bluuebunny/crossref_metadata_2025 huggingface dataset:
Suspension of flexible cylinders in laminar liquid flow
Authors: Derksen Jos J.
Published: February 2020

A methodology for particle‐resolved simulation of dense suspensions of flexible cylindrical particles in Newtonian liquid flow is described. It is based on the Lattice–Boltzmann method for solving the liquid flow and an immersed boundary method for imposing no‐slip at the particle surfaces and providing the distribution of liquid–solid interaction forces over the particle surfaces. These forces—along with contact forces—translate, rotate as well as bend the cylindrical particles. Verification tests have been performed for a single cylinder settling and deforming under gravity at a low Reynolds number. The method has been applied to a clamped flexible cylinder in microchannel flow for which experimental data are available. It then is used to investigate the behavior of hundreds of flexible cylinders with length over diameter aspect ratios of 4 and 6 in a container agitated by an impeller at a Reynolds number of 87 which implies laminar flow. The overall solids volume fraction is 15%. We study the effect of the bending stiffness of the particles on the solids suspension process, on the extent of particle deformation as well as on the torque required to spin the impeller.
Novel semibatch supersaturation control approach for the cooling crystallization of heat‐sensitive materials
Authors: Zhang Teng , Szilágyi Botond , Gong Junbo , Nagy Zoltan K.
Published: February 2020

This article introduces the application of a novel supersaturation control (SSC) approach for the crystallization of heat‐sensitive materials. Traditional SSC implements parabolic temperature profile with slow initial cooling that maximizes growth over nucleation, however, which may also promote heat degradation. The proposed semibatch SSC fixes the crystallization temperature to a sufficiently low value to minimize thermal degradation, and manipulates the flow rate of a higher temperature feed stream to control the supersaturation. The high temperature feed is produced in a continuous dissolver before feeding, thus the solution spends considerably shorter time at high temperature than in the traditional batch cooling crystallization. This work demonstrates the effectiveness of the semibatch operation for the cooling crystallization of heat‐sensitive substances by thorough simulation study as well as experimental investigations. The experimental validation confirmed the simulation results, and both analyses revealed the superiority of semibatch SSC for the crystallization of heat‐sensitive materials.
Social, neurodevelopmental, endocrine, and head size differences associated with atypical deletions in Williams–Beuren syndrome
Authors: Lugo Michael , Wong Zoë C. , Billington Charles J. , Parrish Phoebe C. R. , Muldoon Glennis , Liu Delong , Pober Barbara R. , Kozel Beth A.
Published: February 2020

Williams–Beuren syndrome (WBS) is a multisystem disorder caused by a hemizygous deletion on 7q11.23 encompassing 26–28 genes. An estimated 2–5% of patients have “atypical” deletions, which extend in the centromeric and/or telomeric direction from the WBS critical region. To elucidate clinical differentiators among these deletion types, we evaluated 10 individuals with atypical deletions in our cohort and 17 individuals with similarly classified deletions previously described in the literature. Larger deletions in either direction often led to more severe developmental delays, while deletions containing MAGI2 were associated with infantile spasms and seizures in patients. In addition, head size was notably smaller in those with centromeric deletions including AUTS2. Because children with atypical deletions were noted to be less socially engaged, we additionally sought to determine how atypical deletions relate to social phenotypes. Using the Social Responsiveness Scale‐2, raters scored individuals with atypical deletions as having different social characteristics to those with typical WBS deletions (p = .001), with higher (more impaired) scores for social motivation (p = .005) in the atypical deletion group. In recognizing these distinctions, physicians can better identify patients, including those who may already carry a clinical or FISH WBS diagnosis, who may benefit from additional molecular evaluation, screening, and therapy. In addition to the clinical findings, we note mild endocrine findings distinct from those typically seen in WBS in several patients with telomeric deletions that included POR. Further study in additional telomeric deletion cases will be needed to confirm this observation.
Enamel thickness and growth rates in modern human permanent first molars over a 2000 year period in Britain
Authors: Aris Christopher , Mahoney Patrick , O'Hara Mackie C. , Deter Chris
Published: February 2020

Objectives

This study explores variation and trends in first molar enamel thickness and daily enamel secretion rates over a 2000 year period in Britain.

Methods

Permanent first molars (n = 89) from the Roman, Anglo‐Saxon, and Medieval periods, as well as modern‐day Britain, were analyzed using standard histological methods. Relative enamel thickness (RET) and linear measurements of cuspal and lateral thickness were calculated for mesial cusps. Daily secretion rates (DSRs) were calculated for inner, mid, and outer enamel regions in both cuspal and lateral enamel. Significant differences and trends were identified between samples using nonparametric statistical tests.

Results

Enamel thickness differed between some populations, but no temporal trends were identified. Early Anglo‐Saxon molars had significantly thinner RET than both Late Anglo‐Saxon (p < .00) and Medieval (p < .00) molars. Lateral enamel from the Roman molars was significantly thinner than the modern‐day sample (p = .04). In contrast, a significant slowing trend in DSRs was observed across the more ancient to modern‐day samples in every measured region except the mid‐lateral enamel region.

Discussion

This study presents the first evidence for a gradual slowing in the daily rate that enamel is secreted in molars over the past 2000 years in Britain. However, this trend was not matched by consistent or significant positive or negative shifts in enamel thickness. These findings suggest that modern human molars of similar enamel thickness, from different modern and ancient populations, formed at different rates.
Transcranial Doppler in children with sickle cell disease: Five years of screening experience
Authors: Crow Amanda
Published: February 2020

Introduction

Sickle cell disease (SCD) is an autosomal recessive, inherited disorder of haemoglobin. Children with sickle cell disease (SCD) are at risk of vascular occlusions. If this occurs in the brain, it can result in stroke. Stroke is the leading cause of death and disability in children with SCD.

