bluuebunny/crossref_metadata_2025_split huggingface dataset:
A collaborative two‐stage examination in biomedical sciences: Positive impact on feedback and peer collaboration
Authors: Khong Mei Li , Tanner Julian A. 
Published: June 2020

AbstractExaminations present an intensely focused opportunity for student learning yet opportunities for collaboration, communication, and feedbacks are often wasted. Two‐stage examinations where students first take examinations individually and then repeat the examination in small groups hold promise to address this issue. Here, we pilot and evaluate a two‐stage examination within an advanced undergraduate biomedical sciences course. We evaluated this innovation by triangulation of data from a questionnaire, semi‐structured student interviews, as well as, comparison of student grades between stages of examination across higher‐ and lower‐performing student groups. Quantitative data from the structured questionnaire showed that a majority of students perceived the collaborative stage of two‐stage examinations successful in promoting peer collaboration and communication. Furthermore, there was deepened conceptual understanding and provision of immediate feedback. The two‐stage examination did not, however, ameliorate students' test anxiety. Qualitative data from semi‐structured student interviews were consistent with quantitative data to show that a two‐stage examination provides positive impact particularly on immediate feedback, peer collaboration and communication but contributed to sustained test anxiety possibly due to negative experiences during group interactions. Both lower‐ and higher‐performing students showed improvement in the collaborative stage as compared to the preceding individual stage of two‐stage examination. This would suggest possible benefits of two‐stage examination for learning for all student abilities. This study discusses the advantages and pitfalls of two‐stage examinations for biomedical sciences and will guide informed recommendations for subsequent implementation elsewhere.
Virtual laboratory lessons in enzymology
Authors: Quesada Víctor 
Published: June 2020

AbstractThe recent COVID‐19 pandemic has led to widespread lock‐down strategies that force universities to perform all educational activities remotely. In this context, laboratory lessons pose a significant challenge. Here, I present an on‐line tool that simulates the kinetics of chemical reactions. Enzymatic mechanisms can be easily modeled and followed through time. In addition, professors can customize the interface to hide the reaction mechanism. This setting will force students to design virtual experiments to uncover the mechanism and obtain the relevant enzymatic parameters. While some of the skills developed in a practical lesson cannot be simulated, this tool can be used to teach students important concepts about data acquisition and processing.
Development of a small‐scale rotary lobe‐pump cell culture model for examining cell damage in large‐scale N‐1 seed perfusion process
Authors: Johnstone Patrick , Mast Elena , Hughes Erik , Peng Haofan 
Published: June 2020

AbstractPerfusion technology has been identified as a process improvement capable of eliminating some of the constraints in cell culture and allows for high cell densities and viabilities. However, when implementing this N‐1 seed perfusion platform in large‐scale manufacturing, unexpected cell damage was observed as early as Day 1. Given that the shear rate within recirculation hollow fibers was normalized and aligned correctly across bench, pilot, and manufacture scale, the primary mitigation was placed on the rotary lobe pump. Lowering the pump rate in manufacture scale successfully alleviated the cell damage. To understand the source of cell damage within the pump, a small‐scale rotary lobe‐pump robustness model was developed. Testing different pump flow rates and back pressures, it was concluded that high back pressure can cause cell damage. The back pressure within the system can cause back flow and high shear within small clearances inside the pump, which lead to the primary cell damage observed at a large scale. This shear level can be significantly higher than the shear in the hollow fiber. This pump robustness model can be utilized to aid the perfusion skid design, including pump operation efficiency and cell shear sensitivity. Methods to reduce the back pressure and cell shearing were determined to better predict manufacturing performance in the future.
Single‐access during Impella hemodynamic support utilizing the Railway system
Authors: Whitbeck Matthew G. , Chambers Jeffrey W. 
Published: June 2020

