamin supplements. Patients with serum folate levels <7.0 ng/mL should be evaluated for malnutrition, despite BMI > 25. Folate supplementation should be administered only after excluding coexisting vitamin B12 deficiency.
The crime of apartheid: genealogy of a successful failure
Authors: Sitze Adam
Published: December 2019

This article argues that international criminal law implies a specific form of conscience. It then traces the vicissitudes of that conscience throughout the history of the criminalisation of apartheid in international law. It concludes with three theses about the concept of ‘global apartheid’.
A Depletion of Stop Codons in lincRNA is Owing to Transfer of Selective Constraint from Coding Sequences
Authors: Abrahams Liam , Hurst Laurence D
Published: December 2019

Although the constraints on a gene’s sequence are often assumed to reflect the functioning of that gene, here we propose transfer selection, a constraint operating on one class of genes transferred to another, mediated by shared binding factors. We show that such transfer can explain an otherwise paradoxical depletion of stop codons in long intergenic noncoding RNAs (lincRNAs). Serine/arginine-rich proteins direct the splicing machinery by binding exonic splice enhancers (ESEs) in immature mRNA. As coding exons cannot contain stop codons in one reading frame, stop codons should be rare within ESEs. We confirm that the stop codon density (SCD) in ESE motifs is low, even accounting for nucleotide biases. Given that serine/arginine-rich proteins binding ESEs also facilitate lincRNA splicing, a low SCD could transfer to lincRNAs. As predicted, multiexon lincRNA exons are depleted in stop codons, a result not explained by open reading frame (ORF) contamination. Consistent with transfer selection, stop codon depletion in lincRNAs is most acute in exonic regions with the highest ESE density, disappears when ESEs are masked, is consistent with stop codon usage skews in ESEs, and is diminished in both single-exon lincRNAs and introns. Owing to low SCD, the maximum lengths of pseudo-ORFs frequently exceed null expectations. This has implications for ORF annotation and the evolution of de novo protein-coding genes from lincRNAs. We conclude that not all constraints operating on genes need be explained by the functioning of the gene but may instead be transferred owing to shared binding factors.
The impact of pharmaceutical innovation on the burden of disease in Ireland, 2000–2015
Authors: Lichtenberg Frank R
Published: December 2019

Background

We perform an econometric assessment of the impact that pharmaceutical innovation had on the burden of disease in Ireland.

Methods

We use a difference-in-differences (or two-way fixed effects) research design: we investigate whether diseases for which more new drugs were launched had larger subsequent reductions in mortality. This design controls for the effects of general economic and societal factors (e.g. income, education, and behavioral risk factors), to the extent that those effects are similar across diseases.

Results

New Chemical Entities launched during 1983–1997 are estimated to have reduced the total number of disability-adjusted life-years (DALYs) lost in 2015 by about 234 600.

Conclusions

Pharmaceutical expenditure per DALY gained in 2015 from drugs launched during 1983–1997 was €1137, which indicates that the new drugs launched during 1983–1997 were very cost–effective, overall.
How Teachers Meet in Interdisciplinary Teams: Hangouts, Distribution Centers, and Melting Pots
Authors: Meeuwissen Stephanie N.E. , Gijselaers Wim H. , Wolfhagen Ineke H.A.P. , oude Egbrink Mirjam G.A.
Published: December 2019

Purpose

To explore team learning processes among interdisciplinary teacher teams in the development of integrated health professions education and to investigate students’ perspectives on the quality of the educational courses.

Method

Using an exploratory, sequential mixed-methods design, the first author conducted 17 vignette-guided, semistructured interviews with teachers originating from diverse disciplines. These teachers worked in different courses of integrated, undergraduate health professions programs at the Faculty of Health, Medicine and Life Sciences, Maastricht University, the Netherlands. The interview guide and vignettes were based on team learning research. The interviews sought to establish how interdisciplinary teacher team members work together on integrated curricula. The vignettes reflected constructs of team learning processes: sharing, co-construction, and constructive conflict. Data were collected between November 2017 and March 2018 and analyzed using template analysis. Sequentially, course evaluation data were used to provide a descriptive analysis of students’ perspectives on educational quality (course organization, structure, learning effect, and alignment).