Transcranial Doppler (TCD) has been shown to accurately predict those children at risk of stroke so appropriate preventative treatment can commence.

Method

TCD screening with a non‐imaging Doppler machine to assess stroke risk has been in operation at our institution for 5 years. Eighty‐eight patients attending the haematology clinic for SCD are scanned annually. If abnormal velocities are found, repeat scans are performed at close interval to ensure results are reproducible.

Results

No child has had a stroke since the start of our screening. Seven of the eighty‐eight patients have shown high velocities on annual screening.

Conclusion

The introduction of a TCD programme at out institution has identified children at risk of stroke so they can be closely monitored and potentially receive prophylactic treatment.
Persistence of the processus vaginalis and its related disorders
Authors: Brainwood Michelle , Beirne Geraldene , Fenech Michelle
Published: February 2020

The processus vaginalis is a blind‐ended evagination of the abdominal wall that develops during fetal life and typically undergoes obliteration in early life. Persistence of the processus vaginalis is associated with a number of pathologies including congenital indirect inguinal hernias, communicating hydroceles, funicular and encysted hydroceles, canal of Nuck cysts, and acquired undescended testis. Whilst all are detectable sonographically, there is little educational material relevant to the field of ultrasound with much of the literature directed at surgical and primary care physicians. Furthermore, within the literature there is a lack of consensus on several areas including the anatomy and embryology of the processus vaginalis and the mechanisms behind its obliteration. As such the objective of this paper is to distil the information regarding the persistent processus vaginalis as it is relevant to ultrasound and in doing so address the literature gap for sonographers and sonologists. The anatomy and embryology of the persistent processus vaginalis will be discussed including causative mechanisms for anomalies with their sonographic appearance highlighted.
Paediatric point‐of‐care ultrasound in a resource‐limited Melanesian setting: A case series
Authors: Henry Jonathan
Published: February 2020

Point‐of‐care ultrasound (POCUS) is an imaging modality with high potential impact on the practice of paediatric emergency medicine in resource‐limited settings. Aside from the obvious diagnostic utility, it facilitates safe procedural guidance at the bedside and provides haemodynamic information to guide resuscitation of shocked states. This five‐patient paediatric case series illustrates the range of POCUS modalities used while working in emergency medicine at a regional referral hospital in Vanuatu. Cases described include a teenager with meningococcaemia, femoral central line insertion in an infant, ventricular septal defect in an infant, a child with a leg abscess, and a child with rheumatic heart disease.
Point‐of‐Care Ultrasound echocardiography diagnosis of an atrial myxoma in a child presenting with stroke
Authors: Quinn Nuala , Kalichuran Rohan , Prenderville Terence , McGuinness Jonathan
Published: February 2020

We describe a case of paediatric stroke secondary to atrial myxoma, diagnosed in the Emergency Department by Point‐of‐Care echocardiography. A previously fit and healthy teenage male presented to our paediatric emergency department following a collapse with loss of consciousness. He had suffered a stroke, and had facial paralysis and hemiplegia. His cardiac examination revealed a 3/6 ejection systolic murmur. Whilst his CT was being reported, he had a Point‐of‐Care echocardiogram in the resuscitation room which showed a very large mass arising from the left atrium and occupying >50% of the chamber. A piece of the myxoma had detached and caused the stroke. The patient was rapidly transferred to a cardiac intensive care unit and underwent emergency surgery the same day. His tumour was successfully completely resected, and he has only a mild residual hemiplegia. Cardiac myxoma should be considered in any child who presents with unexplained acute stroke and a cardiac murmur. Point‐of‐Care Ultrasound echocardiography in the Paediatric Emergency Department can be used to make a life‐saving diagnosis, enabling early surgical management and preventing lifelong complications in children.
Dopaminergic Depletion, β‐Amyloid Burden, and Cognition in Lewy Body Disease
Authors: Yoo Han Soo , Lee Sangwon , Chung Seok Jong , Lee Yang Hyun , Lee Phil Hyu , Sohn Young H. , Lee Seungyeoun , Yun Mijin , Ye Byoung Seok
Published: February 2020

Objective

We aimed to determine the association between striatal dopaminergic depletion, cerebral β‐amyloid deposition, and cognitive dysfunction in Lewy body disease (LBD).

Methods

This cross‐sectional study recruited 48 LBD patients (30 with dementia, 18 with mild cognitive impairment) and 15 control subjects from a university‐based hospital. We measured the striatal dopamine transporter (DAT) activity and regional β‐amyloid burden using N‐(3‐[18F]fluoropropyl)‐2β‐carbon ethoxy‐3β‐(4‐iodophenyl) nortropane (FP‐CIT) positron emission tomography (PET) and 18F‐florbetaben (FBB) PET, respectively. The relationship between striatal FP‐CIT uptake, regional cortical FBB uptake, and cognitive function scores was evaluated using path analyses. We also investigated the effects of striatal FP‐CIT uptake and cortical FBB uptake on the interval between motor symptom and dementia onset.

Results

Reduced striatal FP‐CIT uptake was associated with increased FBB uptake in the posterior cortical regions, most prominently in the occipital cortices. Reduced FP‐CIT uptake in the anterior putamen was associated with visuospatial dysfunction with mediation of increased occipital FBB uptake. Reduced FP‐CIT uptake in the posterior putamen and an increased parietal FBB uptake were independently associated with memory dysfunction. Reduced striatal FP‐CIT uptake was associated with attention, language, and frontal/executive dysfunction, independent of amyloid deposition. Increased FBB uptake, especially in the parietal cortex, was associated with earlier onset of dementia.

