bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Growth of Ag Nanodots Decorated Cu2O Porous Nanobelts Networks on Copper Foam for Efficient HER Electrocatalysis
Authors: Song Caixia , Zhao Zeyu , Sun Xinxin , Zhou Yanhong , Wang Ying , Wang Debao 
Published: January 2019

AbstractDeveloping earth‐abundant electrocatalysts for high‐efficiency hydrogen evolution reaction (HER) has become one of the leading research frontiers in energy conversion. Here, the design and in situ growth of Ag nanodots decorated Cu2O porous nanobelts networks on Cu foam (denoted as Ag@Cu2O/CF) are carried out via a simple one‐pot solution strategy at room temperature. Serving as self‐supporting electrocatalysts, Ag@Cu2O porous nanobelts provide plentiful active sites, and the 3D hybrid foams provide fast transportation for electrolyte and short diffusion path for newly formed H2 bubbles, which result in excellent electrocatalytic HER activity and long‐term stability. Owing to the synergistic effect between Ag nanodots and Cu2O porous nanobelts and CF, the hybrid electrocatalyst exhibits a low Tafel slope of 58 mV dec−1, a small overpotential of 108 mV at 10 mA cm−2, and high durability for more than 20 h at a potential of 200 mV for HER in 1.0 mol L−1 KOH solution.
On optimal operational sequence of components in a warm standby system
Authors: Finkelstein Maxim , Hazra Nil Kamal , Cha Ji Hwan 
Published: January 2019

Abstract
We consider an open problem of obtaining the optimal operational sequence for the 1-out-of-n system with warm standby. Using the virtual age concept and the cumulative exposure model, we show that the components should be activated in accordance with the increasing sequence of their lifetimes. Lifetimes of the components and the system are compared with respect to the stochastic precedence order and its generalization. Only specific cases of this optimal problem were considered in the literature previously.
New nonparametric classes of distributions in terms of mean time to failure in age replacement
Authors: Izadi Muhyiddin , Sharafi Maryam , Khaledi Baha-Eldin 
Published: January 2019

Abstract
The mean time to failure (MTTF) function in age replacement is used to evaluate the performance and effectiveness of the age replacement policy. In this paper, based on the MTTF function, we introduce two new nonparametric classes of lifetime distributions with nonmonotonic mean time to failure in age replacement; increasing then decreasing MTTF (IDMTTF) and decreasing then increasing MTTF (DIMTTF). The implications between these classes of distributions and some existing classes of nonmonotonic ageing classes are studied. The characterizations of IDMTTF and DIMTTF in terms of the scaled total time on test transform are also obtained.
Generalized monotonicity in terms of differential inequalities
Authors: Bessenyei Mihály 
Published: January 2019

AbstractThe classical notions of monotonicity and convexity can be characterized via the nonnegativity of the first and the second derivative, respectively. These notions can be extended applying Chebyshev systems. The aim of this note is to characterize generalized monotonicity in terms of differential inequalities, yielding analogous results to the classical derivative tests. Applications in the fields of convexity and differential inequalities are also discussed.
Infinite families of congruences modulo 5 and 7 for the cubic partition function
Authors: Yao Olivia X. M. 
Published: January 2019

AbstractIn 2010, Hei-Chi Chan introduced the cubic partition function a(n) in connection with Ramanujan's cubic continued fraction. Chen and Lin, and Ahmed, Baruah and Dastidar proved that a(25n + 22) ≡ 0 (mod 5) for n ⩾ 0. In this paper, we prove several infinite families of congruences modulo 5 and 7 for a(n). Our results generalize the congruence a(25n + 22) ≡ 0 (mod 5) and four congruences modulo 7 for a(n) due to Chen and Lin. Moreover, we present some non-standard congruences modulo 5 for a(n) by using an identity of Newman. For example, we prove that $a((({15\times 17^{3\alpha }+1})/{8})) \equiv 3^{\alpha +1} \ ({\rm mod}\ 5)$ for α ⩾ 0.
Observational Evidence for Summer Rainfall at Titan's North Pole
Authors: Dhingra Rajani D. , Barnes Jason W. , Brown Robert H. , Burrati Bonnie J. , Sotin Christophe , Nicholson Phillip D. , Baines Kevin H. , Clark Roger N. , Soderblom Jason M. , Jauman Ralf , Rodriguez Sebastien , Mouélic Stéphane Le , Turtle Elizabeth P. , Perry Jason E. , Cottini Valeria , Jennings Don E. 
Published: January 2019

