bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quasi-normal modes of static spherically symmetric black holes in f(R) theory
Authors: Datta Sayak , Bose Sukanta 
Published: January 2020

AbstractWe study the quasi-normal modes (QNMs) of static, spherically symmetric black holes in f(R) theories. We show how these modes in theories with non-trivial f(R) are fundamentally different from those in general relativity. In the special case of $$f(R) = \alpha R^2$$f(R)=αR2 theories, it has been recently argued that iso-spectrality between scalar and vector modes breaks down. Here, we show that such a break down is quite general across all f(R) theories, as long as they satisfy $$f''(0)/(1+f''(0)) \ne 0$$f′′(0)/(1+f′′(0))≠0, where a prime denotes derivative of the function with respect to its argument. We specifically discuss the origin of the breaking of isospectrality. We also show that along with this breaking the QNMs receive a correction that arises when $$f''(0)/(1+f'(0)) \ne 0$$f′′(0)/(1+f′(0))≠0 owing to the inhomogeneous term that it introduces in the mode equation. We discuss how these differences affect the “ringdown” phase of binary black hole mergers and the possibility of constraining f(R) models with gravitational-wave observations. We also find that even though the iso-spectrality is broken in f(R) theories, in general, nevertheless in the corresponding scalar-tensor theories in the Einstein frame it is unbroken.
The Detection of Osthole and Application of Cell Imaging Based on Nitrogen-Doped Carbon Dots
Authors: Wang Ning , Yang Xuefang , Wang Haojiang , Xie Liping , Jia Weihua , Bian Wei , Choi Martin M. F. 
Published: January 2020

A fluorescence probe has been synthesized for the detection of osthole using the nitrogen-doped carbon dots (NCDs) as shown in Fig. 1. The NCDs were fully characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR). Under the optimal experimental conditions, the NCDs fluorescence probe was highly selective and sensitive to osthole. The linear response range for osthole was 5.0–75[Formula: see text][Formula: see text]M with a detection limit of 38[Formula: see text]nM. The mechanism of the interaction of osthole and NCDs was discussed. The fluorescence probe has been applied to the analysis of biological samples. The as-synthesized NCDs with high fluorescence intensity, low toxicity and good biocompatibility were applied to cell imaging.
Transition Metal—Carbon Bond Enthalpies as Descriptor for the Electrochemical Stability of Transition Metal Carbides in Electrocatalytic Applications
Authors: Göhl Daniel , Rueß Holger , Pander Marc , Zeradjanin Aleksandar R. , Mayrhofer Karl J. J. , Schneider Jochen M. , Erbe Andreas , Ledendecker Marc 
Published: January 2020

Transition metal carbides are used for various applications such as hard coating, heterogeneous catalysis, catalyst support material or coatings in fuel cell applications. However, little is known about the stability of their electrochemically active surface in aqueous electrolytes. Herein, the transition metal—carbon bond enthalpy is proposed as stability criterion for various transition metal carbides. The basis is an oxidation mechanism where the rate determining step is the metal—carbon bond cleavage under acidic conditions which was supported by a detailed corrosion study on hexagonal tungsten carbide. In situ flow cell measurements that were coupled to an inductively coupled plasma mass spectrometer corroborated experimentally the linear dependency of the oxidation overpotential on the transition metal—carbon bond enthalpy. The proposed model allows the estimation of the activation overpotential for electrochemical carbide oxidation resulting in a maximized stabilization for carbides in the 4th group (Ti, Zr, Hf). Together with the calculated thermodynamic oxidation potentials, TiC and VC exhibit the highest experimental oxidation potentials (0.85 VRHE). The model can be used for preselecting possible carbide materials for various electrochemical reactions.
Elucidating the Electrochemical Mechanism of NG-Hydroxy-L-Arginine
Authors: Arral Mariah L. , Tooley Christian , Ziino Emily , Halpern Jeffrey Mark 
Published: January 2020