Interpretation

Our results suggest that occipital β‐amyloid deposition may contribute to the association between striatal dopaminergic depletion and visuospatial dysfunction in LBD patients. Although the effects of reduced DAT activity are more prominent than those of β‐amyloid burden on cognitive dysfunction, the latter affects the onset of cognitive dysfunction. ANN NEUROL 2020;87:739–750
Supramolecular Phthalocyanine Assemblies for Improved Photoacoustic Imaging and Photothermal Therapy
Authors: Li Xingshu , Park Eun‐Yeong , Kang Youngnam , Kwon Nahyun , Yang Mengyao , Lee Seunghyun , Kim Won Jong , Kim Chulhong , Yoon Juyoung
Published: February 2020

Phototheranostic nanoplatforms are of particular interest for cancer diagnosis and imaging‐guided therapy. Herein, we develop a supramolecular approach to fabricate a nanostructured phototheranostic agent through the direct self‐assembly of two water‐soluble phthalocyanine derivatives, PcS4 and PcN4. The nature of the molecular recognition between PcS4 and PcN4 facilitates the formation of nanostructure (PcS4‐PcN4) and consequently enables the fabrication of PcS4‐PcN4 with completely quenched fluorescence and reduced singlet oxygen generation, leading to the high photoacoustic and photothermal activity of PcS4‐PcN4. In vivo evaluations suggest that PcS4‐PcN4 could not only efficiently visualize a tumor with high contrast through whole‐body photoacoustic imaging but also enable excellent photothermal therapy for cancer.
Hydrogel‐Immobilized Coacervate Droplets as Modular Microreactor Assemblies
Authors: Liu Jianbo , Tian Liangfei , Qiao Yan , Zhou Shaohong , Patil Avinash J. , Wang Kemin , Li Mei , Mann Stephen
Published: February 2020

Immobilization of compartmentalized microscale objects in 3D hydrogels provides a step towards the modular assembly of soft functional materials with tunable architectures and distributed functionalities. Herein, we report the use of a combination of micro‐compartmentalization, immobilization, and modularization to fabricate and assemble hydrogel‐based microreactor assemblies comprising millions of functionalized polysaccharide–polynucleotide coacervate droplets. The heterogeneous hydrogels can be structurally fused by interfacial crosslinking and coupled as input and output modules to implement a UV‐induced photocatalytic/peroxidation nanoparticle/DNAzyme reaction cascade that generates a spatiotemporal fluorescence read‐out depending on the droplet number density, intensity of photoenergization, and chemical flux. Our approach offers a route to heterogeneous hydrogels with endogenous reactivity and reconfigurable architecture, and provides a step towards the development of soft modular materials with programmable functionality.
Catalytic Enantioselective Synthesis of anti‐Vicinal Silylboronates by Conjunctive Cross‐Coupling
Authors: Meng Yan , Kong Ziyin , Morken James P.
Published: February 2020

Chiral 1,2‐bimetallic reagents are useful motifs in synthetic chemistry. Although syn‐1,2‐bimetallic compounds can be prepared by alkene dimetallation, anti‐1,2‐bimetallics are still rare. The stereospecific 1,2‐metallate shift that occurs during conjunctive cross‐coupling is shown to enable a practical and modular approach to the catalytic synthesis of enantioenriched anti‐1,2‐borosilanes. In addition to reaction development, the synthetic utility of anti‐1,2‐borosilanes was investigated, including applications to the synthesis of anti‐1,2‐diols and anti‐1,2‐amino alcohols
Gold(I)‐Catalyzed Haloalkynylation of Aryl Alkynes: Two Pathways, One Goal
Authors: Kreuzahler Mathis , Haberhauer Gebhard
Published: February 2020

Haloalkynylation reactions provide an efficient method for the simultaneous introduction of a halogen atom and an acetylenic unit. For the first time, we report a gold(I)‐catalyzed haloalkynylation of aryl alkynes that delivers exclusively the cis addition product. This method enables the simple synthesis of conjugated and halogenated enynes in yields of up to 90 %. Notably, quantum chemical calculations reveal an exceptional interplay between the place of the attack at the chloroacetylene: No matter which C−C bond is formed, the same enyne product is always formed. This is only possible through rearrangement of the corresponding skeleton. Hereby, one reaction pathway proceeds via a chloronium ion with a subsequent aryl shift; in the second case the corresponding vinyl cation is stabilized by a 1,3‐chlorine shift. 13C‐labeling experiments confirmed that the reaction proceeds through both reaction pathways.
Preparation of core/shell/shell CoFe2O4/OCMC/Cu (BDC) nanostructure as a magnetically heterogeneous catalyst for the synthesis of substituted xanthenes, quinazolines and acridines under ultrasonic irradiation
Authors: Ghasemzadeh Mohammad Ali , Ghaffarian Fatemeh
Published: February 2020

Highly efficient synthesized magnetic cobalt ferrite nanoparticles supported on OCMC@Cu (BDC) was utilized in the preparation of biologically active heterocyclic compounds through one‐pot three‐component reactions between of aldehydes, dimedone, aryl amines/2‐naphthol/urea under ultrasonic irradiation. This method has various advantages including excellent yields, little catalyst loading, simple procedure, facile catalyst separation, short reaction times, eco‐friendly approach and simple purification. The catalyst was characterized by various spectroscopy methods such as fourier‐transform infrared (FT‐IR), energy‐dispersive X‐ray (EDX), scanning electron microscope (SEM), X‐ray diffraction (XRD) and N2 adsorption–desorption isotherm (BET). Furthermore, the heterocyclic compounds were characterized by spectral techniques. The nanocomposite was simply separated byusing an external magnet, and it can be recycled several times without significant loss of activity.
Renewable Aliphatic Polyesters from Fatty Dienes by Acyclic Diene Metathesis Polycondensation
Authors: Moser Bryan R. , Vermillion Karl E. , Banks Benetria N. , Doll Kenneth M.
Published: February 2020