Results

Three team approaches were identified. In fragmented teams or “hangouts,” teachers individually worked on tasks that they were interested in, leaving their disciplinary mark. Framework-guided teams or “distribution centers” aimed to work within the given frameworks and organizational expectations, striving for disciplinary balance. Integrated teacher teams or “melting pots” used an interdisciplinary approach on all topics and put students at the center. Integrated teams reflected high-level team learning processes and were most satisfied with their (team)work. In contrast, fragmented and framework-guided teams mainly reflected low-level team learning processes. Students evaluated courses of integrated teacher teams highest on all investigated quality items (course organization, structure, learning effect, and alignment).

Conclusions

Successful interdisciplinary teacher teams are represented by an integrated approach with high-level team learning behavior and the best course evaluations. Therefore, health professions education management should actively encourage and facilitate integrated teacher teamwork.
Medical Training and Errors: Competence, Culture, Caring, and Character
Authors: Derse Arthur R.
Published: December 2019

Medical trainees will inevitably make errors as they learn. Errors should be minimized by a stronger focus on competence through better supervision and increased opportunities for simulation, as well as by reinforcing a culture that supports open identification of errors, disclosing errors to patients and families, and that focuses on prevention through quality improvement. Yet, errors are also opportunities for education and remediation. Medicine’s duty of care includes care for those harmed through errors and should also include care for those who have made the error. Errors that cause harm to patients challenge trainees to engage the character traits of honesty, humility, trustworthiness, and compassion and to strengthen the practical wisdom to know when and how to exercise these character traits. The moral core of medicine—care of the patient in circumstances that may be uncertain and imperfect—as well as the duties of honesty, disclosure, repair, and redress may make equanimity (the calmness, composure, and evenness of temper needed in difficult and challenging situations) one of the most important character traits medical educators should identify, nurture, and encourage in trainees.
Controversies in Perioperative Antimicrobial Prophylaxis
Authors: Decker Brooke K. , Nagrebetsky Alexander , Lipsett Pamela A. , Wiener-Kronish Jeanine P. , O’Grady Naomi P.
Published: December 2019

Although clinical guidelines for antibiotic prophylaxis across a wide array of surgical procedures have been proposed by multidisciplinary groups of physicians and pharmacists, clinicians often deviate from recommendations. This is particularly true when recommendations are based on weak data or expert opinion. The goal of this review is to highlight certain common but controversial topics in perioperative prophylaxis and to focus on the data that does exist for the recommendations being made.
Effect of Intravenous Aminocaproid Acid on Blood Loss and Transfusion Requirements After Bilateral Varus Rotational Osteotomy: A Double-blind, Placebo-controlled Randomized Trial
Authors: Swarup Ishaan , Nguyen Joseph , Edmonds Chris , Dodwell Emily , Scher David
Published: December 2019

Background:

ε-Aminocaproic acid (EACA) is an antifibrinolytic agent that has been shown to decrease blood loss and transfusion requirements in several populations undergoing various surgical procedures. However, the efficacy of EACA has not been assessed in pediatric patients with cerebral palsy undergoing bilateral varus rotational femoral osteotomies. The purpose of this study was to assess the efficacy of intravenous EACA in reducing calculated intraoperative blood loss and transfusions in this population.

Methods:

Patients aged 18 years or younger were eligible. Patients were randomized to receive EACA or placebo (saline), and randomization was stratified based on sex and whether or not additional soft tissue or osseous procedures were performed. On the basis of retrospective data, the calculated sample size was 12 patients per arm to detect a difference of 250-mL blood loss. The primary outcome was calculated intraoperative blood loss. Secondary outcomes included transfusion requirements, 24-hour drain output, length of stay, and incidence of complications.

Results:

The mean age of patients in this study was 8 years (SD: 2.4 y). There were no differences in age, sex, height, weight, type of anesthesia, operative time, and associated procedures between the EACA and placebo groups (P>0.05). Preoperative hematocrit was lower in the EACA group (37.1 vs. 40.0, P=0.04). Calculated intraoperative blood loss was 536 mL in the EACA group and 628 mL in the placebo group (P=0.45). Transfusions were required in 62% of patients in the EACA group and 67% of patients in the placebo group (P=0.68). Total 24-hour drain output was 72.5 mL in the EACA group and 103.3 mL in the placebo group (P=0.37). Length of stay was similar between both groups, and there were no drug or placebo-related complications in either group.

