bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hematopoietic stem cells self-renew symmetrically or gradually proceed to differentiation
Authors: Barile Melania , Busch Katrin , Fanti Ann-Kathrin , Greco Alessandro , Wang Xi , Oguro Hideyuki , Zhang Qin , Morrison Sean J. , Rodewald Hans-Reimer , Höfer Thomas 
Published: August 2020

SUMMARYIt is not known whether hematopoietic stem cells (HSCs) undergo symmetric or asymmetric cell divisions in the unperturbed bone marrow. Here, we integrate data from HSC fate mapping and cell-cycle-dependent labeling through mathematical inference and thus gain insight into how HSCs coordinate self-renewal with differentiation. We find that most HSC divisions in adult mice are symmetric self-renewing, replacing HSCs lost by direct differentiation and death, and slowly expanding the HSC population. This expansion maintains constant HSC output to multipotent progenitors (MPPs), despite declining HSC differentiation rate with age. We identify a linear hierarchy of differentiation states between tip HSCs and MPPs, whereTie2-driven HSC fate mapping fully covers the progression of the differentiating cells. A turning point from self-renewal to accelerated cell differentiation occurs between early-stage and late-stage MPPs, just before lineage differentiation becomes manifest in single-cell transcriptomes. This stem cell hierarchy precedes lineage differentiation and may limit mutation accumulation in the hematopoietic system.
Computational Hot-Spot Analysis of the SARS-CoV-2 Receptor Binding Domain / ACE2 Complex
Authors: Rosario Pedro A. , McNaughton Brian R. 
Published: August 2020

AbstractInfection and replication of SARS CoV-2 (the virus that causes COVID-19) requires entry to the interior of host cells. In humans, a Protein-Protein Interaction (PPI) between the SARS CoV-2 Receptor-Binding Domain (RBD) and the extracellular peptidase domain of ACE2, on the surface of cells in the lower respiratory tract, is an initial step in the entry pathway. Inhibition of the SARS CoV-2 RBD / ACE2 PPI is currently being evaluated as a target for therapeutic and/or prophylactic intervention. However, relatively little is known about the molecular underpinnings of this complex. Employing multiple computational platforms, we predicted ‘hot-spot’ residues in a positive control PPI (PMI / MDM2) and the CoV-2 RBD/ACE2 complex. Computational alanine scanning mutagenesis was performed to predict changes in Gibbs’ free energy that are associated with mutating residues at the positive control (PMI/MDM2) or SARS RBD/ACE2 binding interface to alanine. Additionally, we used the Adaptive Poisson-Boltzmann Solver to calculate macromolecular electrostatic surfaces at the interface of the positive control PPI and SARS CoV-2 / ACE2 PPI. Collectively, this study illuminates predicted hot-spot residues, and clusters, at the SARS CoV-2 RBD / ACE2 binding interface, potentially guiding the development of reagents capable of disrupting this complex and halting COVID-19.
Upgrades of coastal protective infrastructure affect benthic communities
Authors: Mamo Lea T. , Porter Augustine G. , Tagliafico Alejandro , Coleman Melinda A. , Smith Stephen D. A. , Figueira Will F. , Kelaher Brendan P. 
Published: August 2020

Abstract

Sea‐level rise, storm surges, ageing and wear are forcing upgrades to breakwaters and sea walls to protect coastal areas from erosion and inundation. Such upgrades involve the introduction of new material which may consequently act as an ecological disturbance that can alter established marine communities and ecosystem function. Mitigating ecological impacts requires an understanding of how species assemblages are affected by such works.

Here, we use the major upgrade of a regularly wave‐overtopped breakwater as a case study to evaluate the impacts of upgrades to hard coastal protective infrastructure on benthic rocky reef communities. An asymmetrical Before‐After Control‐Impact (BACI) experimental design was used to test interactive effects of the infrastructure upgrades on benthic communities.

While benthic assemblages were not significantly different from controls prior to the upgrade, improving the defensive capacity of the breakwater significantly changed community structure. Notably, most taxonomic groups showed higher cover at the control sites than at the impacted site post‐upgrade, with articulated calcareous algae (e.g. Corallina officinalis and Amphiroa anceps) showing an opposite trend.