Three renewable, linear, aliphatic polyesters were prepared by Acyclic diene metathesis (ADMET) polymerization of α,ω‐dienes derived from fatty acids. Condensation of 9‐decenoic acid with allyl 9‐decenoate, ethylene glycol, and 9‐decen‐1‐ol proceeded in high conversion (≥94%) and purity (>99%) to give α,ω‐dienes suitable for subsequent polycondensation. Polymerization was achieved using 1.0 mol% Hoveyda‐Grubbs second‐generation metathesis catalyst in combination with 2.0 mol% 2,6‐dichloro‐1,4‐benzoquinone as an isomerization inhibitor under vacuum to drive equilibria toward polymer formation via ethene removal. Polymerization in the presence of solvent promoted ring‐closing metathesis (RCM) at the expense of polymer, with cyclization increasing as the concentration of monomer decreased. Thus, ADMET polymerizations were performed in bulk to mitigate RCM. The resulting polymers with M
n and Ð that ranged from 6.6 to 8.9 kDa and 1.75–2.14, respectively, contained 76% or more of renewable carbon content and exhibited atom and carbon economies of greater than 84%. Melt (T
m) and crystallization (T
c) temperatures were 20.8–48.4 °C and 3.8–37.6 °C, respectively, and increased as ester density decreased within polymer structures. Sub‐ambient glass transitions ranged from −10.3 to −50.0 °C. Lastly, the polymers were thermally stable below 320 °C, as 10% mass loss (T10) occurred above 340 °C, which indicated that they existed as liquids for at least 319 °C (T10 − T
m) before decomposing.
The utilization of synthesis gas for the deoxygenation of cyclohexanone over alumina‐supported catalysts: Screening catalysts
Authors: Bakhtyari Ali , Sakhayi Adele , Rahimpour Mohammad Reza , Raeissi Sona
Published: February 2020

Environmental regulations motivate the industries to replace conventional fuels and chemicals by those produced from biomass. In this regard, hydrodeoxygenation of lignin compounds is of a great deal of attention. Synthesis gas could be utilized instead of pure hydrogen for the cleavage of oxygen‐containing chemical bonds through hydrodeoxygenation. Following this, the utilization of synthesis gas is investigated in the present contribution. A wide range of commercial alumina‐supported catalysts is investigated. The experimental results of cyclohexanone hydrodeoxygenation in the presence of pure hydrogen and synthesis gas at 573 K and 20 bar of total pressure are presented and discussed. The whole investigated catalysts show good activity toward the hydrodeoxygenation of cyclohexanone. Methylatedbenzene derivatives are produced from cyclohexanone hydrodeoxygenation for the first time. The catalysts composed of platinum showed the best performance. By utilizing a chlorinated platinum catalyst, 89.6% cyclohexanone conversion, 100% total hydrocarbon selectivity, and 44.6% total hydrocarbon yield are obtained. In the case of syngas‐assisted hydrodeoxygenation, 80.1% cyclohexanone conversion, 100% total hydrocarbon selectivity, and 29.6% total hydrocarbon yield are obtained by utilizing the same catalyst. The presence of methylated aromatics proves the accomplishment of methanation or direct aromatization reactions in the presence of carbon oxides and hydrogen.
Artisanal fishing activities and their documented interactions with juvenile white sharks inside a nursery area
Authors: García‐Rodríguez Emiliano , Sosa‐Nishizaki Oscar
Published: February 2020

Juvenile white sharks distribute in coastal nursery areas, which are essential for population growth. Bahía Sebastián Vizcaíno (BSV), Mexico, is a white shark nursery area in the north‐eastern Pacific. Despite existing regulations forbidding the capture of white sharks, incidental catches still occur in some areas.

Artisanal fisheries constitute one of the most important economic activities in BSV, yet no formal description of either these fisheries or the incidental catch of juvenile white sharks exists due to the poor data reporting system, thus preventing a clear understanding of the implications of these catches for the white shark population of the north‐eastern Pacific.

Artisanal fishing activities and their interactions with juvenile white sharks in BSV are described based on fishermen's knowledge. Artisanal fisheries in BSV are multi‐specific, targeting mostly bottom‐related species (e.g. white seabass and California halibut) that are also common prey for juvenile white sharks. These activities are the only source of income for the majority of fishermen in BSV and are conducted throughout the year, with gillnets being the main fishing gear.

White sharks are incidentally caught in bottom gillnets mainly during the summer, although another peak in incidental catch was recorded during winter, possibly related to the presence of juvenile white sharks from California, USA. The most common size of juvenile white sharks incidentally caught was <2 m in the nearshore areas close to the mouth of the Ojo de Liebre Lagoon; larger juveniles (~3 m) were caught in areas near Cedros, Natividad, and San Benito Islands.