Conclusions:

There was no difference in blood loss or transfusion requirements associated with EACA compared with placebo; however, this study is underpowered to detect smaller differences in blood loss. Additional studies with larger sample sizes are needed to confirm these findings and further elucidate the indications for antifibrinolytic agents in pediatric patients.

Level of Evidence

Level I.
Polypharmacy in HIV: recent insights and future directions
Authors: Edelman E. Jennifer , Rentsch Christopher T. , Justice Amy C.
Published: December 2019

Purpose of review

Update findings regarding polypharmacy among people with HIV (PWH) and consider what research is most needed.

Recent findings

Among PWH, polypharmacy is common, occurs in middle age, and is predominantly driven by nonantiretroviral (ARV) medications. Many studies have demonstrated strong associations between polypharmacy and receipt of potentially inappropriate medications (PIMS), but few have considered actual adverse events. Falls, delirium, pneumonia, hospitalization, and mortality are associated with polypharmacy among PWH and risks remain after adjustment for severity of illness.

Polypharmacy is a growing problem and mechanisms of injury likely include potentially inappropriate medications, total drug burden, known pairwise drug interactions, higher level drug interactions, drug--gene interactions, and drug--substance use interactions (alcohol, extra-medical prescription medication, and drug use). Before we can effectively design interventions, we need to use observational data to gain a better understanding of the modifiable mechanisms of injury. As sicker individuals take more medications, analyses must account for severity of illness. As self-report of substance use may be inaccurate, direct biomarkers, such as phosphatidylethanol (PEth) for alcohol are needed. Large samples including electronic health records, genetics, accurate measures of substance use, and state of the art statistical and artificial intelligence techniques are needed to advance our understanding and inform clinical management of polypharmacy in PWH.
Pseudocarcinomatous Hyperplasia, Squamous Cell Carcinoma, and Keratoacanthoma Associated to Lymphomas of the Skin and External Mucous Membranes: A Case Report and Literature Review
Authors: Jeunon Thiago , Assoni Ariane , Verdolin Annelise
Published: December 2019

Pseudocarcinomatous hyperplasia (PCH) is a benign reactive epithelial proliferation that may be associated to lymphomas of the skin or external mucous membranes. We present a case of single lesion mycosis fungoides (Woringer-Kollop's reticulosis pagetoid) associated with PCH that was initially misdiagnosed as squamous cell carcinoma (SCC) and review all PubMed-indexed previously reported cases on lymphomas of the skin or external mucous membranes associated to PCH, SCC, and keratoacanthomas. Including our own case, we collected data of 114 cases of cutaneous or mucosal lymphoproliferative disorders associated to PCH, 3 cases associated to SCC, and other 3 cases associated to keratoacanthomas. All cases were tabulated to the following parameters whenever data was available: sex, age, previous medical conditions, number of lesions (single × multiple), site of involvement (mucosa, skin or both), clinical impression, initial equivocal histopathologic diagnosis, final diagnosis, keratinocytic atypia (presence × absence), lymphocytic atypia (presence × absence), CD30-status, and treatment.
Rapid BRAF Mutation Testing in Pigmented Melanomas
Authors: Petty Danielle R. , Hassan Omer A. , Barker Callie S. , O'Neill Stacey S.
Published: December 2019