Synthesis and applications. Ecological implications and structural limitations make regular upgrading of existing infrastructure unsuitable as a long‐term management strategy. More sustainable alternatives need to be considered, such as decommissioning of structures and retreat from flood‐prone areas. This transition, however, will take time and requires a change of mindset and policies. Where upgrades are urgent, eco‐engineering techniques can mitigate impacts to habitats and associated taxa.
On mutualism, models, and masting: The effects of seed‐dispersing animals on the plants they disperse
Authors: Moore Christopher M. , Dittel Jacob W. 
Published: August 2020

Abstract

Species interactions are context dependent, in that their direction and magnitude can vary across ecological conditions. For seed dispersal interactions—especially interactions between plants and seed‐caching animals—the direction of the interactions is often obscured because of seed mortality inherent in seed handling and the delayed effects of fitness benefits received by plants. It is, therefore, an open question in ecology to understand the ecological contexts under which seed dispersal interactions are facilitative, antagonistic or null.

We review the fitness benefits of animal‐mediated seed dispersal, extend a recently published model to include negative density‐dependent effects, and review the feedback between seed production (with a focus on masting) and seed‐caching animal populations.

Negative density‐dependent effects are pervasive and strongly affect the direction of plant‐seed‐disperser interactions, and including them into models will give a more accurate understanding of the direction of the interaction. Including negative density‐dependent effects also makes the interpretation of interaction more mutualistic since seed dispersers decrease seed densities. Additionally, there is substantial interannual variability in seed production in most nut‐producing plant species, and the lags between seed production and seed‐disperser population sizes complicate and limit inferences made about the direction of interactions in any given short‐term study.

Synthesis. If we wish to know the direction of species interactions in real ecological communities, we need models that contain a minimum level of biological realism. For complex and long‐term phenomena such as context‐dependent species interactions we should embrace a multifaceted approach of short‐term field research, long‐term field research, simple models, and complex models to form a more robust understanding of the ecological problem of context dependency.
First description of betalains biosynthesis in an aquatic organism: characterization of 4,5‐DOPA‐extradiol‐dioxygenase activity in the cyanobacteria Anabaena cylindrica
Authors: Guerrero‐Rubio María Alejandra , García‐Carmona Francisco , Gandía‐Herrero Fernando 
Published: August 2020

SummaryThe biosynthesis of betalamic acid, the structural unit of pigments betalains, is performed by enzymes with 4,5‐DOPA‐extradiol‐dioxygenase activity. These enzymes were believed to be limited to plants of the order Caryophyllales and to some fungi. However, the discovery of Gluconacetobacter diazotrophicus as the first betalain‐forming bacterium opened a new field in the search for novel biological systems able to produce betalains. This paper describes molecular and functional characterization of a novel dioxygenase enzyme from the aquatic cyanobacterium Anabaena cylindrica. The enzyme was found to be a homodimer of a polypeptide of 17.8 kDa that, opposite to previous related enzymes, showed a strong inhibition by excess of the precursor L‐DOPA. However, its heterologous expression has allowed detecting the formation of the main compounds in the biosynthetic pathway of betalains. In addition, phylogenetic analysis has shown that this enzyme is not close related to enzymes from plants, fungi or proteobacteria such as G. diazotrophicus. The presence of enzymes that produce these health‐promoting compounds is more diverse than expected. The discovery of this novel dioxygenase in the phylum cyanobacteria expands the presence of betalamic acid‐forming enzymes in organisms of different nature with no apparent relationship among them.
Clinical Course and Factors Associated With Hospitalization and Critical Illness Among COVID‐19 Patients in Chicago, Illinois
Authors: Gottlieb Michael , Sansom Sarah , Frankenberger Casey , Ward Edward , Hota Bala 
Published: August 2020