The multi‐specific nature of BSV artisanal fisheries and their socio‐economic value, and the high post‐release survival of juvenile white sharks suggest that future regulatory actions should focus on the release of incidentally caught live juvenile white sharks and the involvement of the BSV fishing community to increase the effectiveness of management efforts.
Quercetin alleviates hyperthyroidism‐induced liver damage via Nrf2 Signaling pathway
Authors: Zhao Pengxin , Hu Zhigang , Ma Weiyuan , Zang Leilei , Tian Zhisheng , Hou Qian
Published: February 2020

Quercetin is a plant flavonoid and has antioxidative properties. In this study, we evaluated the therapeutic effect of quercetin on thyroid dysfunction in L‐thyroxin (LT4)‐induced hyperthyroidism rats. LT4 was used to prepare the experimental hyperthyroidism model via the intraperitoneal injection. Quercetin was injected at a series doses (5, 50, and 100 mg/kg) to LT4‐induced hypothyroidism rats once a day for 14 days. The body weight and food intake were measured once a week. The levels of thyroid hormones, liver function, oxidative stress markers, and antioxidant markers were measured using commercial enzyme‐linked immunosorbent assay kits. Hematoxylin–eosin staining was used to observe the thyroid tissue histological changes. The levels of nuclear and total nuclear factor erythroid 2‐related factor 2 (Nrf2) were determined by western blot. The liver oxidative stress markers in LT4‐induced hyperthyroidism Nrf2 knockout rats were determined to evaluate the role of Nrf2 on quercetin induced protective effects. LT4 administration increased the levels of serum triiodothyronine and thyroxine, activity of oxidative stress markers with a parallel decrease in antioxidant markers and Nrf2. However, the simultaneous administration of quercetin, reversed all these effects indicating its potential in the regulation of hyperthyroidism. Furthermore, the loss function of Nrf2 diminished these effects resulting from the quercetin application, indicating the inhibitory effects caused by the quercetin may be involved in Nrf2 signaling pathway. These results indicate that quercetin could be used to protect against experimental hyperthyroidism‐induced liver damage via Nrf2 signaling pathway.
Expanding and understanding the CRISPR toolbox for Bacillus subtilis with MAD7 and dMAD7
Authors: Price Marcus A. , Cruz Rita , Bryson James , Escalettes Franck , Rosser Susan J.
Published: February 2020

The CRISPR‐Cas9 system has become increasingly popular for genome engineering across all fields of biological research, including in the Gram‐positive model organism Bacillus subtilis. A major drawback for the commercial use of Cas9 is the IP landscape requiring a license for its use, as well as reach‐through royalties on the final product. Recently an alternative CRISPR nuclease, free to use for industrial R&D, MAD7 was released by Inscripta (CO). Here we report the first use of MAD7 for gene editing in B. subtilis, in which editing rates of 93% and 100% were established. Additionally, we engineer the first reported catalytically inactive MAD7 (dMAD7) variant (D877A, E962A, and D1213A) and demonstrate its utility for CRISPR interference (CRISPRi) at up to 71.3% reduction of expression at single and multiplexed target sites within B. subtilis. We also confirm the CRISPR‐based editing mode of action in B. subtilis providing evidence that the nuclease‐mediated DNA double‐strand break acts as a counterselection mechanism after homologous recombination of the donor DNA.
A new twist on the graduate student journal club: Using a topic‐centered approach to promote student engagement
Authors: Bimczok Diane , Graves John
Published: February 2020

Journal clubs are widely used as an educational tool in graduate life science programs. In journal clubs, students are assigned to read specific journal articles to achieve a broad knowledge in their field of study and to gain competence in reading and assessing scientific publications. However, students often show low motivation to read assigned articles, and under‐prepared students contribute little to in‐class discussions. In order to promote student engagement in graduate‐level journal clubs, we used an inverted, student‐centered format that focuses on a scientific question or topic rather than specific publications. Both the weekly topics and the scientific publications were selected by the students and focused on aspects of the students' thesis research. For each weekly topic, students were asked to find papers, read the papers and summarize the findings during class, which led to the presentation of a variety of approaches and viewpoints. This approach trained students in literature search, focused reading and oral presentation skills and provided a broad overview of the research in the selected topic areas. Student feedback showed a high level of acceptance of the new format. We propose this inverted journal club format as a useful alternative to traditional formats, because it focuses on a different scientific skill set and leads to increased student engagement through its student‐centered approach.
Utilizing the Regional Acceleratory Phenomenon and Dental Implant Anchorage for Distalization and Intrusion of a Mesially Tipped Mandibular Molar: A Case Report
Authors: Vargas Anthony A. , Bruin Daniel B. , Stewart Michael J. , Wilding Jake T. , Dunham Daniel D. , Weber Diana W. , Johnson Thomas M.
Published: February 2020

Introduction

Introduction of a surgical insult in conjunction with orthodontic therapy has been shown to accelerate treatment in minor tooth movement and comprehensive orthodontic cases by induction of the regional acceleratory phenomenon (RAP). When applying this concept to a molar tipped into an adjacent edentulous site, a dental implant can be planned to anchor the movement.

Case Presentation

A generally and periodontally healthy 25‐year‐old patient presented missing tooth #19, with tooth #18 mesially tipped into the first molar crown space. A dental implant was placed in the #19 position. Following osseointegration, the implant anchored orthodontic movement of the adjacent tooth, which was initiated in conjunction with third molar extraction.

Conclusion

Favorable biomechanics for molar uprighting can be achieved using an osseointegrated implant and a customized orthodontic device. The presented technique facilitates implant site development without delaying placement of the fixture and simplifies fabrication of a harmonious and anatomic implant‐supported restoration. Induction of the RAP may hasten treatment completion.
Slender versus conventional approach reduces post‐procedural upper extremity dysfunction after transradial coronary procedures
Authors: Amoroso Giovanni , van der Brug Sander , Franx Valerie , van Dullemen Anneleen , van der Vecht‐Kroeze Gerda , van Duinen Mieke
Published: February 2020

Aims

We compared the incidence of post‐procedural radial artery occlusion (RAO) and upper extremity dysfunction (UED), in patients undergoing conventional versus slender transradial (TRA) coronary procedures.

