bluuebunny/crossref_metadata_2025_split huggingface dataset:
A digital light processing 3D printed magnetic bioreactor system using silk magnetic bioink
Authors: Ajiteru Olatunji , Choi Kyu Young , Lim Tae Hyeon , Kim Do Yeon , Hong Heesun , Lee Young Jin , Lee Ji Seung , Lee Hanna , Suh Ye Ji , Sultan Md Tipu , Lee Ok Joo , Kim Soon Hee , Park Chan Hum 
Published: April 2021

Abstract
Among various bioreactors used in the field of tissue engineering and regenerative medicine, a magnetic bioreactor is more capable of providing steady force to the cells while avoiding direct manipulation of the materials. However, most of them are complex and difficult to fabricate, with drawbacks in terms of consistency and biocompatibility. In this study, a magnetic bioreactor system and a magnetic hydrogel were manufactured by single-stage three-dimensional (3D) printing with digital light processing (DLP) technique for differentiation of myoblast cells. The hydrogel was composed of a magnetic part containing iron oxide and glycidyl-methacrylated silk fibroin, and a cellular part printed by adding mouse myoblast cell (C2C12) to gelatin glycidyl methacrylate, that was placed in the magnetic bioreactor system to stimulate the cells in the hydrogel. The composite hydrogel was steadily printed by a one-stage layering technique using a DLP printer. The magnetic bioreactor offered mechanical stretching of the cells in the hydrogel in 3D ways, so that the cellular differentiation could be executed in three dimensions just like the human environment. Cell viability, as well as gene expression using quantitative reverse transcription-polymerase chain reaction, were assessed after magneto-mechanical stimulation of the myoblast cell-embedded hydrogel in the magnetic bioreactor system. Comparison with the control group revealed that the magnetic bioreactor system accelerated differentiation of mouse myoblast cells in the hydrogel and increased myotube diameter and length in vitro. The DLP-printed magnetic bioreactor and the hydrogel were simply manufactured and easy-to-use, providing an efficient environment for applying noninvasive mechanical force via FDA-approved silk fibroin and iron oxide biocomposite hydrogel, to stimulate cells without any evidence of cytotoxicity, demonstrating the potential for application in muscle tissue engineering.
Optical behaviour of γ-black CsPbI3 phases formed by quenching from 80 °C and 325 °C
Authors: Valastro Salvatore , Mannino Giovanni , Smecca Emanuele , Sanzaro Salvatore , Deretzis Ioannis , Magna Antonino La , Jena Ajay Kumar , Miyasaka Tsutomu , Alberti Alessandra 
Published: April 2021

Abstract
The orthorhombic γ-black phase of CsPbI3 is well-known to be unstable at room temperature and strategies are needed to counteract its transformation tendency. In this paper we compare γ-black CsPbI3 thin films (∼80 nm) formed via two different routes: a fast quenching of the cubic α-phase from 325 °C (HT-γ) or spontaneously cooling the layer from 80 °C (LT-γ). The successful application of the second procedure is allowed by the use of a mother solution containing Europium with an Eu/Pb ratio as small as 5%. This has been indeed used to form both LT-γ and HT-γ thin films. The phase transition during the heating and cooling pathways is followed in situ by spectroscopic ellipsometry and x-ray diffraction analyses. We demonstrate that both γ-black phases exhibit the same absorption features and critical points as depicted in very details by the dielectric functions. Minor differences can be found in the intensity of the absorption coefficient, assigned to an improved lattice quality in the layer that has experienced the high temperature path. On the other hand, α-black and δ-yellow phases show different critical points in the optical transitions. Besides providing benchmarking optical parameters to discriminates the different phases, we demonstrate that the LT-γ phase closely competes with the HT-γ counterpart during stress tests for stability, with the first one more suited for tandem monolithic architectures that require thermal treatments under 200 °C.
Introduction
Authors: Wallace David 
Published: April 2021

Abstract
This introductory chapter provides an overview of philosophy of physics, which is an interdisciplinary field sitting between physics proper, mainstream philosophy, and the general philosophy of science, and communicating ideas and insights between them. Philosophy of physics is mostly concerned not with physics as a whole but with particular areas within it. Given a field in physics, one can consider the conceptual—that is, philosophical—questions that arise in that field, and the problems in each sub-field are distinctive. The chapter briefly discusses many of these, including some in cutting-edge areas of physics like quantum cosmology, black holes, and string theory. But it notes that the bulk of work in philosophy of physics is concerned with three areas where the physics is reasonably well established: the philosophy of spacetime; the philosophy of statistical mechanics; and the philosophy of quantum mechanics.
Regional scale pressures on reefs
Authors: Sheppard Charles 
Published: April 2021