BRAF mutations are present in ∼40%–60% of melanomas, and targeted therapy in advanced-stage melanoma is associated with improvement in overall and progression-free survival. Accordingly, BRAF mutation determination is standard-of-care in metastatic melanoma, and a rapid, accurate assay is desirable. Melanin can present unique challenges due to inhibition of the polymerase chain reaction. The novel cartridge-based Idylla platform offers rapid molecular oncology testing; however, a formal evaluation of the impact of melanin on testing heretofore has not been explored. In this study, we evaluated the performance of Idylla BRAF mutation detection in 23 melanomas including resections, small biopsies, and cytology cell blocks. Pathologists assigned each case a pigment score from 0 to 2 based on extent of melanin content. Samples with a pigment score of 2 were successfully resulted, thus demonstrating that high melanin content did not inhibit the assay. Sensitivity and specificity of BRAF mutation detection were 100% compared with reference laboratory testing. Tissue input requirements were low, with the Idylla successfully detecting a BRAF mutation in cell block material containing only ∼400 tumor cells. The assay was simple and quick to perform, with total hands-on time of 5–10 minutes and instrument time ∼90 minutes. In summary, the Idylla BRAF mutation assay provides rapid, robust testing for melanomas with high melanin content, including samples with limited material. The assay requires minimal technical expertise, making mutation status determination accessible in a range of clinical laboratory settings. The total assay time of <2 hours facilitates prompt results to guide patient care decisions.
Gynecologic Oncology: Challenges of Minimally Invasive Surgery In a Field of Maximal Complexities
Authors: LYONS YASMIN A. , STEPHAN JEAN-MARIE , GONZALEZ BOSQUET JESUS , GOODHEART MICHAEL J.
Published: December 2019

Minimally invasive surgery has become a standard in the surgical treatment for many women with gynecologic cancers. Within the scope of minimally invasive surgery, several techniques exist. Here, we provide an overview of the challenging and controversial aspects of minimally invasive surgery in the field of gynecologic oncology, including single-site surgery, operating on morbidly obese patients, sentinel lymph node mapping, and recent trials and controversy of treating gynecologic cancer patients with a minimally invasive surgical approach.
Diagnosis and management of low-flow, low-gradient aortic stenosis
Authors: Salemi Arash , Hameed Irbaz , Khan Faiza M. , Gaudino Mario
Published: December 2019

Purpose of review

The severity of low-flow, low-gradient aortic stenosis cases continue to be misunderstood because of challenging diagnosis, and treatment remains complex. We discuss current diagnostic and treatment modalities for low-flow, low-gradient aortic stenosis.

Recent findings

This article summarizes current guidelines and best practices for the management of low-flow, low-gradient aortic stenosis.

Low-flow, low-gradient aortic stenosis is a difficult entity to diagnose and treat. Various diagnostic modalities are needed to accurately determine the severity of aortic stenosis and potential treatment benefit. True-severe classical and paradoxical low-flow, low-gradient aortic stenosis can be distinguished from pseudo-severe aortic stenosis by dobutamine stress echocardiography and/or multidetector computed tomography. Once the distinction is made, aortic valve replacement results in better outcomes compared with conservative management. Although both surgical and transcatheter aortic valve replacement result in adequate outcomes, the decision between the two treatment strategies is based on patient characteristics, valve morphology, and other risk factors.
THICKNESSES OF SCLERA AND LAMINA CRIBROSA IN PATIENTS WITH CENTRAL RETINAL VEIN OCCLUSION
Authors: Adiyeke Seda Karaca , Kutlu Neslisah , Aytogan Hasan , Aras Buket , Yoyler Gokhan , Ture Gamze , Talay Ekrem , Talay Dayangac Gulsah
Published: December 2019

Purpose:

To evaluate thicknesses of sclera and lamina cribrosa (LC) in central retinal vein occlusion (CRVO).

Method:

Thirty-two patients with CRVO (mean age 62.2 ± 11.6 years, women/men 18/14) and 35 age- and sex-matched healthy volunteers were included into the study. Scleral thickness was measured at scleral spur and at 1 to 3 mm from scleral spur in four quadrants (temporal, nasal, super, and inferior) using anterior segment optical coherence tomography. Lamina cribrosa was measured using optic disk enhanced depth imaging optical coherence tomography.