Methods and results

UED was assessed by the QuickDASH, before conventional (i.e., ≥6F) and slender (i.e., “virtual” 3F to 5F) procedures, after 2 weeks and 2 months. RAO was assessed by Duplex in patients with an abnormal reversed Barbeau test (RBT). A total of 212 patients were included, UED after 2 weeks was 12%, and after 2 months 7% (p = <.001). RAO occurred in 3%. Multivariate analysis showed an OR of 0.26 (CI0.08–0.84) for UED at 2 weeks (p = .03) in favor of slender TRA. In patients with RAO, UED did not improve at 2 months (2/5, 40%, p = .046).

Conclusions

The occurrence of UED after TRA procedures is temporary except for patients with RAO. Slender TRA seems able to reduce short term UED.
Phasic pressure measurements for coronary and valvular interventions using fluid‐filled catheters: Errors, automated correction, and clinical implications
Authors: Johnson Daniel T. , Fournier Stephane , Kirkeeide Richard L. , De Bruyne Bernard , Gould K. Lance , Johnson Nils P.
Published: February 2020

Objectives

We sought to develop an automatic method for correcting common errors in phasic pressure tracings for physiology‐guided interventions on coronary and valvular stenosis.

Background

Effective coronary and valvular interventions rely on accurate hemodynamic assessment. Phasic (subcycle) indexes remain intrinsic to valvular stenosis and are emerging for coronary stenosis. Errors, corrections, and clinical implications of fluid‐filled catheter phasic pressure assessments have not been assessed in the current era of ubiquitous, high‐fidelity pressure wire sensors.

Methods

We recruited patients undergoing invasive coronary physiology assessment. Phasic aortic pressure signals were recorded simultaneously using a fluid‐filled guide catheter and 0.014″ pressure wire before and after standard calibration as well as after pullback. We included additional subjects undergoing hemodynamic assessment before and after transcatheter aortic valve implantation. Using the pressure wire as reference standard, we developed an automatic algorithm to match phasic pressures.

Results

Removing pressure offset and temporal shift produced the largest improvements in root mean square (RMS) error between catheter and pressure wire signals. However, further optimization <1 mmHg RMS error was possible by accounting for differential gain and the oscillatory behavior of the fluid‐filled guide. The impact of correction was larger for subcycle (like systole or diastole) versus whole‐cycle metrics, indicating a key role for valvular stenosis and emerging coronary pressure ratios.

Conclusions

When calibrating phasic aortic pressure signals using a pressure wire, correction requires these parameters: offset, timing, gain, and oscillations (frequency and damping factor). Automatically eliminating common errors may improve some clinical decisions regarding physiology‐based intervention.
3‐Dimensional printing to predict paravalvular regurgitation after transcatheter aortic valve replacement
Authors: Reiff Christopher , Zhingre Sanchez Jorge D. , Mattison Lars M. , Iaizzo Paul A. , Garcia Santiago , Raveendran Ganesh , Gurevich Sergey
Published: February 2020

Background

There is no effective method to predict paravalvular regurgitation prior to transcatheter aortic valve replacement (TAVR).

Methods

We retrospectively analyzed pre‐TAVR computed tomography (CT) scans of 20 patients who underwent TAVR for severe, calcific aortic stenosis and subsequently printed 3‐dimensional (3D) aortic root models of each patient. Models were printed using Ninjaflex thermoplastic polyurethane (TPU) (Ninjatek Manheim, PA) and TPU 95A (Ultimaker, Netherlands) on Ultimaker 3 Extended 3D printer (Ultimaker, Netherlands). The models were implanted at nominal pressure with same sized Sapien balloon‐expandable frames (Edwards Lifesciences, CA) as received in‐vivo. Ex‐vivo implanted TAVR models (eTAVR) were scanned using Siemens SOMATOM flash dual source CT (Siemens, Malvern, PA) and then analyzed with Mimics software (Materialize NV, Leuven, Belgium) to evaluate relative stent appositions. eTAVR were then compared to post‐TAVR echocardiograms for each patient to assess for correlations of identified and predicted paravalvular leak (PVL) locations.

Results

A total of 20 patients (70% male) were included in this study. The median age was 77.5 (74–83.5) years. Ten patients were characterized to elicit mild (9/10) or moderate (1/10) PVL, and 10 patients presented no PVL. In patients with echocardiographic PVL, eTAVR 3D model analyses correctly identified the site of PVL in 8/10 cases. In patients without echocardiographic PVL, eTAVR 3D model analyses correctly predicted the lack of PVL in 9/10 cases.

Conclusion

3D printing may help predict the potential locations of associated PVL post‐TAVR, which may have implications for optimizing valve selection and sizing.
Changes in quality of life in patients with low‐flow aortic stenosis undergoing transcatheter aortic valve replacement
Authors: Ahmed Aisha , Alsidawi Said , Bae Richard , Cavalcante Joao , Fukui Miho , Gössl Mario , Sorajja Paul , Garcia Santiago
Published: February 2020

Background

We sought to quantify and compare changes in quality of life measures after transcatheter aortic valve replacement (TAVR) in patients with low‐flow (LF) and normal‐flow (NF) aortic stenosis (AS).