NG-Hydroxy-L-arginine (NOHA) is a stable intermediate product in the urea cycle that can be used to monitor the consumption of L-arginine by nitrous oxide synthase (NOS) to produce nitric oxide (NO) and L-citrulline. Research has implicated the urea cycle in many diseases and NO has cultivated interest as a potential biomarker for neural health. Electrochemical detection is an established, cost-effective method that can successfully detect low levels of analyte concentrations. As one of the few electrochemically active species in the urea cycle, NOHA shows promise as a biomarker for monitoring disruptions in this biochemical process. In this study, we show that NOHA has an oxidation peak at +355 mV vs Ag/AgCl at a glassy carbon electrode. In addition, cyclic voltammetry studies with structural analogs—alanine and N-hydroxyguanidine—allowed us to approximate the oxidation wave at +355 mV vs Ag/AgCl to be a one electron process. Diffusivity of NOHA was found using linear scan voltammetry with a rotating disk electrode and approximated at 5.50 × 10−5 cm2 s−1. Ample work is still needed to make a robust biosensor, but the results here characterize the electrochemical activity and represent principle steps in making a NOHA biosensor.
Transient Sox9 Expression Facilitates Resistance to Androgen-Targeted Therapy in Prostate Cancer
Authors: Nouri Mannan , Massah Shabnam , Caradec Josselin , Lubik Amy A. , Li Na , Truong Sarah , Lee Ahn R. , Fazli Ladan , Ramnarine Varune R. , Lovnicki Jessica M. , Moore Jackson , Wang Mike , Foo Jane , Gleave Martin E. , Hollier Brett G. , Nelson Colleen , Collins Colin , Dong Xuesen , Buttyan Ralph 
Published: January 2020

Abstract

Purpose:
Patients with metastatic prostate cancer are increasingly presenting with treatment-resistant, androgen receptor–negative/low (AR−/Low) tumors, with or without neuroendocrine characteristics, in processes attributed to tumor cell plasticity. This plasticity has been modeled by Rb1/p53 knockdown/knockout and is accompanied by overexpression of the pluripotency factor, Sox2. Here, we explore the role of the developmental transcription factor Sox9 in the process of prostate cancer therapy response and tumor progression.

Experimental Design:
Unique prostate cancer cell models that capture AR−/Low stem cell–like intermediates were analyzed for features of plasticity and the functional role of Sox9. Human prostate cancer xenografts and tissue microarrays were evaluated for temporal alterations in Sox9 expression. The role of NF-κB pathway activity in Sox9 overexpression was explored.

Results:
Prostate cancer stem cell–like intermediates have reduced Rb1 and p53 protein expression and overexpress Sox2 as well as Sox9. Sox9 was required for spheroid growth, and overexpression increased invasiveness and neural features of prostate cancer cells. Sox9 was transiently upregulated in castration-induced progression of prostate cancer xenografts and was specifically overexpressed in neoadjuvant hormone therapy (NHT)–treated patient tumors. High Sox9 expression in NHT-treated patients predicts biochemical recurrence. Finally, we link Sox9 induction to NF-κB dimer activation in prostate cancer cells.

Conclusions:
Developmentally reprogrammed prostate cancer cell models recapitulate features of clinically advanced prostate tumors, including downregulated Rb1/p53 and overexpression of Sox2 with Sox9. Sox9 is a marker of a transitional state that identifies prostate cancer cells under the stress of therapeutic assault and facilitates progression to therapy resistance. Its expression may index the relative activity of the NF-κB pathway.
Analysis of Pre- and Posttreatment Tissues from the SWOG S0800 Trial Reveals an Effect of Neoadjuvant Chemotherapy on the Breast Cancer Genome
Authors: Powles Ryan L. , Wali Vikram B. , Li Xiaotong , Barlow William E. , Nahleh Zeina , Thompson Alastair M. , Godwin Andrew K. , Hatzis Christos , Pusztai Lajos 
Published: January 2020

Abstract

Purpose:
We performed whole-exome sequencing (WES) of pre- and posttreatment cancer tissues to assess the somatic mutation landscape of tumors before and after neoadjuvant taxane and anthracycline chemotherapy with or without bevacizumab.

Experimental Design:
Twenty-nine pretreatment biopsies from the SWOG S0800 trial were subjected to WES to identify mutational patterns associated with response to neoadjuvant chemotherapy. Nine matching samples with residual cancer after therapy were also analyzed to assess changes in mutational patterns in response to therapy.

Results:
In pretreatment samples, a higher proportion of mutation signature 3, a BRCA-mediated DNA repair deficiency mutational signature, was associated with higher rate of pathologic complete response (pCR; median signature weight 24%, range 0%–38% in pCR vs. median weight 0%, range 0%–19% in residual disease, Wilcoxon rank sum, Bonferroni P = 0.007). We found no biological pathway level mutations associated with pCR or enriched in posttreatment samples. We observed statistically significant enrichment of high functional impact mutations in the “E2F targets” and “G2–M checkpoint” pathways in residual cancer samples implicating these pathways in resistance to therapy and a significant depletion of mutations in the “myogenesis pathway” suggesting the cells harboring these variants were effectively eradicated by therapy.