Abstract
One consequence of the extremely high biodiversity found on reefs is the enormous number of interlocking connections between components. But connections can be destroyed by many kinds of stressors such as pollutants, as can the species themselves. Some species or processes have high redundancy—if destroyed others can fill their role on a reef—while other species or processes may be more or less irreplaceable, in which case when they are destroyed key processes maintaining a healthy reef can be destroyed too. Because so many countries and human communities are dependent on reefs, reef degradation, which is now occurring on a very worrying scale, is of increasing concern. Impacts fall into two main categories: those caused by numerous, usually localized, impacts, such as different forms of pollution and shoreline developments that create large quantities of sediment; and those caused by the more recently recognized, and probably more serious, long-term factors associated with climate change. All of these are ultimately interlinked and all are caused by human activities. Many occur concurrently, each exacerbating the harmful effects of others, and many are synergistic in their impacts. Sewage, nutrient run-off, landfill, dredging, and sedimentation are most important, as are chemicals, pesticides, and metals. Coral diseases are increasing also, commonly as a result. In many areas now too overfishing has become critical and may be the most ecosystem-distorting factor of all.
De Novo Inflammatory Bowel Disease Rarely Occurs During Posttransplant Immunosuppression
Authors: Fang Jiayun M , Lamps Laura , Yeboah-Korang Amoah , Cheng Jerome , Westerhoff Maria 
Published: April 2021

AbstractObjectivesDe novo chronic idiopathic inflammatory bowel disease (CIIBD) is reported to occur at higher rates in posttransplant patients than that of the general population. The previous reports, however, included patients with primary sclerosing cholangitis (PSC), a known association with CIIBD. Hence, we investigated how often posttransplant de novo CIIBD occurs in the absence of PSC.MethodsWe identified 185 posttransplant adults without a history of PSC or CIIBD, who had undergone colonoscopy between July 2013 and June 2020. Biopsies were reviewed and clinical data were gathered.ResultsCIIBD-like colitis accounted for 1.1% (2/185) of our cohort. The 2 affected patients were already taking multiple immunosuppressive therapies. They were initially placed on standard CIIBD maintenance therapy, but then required escalation therapy. One patient had persistent active colitis despite escalation therapy, while the other subsequently had resolution of symptoms and developed quiescent disease.ConclusionsThe incidence of CIIBD-like colitis in our study population was lower than what has been previously described. Both patients had a poor response to standard CIIBD therapy, raising the question whether their diagnosis is truly de novo CIIBD or another immunologic process.
Differences in Hypertension Prevalence and Hypertension Control by Urbanization Among Adults in the United States, 2013–2018
Authors: Ostchega Yechiam , Hughes Jeffery P , Zhang Guangyu , Nwankwo Tatiana , Graber Jessica , Nguyen Duong T 
Published: April 2021

Abstract

Background
To examine the associations between urbanization and hypertension, stage II hypertension, and hypertension control.

Methods
Data on 16,360 US adults aged 18 years or older from the 2013–2018 National Health and Nutrition Examination Survey (NHANES) were used to estimate the prevalence of hypertension (blood pressure (BP) ≥130/80 mm Hg or use of medication for hypertension), stage II hypertension (BP ≥140/90 mm Hg), and hypertension control (BP &lt;130/80 mm Hg among hypertensives) by urbanization, classified by levels of metropolitan statistical areas as large MSAs (population ≥1,000,000), medium to small MSAs (population 50,000–999,999), and non-MSAs (population &lt;50,000).

Results
All prevalence ratios (PRs) were compared with large MSAs and adjusted for demographics and risk factors. The PRs of hypertension were 1.07 (95% confidence interval (CI) = 0.99–1.14) for adults residing in medium to small MSAs and 1.06 (95% CI = 0.99–1.13) for adults residing in non-MSAs. For stage II hypertension, the PRs were higher for adults residing in medium to small MSAs 1.21 (95% CI = 1.06–1.36) but not for adults residing in non-MSAs 1.06 (95% CI = 0.88–1.29). For hypertension control, the PRs were 0.96 (95% CI = 0.91–1.01) for adults residing in medium to small MSAs and 1.00 (95% CI = 0.93–1.06) for adults residing in non-MSAs.

