bluuebunny/crossref_metadata_2025_split huggingface dataset:
The tight-binding formulation of the Kronig-Penney model
Authors: Marsiglio F. , Pavelich R. L. 
Published: November 2017

AbstractElectronic band structure calculations are frequently parametrized in tight-binding form; the latter representation is then often used to study electron correlations. In this paper we provide a derivation of the tight-binding model that emerges from the exact solution of a particle bound in a periodic one-dimensional array of square well potentials. We derive the dispersion for such a model, and show that an effective next-nearest-neighbour hopping parameter is required for an accurate description. An electron-hole asymmetry is prevalent except in the extreme tight-binding limit, and emerges through a “next-nearest-neighbour” hopping term in the dispersion. We argue that this does not necessarily imply next-nearest-neighbour tunneling; this assertion is demonstrated by deriving the transition amplitudes for a two-state effective model that describes a double-well potential, which is a simplified precursor to the problem of a periodic array of potential wells. A next-nearest-neighbour tunneling parameter is required for an accurate description even though there are no such neighbours.
Glimpses of the past activity of Sgr A★ inferred from X-ray echoes in Sgr C
Authors: Chuard D. , Terrier R. , Goldwurm A. , Clavel M. , Soldi S. , Morris M. R. , Ponti G. , Walls M. , Chernyakova M. 
Published: November 2017

Context. For a decade now, evidence has accumulated that giant molecular clouds located within the central molecular zone of our Galaxy reflect X-rays coming from past outbursts of the Galactic supermassive black hole. However, the number of illuminating events as well as their ages and durations are still unresolved questions.
Aims. We aim to reconstruct parts of the history of the supermassive black hole Sgr A★ by studying this reflection phenomenon in the molecular complex Sgr C and by determining the line-of-sight positions of its main bright substructures.
Methods. Using observations made with the X-ray observatories XMM-Newton and Chandra and between 2000 and 2014, we investigated the variability of the reflected emission, which consists of a Fe Kα line at 6.4 keV and a Compton continuum. We carried out an imaging and a spectral analysis. We also used a Monte Carlo model of the reflected spectra to constrain the line-of-sight positions of the brightest clumps, and hence to assign an approximate date to the associated illuminating events.
Results. We show that the Fe Kα emission from Sgr C exhibits significant variability in both space and time, which confirms its reflection origin. The most likely illuminating source is Sgr A★. On the one hand, we report two distinct variability timescales, as one clump undergoes a sudden rise and fall in about 2005, while two others vary smoothly throughout the whole 2000–2014 period. On the other hand, by fitting the Monte Carlo model to the data, we are able to place tight constraints on the 3D positions of the clumps. These two independent approaches provide a consistent picture of the past activity of Sgr A★, since the two slowly varying clumps are located on the same wavefront, while the third (rapidly varying) clump corresponds to a different wavefront, that is, to a different illuminating event.
Conclusions. This work shows that Sgr A★ experienced at least two powerful outbursts in the past 300 yrs, and for the first time, we provide an estimation of their age. Extending this approach to other molecular complexes, such as Sgr A, will allow this two-event scenario to be tested further.
Fluorine in the solar neighborhood: Chemical evolution models
Authors: Spitoni E. , Matteucci F. , Jönsson H. , Ryde N. , Romano D. 
Published: November 2017