AbstractA single‐access technique during mechanical circulatory support (MCS) and percutaneous coronary intervention (PCI) has been described for those patients where an additional arterial access site is not available or desired. This technique utilizes the Impella (Abiomed, Danvers, MA) 14 French (F) sheath as a single‐access point, with a 7 F sheath through the 14 F sheath hemostatic valve next to the Impella catheter (Abiomed). However, this technique is limited to a 7 F sheath or smaller and can be difficult requiring multiple attempts and limit guide catheter manipulation. We describe a single‐access technique utilizing the Impella (Abiomed) 14 F sheath and a standard 7 F guide catheter placed sheathless through the 14 F sheath hemostatic valve utilizing the Railway Sheathless Access System (Cortis, Santa Clara, CA).
SAPIEN S3 valve deployment in the pulmonary position using the gore DrySeal sheath to protect the tricuspid valve
Authors: Stapleton Gary E. , Gowda Srinath T , Bansal Manish , Khan Asra , Qureshi Athar M , Justino Henri 
Published: June 2020

AbstractBackgroundTricuspid valve injury can occur during implantation of a SAPIEN valve in the pulmonary position. We describe our experience using a long Gore DrySeal (GDS) sheath to protect the tricuspid valve during advancement of the Commander delivery system.MethodsRetrospective single center review of all patients who underwent placement of a SAPIEN valve in the right ventricular outflow tract between January 2016 and April 2020. Patients were divided into two groups: delivery of the valve using standard technique (Group I), and with the use of a GDS (Group II), for comparison.ResultsThere were 48 patients in total: 25 in Group I and 23 in Group II. In Group II, the first 10 patients had a 29 mm S3 placed through a 26 French (Fr), 65 cm GDS. We then performed additional crimping of the S3 onto the balloon after the balloon catheter was withdrawn to position the valve on the balloon outside the body. Subsequently, seven had a 29 mm S3 placed through a 24 Fr GDS, and four had a 26 mm S3 placed through a 22 Fr GDS including one weighing 16 kg. Two had a 23 mm S3 placed through a 22Fr GDS as the 20Fr GDS was not available in our lab. Severe tricuspid valve injury occurred in 2/25 (8%) of Group I patients and 0/23 of Group II patients.ConclusionUse of a long GDS may protect the tricuspid valve from injury during implantation of the S3 valve in the pulmonary position, and is technically feasible in smaller patients.
Facet‐dependent Chlorine and Oxygen Evolution Selectivity on RuO2: An Ab initio Atomistic Thermodynamic Study
Authors: Saha Sulay , Gayen Pralay , Ramani Vijay K. 
Published: June 2020

AbstractThe chlorine evolution reaction (CER) and oxygen evolution reaction (OER) occur simultaneously due to the low difference (0.13 V) in their standard potentials. RuO2 is the state‐of‐art electrocatalyst used for both OER and CER. The activity and selectivity of different RuO2 low‐index facets, namely (100), (110), (111), (001) and (101), are investigated through ab‐initio density functional theory (DFT) based calculations. The selectivity of different facets is explored in a mixed OER‐CER region by combining Pourbaix diagrams and linear scaling relationships. The difference in limiting overpotential of OER and CER is identified as the selectivity descriptor (SDCER). The most CER‐ and OER‐selective facets are found to be (101) (SDCER=0.39 V) and (001) (SDCER=0.14 V), respectively. The understanding of facet dependent CER selectivity in RuO2 can be extended as a design strategy to modulate OER and CER activity and selectivity as per design requirements.
Heteroarene‐tethered Functionalized Alkyne Metamorphosis
Authors: Bag Debojyoti , Sawant Sanghapal D. 
Published: June 2020

AbstractHeteroarene‐tethered functionalized alkynes are multipotent synthons in organic chemistry. This detailed Review described herein offers a thorough discussion of the metamorphosis of heteroarene‐tethered functionalized alkynes, an area which has earned much attention over the past decade in the straightforward synthesis of architecturally complex heterocyclic scaffolds in atom and step economic manner. Depending upon the variety of functionalized alkynes, this Review is divided into multiple sections. Amongst the vast array of synthetic transformations covered, dearomatizing spirocyclizations and cascade spirocyclization/rearrangement are of great interest. Synthetic transformations involving the heteroarene‐tethered functionalized alkynes with scope, challenges, limitations, mechanism, their application in the total synthesis of natural products and future perceptions are surveyed.
Easy Access to Phosphine‐Borane Building Blocks
Authors: de Jong G. Bas , Ortega Nuria , Lutz Martin , Lammertsma Koop , Slootweg J. Chris 
Published: June 2020