AbstractBackgroundSARS‐CoV‐2 is a global pandemic associated with significant morbidity and mortality. However, information from United States cohorts is limited. Understanding predictors of admission and critical illness in these patients is essential to guide prevention and risk stratification strategies.MethodsThis was a retrospective, registry‐based cohort study including all patients presenting to Rush University Medical Center in Chicago, Illinois, with COVID‐19 from March 4, 2020 to June 21, 2020. Demographic, clinical, laboratory, and treatment data were obtained from the registry and compared between hospitalized and nonhospitalized patients as well as those with critical illness. We used logistic regression modeling to explore risk factors associated with hospitalization and critical illness.ResultsA total of 8,673 COVID‐19 patients were included in the study, of whom 1,483 (17.1%) were admitted to the hospital and 528 (6.1%) were admitted to the intensive care unit. Risk factors for hospital admission included advanced age, male sex (odds ratio [OR] = 1.69, 95% confidence interval [CI] = 1.44 to 1.98), Hispanic/Latino ethnicity (OR = 1.52, 95% CI = 1.18 to 1.92), hypertension (OR = 1.77, 95% CI = 1.46 to 2.16), diabetes mellitus (OR = 1.84, 95% CI = 1.53 to 2.22), prior CVA (OR = 3.20, 95% CI = 1.99 to 5.14), coronary artery disease (OR = 1.45, 95% CI = 1.03 to 2.06), heart failure (OR = 1.79, 95% CI = 1.23 to 2.61), chronic kidney disease (OR = 2.60, 95% CI = 1.77 to 3.83), end‐stage renal disease (OR = 2.22, 95% CI = 1.12 to 4.41), cirrhosis (OR = 2.03, 95% CI = 1.42 to 2.91), fever (OR = 1.43, 95% CI = 1.19 to 1.71), and dyspnea (OR = 4.53, 95% CI = 3.75 to 5.47). Factors associated with critical illness included male sex (OR = 1.45, 95% CI = 1.12 to 1.88), congestive heart failure (OR = 1.45, 95% CI = 1.00 to 2.12), obstructive sleep apnea (OR = 1.58, 95% CI = 1.07 to 2.33), blood‐borne cancer (OR = 3.53, 95% CI = 1.26 to 9.86), leukocytosis (OR = 1.53, 95% CI = 1.15 to 2.17), elevated neutrophil‐to‐lymphocyte ratio (OR = 1.61, 95% CI = 1.20 to 2.17), hypoalbuminemia (OR = 1.80, 95% CI = 1.39 to 2.32), elevated AST (OR = 1.66, 95% CI = 1.20 to 2.29), elevated lactate (OR = 1.95, 95% CI = 1.40 to 2.73), elevated D‐Dimer (OR = 1.44, 95% CI = 1.05 to 1.97), and elevated troponin (OR = 3.65, 95% CI = 2.03 to 6.57).ConclusionThere are a number of factors associated with hospitalization and critical illness. Clinicians should consider these factors when evaluating patients with COVID‐19.
Clinical features and outcomes of endovascular treatment of latent pseudoaneurysmal bleeding after pancreaticoduodenectomy
Authors: Hwang Kyungyeon , Lee Jae Hoon , Hwang Dae Wook , Song Ki Byung , Kwon Jaewoo , Gwon Dong Il , Shin Ji Hoon , Kim Song Cheol 
Published: August 2020

AbstractBackgroundThe endovascular treatment is the first‐line therapy for late massive arterial haemorrhage after pancreaticoduodenectomy (PD). This study aimed to evaluate the clinical features and outcomes of patients who experienced pseudoaneurysm (PA) bleeding after PD and treated with transcatheter arterial embolization (TAE) and stent‐graft placement (SGP).MethodsA total of 37 patients (TAE = 16, stent graft = 16, both = 5) had an endovascular treatment due to hepatic artery PA bleeding after PD at our institution from January 2008 to December 2018.ResultsThere were 35 men and two women with a mean age of 62 years (range 45–82 years). The latency of bleeding ranged from postoperative days 3 to 46 (median day 21). The most common site of bleeding was gastroduodenal artery stump (n = 22). In TAE group (n = 16), the technical success rate was 100% and the clinical success rate was 87.5%. In SGP group (n = 16), the technical and clinical success rates were 100% and 93.8%. Five patients underwent SGP and TAE simultaneously; TAE was performed to prevent endoleak. A total of three patients experienced hepatic ischaemia (TAE = 2, SGP = 1). However, there was no statistically significant difference of hepatic ischaemia occurrence between the two groups P = 0.55).ConclusionsIn patients with suspected PA, urgent angiography should be considered immediately for diagnosis and treatment. The SGP can be performed first if it is technically feasible. However, TAE is also a safe and effective treatment in patients with intact portal flow, as well as those with preserved collateral pathways after hepatobiliary surgery.
Occupational allergy to phytase: case series of eight production workers exposed to animal feed additives
Authors: Kuske Marvin , Berndt Katja , Spornraft‐Ragaller Petra , Neumeister Volker , Raulf Monika , Sander Ingrid , Koschel Dirk , Bickhardt Jakob , Beissert Stefan , Bauer Andrea 
Published: August 2020