Context. In light of new observational data related to fluorine abundances in solar neighborhood stars, we present chemical evolution models testing various fluorine nucleosynthesis prescriptions with the aim to best fit those new data.
Aim. We consider chemical evolution models in the solar neighborhood testing various nucleosynthesis prescriptions for fluorine production with the aim of reproducing the observed abundance ratios [F/O] versus [O/H] and [F/Fe] versus [Fe/H]. We study in detail the effects of various stellar yields on fluorine production.
Methods. We adopted two chemical evolution models: the classical two-infall model, which follows the chemical evolution of halo-thick disk and thin disk phases; and the one-infall model, which is designed only for thin disk evolution. We tested the effects on the predicted fluorine abundance ratios of various nucleosynthesis yield sources, that is, asymptotic giant branch (AGB) stars, Wolf–Rayet (W-R) stars, Type II and Type Ia supernovae, and novae.
Results. The fluorine production is dominated by AGB stars but the W-R stars are required to reproduce the trend of the observed data in the solar neighborhood with our chemical evolution models. In particular, the best model both for the two-infall and one-infall cases requires an increase by a factor of 2 of the W-R yields. We also show that the novae, even if their yields are still uncertain, could help to better reproduce the secondary behavior of F in the [F/O] versus [O/H] relation.
Conclusions. The inclusion of the fluorine production by W-R stars seems to be essential to reproduce the new observed ratio [F/O] versus [O/H] in the solar neighborhood. Moreover, the inclusion of novae helps to reproduce the observed fluorine secondary behavior substantially.
Using Organic Synthesis and Chemical Analysis to Understand the Photochemistry of Spore Photoproduct and Other Pyrimidine Dimers
Authors: Li Lei 
Published: November 2017

Pyrimidine dimerization is the dominant DNA photoreaction occurring in vitro and in vivo. Three types of dimers, cyclobutane pyrimidine dimers (CPDs), pyrimidine (6-4) pyrimidone photoproducts (6-4PPs), and the spore photoproduct (SP), are formed from the direct dimerization process; it is of significance to understand the photochemistry and photobiology of these dimers. Traditionally, pyrimidine dimerization was studied by using the natural pyrimidine residues thymine and cytosine, which share similar chemical structures and similar reactivity, making it sometimes less straightforward for one to identify the key pyrimidine residue that needs to be excited to trigger the photoreaction. We thus adopted synthetic chemistry to selectively modify the pyrimidine residues or to introduce pyrimidine analogs to the selected positions before UV irradiation is applied. By monitoring the subsequent outcomes from the photoreaction, we were able to gain unique mechanistic insights into the photochemistry of SP as well as of CPDs and 6-4PPs. Moreover, our approaches have resulted in several useful “tools” that can facilitate the understanding of lesion photobiology. Our results summarized in this account illustrate what organic synthesis/chemical analysis may allow us to achieve in future DNA lesion biology studies. 1	Introduction 2	Using the Deuterium Labeling Strategy to Understand SP Formation 3	Using Microcrystals to Reveal the Reaction Intermediates in SP Formation 4	Using a Phosphate Isostere to Understand the SP Structure 5	Synthesis of SP Phosphoramidite and SP Structural Studies 6	Using a Thymine Isostere to Understand CPD Formation 7	Using a Thymine Isostere to Understand 6-4PP Photoreaction 8	Understanding the Chemical Stability of SP 9	Understanding the Chemical Stability of 6-4PP10	Summary and Perspectives for Future Research
Are the Domains Considered by ICF Comprehensive Enough to Conceptualize Participation in the Patient with Hand Injuries?
Authors: Layeghi Fereydoun , Hosseini Seyyed , Hamidreza Khanke , Asgari Ali , Farzad Maryam 
Published: November 2017

Background Although participation is a core concept in multiple models of disability, there is no consensus on its definition.
Objective The aim of this study was to extract participation domains based on review of theories, available outcome measures, and interviews with experts and the person with hand injuries to compare with the ICF domains of participation.
Methods A qualitative approach using a deductive content analysis was employed to extend definitions of participation from theories. Later on, inductive qualitative method using semistructured interview with five experts in different fields and 30 patients with different hand injuries was used. Coding was performed with extracted domains from the content of data, and finally, the extracted domains were compared with the ICF domains of participation.
Results Some of the extracted domains were not considered in ICF.
Conclusion Subjective participation is the main forbearance part. Role, leisure, domestic life, environment, and others are also main missing meanings. This limitation can hinder measuring disability and health.
Value of Resistin in Early Onset Neonatal Sepsis
Authors: Ozdemir Abdurrahman , Elgormus Yusuf 
Published: November 2017