Conclusions
Among US adults, urbanization was associated with stage II hypertension.
Effects of a Collaborative, Community Hospital Network for Antimicrobial Stewardship Program Implementation
Authors: Moehring Rebekah W , Yarrington Michael E , Davis Angelina E , Dyer April P , Johnson Melissa D , Jones Travis M , Spires S Shaefer , Anderson Deverick J , Sexton Daniel J , Dodds Ashley Elizabeth S 
Published: April 2021

Abstract

Background
Individual hospitals may lack expertise, data resources, and educational tools to support antimicrobial stewardship programs (ASP).

Methods
We established a collaborative, consultative network focused on hospital ASP implementation. Services included on-site expert consultation, shared database for routine feedback and benchmarking, and educational programs. We performed a retrospective, longitudinal analysis of antimicrobial use (AU) in 17 hospitals that participated for at least 36 months during 2013–2018. ASP practice was assessed using structured interviews. Segmented regression estimated change in facility-wide AU after a 1-year assessment, planning, and intervention initiation period. Year 1 AU trend (1–12 months) and AU trend following the first year (13–42 months) were compared using relative rates (RR). Monthly AU rates were measured in days of therapy (DOT) per 1000 patient days for overall AU, specific agents, and agent groups.

Results
Analyzed data included over 2.5 million DOT and almost 3 million patient-days. Participating hospitals increased ASP-focused activities over time. Network-wide overall AU trends were flat during the first 12 months after network entry but decreased thereafter (RR month 42 vs month 13, 0.95, 95% confidence interval [CI]: .91–.99). Large variation was seen in hospital-specific AU. Fluoroquinolone use was stable during year 1 and then dropped significantly. Other agent groups demonstrated a nonsignificant downward trajectory after year 1.

Conclusions
Network hospitals increased ASP activities and demonstrated decline in AU over a 42-month period. A collaborative, consultative network is a unique model in which hospitals can access ASP implementation expertise to support long-term program growth.
Epidermal growth factor receptor-dependent maintenance of cardiac contractility
Authors: Guo Shuchi , Okyere Ama Dedo , McEachern Erin , Strong Joshua L , Carter Rhonda L , Patwa Viren C , Thomas Toby P , Landy Melissa , Song Jianliang , Lucchese Ana Maria , Martin Thomas G , Gao Erhe , Rajan Sudarsan , Kirk Jonathan A , Koch Walter J , Cheung Joseph Y , Tilley Douglas G 
Published: April 2021

Abstract

Aims
Epidermal growth factor receptor (EGFR) is essential to the development of multiple tissues and organs and is a target of cancer therapeutics. Due to the embryonic lethality of global EGFR deletion and conflicting reports of cardiac-overexpressed EGFR mutants, its specific impact on the adult heart, normally or in response to chronic stress, has not been established. Using complimentary genetic strategies to modulate cardiomyocyte-specific EGFR expression, we aim to define its role in the regulation of cardiac function and remodelling.

Methods and results
A floxed EGFR mouse model with α-myosin heavy chain-Cre-mediated cardiomyocyte-specific EGFR downregulation (CM-EGFR-KD mice) developed contractile dysfunction by 9 weeks of age, marked by impaired diastolic relaxation, as monitored via echocardiographic, haemodynamic, and isolated cardiomyocyte contractility analyses. This contractile defect was maintained over time without overt cardiac remodelling until 10 months of age, after which the mice ultimately developed severe heart failure and reduced lifespan. Acute downregulation of EGFR in adult floxed EGFR mice with adeno-associated virus 9 (AAV9)-encoded Cre with a cardiac troponin T promoter (AAV9-cTnT-Cre) recapitulated the CM-EGFR-KD phenotype, while AAV9-cTnT-EGFR treatment of adult CM-EGFR-KD mice rescued the phenotype. Notably, chronic administration of the β-adrenergic receptor agonist isoproterenol effectively and reversibly compensated for the contractile dysfunction in the absence of cardiomyocyte hypertrophy in CM-EGFR-KD mice. Mechanistically, EGFR downregulation reduced the expression of protein phosphatase 2A regulatory subunit Ppp2r3a/PR72, which was associated with decreased phosphorylation of phospholamban and Ca2+ clearance, and whose re-expression via AAV9-cTnT-PR72 rescued the CM-EGFR-KD phenotype.