Conclusions:
These results suggest that genomic disturbances in BRCA-related DNA repair mechanisms, reflected by a dominant mutational signature 3, confer increased chemotherapy sensitivity. Cancers that survive neoadjuvant chemotherapy frequently have alterations in cell-cycle–regulating genes but different genes of the same pathways are affected in different patients.
Elite Intratumoral T-cell Clonotypes (The 1%) Effect “Trickle-Down Cytotoxicity”
Authors: Henick Brian S. 
Published: January 2020

Abstract

Careful study of T-cell clonal dynamics in patients with non–small cell lung cancer treated with neoadjuvant nivolumab suggests that successful trafficking of clones from a proliferative burst in the periphery to the tumor associates with major pathologic response. Integration of these findings with functional analysis may augment current therapeutic strategies.
See related article by Zhang et al., p. 1327
Sensibilidade performativa e comunicação das coisas
Authors: Lemos André Luiz Martins , Bitencourt Elias Cunha 
Published: January 2020

O objetivo deste artigo é afirmar o caráter social dos objetos e apresentar o que diferencia as redes sociotécnicas de objetos cotidianos daquelas de objetos aumentados digitalmente – as quais caracterizam a Internet das Coisas. Denominamos essa diferença de sensibilidade performativa. Mostraremos que a sensibilidade performativa não é uma característica técnica de sensores e atuadores, mas uma propriedade que amplia o objeto de modo infocomunicacional em uma rede de comunicação também mais ampla, a partir de performances e procedimentos algorítmicos. Destacamos como essa sensibilidade performativa pode ser vista como um elemento fundamental para pensar um modelo de comunicação das coisas, explorando as narrativas procedimentais da Fitbit Charge HR2.
Effects of Post-Translational Modifications of Fibrinogen on Clot Formation, Clot Structure, and Fibrinolysis
Authors: de Vries Judith J. , Snoek Charlotte J.M. , Rijken Dingeman C. , de Maat Moniek P.M. 
Published: January 2020

Objective:
Post-translational modifications of fibrinogen influence the occurrence and progression of thrombotic diseases. In this systematic review, we assessed the current literature on post-translational modifications of fibrinogen and their effects on fibrin formation and clot characteristics.

Approach and Results:
A systematic search of Medline, Embase, Cochrane Library, and Web of Science was performed to find studies reporting post-translational modifications of fibrinogen and the effects on clot formation and structure. Both in vitro studies and ex vivo studies using patient material were included. One hundred five articles were included, describing 11 different modifications of fibrinogen. For the best known and studied modifications, conclusions could be drawn about their effect on clot formation and structure. Oxidation, high levels of nitration, and glycosylation inhibit the rate of polymerization, resulting in dense clots with thinner fibers, while low levels of nitration increase the rate of polymerization. Glycation showed different results for polymerization, but fibrinolysis was found to be decreased, as a consequence of increased density and decreased permeability of clots. Acetylation also decreases the rate of polymerization but results in increased fiber diameters and susceptibility to fibrinolysis. Other modifications were studied less or contrasting results were found. Therefore, substantial gaps in the knowledge about the effect of post-translational modifications remain.

Conclusions:
Overall, post-translational modifications do affect clot formation and characteristics. More studies need to be performed to reveal the effects of all post-translational modifications and the effects on thrombotic diseases. Expanding the knowledge about modifications of fibrinogen can ultimately contribute to optimizing treatments for thrombotic diseases.
Involvement of Low‐Density Lipoprotein Receptor in the Pathogenesis of Pulmonary Hypertension
Authors: Umar Soban , Ruffenach Gregoire , Moazeni Shayan , Vaillancourt Mylene , Hong Jason , Cunningham Christine , Cao Nancy , Navab Sara , Sarji Shervin , Li Min , Lee Lisa , Fishbein Greg , Ardehali Abbas , Navab Mohamad , Reddy Srinivasa T. , Eghbali Mansoureh 
Published: January 2020

Background

Recently, we and others have reported a causal role for oxidized lipids in the pathogenesis of pulmonary hypertension (
PH
). However, the role of low‐density lipoprotein receptor (
LDL
‐R) in
PH
is not known.