SummaryBackgroundIn agricultural meat production, adding enzymes such as phytase to animal feed is widespread, but there is little awareness of the allergenic potential and health risks of these fungal enzymes.Patients and MethodsWe report on eight patients working in a plant producing phytase granulates. All patients complained about work‐related rhinitis occurring within six months of the onset of exposure to phytase dust. Asthmatic symptoms and contact urticaria also occurred. To detect sensitizations to phytase, skin prick‐, patch‐, and basophil activation test were carried out with the factory product. Levels of IgE and IgG against phytase were also measured.ResultsThere was a positive reaction to phytase with skin prick testing in seven of the eight patients. IgE specific to phytase was detectable in four of the eight patients, and IgG specific to phytase was detectable in six of the eight patients. The basophil activation test was positive in four out of seven patients tested, but the patch test was negative in all patients tested. Transfer to a different workplace with no exposure to phytase completely eliminated the symptoms.ConclusionsMold enzymes such as phytase are highly potent occupational allergens. Occupational safety measures must be strictly implemented in order to protect the health of workers.
The rise of market power and Ramsey‐optimal policy implications
Authors: Kiarsi Mehrab 
Published: August 2020

AbstractDe Loecker, Eeckhout, and Unger document that since 1980 aggregate markups in the U.S. economy have significantly increased from 21% above cost to 61% now. In light of this evidence, this paper revisits optimal fiscal and monetary policy recommendations of standard New Keynesian models and shows that under empirically relevant calibrations of market power they radically change: the optimal inflation rate becomes significantly positive and its optimal volatility sharply rises. Moreover, inflation behaves like a random walk in response to unexpected fiscal shocks. Thus, price stability ceases to be the optimal policy outcome.
Continuing education activities improve dentists’ self‐efficacy to manage oral mucosal lesions and oral cancer
Authors: Braun Liliana W. , Martins Marco A. T. , Romanini Juliana , Rados Pantelis V , Martins Manoela D. , Carrard Vinicius C. 
Published: August 2020

AbstractObjectivesThis cross‐sectional study aims to evaluate whether Continuing Education Activities (CEA) influence dentists’ behaviour in relation to oral lesions. The secondary aim is to assess the association between dentists’ perception of learning adequacy and self‐efficacy for oral mucosal lesion management.MethodsA self‐administered online questionnaire was conducted on dentists working at the public health system of Rio Grande do Sul State, Brazil. The questionnaire included questions pertaining to perception of adequacy for oral diagnosis classes upon graduation, participation in oral cancer CEA and self‐efficacy in managing oral mucosal lesions.Results221 dentists from 91 municipalities answered the questionnaire. Most participants were female (71.5%) with a mean age of 38.3 years. Perception of learning as adequate during undergraduate coursework was associated with self‐efficacy to diagnose, biopsy, and treat oral mucosal lesions (P < .05, Chi‐squared test). However, 83.3% of dentists considered the time devoted to these topics prior to graduation insufficient. The frequency of oral lesion detection was related to self‐efficacy to treat oral lesions and detecting oral cancer (P < .05, Chi‐squared test). Among dentists who detected oral lesions frequently, 88.9% had attended CEA, whereas 11.1% of them had never attended these activities.ConclusionsCEA may improve awareness and efficacy of primary healthcare professional's detection of oral cancer.
Latitudinal differences in early growth of largehead hairtail (Trichiurus japonicus) in relation to environmental variables
Authors: Sun Peng , Chen Qi , Fu Caihong , Xu Yi , Sun Runlong , Li Jianchao , Yu Haiqing , Zhang Chi , Liu Yang , Ye Zhenjiang , Tian Yongjun , Heino Mikko 
Published: August 2020