AbstractMethane rain on Saturn's moon Titan makes it the only place, other than Earth, where rain interacts with the surface. When and where that rain wets the surface changes seasonally in ways that remain poorly understood. Here we report the discovery of a bright ephemeral feature covering an area of 120,000 km2 near Titan's north pole in observations from Cassini's near‐infrared instrument, Visual and Infrared Mapping Spectrometer on 7 June 2016. Based on the overall brightness, spectral characteristics, and geologic context, we attribute this new feature to specular reflections from a rain‐wetted solid surface like those off of a sunlit wet sidewalk. The reported observation is the first documented rainfall event at Titan's north pole and heralds the arrival of the northern summer (through climatic evidence), which has been delayed relative to model predictions. This detection helps constrain Titan's seasonal change and shows that the “wet‐sidewalk effect can be used to identify other rain events.”
Spatial Gradients in Geomagnetic Storm Time Currents Observed by Swarm Multispacecraft Mission
Authors: Vichare Geeta , Thomas Neethal , Shiokawa Kazau , Bhaskar Ankush , Sinha Ashwini Kumar 
Published: January 2019

AbstractThis paper presents a comprehensive study of geomagnetic storm time currents using magnetic field recorded by multispacecraft polar‐orbiting mission, Swarm. During geomagnetic storm period, the magnetic field variations obtained after removing the internal geomagnetic field and quiet time contributions can be considered as a proxy for storm time currents and are found to follow the temporal profile of Dst index very closely. These variations at the equatorial crossings recorded by multiple‐spacecraft are used to estimate the Dst values and are found to have a good match with the ground‐based Dst index. The average deviation between these two is around 4–13%. We have estimated the asymmetry by taking the difference between the magnetic field variations at two local time sectors separated by 12 hr. The estimated asymmetry shows a good match with the AsyH‐index, especially when satellite traverses in the dawn‐dusk sector. In general, the magnetic field variations are stronger in the night‐to‐dusk sector than day‐to‐dawn sector, which could be due to the larger pressure‐gradients near night‐to‐dusk caused by ion movements. The important advantage of Swarm mission is that it provides an opportunity to investigate the longitudinal gradients in the storm time magnetic fields. It is observed that in general, the gradients are stronger during the main phase of the storm, centered near the equator with a latitudinal width of ~20–30° in both the hemispheres, and are supportive to the scenario of particle‐injection from the magnetotail. The stronger gradients are observed at higher latitudes (~40°) during the episodes of substorms and might be associated with the ionospheric/field‐aligned currents.
Multiplicity of Galactic Cepheids from long-baseline interferometry
Authors: Gallenne A. , Kervella P. , Borgniet S. , Mérand A. , Pietrzyński G. , Gieren W. , Monnier J. D. , Schaefer G. H. , Evans N. R. , Anderson R. I. , Baron F. , Roettenbacher R. M. , Karczmarek P. 
Published: January 2019

Aims. We aim at detecting and characterizing the main-sequence companions of a sample of known and suspected Galactic binary Cepheids. The long-term objective is to accurately and independently measure the Cepheid masses and distances.
Methods. We used the multi-telescope interferometric combiners CHARA/MIRC and VLTI/PIONIER to detect and measure the astrometric positions of the high-contrast companions orbiting 16 bright Galactic Cepheids. We made use of the CANDID algorithm to search for the companions and set detection limits from interferometric observations. We also present new high-precision radial velocity measurements which were used to fit radial pulsation and orbital velocities.
Results. We report the detection of the companions orbiting the Cepheids U Aql, BP Cir, and S Mus, possible detections for FF Aql, Y Car, BG Cru, X Sgr, V350 Sgr, and V636 Sco, while no component is detected around U Car, YZ Car, T Mon, R Mus, S Nor, W Sgr, and AH Vel. For U Aql and S Mus, we performed a preliminary orbital fit combining their astrometric measurements with newly obtained high-precision single-line radial velocities, providing the full set of orbital elements and pulsation parameters. Assuming the distance from a period-luminosity (P-L) relation for both Cepheids, we estimated preliminary masses of MU Aql = 4.97 ± 0.62 M⊙ and MS Mus = 4.63 ± 0.99 M⊙. For YZ Car, W Sgr, V350 Sgr, and V636 Sco, we revised the spectroscopic orbits using new high-precision radial velocities, while we updated the pulsation parameters for BP Cir, BG Cru, S Nor, and AH Vel. Our interferometric observations also provide measurements of the angular diameters, which can be used in a Baade-Wesselink type analysis.
Conclusions. We now have several astrometric detections of Cepheid companions. When radial velocities of the companions are available, such systems will provide accurate and independent masses and distances. Orbital parallaxes with an accuracy better than 5% will be particularly useful for a better calibration of the P-L relation. The final Gaia parallaxes will also be particularly helpful for single-line spectroscopic systems, where mass and distance are degenerate. Mass measurements are necessary for a better understanding of the age and evolution of Cepheids.
Unemployment sequences and the risk of poverty: from counting duration to contextualizing sequences
Authors: Pohlig Matthias 
Published: January 2019