Methods and Results

We examined the role of
LDL
‐R in the development of
PH
and determined the efficacy of high‐density lipoprotein mimetic peptide 4F in mitigating
PH
. Explanted human lungs and plasma from patients with PH and control subjects were analyzed for gene expression, histological characteristics, and lipoprotein oxidation. Male
LDL
‐R null (
LDL
‐R knockout) mice (12–15 months old) were fed chow, Western diet (
WD
),
WD
with 4F, and
WD
with scramble peptide for 12 weeks. Serial echocardiography, cardiac catheterization, oxidized
LDL
assay, real‐time quantitative reverse transcription–polymerase chain reaction, and histological analysis were performed. The effect of
LDL
‐R knockdown and oxidized
LDL
on human pulmonary artery smooth muscle cell proliferation was assessed in vitro.
LDL
‐R and
CD
36 expression levels were significantly downregulated in the lungs of patients with PH. Patients with PH also had increased lung lipid deposits, oxidized
LDL
, E06 immunoreactivity, and plasma oxidized
LDL
/
LDL
ratio.
LDL
‐R knockout mice on
WD
developed
PH
, right ventricular hypertrophy, right ventricular dysfunction, pulmonary vascular remodeling, fibrosis, and lipid deposition in lungs, aortic atherosclerosis, and left ventricular dysfunction, which were prevented by 4F. Interestingly,
PH
in
WD
group preceded left ventricular dysfunction. Oxidized
LDL
or
LDL
‐R knockdown significantly increased proliferation of human pulmonary artery smooth muscle cells in vitro.

Conclusions

Human
PH
is associated with decreased
LDL
‐R in lungs and increased oxidized
LDL
in lungs and plasma.
WD‐
fed
LDL
‐R knockout mice develop
PH
and right ventricular dysfunction, implicating a role for
LDL
‐R and oxidized lipids in
PH
.
Abnormal Serum Sodium is Associated With Increased Mortality Among Unselected Cardiac Intensive Care Unit Patients
Authors: Breen Thomas , Brueske Benjamin , Sidhu Mandeep S. , Murphree Dennis H. , Kashani Kianoush B. , Barsness Gregory W. , Jentzer Jacob C. 
Published: January 2020

Background

Abnormal serum sodium levels have been associated with higher mortality among patients with acute coronary syndromes and heart failure. We sought to describe the association between sodium levels and mortality among unselected cardiac intensive care unit (
CICU
) patients.

Methods and Results

We retrospectively reviewed consecutive adult patients admitted to our cardiac intensive care unit from 2007 to 2015. Hyponatremia and hypernatremia were defined as admission serum sodium <135 and >145
mE
q/L, respectively. In‐hospital mortality was assessed by multivariable regression, and postdischarge mortality was evaluated by Cox proportional‐hazards analysis. We included 9676 patients with a mean age of 68±15 years (37.5% females). Hyponatremia occurred in 1706 (17.6%) patients, and hypernatremia occurred in 322 (3.3%) patients; these groups had higher illness severity and a greater number of comorbidities. Risk of hospital mortality was higher with hyponatremia (15.5% versus 7.5%; unadjusted odds ratio, 2.41; 95%
CI
, 2.06–2.82;
P
<0.001) or hypernatremia (17.7% versus 8.6%; unadjusted odds ratio, 2.82; 95%
CI
, 2.09–3.80;
P
<0.001), with a J‐shaped relationship between admission sodium and mortality. After multivariate adjustment, only hyponatremia was significantly associated with in‐hospital mortality (adjusted odds ratio, 1.42; 95% CI, 1.14–1.76;
P
=0.002). Among hospital survivors, risk of postdischarge mortality was higher in patients with hyponatremia (adjusted hazard ratio, 1.28; 95%
CI
, 1.17–1.41;
P
<0.001) or hypernatremia (adjusted hazard ratio, 1.36; 95%
CI,
1.12–1.64;
P
=0.002).

Conclusions
Hyponatremia and hypernatremia on admission to the cardiac intensive care unit are associated with increased unadjusted short‐ and long‐term mortality. Further studies are needed to determine whether correcting abnormal sodium levels can improve outcomes in cardiac intensive care unit patients.
Safety and Outcomes of Intravenous Thrombolysis in Posterior Versus Anterior Circulation Stroke
Authors: Keselman Boris , Gdovinová Zuzana , Jatuzis Dalius , Melo Teresa Pinho E. , Vilionskis Aleksandras , Cavallo Roberto , Frol Senta , Jurak Lubomir , Koyuncu Bahar , Nunes Ana Paiva , Petrone Alfredo , Lees Kennedy R. , Mazya Michael V. 
Published: January 2020

Background and Purpose—
Posterior circulation stroke (PCS) accounts for 5% to 19% of patients with acute stroke receiving intravenous thrombolysis. We aimed to compare safety and outcomes following intravenous thrombolysis between patients with PCS and anterior circulation stroke (ACS) and incorporate the results in a meta-analysis.