AbstractThe diagnosis of neonatal sepsis is usually difficult because the sign and symptoms are nonspecific. Although C-reactive protein (CRP) and procalcitonin (PCT) are the most commonly used auxiliary tests, they are not reliable enough markers to be used for diagnosis of neonatal sepsis. This study aimed to evaluate the efficacy of resistin in diagnosing early onset neonatal sepsis and to compare its effectiveness to CRP and PCT. This prospective study was performed in the neonatal intensive care unit of Medicine Hospital between June and September 2016. Twenty-nine infants in the sepsis group and 33 infants in the control group were recruited. The Töllner scoring system was used for clinical signs. The hematologic parameters were evaluated using the Manroe and Rodwell scoring systems. The blood samples for CRP, PCT, and resistin were collected at admission (T0), and at 72 hours (T3). Mean plasma resistin level at T0 was 54.20 ± 39.3 ng/mL in the sepsis group and 34.92 ± 6.9 ng/mL in the control group. The sensitivity at T0 for resistin was 76%, and the specificity was 67%. The values of area under the curve (AUC) for CRP, PCT, and resistin were 0.84, 0.66, and 0.72, respectively. We found the diagnostic value of resistin to be lower than CRP, although its plasma levels were elevated. Therefore, we propose that resistin has limited value in diagnosis and follow-up of early-onset neonatal sepsis.
Critical interventions in debates on the Arab revolutions: centring class
Authors: Salem Sara 
Published: November 2017

SUMMARY
Salem contrasts De Smet’s contribution to the debates on revolution and counter-revolution in Egypt with other important materialist readings of the uprisings. Echoing the centrality of class analysis employed in Gramsci on Tahrir, Salem challenges De Smet’s reading of the Nasserist period and situates Nasserism within a broader pattern of coeval political struggles in Africa.
What is the students’ interest in biology after the biology curriculum modification?
Authors: Čipková Elena , Karolčík Štefan , Dudová Natália , Nagyová Soňa 
Published: November 2017

ABSTRACTDecreasing interest in Science among students, confirmed by several investigations, calls for the need to revise the contents of the curricula for Science subjects, including Biology. Modern Biology curricula should not only contain key biological concepts but also provide a teacher with sufficient space to develop students’ competencies of scientific work and positive attitudes to Science. When preparing the curriculum, it is necessary to consider also students’ interest in selected curriculum topics and their benefit for everyday life. The objective of our research was to identify whether the performed transformation of the Biology curriculum for elementary schools increased the students’ interest in Biology and the contents thereof. We were also investigating students’ preferences in their interest in Biology topics and their interest in selected teaching methods and approaches. Our research confirmed the positive interest in Biology among majority of students who prefer direct, active participation in the process of knowledge acquisition through the study and exploration of living organisms as well as by the execution and assessment of practicals and experiments.
Identifying functionally informative evolutionary sequence profiles
Authors: Gil Nelson , Fiser Andras 
Published: November 2017

Abstract

Motivation
Multiple sequence alignments (MSAs) can provide essential input to many bioinformatics applications, including protein structure prediction and functional annotation. However, the optimal selection of sequences to obtain biologically informative MSAs for such purposes is poorly explored, and has traditionally been performed manually.

Results
We present Selection of Alignment by Maximal Mutual Information (SAMMI), an automated, sequence-based approach to objectively select an optimal MSA from a large set of alternatives sampled from a general sequence database search. The hypothesis of this approach is that the mutual information among MSA columns will be maximal for those MSAs that contain the most diverse set possible of the most structurally and functionally homogeneous protein sequences. SAMMI was tested to select MSAs for functional site residue prediction by analysis of conservation patterns on a set of 435 proteins obtained from protein–ligand (peptides, nucleic acids and small substrates) and protein–protein interaction databases.

Availability and implementation
A freely accessible program, including source code, implementing SAMMI is available at https://github.com/nelsongil92/SAMMI.git.