Methods

We included 297 patients treated with TAVR at Abbott Northwestern Hospital from January 2015 to October 2017. Health status was assessed at baseline and 30 days post‐procedure using the Kansas City Cardiomyopathy Questionnaire 12 (KCCQ‐12). Overall (KCCQ‐OS) and domain‐specific (physical limitation, symptom frequency, quality of life, and social limitation) scores were compared in three subsets of patients as defined by stroke volume index (≤ or >35 ml/m2), ejection fraction (EF) (≤ or >40%), and mean gradient (≤ or >40 mmHg).

Results

Of the 297 patients included, 129 (43%) had NF high‐gradient (NF AS group) and 168 (56%) had LF severe AS, including 25 (8%) with low EF (8%) (“Classical” low‐flow low‐gradient LEF [LF‐LG‐LEF] group) and 143 (48%) with preserved EF (“Paradoxical” LF‐LG group). At baseline, patients with LF‐LG‐LEF AS had more severe impairment in symptoms frequency (p = .06) but similar KCCQ‐OS. At 1‐month after TAVR, all groups had moderate improvements in quality of life (Delta KCCQ‐OS: “Classical” LF‐LG‐LEF 18 ± 21, paradoxical AS 14 ± 18, and NF AS 15 ± 16, p = .57). During a median follow‐up time of 2.4 years, there was no difference in mortality (p = .34) but patients with paradoxical LF‐LG AS had a higher risk of rehospitalization for heart failure (p = .01).

Conclusions

Patients with LF severe AS derive significant improvements in quality of life measures after TAVR, indistinguishable from patients with NF AS.
Zearalenone‐malonyl‐glucosides as phase II metabolites in plant cell suspension cultures
Authors: Kohn Beate N. , Bunzel Mirko
Published: February 2020

Background and objectives

Conjugation of mycotoxins in the phase II metabolism of plants results in modified mycotoxins such as glucosides and malonyl‐glucosides. However, malonyl‐glucosides have not yet been completely elucidated for zearalenone (ZEN). Thus, the aim of this study was to produce and isolate malonyl‐glucosides of ZEN for an unambiguous identification by NMR spectroscopy.

Findings

Zearalenone was incubated in plant cell suspension cultures of wheat, soy, and tobacco, and phase II metabolites were analyzed by using LC‐DAD‐MS, ‐HRMS, and NMR spectroscopy. Four main metabolites of ZEN were detected in the cell extracts and identified as two glucosides (attached in positions 14 and 16) and their 6´‐malonyl derivatives.

Conclusions

Zearalenone‐malonyl‐glucosides should be incorporated in future analyses of modified mycotoxins because of their potential relevance for food and feed safety.

Significance and novelty

For the first time, the structures of the two malonyl‐glucosides of ZEN were unambiguously identified by NMR spectroscopy after preparative isolation as 14‐O‐(6’‐O‐malonyl‐β‐D‐glucopyranosyl)ZEN and 16‐O‐(6’‐O‐malonyl‐β‐D‐glucopyranosyl)ZEN.
Boosting the Oxygen Reduction Performance via Tuning the Synergy between Metal Core and Oxide Shell of Metal−Organic Frameworks‐Derived Co@CoOx
Authors: Wang Hao , Kou Rong‐Hui , Jin Qiu , Liu Yu‐Zi , Yin Feng‐Xiang , Sun Cheng‐Jun , Wang Liang , Ma Zhi‐Yuan , Ren Yang , Liu Ning , Chen Biao‐Hua
Published: February 2020

Co core@Co oxide shell (Co@CoOx) catalysts represent a large family with promising oxygen reduction reaction (ORR) catalytic activity. However, inadequate understanding of Co@CoOx synergy prohibits further pursuit of catalytic performance enhancement. Herein, a Co zeolitic−imidazolate framework was converted into metallic Co, followed by controlled air treatment to form Co@CoOx. The composition and structure evolution as a function of air treatment temperature were studied thoroughly through conventional and synchrotron (both ex‐situ and in‐situ) characterizations, confirming the coexistence of CoO and Co3O4 in the shell. The optimal catalyst showed an ORR half‐wave potential of 0.87 V (vs. RHE) in an alkaline half‐cell and delivered high discharge capacity in an aprotic Li−O2 battery (7,124 mAh gCat+C−1) and an aqueous Zn−air battery (694 mAh gZn−1) with good performance retention after durability test. Modeling simulation and density functional theory calculation confirmed the charge donation from metal core to oxide shell and shed light on new insights of how metal@metal oxide synergy impacted the ORR via tuning the charge conductivity, oxygen affinity and intermediate transfer pathway. This work opens up a venue to boost ORR catalytic activity from an interfacial synergy perspective.
Comparison of variable selection methods in partial least squares regression
Authors: Mehmood Tahir , Sæbø Solve , Liland Kristian Hovde
Published: February 2020

Through the remarkable progress in technology, it is getting easier and easier to generate vast amounts of variables from a given sample. The selection of variables is imperative for data reduction and for understanding the modeled relationship. Partial least squares (PLS) regression is among the modeling approaches that address high throughput data. A considerable list of variable selection methods has been introduced in PLS. Most of these methods have been reviewed in a recently conducted study. Motivated by this, we have therefore conducted a comparison of available methods for variable selection within PLS. The main focus of this study was to reveal patterns of dependencies between variable selection method and data properties, which can guide the choice of method in practical data analysis. To this aim, a simulation study was conducted with data sets having diverse properties like the number of variables, the number of samples, model complexity level, and information content. The results indicate that the above factors like the number of variables, number of samples, model complexity level, information content and variant of PLS methods, and their mutual higher‐order interactions all significantly define the prediction capabilities of the model and the choice of variable selection strategy.
Selective Catalytic Synthesis of 1,2‐ and 8,9‐Cyclic Limonene Carbonates as Versatile Building Blocks for Novel Hydroxyurethanes
Authors: Maltby Katarzyna A. , Hutchby Marc , Plucinski Pawel , Davidson Matthew G. , Hintermair Ulrich
Published: February 2020