AbstractResearch has consistently shown that unemployment is a strong predictor for income poverty. So far, most studies have focused on the duration of unemployment to account for differences in income poverty. However, this practice may mistreat trajectories which conform less to the norm of continuous full-time employment before unemployment. In this article, I first develop a generalized framework which contextualizes unemployment sequences according to duration as well as timing and order. Second, I apply a sequence analysis to longitudinal data from five European welfare states—Austria, the Netherlands, Poland, Spain, and Sweden—using the European Union Statistics on Income and Living Conditions. Thereby, I construct a typology of unemployment sequences which includes some non-standard types of unemployment sequences. These sequences contain inactivity, part-time employment and self-employment spells and have an increased poverty risk. Thus, the sequence-based framework and the sequence analysis are able to contextualize unemployment sequences better than the conventional measure of unemployment duration.
Vitamin D and childhood asthma: causation and contribution to disease activity
Authors: Litonjua Augusto A. 
Published: January 2019

Purpose of review
To review the literature of the past 18 months (April 2017 through September, 2018) relating to vitamin D and childhood asthma.

Recent findings
A combined analysis of two clinical trials of maternal vitamin D supplementation trials showed a significant protective effect of vitamin D supplementation trials in the primary prevention of asthma and recurrent wheeze up to age 3 years. Secondary analyses from these trials have also suggested that initial maternal vitamin D status could affect the response to supplementation during pregnancy, with the biggest protective effect in children born to mothers with initial 25hydroxyvitamin D (25OHD) levels of at least 30 ng/ml. A postnatal, 6-month vitamin D supplementation trial in black, premature babies showed a 34% decreased risk of recurrent wheezing at 1 year among the infants who received supplementation. An individual patient data meta-analysis of published clinical trials concluded that vitamin D supplementation decreased the risk of asthma exacerbations in those with 25OHD levels less than 10 ng/ml. Results of observational analyses on primary prevention of asthma and in prevention of exacerbations remain mixed, with the bulk of the evidence suggesting that there is a protective effect of higher vitamin D levels.

Summary
Evidence continues to accumulate that vitamin D supplementation helps to prevent the development of asthma and recurrent wheeze in early life, and may also help in the management of asthma. The level(s) of circulating vitamin D that maximizes these effects remains to be identified.
Symptom-based patient-reported outcomes in adults with eosinophilic esophagitis: value for treatment monitoring and randomized controlled trial design
Authors: Safroneeva Ekaterina , Schoepfer Alain M. 
Published: January 2019

Purpose of review
In adults with eosinophilic esophagitis (EoE), a chronic, inflammatory immune-mediated condition of the esophagus, both inflammation and fibrosis are likely associated with symptom generation. Therefore, assessing symptom-based patient-reported outcomes (PROs), defined by US Food and Drug Administration as ‘any report of the status of a patient's health condition that comes directly from the patients, without interpretation of the patient's response by a clinician or anyone else’, is important in the context of trials and observational studies of emerging therapies.

Recent findings
For purposes of treatment monitoring, lack of symptoms does not predict the absence of biologic inflammation; hence, endoscopy with esophageal biopsies should be performed to check for residual inflammation. Lack of inflammation does not predict lack of symptoms, and the presence of subepithelial fibrosis cannot be excluded. No published instrument currently measures the frequency of dysphagia described all possible ways, strategies of living with this symptom and various pain types. In randomized controlled trials, in which symptom response was detected using validated PRO measures, only modest decreases in symptom scores were observed.