Methods—
We included patients in the Safe Implementation of Treatments in Stroke Thrombolysis Registry 2013 to 2017 with computed tomography/magnetic resonance angiographic occlusion data. Outcomes were parenchymal hematoma, symptomatic intracerebral hemorrhage (SICH) per SITS-MOST (Safe Implementation of Thrombolysis in Stroke Monitoring Study), ECASS II (Second European Co-operative Stroke Study) and NINDS (Neurological Disorders and Stroke definition), 3-month modified Rankin Scale score, and death. Adjustment for SICH risk factors (age, sex, National Institutes of Health Stroke Scale, blood pressure, glucose, and atrial fibrillation) and center was done using inverse probability treatment weighting, after which an average treatment effect (ATE) was calculated. Meta-analysis of 13 studies comparing outcomes in PCS versus ACS after intravenous thrombolysis was conducted.

Results—

Of 5146 patients, 753 had PCS (14.6%). Patients with PCS had lower median National Institutes of Health Stroke Scale: 7 (interquartile range, 4–13) versus 13 (7–18),
P
<0.001 and fewer cerebrovascular risk factors. In patients with PCS versus ACS, parenchymal hematoma occurred in 3.2% versus 7.9%, ATE (95% CI): −4.7% (−6.3% to 3.0%); SICH SITS-MOST in 0.6% versus 1.9%, ATE: −1.4% (−2.2% to −0.7%); SICH NINDS in 3.1% versus 7.8%, ATE: −3.0% (−6.3% to 0.3%); SICH ECASS II in 1.8% versus 5.4%, ATE: −2.3% (−5.3% to 0.7%). In PCS versus ACS, 3-month outcomes (70% data availability) were death 18.5% versus 20.5%, ATE: 6.0% (0.7%–11.4%); modified Rankin Scale score 0–1, 45.2% versus 37.5%, ATE: 1.7% (−6.6% to 3.2%); modified Rankin Scale score 0–2, 61.3% versus 49.4%, ATE: 2.4% (3.1%–7.9%). Meta-analysis showed relative risk for SICH in PCS versus ACS being 0.49 (95% CI, 0.32–0.75).

Conclusions—
The risk of bleeding complications after intravenous thrombolysis in PCS was half that of ACS, with similar functional outcomes and higher risk of death, acknowledging limitations of the National Institutes of Health Stroke Scale for stroke severity or infarct size adjustment.
Windows of Opportunity for Skillful Forecasts Subseasonal to Seasonal and Beyond
Authors: Mariotti Annarita , Baggett Cory , Barnes Elizabeth A. , Becker Emily , Butler Amy , Collins Dan C. , Dirmeyer Paul A. , Ferranti Laura , Johnson Nathaniel C. , Jones Jeanine , Kirtman Ben P. , Lang Andrea L. , Molod Andrea , Newman Matthew , Robertson Andrew W. , Schubert Siegfried , Waliser Duane E. , Albers John 
Published: January 2020

AbstractThere is high demand and a growing expectation for predictions of environmental conditions that go beyond 0–14-day weather forecasts with outlooks extending to one or more seasons and beyond. This is driven by the needs of the energy, water management, and agriculture sectors, to name a few. There is an increasing realization that, unlike weather forecasts, prediction skill on longer time scales can leverage specific climate phenomena or conditions for a predictable signal above the weather noise. Currently, it is understood that these conditions are intermittent in time and have spatially heterogeneous impacts on skill, hence providing strategic windows of opportunity for skillful forecasts. Research points to such windows of opportunity, including El Niño or La Niña events, active periods of the Madden–Julian oscillation, disruptions of the stratospheric polar vortex, when certain large-scale atmospheric regimes are in place, or when persistent anomalies occur in the ocean or land surface. Gains could be obtained by increasingly developing prediction tools and metrics that strategically target these specific windows of opportunity. Across the globe, reevaluating forecasts in this manner could find value in forecasts previously discarded as not skillful. Users’ expectations for prediction skill could be more adequately met, as they are better aware of when and where to expect skill and if the prediction is actionable. Given that there is still untapped potential, in terms of process understanding and prediction methodologies, it is safe to expect that in the future forecast opportunities will expand. Process research and the development of innovative methodologies will aid such progress.