AbstractIn this paper, we highlight the synthesis of a variety of primary phosphine‐boranes (RPH2⋅BH3) from the corresponding dichlorophosphines, simply by using Li[BH4] as reductant and provider of the BH3 protecting group. The method offers facile access not only to alkyl‐ and arylphosphine‐boranes, but also to aminophosphine‐boranes (R2NPH2⋅BH3) that are convenient building blocks but without the protecting BH3 moiety thermally labile and notoriously difficult to handle. The borane‐protected primary phosphines can be doubly deprotonated using n‐butyllithium to provide soluble phosphanediides Li2[RP⋅BH3] of which the phenyl‐derivative Li2[PhP⋅BH3] was structurally characterized in the solid state.
Disulfide Bond Replacement with 1,4‐ and 1,5‐Disubstituted [1,2,3]‐Triazole on C‐X‐C Chemokine Receptor Type 4 (CXCR4) Peptide Ligands: Small Changes that Make Big Differences
Authors: Tomassi Stefano , Trotta Anna Maria , Ieranò Caterina , Merlino Francesco , Messere Anna , Rea Giuseppina , Santoro Federica , Brancaccio Diego , Carotenuto Alfonso , D'Amore Vincenzo Maria , Di Leva Francesco Saverio , Novellino Ettore , Cosconati Sandro , Marinelli Luciana , Scala Stefania , Di Maro Salvatore 
Published: June 2020

AbstractHere we investigated the structural and biological effects ensuing from the disulfide bond replacement of a potent and selective C‐X‐C chemokine receptor type 4 (CXCR4) peptide antagonist, with 1,4‐ and 1,5‐ disubstituted 1,2,3‐triazole moieties. Both strategies produced candidates that showed high affinity and selectivity against CXCR4. Notably, when assessed for their ability to modulate the CXCL12‐mediated cell migration, the 1,4‐triazole variant conserved the antagonistic effect in the low‐mid nanomolar range, while the 1,5‐triazole one displayed the ability to activate the migration, becoming the first in class low‐molecular‐weight CXCR4 peptide agonist. By combining NMR and computational studies, we provided a valuable model that highlighted differences in the interactions of the two peptidomimetics with the receptor that could account for their different functional profile. Finally, we envisage that our findings could be translated to different GPCR‐interacting peptides for the pursuit of novel chemical probes that could assist in dissecting the complex puzzle of this fundamental class of transmembrane receptors.
High‐performance photocatalysts for the selective oxidation of alcohols to carbonyl compounds
Authors: Rangarajan Goutham , Yan Ning , Farnood Ramin 
Published: June 2020

AbstractWith an increase in awareness about the need for green chemistry, there is a shift in focus towards identifying eco‐compatible technologies that can improve product yield and eliminate the use or generation of hazardous compounds. An immediate practical example of such an approach is the development of sustainable methods for alcohol oxidation as alternatives to the current processes that are energy intensive and rely on ecotoxic chemicals. In this regard, heterogeneous photocatalysis has been identified as a robust technique to catalyze reactions under benign conditions, which would otherwise require harsh synthesis routes. With the advent of materials sciences and nanotechnology, there has been a tremendous increase in the scope of applicability of photocatalysis in fine chemicals synthesis. Though an attractive choice, much of the fundamental information pertaining to catalyst activity, selectivity and reaction conditions for optimum conversion are still to be investigated for most of these systems. To this end, this review will encompass recent achievements in the selective photocatalytic oxidation of alcohols by harnessing solar radiation as a viable source of energy. The discussion will be arranged based on common types of photocatalysts reported in literature, namely metal oxides (eg, TiO2 and ZnO, Nb2O5), sulphides (eg, CdS, CuS, and Bi2S3), and carbonaceous photocatalysts (eg, g‐C3N4). Several such candidates for photocatalysts will be discussed critically with the aim of providing useful insight into developing selective photocatalysts that can oxidize alcohols via eco‐friendly pathways along with high yields.
Evaluating the effect of reference genome divergence on the analysis of empirical RADseq datasets
Authors: Bohling Justin 
Published: June 2020