Summary
Accessing full EoE symptom spectrum and optimizing PRO measures remains a challenge that should be tackled to reliably assess response to existing and emerging therapies.
Fostering Transformative Learning in a Social Pediatrics Research Summer Studentship
Authors: Talarico Susanna , Zubairi Mohammad , Daneman Denis , Punnett Angela , Martimianakis Maria Athina (Tina) 
Published: January 2019

Problem
Teaching future doctors the skills necessary to address health disparities is a challenge for medical educators. In response, the authors developed and implemented the Social Pediatrics Research Summer Studentship (SPReSS) program for medical students at the University of Toronto.

Approach
The curriculum incorporated research and clinical placements into a formal seminar series. Participating students were required to complete a research project and to write a reflection describing a situation that challenged their thinking. The authors and curriculum developers applied transformative learning principles not only to facilitate critical reflection and learning in the students but also as an innovative approach to program development and evaluation. The authors conducted a thematic analysis of the reflections of 23 students participating in the program in June and July 2013, 2014, and 2015 to evaluate the SPReSS program.

Outcomes
The analysis revealed students’ empathic responses to marginalized patients, and these responses acted as triggers for critical reflection. Students described feeling empowered to act as advocates and wrote that these feelings were reinforced through faculty members’ role modeling. According to their reflections, students found the program both challenging and rewarding, particularly the integration of the clinical and research experiences which made broader sociopolitical phenomena introduced through assigned readings and seminar discussions concrete.

Next Steps
The authors are exploring models, including a fourth-year selective or multiyear longitudinal experience, to support more students. They also hope to involve more community partners and to evaluate long-term outcomes of participants.
Confirming the Presence of Unrecognized Meniscal Injuries on Magnetic Resonance Imaging in Pediatric and Adolescent Patients With Anterior Cruciate Ligament Tears
Authors: Munger Alana M. , Gonsalves Nicholas R. , Sarkisova Natalya , Clarke Emily , VandenBerg Curtis D. , Pace J. Lee 
Published: January 2019

Background:
Prior research has shown decreased accuracy of meniscal injury detection using magnetic resonance imaging (MRI) for anterior cruciate ligament (ACL)-deficient adult patients as well as ACL-deficient pediatric and adolescent patients. The objectives of this study were the following: (1) assess the diagnostic ability of MRI in detecting meniscal injuries for pediatric and adolescent patients undergoing arthroscopic ACL reconstruction and (2) characterize the unrecognized meniscal injuries.

Methods:
The sensitivity, specificity, positive predictive value, and negative predictive value of meniscal tears (medial, lateral, or both) on MRI were calculated for the 107 patients in this cohort. Fisher exact tests were used to compare event frequencies between medial meniscal (MM) and lateral meniscal (LM) tears. One-way analysis of variance tests were performed to compare event rates between the location and type of unrecognized meniscal tears.

Results:
The median age of the cohort was 15 (range: 7 to 18). The sensitivity, specificity, positive predictive value, and negative predictive value of MRI in detecting meniscal tears (medial, lateral, or both) in ACL-deficient pediatric and adolescent patients was 62.3%, 68.4%, 78.2%, and 50.0%, respectively. There were 26 (24.3%) cases in which a meniscal injury was not detected on MRI, but was discovered arthroscopically (MM: 5 knees, LM: 20 knees, both: 1 knee). These unrecognized meniscal injuries were more commonly the LM than the MM (77.8%, P-value=0.100), a vertical/longitudinal tear type (77.8%, P-value <0.001), and located in the posterior horn (74.1%, P-value <0.001).

Conclusions:
In this ACL-deficient pediatric and adolescent cohort, there were 26 (24.3%) patients with unrecognized meniscal injuries. A vertical tear in the posterior horn was the most commonly unrecognized meniscal injury, supporting the findings of prior research postulating that the location and configuration of a tear influence the accuracy of MRI in detecting these injuries. More research is needed to investigate strategies to improve the detection of meniscal tears in pediatric and adolescent patients preoperatively. These findings have implications with regard to patient counseling, operative planning, anticipatory guidance with regard to postoperative rehabilitation, recovery expectations, and surgical outcomes.