Conclusions
Altogether, our study highlights a previously unrecognized role for EGFR in maintaining contractile homeostasis under physiologic conditions in the adult heart via regulation of PR72 expression.
MEASURING SELECTION COEFFICIENTS AFFECTING THE ALCOHOL DEHYDROGENASE POLYMORPHISM IN DROSOPHILA MELANOGASTER
Authors: Wilson S R , Oakeshott J G , Gibson J B , Anderson P R 
Published: April 2021

ABSTRACT
This paper describes a perturbation experiment on the frequency of the F and S Alcohol dehydrogenase (Adh) alleles of D. melanogaster. Fifty-four isofemale lines set up from three wild populations and with initial F frequencies of either 0.25, 0.50 or 0.75 were maintained on standard laboratory food medium at 22°. At generations 4, 12 and 20 the lines were again scored for Adh gene frequencies. Maximum likelihood procedures were used to estimate selection coefficients for the Adh genotypes. An analysis of deviance was used to compare the coefficients against expectations under the hypotheses of neutrality and of constant values for the three base populations, and for the three initial gene frequency classes. Highly-significant departures from neutrality were observed; over all 54 lines, the set of relative fitnesses for S/S:F/S:F/F was estimated as 1.00:1.08:1.08. In addition, there were significant differences between lines in the outcome of selection which were not attributable to differences between base populations or initial F frequencies. These residual between-line differences, as well as some between-generation, within-line differences are discussed in terms of linkage disequilibria with background genes and electrophoretically cryptic variation at the Adh locus.
PREFERENTIAL MATING IN SYMMETRIC MULTILOCUS SYSTEMS: LIMITS FOR MULTIALLELISM AND FOR MANY LOCI
Authors: Raper J 
Published: April 2021

ABSTRACT
Models in which general forms of preferential mating have been superimposed on the framework of the symmetric heterozygosity selection regime have been examined previously with respect to the existence and local stability of a central polymorphic equilibrium. The results are now extended to produce the limiting form of the stability conditions in two cases: First, where the number of alleles per locus is assumed to be very large; second, where the number of loci affecting the character is very large. It is argued that some type of frequency dependence in the mating pattern must be included, and a particular case is examined in detail. It is shown that multiallelism is ambiguous in its effect on stability, while an increasing number of loci, at least under zero linkage, leads to a simple stability condition which is analogous to the one-locus heterosis principle. Assortative mating appears to be more likely to produce a stable central polymorphism under high levels of allelism than is sexual selection, but is relatively very much weaker than sexual or viability selection if the number of loci involved is large.
DOMINANT MUTATORS IN ESCHERICHIA COLI
Authors: Cox E C , Horner D L 
Published: April 2021

ABSTRACT
In this paper we report on the isolation and genetic analysis of a series of strong mutators mapping at five minutes on the E. coli chromosome. These mutations are dominant and show no evidence of interaction in merodiploids. Cultures grown in broth medium exhibit mutant frequencies five to six orders of magnitude higher than mut+ strains. Cultures propagated in minimal salts media mutate at rates one to three orders higher than wild-type. Three-factor crosses have been used to order these mutators relative to metD, proA, and a Tn10 insertion near five minutes.
EVIDENCE FOR A POLYMORPHISM IN GAMETIC SEGREGATION USING A MALATE DEHYDROGENASE LOCUS IN THE TETRAPLOID TREEFROG HYLA VERSICOLOR
Authors: Danzmann Roy G , Bogart James P 
Published: April 2021

ABSTRACT
Artificial cross combinations of tetraploid Hyla versicolor were analyzed electrophoretically using a polymorphic malate dehydrogenase locus (MDH-1) to determine the mechanism of chromosome segregation. Models for differentiating between disomic and tetrasomic inheritance are presented and tested. In some crosses progeny genotypes fit a disomic mode of segregation. In other crosses there is only evidence for a tetrasomic mode of segregation. Additional crosses produced genotypic ratios which conformed to either a disomic or tetrasomic mode of segregation. The same type of inheritance was demonstrated for any individual when used in multiple cross combinations. These results suggest that there exists in H. versicolor a polymorphism with respect to segregation of gametes, resulting from differences in chromosome pairings during meiosis I.
SUBSTRATE-PREFERENCE POLYMORPHISM AT AN ESTERASE LOCUS OF DROSOPHILA MOJAVENSIS
Authors: Zouros E , van Delden W 
Published: April 2021