Supplementary information
Supplementary data are available at Bioinformatics online.
Quality of Life of Adult Survivors After Extra Corporeal Membrane Oxygenation (ECMO)
Authors: Galazzi Alessandro , Brambilla Alessandra , Grasselli Giacomo , Pesenti Antonio , Fumagalli Roberto , Lucchini Alberto 
Published: November 2017

Introduction:
Extracorporeal Membrane Oxygenation (ECMO) is a technique used in the treatment of patients with severe respiratory failure. A lot of studies in the literature investigated the survival rate of patients treated with ECMO, but few are those that assess the long-term outcomes and the quality of life (QoL) of survivors.

Materials and Methods:
A retrospective observational study with prospective QoL assessment through administration of the questionnaire EuroQol-5 Dimension was conducted in acute respiratory distress syndrome patients who h ad ECMO as a rescue therapy for reversible refractory hypoxemia from January 2013 until December 2015 in an Italian referral ECMO center.

Results:
Forty patients were enrolled, but the telephone interview was possible only in 17. The interviewed patients presented a reduction in QoL in the items concerning pain (59%), followed by problems regarding mobility (47%) and anxiety (47%). The patients' perceived QoL, showed in a 0 to100 scale (0 being the worst, 100 being the best value), is of 75% (interquartile range, 70-80).

Discussion:
The problems found are in agreement with the literature about this particular type of patients.

Conclusion:
Most ECMO patients have good physical and social functioning after hospital discharge.
A Protective Eye Shield Reduces Limbal Strain and Its Variability During Simulated Sleep in Adults With Glaucoma
Authors: Flatau Alison , Solano Francisco , Jefferys Joan L. , Damion Christopher , Quigley Harry A. 
Published: November 2017

Purpose:
To determine the effect of wearing a protective eye shield (mask) on limbal strain magnitude and variability in glaucoma eyes when sleeping with 1 side of the face down (FD) against a pillow.

Methods:
A prospective, randomized, interventional trial was conducted at the Wilmer Eye Institute with 36 glaucoma patients. A contact lens sensor measured limbal strain (output in equivalent millivolts) during intervals of up to 60 minutes in lateral decubitus, FD, and supine positions. Eighteen subjects wore a mask during 1 of 2 FD intervals, with randomized assignment of the interval. Data from additional trials with no mask were included in some analyses. In addition, some facial-feature dimensions from 3D scanned images of 23 subjects were compared with limbal strain data.

Results:
Wearing a mask trends toward a reduced mean change in contact lens sensor output (limbal strain) on moving to a FD positions [+34.1 mVeq, P=0.01 reduced by −22.3 mVeq, P=0.09 (n=36)]. Mask wearing reduced variability in strain while FD [−22.8 mVeq, P=0.04 (n=18)]. In eyes with past progressive visual field loss, the effect of the mask reduced mean strain change when moving to FD [−44.8 mVeq, P=0.02 (n=31)]. Longer corneal apex to nose-tip and to temple lengths were associated with reduced variability while FD [P=0.02 and 0.04, respectively (n=23)]. Treating both lengths as confounding factors increased statistical significance, particularly for analysis of the no-mask change in strain data moving to and from the FD position [P=0.004 to 0.002 and P=0.03 to 0.01 (n=23)].

Conclusion and Relevance:
Wearing a mask reduced limbal strain and variation in limbal strain during simulated FD sleep, particularly in eyes with past field worsening, as did some facial features.
Relationship Between Open-angle Glaucoma and Stroke: A 2010 to 2012 Korea National Health and Nutrition Examination Survey
Authors: Lee Won June , Jeoung Jin Wook , Na Kyeong Ik , Kim Young Kook , Kim Chan Yun , Park Ki Ho 
Published: November 2017

Purpose:
To determine the relationship between open-angle glaucoma (OAG) and stroke in the Korean population.

Materials and Methods:
This study was a population-based, cross-sectional study that used data from the Korea National Health and Nutrition Examination Survey (KNHANES), a complex, stratified, multistage, probability-cluster survey. We analyzed a total of 11,959 participants who were above 40 years old and were included in the fifth KNHANES database (2010 to 2012 data). Weighted prevalence of OAG and stroke in various populations were estimated. Univariate and multivariate logistic regressions were performed to examine potential risk factors for stroke, including OAG. Multivariate adjusted odds ratios (OR) for stroke were examined in subjects with and without OAG. Subjects were also examined by hypertension and diabetes status.