Level of Evidence:
Level IV.
High-Risk Human Papillomavirus E6/E7 mRNA Is Rarely Detected in Nonanogenital Cutaneous Squamous Cell Carcinoma: An RNA In Situ Hybridization–Based Tissue Microarray Study
Authors: Fujimoto Masakazu , Matsuzaki Ibu , Takahashi Yuichi , Iwahashi Yoshifumi , Warigaya Kenji , Kojima Fumiyoshi , Jinnin Masatoshi , Murata Shin-ichi 
Published: January 2019

Abstract:
High-risk human papillomavirus (HR-HPV) is known to play an oncogenic role in squamous cell carcinoma (SCC) at certain anatomical sites, namely the uterine cervix, oropharynx, and anogenital skin. However, the association between HR-HPV and nonanogenital cutaneous SCC (CSCC) remains controversial. In this study, we addressed this controversy by performing HR-HPV E6/E7 mRNA in situ hybridization (ISH) on 243 CSCC samples. A cocktail of E6/E7 mRNA ISH probes, recognizing 18 HR-HPV genotypes, was applied to a tissue microarray of paraffin-embedded sections of 154 invasive and 89 in situ CSCC specimens. The anatomical sites of CSCC included the head and neck (n = 100), extremities (n = 100), trunk (n = 25), and anogenitalia (n = 18). We also investigated the correlation between the p16 expression and HR-HPV status by immunohistochemistry. The results of HR-HPV E6/E7 mRNA ISH showed that 5.8% (14/243) of all CSCC samples were positive for HR-HPV, including 66.7% (12/18) of the anogenital and only 0.9% (2/225) of the nonanogenital CSCC samples (P < 0.01). For the detection of diffuse p16 expression by immunohistochemistry, the sensitivity was 100% (14/14 HR-HPV–positive CSCC samples), and the specificity was 72.1% (165/229 HR-HPV–negative specimens). Thus, HR-HPV E6/E7 mRNA was rarely detected in nonanogenital CSCC, making it unlikely that the virus contributes to the pathogenesis of this malignancy. In addition, p16 immunoreactivity has a limited value as a surrogate marker for transcriptionally active HR-HPV in nonanogenital CSCC.
Hailey–Hailey–Like Pattern of Acantholysis on the Scalp Should Raise the Possibility of Incipient Pemphigus Vulgaris
Authors: Gottesman Silvija P. , Abedi Syed M. , Rosen Jason R. , Gottlieb Geoffrey J. 
Published: January 2019

Abstract:
Hailey–Hailey disease (familial benign chronic pemphigus) is a genodermatosis with a typical clinical presentation of macerated plaques involving intertriginous areas of the body and affects multiple family members. Epidermal acanthosis, incipient, and completed acantholysis of many of the spinous keratinocytes of the epidermis and foci of dyskeratosis are well-recognized histologic findings. We have observed solitary lesions on the “scalp” of patients having a Hailey–Hailey–like pattern, and not the suprabasilar clefting of pemphigus represents the first manifestation of pemphigus vulgaris, which was confirmed with direct immunofluorescence in all our patients.
The effects of genetic variants related to insulin metabolism pathways and the interactions with lifestyles on colorectal cancer risk
Authors: Jung Su Yon , Zhang Zuo-Feng 
Published: January 2019

Abstract

Objectives:
Genetic variants in metabolic signaling pathways may interact with lifestyle factors, such as dietary fatty acids, influencing postmenopausal colorectal cancer (CRC) risk, but these interrelated pathways are not fully understood.

Methods:
In this study, we examined 54 single-nucleotide polymorphisms (SNPs) in genes related to insulin-like growth factor-I/insulin traits and their signaling pathways and lifestyle factors in relation to postmenopausal CRC, using data from 6,539 postmenopausal women in the Women's Health Initiative Harmonized and Imputed Genome-Wide Association Studies. By employing a two-stage random survival forest analysis, we evaluated the SNPs and lifestyle factors by ranking them according to their predictive value and accuracy for CRC.

Results:
We identified four SNPs (IRS1 rs1801123, IRS1 rs1801278, AKT2 rs3730256, and AKT2 rs7247515) and two lifestyle factors (age and percentage calories from saturated fatty acids) as the top six most influential predictors for CRC risk. We further examined interactive effects of those factors on cancer risk. In the individual SNP analysis, no significant association was observed, but the combination of the four SNPs, age, and percentage calories from saturated fatty acid (≥11% per day) significantly increased the risk of CRC in a gene and lifestyle dose-dependent manner.

Conclusions:
Our findings provide insight into gene–lifestyle interactions and will enable researchers to focus on individuals with risk genotypes to promote intervention strategies. Our study suggests the careful use of data on potential genetic targets in clinical trials for cancer prevention to reduce the risk for CRC in postmenopausal women.