ABSTRACT
In a larval esterase of Drosophila mojavensis there are alleles whose products preferentially hydrolyze α-naphthyl esters, whereas the majority of the alleles hydrolyze preferentially β-naphthyl esters. In a collection of laboratory stocks α alleles have a frequency of 15%. Three different mobilities of α alleles were discovered, suggesting a polymorphism rather than a single mutation event. If substrate-preference polymorphisms are common among "multiple-substrate" enzymes (category II of Gillespie and Langley 1974), allozyme variation at these enzyme loci may well be maintained by balancing selection.
ASSOCIATION OF ENDOSPERM REDUCTION WITH PARENTAL IMPRINTING IN MAIZE
Authors: Lin Bor-Yaw 
Published: April 2021

ABSTRACT
Among 38 reciprocal translocations between the maize B chromosome and the proximal region of the long arm of chromosome 10 were six interchanges associated with reduced endosperm development. These six have breakpoints that are the most proximal of the set and constitute a graded series with those broken nearer the centromere which have the most abnormal phenotypes. The group of six defines three major regions that produce the endosperm effects. The remaining 32 translocations reduce kernel size very slightly, suggesting the presence of a fourth region distal to all break-points.—The affected class of kernels lacks a paternally derived representative of that segment of 10L translocated to the B centromeric element (B10 chromosome; 10 10 B10). An accompanying class of kernel in which the paternal B10 chromosome is duplicated in the endosperm (10 10 10B B10 B10) is normal. Kernels of the same endosperm constitution synthesized by introducing both 10 and B10 maternally, however, are defective, resembling 10 10 10B. Maternal B10's are therefore unable to compensate for the absence of a paternal B10. Clearly expression of the 10L genes involved supports normal endosperm growth only following pollen transmission.
TESTING NEUTRALITY IN SUBDIVIDED POPULATIONS
Authors: Slatkin Montgomery 
Published: April 2021

ABSTRACT
Statistical tests of the neutrality hypothesis that are based on the sampling theory of Ewens (1972) require the assumption of panmixia. It is proposed that for a population comprising numerous local populations with weak gene flow among them, tests based on Ewens' theory can be applied separately to samples from each local population. At low levels of gene flow, migration acts primarily like mutation, introducing new alleles to each local population. It is shown with simulation results that, at low levels of migration, correlations in allele frequencies among demes are sufficiently small that the results from the application of Ewens' theory to each deme are statistically independent. It is also shown that, by combining the results of the tests in different demes, some statistical power to detect deviations from neutrality is gained. The method is illustrated with the application to data on a salamander species. At low levels of gene flow, population subdivision must be taken account of in testing neutrality and the proposed test provides one way to do so.
COLD-SENSITIVE CELL-DIVISION-CYCLE MUTANTS OF YEAST: ISOLATION, PROPERTIES, AND PSEUDOREVERSION STUDIES
Authors: Moir Don , Stewart Sue E , Osmond Barbara C , Botstein David 
Published: April 2021

ABSTRACT
We isolated 18 independent recessive cold-sensitive cell-division-cycle (cdc) mutants of Saccharomyces cerevisiae, in nine complementation groups. Terminal phenotypes exhibited include medial nuclear division, cytokinesis, and a previously undescribed terminal phenotype consisting of cells with a single small bud and an undivided nucleus. Four of the cold-sensitive mutants proved to be alleles of CDC11, while the remaining mutants defined at least six new cell-division-cycle genes: CDC44, CDC45, CDC48, CDC49, CDC50 and CDC51.—Spontaneous revertants from cold-sensitivity of four of the medial nuclear division cs cdc mutants were screened for simultaneous acquisition of a temperature-sensitive phenotype. The temperature-sensitive revertants of four different cs cdc mutants carried single new mutations, called Sup/Ts to denote their dual phenotype: suppression of the cold-sensitivity and concomitant conditional lethality at 37°. Many of the Sup/Ts mutations exhibited a cell-division-cycle terminal phenotype at the high temperature, and they defined two new cdc genes (CDC46 and CDC47). Two cold-sensitive medial nuclear division cdc mutants representing two different cdc genes were suppressed by different Sup/Ts alleles of another gene which also bears a medial nuclear division function (CDC46). In addition, the cold-sensitive medial nuclear division cdc mutant csH80 was suppressed by a Sup/Ts mutation yielding an unbudded terminal phenotype with an undivided nucleus at the high temperature. This mutation was an allele of CDC32. These results suggest a pattern of interaction among cdc gene products and indicate that cdc gene proteins might act in the cell cycle as complex specific functional assemblies.