Results:

The sclera was thicker in affected eyes of the CRVO group than healthy subjects at scleral spur in four quadrants (738.7 ± 30.9 µm vs. 702 ± 30.8 µm in temporal, 700.4 ± 19.7 µm vs. 673 ± 13.7 µm in superior, 693 ± 19.3 µm vs. 665.3 ± 24.2 µm in nasal, 810.7 ± 28.9 µm vs. 784.5 ± 23.7 µm in inferior quadrants, respectively; P ˂ 0.05 for all). Lamina cribrosa thickness in affected eyes of the CRVO group was significantly higher than that of healthy subjects (285.2 ± 12.7 µm vs. 266.4 ± 10.7 µm, respectively; P ˂ 0.01). The correlation between scleral thickness and LC thickness was moderate at scleral spur of temporal and superior quadrants of affected eyes (r = 0.510 and r = 0.420, respectively).

Conclusion:

Thicknesses of sclera and LC are increased in the CRVO, which may play a role in the pathogenesis of the disease.
CLINICAL OUTCOME OF POLYPOIDAL CHOROIDAL VASCULOPATHY/ANEURYSMAL TYPE 1 NEOVASCULARIZATION ACCORDING TO CHOROIDAL VASCULAR MORPHOLOGY
Authors: Baek Jiwon , Lee Jae Hyung , Lee Kook , Chung Byung Joo , Lee Won Ki
Published: December 2019

Purpose:

To determine the impact of choroidal vascular morphology on clinical outcomes in patients with polypoidal choroidal vasculopathy/aneurysmal Type 1 neovascularization.

Methods:

Sixty-six eyes with polypoidal choroidal vasculopathy/aneurysmal Type 1 were included. Eyes were subdivided according to the choroidal vascular morphology of the large vessel layer on optical coherence tomography en face images: focal (n = 39) versus diffuse (n = 27) pachyvessels. All patients were treated with intravitreal ranibizumab pro re nata with or without rescue photodynamic therapy.

Results:

Best-corrected visual acuity at baseline, 6, and 12 months did not differ between groups (P = 0.394, 0.142, and 0.292). At Month 3, best-corrected visual acuity was worse, and the proportion of eyes with fluid was higher in the focal group (P = 0.016 and 0.024). Among responders, the number of injections during 12-month follow-up was higher in the focal group (P = 0.033). During the total follow-up period, photodynamic therapy was required in 15 eyes (10 focal and 5 diffuse group, P = 0.497). The injection-free period after the photodynamic therapy was shorter in the focal group (P = 0.018).

Conclusion:

The polypoidal choroidal vasculopathy/aneurysmal Type 1 eyes with a diffuse pattern of pachyvessels required fewer injections during 12-month follow-up and showed a longer injection-free period after rescue photodynamic therapy.
Spatial Hearing as a Function of Presentation Level in Moderate-to-Severe Unilateral Conductive Hearing Loss
Authors: Thompson Nicholas J. , Kane Stacey L. G. , Corbin Nicole E. , Canfarotta Michael W. , Buss Emily
Published: December 2019

Hypothesis:

Patients with moderate-to-severe unilateral conductive hearing loss (UCHL) can make use of binaural difference cues when stimuli are presented at a high enough intensity to provide audibility in the affected ear.

Background:

Spatial hearing is essential for listening in complex environments and sound source localization. Patients with UCHL have decreased access to binaural difference cues, resulting in poorer spatial hearing abilities compared with listeners with normal hearing.

Methods:

Twelve patients with moderate-to-severe UCHL, most due to atresia (83.3%), and 12 age-matched controls with normal hearing bilaterally participated in this study. Outcome measures included: 1) spatial release from masking, and 2) sound source localization. Speech reception thresholds were measured with target speech (Pediatric AzBio sentences) presented at 0 degree and a two-talker masker that was either colocated with the target (0 degree) or spatially separated from the target (symmetrical, ±90 degrees). Spatial release from masking was quantified as the difference between speech reception thresholds in these two conditions. Localization ability in the horizontal plane was assessed in a 180 degree arc of 11 evenly-spaced loudspeakers. These two tasks were completed at 50 and 75 dB SPL.

Results:

Both children and adults with UCHL performed more poorly than controls when recognizing speech in a spatially separated masker or localizing sound; however, this group difference was larger at 50 than 75 dB SPL.

Conclusion:

Patients with UCHL experience improved spatial hearing with the higher presentation level, suggesting that the auditory deprivation associated with a moderate-to-severe UCHL does not preclude exposure to—or use of—binaural difference cues.