AbstractThe advent of high‐throughput sequencing (HTS) has made genomic‐level analyses feasible for nonmodel organisms. A critical step of many HTS pipelines involves aligning reads to a reference genome to identify variants. Despite recent initiatives, only a fraction of species has publically available reference genomes. Therefore, a common practice is to align reads to the genome of an organism related to the target species; however, this could affect read alignment and bias genotyping. In this study, I conducted an experiment using empirical RADseq datasets generated for two species of salmonids (Actinopterygii; Teleostei; Salmonidae) to address these questions. There are currently reference genomes for six salmonids of varying phylogenetic distance. I aligned the RADseq data to all six genomes and identified variants with several different genotypers, which were then fed into population genetic analyses. Increasing phylogenetic distance between target species and reference genome reduced the proportion of reads that successfully aligned and mapping quality. Reference genome also influenced the number of SNPs that were generated and depth at those SNPs, although the affect varied by genotyper. Inferences of population structure were mixed: increasing reference genome divergence reduced estimates of differentiation but similar patterns of population relationships were found across scenarios. These findings reveal how the choice of reference genome can influence the output of bioinformatic pipelines. It also emphasizes the need to identify best practices and guidelines for the burgeoning field of biodiversity genomics.
Unraveling the mystery of the glacier bear: Genetic population structure of black bears (Ursus americanus) within the range of a rare pelage type
Authors: Lewis Tania , Roffler Gretchen , Crupi Anthony , Maraj Ramona , Barten Neil 
Published: June 2020

AbstractGlacier bears are a rare grey color morph of American black bear (Ursus americanus) found only in northern Southeast Alaska and a small portion of western Canada. We examine contemporary genetic population structure of black bears within the geographic extent of glacier bears and explore how this structure relates to pelage color and landscape features of a recently glaciated and highly fragmented landscape. We used existing radiocollar data to quantify black bear home‐range size within the geographic range of glacier bears. The mean home‐range size of female black bears in the study area was 13 km2 (n = 11), whereas the home range of a single male was 86.9 km2. We genotyped 284 bears using 21 microsatellites extracted from noninvasively collected hair as well as tissue samples from harvested bears. We found ten populations of black bears in the study area, including several new populations not previously identified, divided largely by geographic features such as glaciers and marine fjords. Glacier bears were assigned to four populations found on the north and east side of Lynn Canal and the north and west side of Glacier Bay with a curious absence in the nonglaciated peninsula between. Lack of genetic relatedness and geographic continuity between black bear populations containing glacier bears suggest a possible unsampled population or an association with ice fields. Further investigation is needed to determine the genetic basis and the adaptive and evolutionary significance of the glacier bear color morph to help focus black bear conservation management to maximize and preserve genetic diversity.
Macroinvertebrate communities in streams with contrasting water sources in the Japanese Alps
Authors: Milner Alexander M. , Docherty Catherine , Windsor Fredric M. , Tojo Koji 
Published: June 2020