AbstractLargehead hairtail (Trichiurus japonicus) in the China Seas shows an increasing catch trend, despite continued overexploitation, which could be attributed to improved recruitment as a result of strengthened early growth. To understand the early growth variability of largehead hairtail, we examined the linkages between early growth, as revealed by otolith microstructure, and the associated environmental variables over both spatial and temporal scales. Young‐of‐the‐Year largehead hairtail were collected from three regions in the Bohai, Yellow and East China Seas between 29° and 39° N. Daily increment widths of sagittal otoliths were measured and used as a proxy for somatic growth. We found two spawning cohorts, Spring‐ and Summer‐spawned cohorts, that showed latitudinal differences in both mean growth and growth pattern. The transition time from larval to juvenile stage was identified at around 40 days. Daily increment widths of two cohorts showed similar growth pattern in the first 40 days, while location had a marked effect on daily growth over 41–110 days. This suggests physiologically constrained growth pattern in larval stage, but more plastic growth subject to habitat‐specific influences in juvenile stage. The gradient forest analysis identified sea bottom temperature, vertical temperature gradient, and sea surface salinity, as the most important variables in determining early growth. Latitudinal differences in early growth pattern and their response to environmental variables suggest adaptive plasticity of early growth, which has notable implication for the management and sustainable utilization of this important but heavily exploited resource in the China Seas.
Biocompatibility, induction of mineralization and antimicrobial activity of experimental intracanal pastes based on glass and glass‐ceramic materials
Authors: de Araújo Lopes J. M. , Benetti F. , Rezende G. C. , Souza M. T. , Conti L. C. , Ervolino E. , Jacinto R. C. , Zanotto E. D. , Cintra L. T. A. 
Published: August 2020

AbstractAimTo evaluate the biocompatibility, induction of mineralization and antimicrobial activity of experimental intracanal pastes based on two glass and glass‐ceramic materials. Calcium hydroxide (Ca(OH)2) paste was used as the positive control.MethodologyThe glass‐ceramic powder [two‐phased Biosilicate (BS‐2P)] and F18 bioactive glass were mixed with distilled water (ratio 2 : 1), inserted in polyethylene tubes and implanted in the subcutaneous tissues of 16 rats. Empty tubes were used as negative control. After 7 and 30 days (n = 8), the rats were euthanized for haematoxylin–eosin, von Kossa, polarized light and osteopontin (OPN) immunolabeling analysis. Direct contact tests using a suspension of each paste were performed with Enterococcus faecalis planktonic cells to evaluate antimicrobial activity (24 h of contact), in a pilot study. The number of CFU mL−1 was calculated for each group. The antimicrobial analysis data were submitted to one‐way anova and Tukey tests, whilst biocompatibility and immunohistochemical data were submitted to the Kruskal–Wallis and Dunn tests (P < 0.05).ResultsMost specimens of the control, BS‐2P and Ca(OH)2 groups were associated with moderate inflammation seven days following implantation, whilst F18 was associated with moderate to severe inflammation, without differences amongst the groups (P > 0.05). At 30 days, most specimens of control, F18 and BS‐2P groups had mild inflammation, whilst Ca(OH)2 had mild to moderate inflammation; however, no differences were determined amongst the groups (P > 0.05). The fibrous capsule was thick at 7 days, becoming thin at 30 days. All pastes induced von Kossa‐positive structures and were birefringent to polarized light. At seven days, the BS‐2P group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P < 0.05). At 30 days, the F18 group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P < 0.05). All pastes reduced the total number of E. faecalis; however, the reduction was only significant when comparing BS‐2P and Ca(OH)2 groups to the control (P < 0.05). Only calcium hydroxide eliminated E. faecalis.ConclusionsExperimental BS‐2P and F18 pastes were biocompatible, stimulated biomineralization and induced significant OPN immunolabeling compared to Ca(OH)2. Only the BS‐2P paste demonstrated antimicrobial activity comparable to Ca(OH)2.
Microstructure and mechanical property of (TiB2‐SiC) agglomerate‐toughened B4C‐TiB2‐SiC composites
Authors: Wang Shuai , Deng Yangyang , Gao Shuaibo , Yang Mingsheng , Xing Pengfei 
Published: August 2020

AbstractB4C‐TiB2‐SiC composites toughened by (TiB2‐SiC) agglomerates were prepared via reactive hot pressing with B4C and TiSi2 as raw materials. Phase composition, microstructure, and mechanical properties of the fabricated composites were investigated. The function of (TiB2‐SiC) agglomerates was analyzed, and the strengthening and toughening mechanism were also discussed. Results indicated that some of the in situ formed TiB2 and SiC were interlocked to form special (TiB2‐SiC) agglomerates in the matrix. The good comprehensive performances of 510 MPa flexural strength, 5.84 MPa·m1/2 fracture toughness, and 31.93 GPa hardness were obtained in the composites fabricated with 30 wt% TiSi2. The in situ introduced fine TiB2 and SiC grains refined the grains of B4C due to the pinning effect, which enhanced the strength. The special (TiB2‐SiC) agglomerates and the existing toughening phenomena such as crack deflection, branching, and microcrack regions induced by the mismatch of thermal expansion coefficients, had cumulative effects on improving the fracture toughness.