Results:
Stroke patients had a significantly higher OAG prevalence (8.5%) than nonstroke patients (3.8%; P<0.001). After adjusting for selected risk factors, the presence of OAG tended to be associated with stroke (adjusted OR=1.629), but this result was not statistically significant (P=0.053). Stroke and OAG were significantly associated with each other in subjects with hypertension (OR=2.059; P=0.010) and diabetes (OR=2.649; P=0.040). In addition, the associations of stroke and other systemic diseases were stronger when OAG was a comorbid condition.

Conclusions:
Although there was no overall statistical significance, patients with OAG had an increased risk of stroke, among those with systemic comorbidities, including hypertension and diabetes. Our results may provide insight on the underlying mechanisms of OAG and their association with stroke development.
Concerns of Anophthalmic Patients Wearing Cryolite Glass Prosthetic Eyes
Authors: Rokohl Alexander C. , Koch Konrad R. , Trester Marc , Trester Wolfgang , Pine Keith R. , Heindl Ludwig M. 
Published: November 2017

Purpose:
To identify the main concerns of patients experienced in wearing cryolite glass prosthetic eyes and to investigate how these have changed over time.

Methods:
One hundred six patients experienced in wearing prosthetic eyes for at least 2 years were asked to complete an anonymous questionnaire regarding prosthetic eye concerns at the time of initial eye loss and at the present time. Main outcome measures included changes in levels of concern over time.

Results:
Initially, the participants were mainly concerned about their appearance, health of the fellow eye, and coping with monocularity. Over time, there was a significant increase of the level of concern regarding the health of the remaining eye (p < 0.001) and regarding watering, crusting, and discharge (p < 0.001). Loss of balance did not change significantly (p = 0.302). All other concerns decreased significantly over time (p < 0.001), with levels of concern about appearance decreasing the most. The current leading concern was the health of the remaining eye followed by concerns about watering, crusting, and discharge. Length of time since natural eye loss was the most important explanatory variable, with significant impact on the concerns about appearance (p = 0.013), retention of the prosthetic eye (p = 0.002), and eyelid contour (p = 0.004).

Conclusions:
Health of the remaining eye is the most common current concern of anophthalmic patients, acknowledging the need of good ophthalmologic follow up after losing an eye. The second most important concern is with watering, crusting, and discharge, suggesting further research for establishing an evidence-based protocol for cryolite glass prosthetic eye maintenance and supportive treatment.
Polycythemia vera and essential thrombocythemia: algorithmic approach
Authors: Vannucchi Alessandro M. , Guglielmelli Paola , Tefferi Ayalew 
Published: November 2017

Purpose of review
To describe an algorithm-based approach, whenever available, to the diagnosis, the risk stratification criteria informing therapy and the current management of polycythemia vera and essential thrombocythemia.

Recent findings
Description of recurrent genetic abnormalities in driver genes, including Janus Kinase 2 (JAK2), myeloproliferative leukemia and calreticulin, a better appreciation of the key diagnostic role of bone marrow features, results of large epidemiologic studies and a few but landmark controlled clinical trials produced in the last decade, all resulted in a reappraisal of the approach to polycythemia vera and essential thrombocythemia.

Summary
The revised 2017 WHO classification of polycythemia vera and essential thrombocythemia allows early diagnosis and accurate distinction from other chronic myeloproliferative neoplasms, particulary prefibrotic myelofibrosis. The prognostic value of selected mutations is being appreciated and JAK2V617F mutation is currently incorporated as risk variable in prognostic system for essential thrombocythemia. Risk-adjusted stratification is used to select therapeutic approaches that include target agents. However, there is not yet a curative approach to these hematologic neoplasms, and although their management has much improved in the last decades, the associated morbidity and mortality remains significant and may be worsened by toxicities of therapeutic agents. Therefore, several clinically relevant endpoints remain unmet.