The selective catalytic synthesis of limonene‐derived monofunctional cyclic carbonates and their subsequent functionalisation via thiol–ene addition and amine ring‐opening is reported. A phosphotungstate polyoxometalate catalyst used for limonene epoxidation in the 1,2‐position is shown to also be active in cyclic carbonate synthesis, allowing a two‐step, one‐pot synthesis without intermittent epoxide isolation. When used in conjunction with a classical halide catalyst, the polyoxometalate increased the rate of carbonation in a synergistic double‐activation of both substrates. The cis isomer is shown to be responsible for incomplete conversion and by‐product formation in commercial mixtures of 1,2‐limomene oxide. Carbonation of 8,9‐limonene epoxide furnished the 8,9‐limonene carbonate for the first time. Both cyclic carbonates underwent thiol–ene addition reactions to yield linked di‐monocarbonates, which can be used in linear non‐isocyanate polyurethanes synthesis, as shown by their facile ring‐opening with N‐hexylamine. Thus, the selective catalytic route to monofunctional limonene carbonates gives straightforward access to monomers for novel bio‐based polymers.
Two Orthogonal Halogen‐Bonding Interactions Directed 2D Crystalline Supramolecular J‐Dimer Lamellae
Authors: Su Meihui , Yan Xiaosa , Guo Xia , Li Quanwen , Zhang Yushi , Li Changhua
Published: February 2020

Dye assemblies exhibit fascinating properties and performances, both of which depend critically on the mutual packing arrangement of dyes and on the supramolecular architecture. Herein, we engineered, for the first time, an intriguing chlorosome‐mimetic 2D crystalline J‐dimer lamellar structure based on halogenated dyes in aqueous media by employing two distinct orthogonal halogen‐bonding (XB) interactions. As the only building motif, antiparallel J‐dimer was formed and stabilized by single π‐stacking and dual halogen⋅⋅⋅π interactions. With two substituted halogen atoms acting as XB donors and the other two acting as acceptors, the constituent J‐dimer units were linked by quadruple highly‐directional halogen⋅⋅⋅halogen interactions in a staggered manner, resulting in unique 2D lamellar dye assemblies. This work champions and advances halogen‐bonding as a remarkably potent tool for engineering dye aggregates with a controlled molecular packing arrangement and supramolecular architecture.
Structure of heroin in a solution revealed by chiroptical spectroscopy
Authors: Králík František , Fagan Patrik , Kuchař Martin , Setnička Vladimír
Published: February 2020

In this work, the 3‐D structure of the well‐known opioid drug heroin in a solution was investigated. The goal was to provide a complete and detailed description of the stable conformers with their relative abundances. This knowledge is very important from the pharmaceutical and forensic point of view as it could help significantly with deeper understanding of heroin's metabolism and the development of antagonist medicines for the case of an overdose. As heroin is a chiral compound with five stereogenic centres, the methods of chiroptical spectroscopy supplemented by density functional theory (DFT) calculations were applied to study its conformations in chloroform solution. The selected chiroptical methods, namely, electronic circular dichroism (ECD) and vibrational circular dichroism (VCD), are inherently sensitive to the 3‐D structure of small‐ to medium‐sized chiral organic molecules. A thorough conformational analysis revealed four stable conformers of heroin in chloroform solution, where the conductor‐like polarizable continuum model of the solvent was used for all the calculations. The simulated ultraviolet (UV), infrared (IR), ECD, and VCD spectra were compared with the experimental ones and very good agreement was found, which enabled a detailed structure description and interpretation of the spectra. Chiroptical spectroscopy in combination with DFT calculations proved to be a very sensitive tool for the analysis of the 3‐D structure of heroin in a solution in contrast with conventional spectroscopic methods. Especially, the application of VCD seems to be a promising approach for monitoring structural changes, for instance, those caused by solvents or interactions with other agents.
Comparison of polysaccharide‐based and protein‐based chiral liquid chromatography columns for enantioseparation of drugs
Authors: Fu Yandi , Borrull Francesc , Fontanals Núria , Marcé Rosa Maria
Published: February 2020

Two different columns—Lux Cellulose‐1 and Chiralpak CBH—were evaluated for their chiral recognition abilities for eight drugs comprising three β‐blockers, one antacid, and four cathinones in polar‐organic elution mode and reversed‐phase elution mode, respectively. The factors that affected the enantioseparation were tested and optimized to develop a suitable chiral separation method whose LC conditions are compatible with MS detection. In polar‐organic elution mode with the Lux Cellulose‐1 column, methanol and acetonitrile were tested as the main components of the mobile phase. In addition, the effects of adding isopropanol as organic modifier, acidic additives (formic acid), and basic additives (diethylamine) were evaluated. In reversed‐phase elution mode with the Chiralpak CBH column, the effect of type and concentration of organic modifier (isopropanol, acetonitrile, and methanol), the mobile phase pH (6.4 and 5.0), and buffer concentration (1mM‐20mM ammonium acetate) were evaluated. The best enantioseparation was achieved with the Chiralpak CBH column with a mobile phase composed of 5mM ammonium acetate aqueous (pH = 6.4)/methanol (95/5, v/v) at a flow rate of 0.1 mL/min and a temperature of 30°C. Under these conditions, six of eight chiral drugs were baseline separated.