AbstractAlpine streams are typically fed from a range of water sources including glacial meltwater, snowmelt, groundwater flow, and surface rainfall runoff. These contributions are projected to shift with climate change, particularly in the Japanese Alps where snow is expected to decrease, but rainfall events increase. The overarching aim of the study was to understand the key variables driving macroinvertebrate community composition in groundwater and snowmelt‐fed streams (n = 6) in the Kamikochi region of the northern Japanese Alps (April–December 2017). Macroinvertebrate abundance, species richness, and diversity were not significantly different between the two stream types. Community structure, however, was different between groundwater and snowmelt‐fed streams with macroinvertebrate taxa specialized for the environmental conditions present in each system. Temporal variation in the abundance, species richness, and diversity of macroinvertebrate communities was also significantly different between groundwater and snowmelt streams over the study period, with snowmelt streams exhibiting far higher levels of variation. Two snowmelt streams considered perennial proved to be intermittent with periodic drying of the streambed, but the macroinvertebrates in these systems rebounded rapidly after flows resumed with no reduction in taxonomic diversity. These same streams, nevertheless, showed a major reduction in diversity and abundance following periods of high flow, indicating floods rather than periodic drying was a major driver of community structure. This conclusion was also supported from functional analyses, which showed that the more variable snowmelt streams were characterized by taxa with resistant, rather than resilient, life‐history traits. The findings demonstrate the potential for significant turnover in species composition with changing environmental conditions in Japanese alpine stream systems, with groundwater‐fed streams potentially more resilient to future changes in comparison to snowmelt‐fed streams.
Animal aggregations promote emergent aquatic plant production at the aquatic–terrestrial interface
Authors: Lopez Jonathan W. , Parr Thomas B. , Allen Daniel C. , Vaughn Caryn C. 
Published: June 2020

AbstractThe roles mobile animals and abiotic processes play as vectors for resource transfers between ecosystems (“subsidies”) are well studied, but the idea that resources from animals with limited mobility may be transported across boundaries through intermediate taxa remains unexplored. Aquatic plants (“macrophytes”) are globally distributed and may mediate transfers of aquatic‐derived nutrients from aggregations of aquatic animals to terrestrial ecosystems when consumed by terrestrial herbivores. We used mesocosms (94 × 44 cm) to test whether aquatic animal‐generated biogeochemical hotspots increase growth and nutrient content in macrophytes using the macrophyte Justicia americana and freshwater mussels. Justicia americana biomass production increased and belowground biomass allocation changed with increasing mussel density. At high mussel density, water‐column phosphorus increased and carbon:phosphorus ratios in J. americana tissues decreased. We deployed motion‐sensing cameras to explore herbivory on J. americana growing along the margins of the Kiamichi River, Oklahoma, and documented feeding by large mammals (Odocoileus virginianus, Sus scrofa, and Bos taurus). Thus, biogeochemical hotspots generated by aquatic animal aggregations can promote macrophyte production that subsequently is transferred to terrestrial animals. More broadly, this suggests that reductions in aquatic animal biomass may have bottom‐up impacts that indirectly affect terrestrial ecosystems via plant–animal interactions bridging ecosystem boundaries.
Emotions matter: The role of emotional approach coping in chronic pain
Authors: Ziadni Maisa S. , You Dokyoung S. , Johnson Lucia , Lumley Mark A. , Darnall Beth D. 
Published: June 2020

AbstractBackgroundEmotional approach coping (EAC) is a potentially adaptive emotion‐focused coping style that involves understanding or processing one's emotions and expressing them appropriately. Although EAC has been studied in various populations, little is known about this construct among people with chronic pain, including potential mediators such as negative affect, which might link EAC to pain‐related variables, and moderators of these relationships.MethodsParticipants (N = 670; 76% women; 30% older adults—age 60 or over) with chronic pain completed online the Emotional Approach Coping Scale and measures of pain severity, pain interference and negative affect. Analyses correlated EAC to pain severity and interference and tested whether gender and age group (older adults versus young/middle‐age adults) moderated the mediated relationships of EAC with pain‐related variables through negative affect.ResultsFindings reveal that higher EAC was associated with lower pain intensity through lower negative affect in the young/middle‐age portion of the sample, but not older adults. Also, higher EAC was associated with lower pain interference through lower negative affect among women in the sample, but not men. The associations of EAC to pain intensity and interference are small in magnitude, however, and should be considered preliminary.ConclusionEAC is associated with lower pain intensity in young/middle‐age adults and lower pain interference in women, and lower negative affect mediates these relationships. These results suggest the potential value of assessing and bolstering emotional approach coping processes in some people with chronic pain.