bluuebunny/crossref_metadata_2025 huggingface dataset:
Bond Strength of Zirconia to Different Core Materials
Authors: Torres Carlos Rocha Gomes , Pucci César R , Borges Alessandra B , Frattes Fabiana C , de Oliveira JB Sorte
Published: November 2016

Background

Since bonding to zirconia is still questionable, the aim of this study was to evaluate the bond strength of yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) to different materials used to manufacture dental cores, employing a universal self-etching adhesive system.

Materials and methods

Cylinders obtained from blocks of Y-TZP Zirconia were sintered in a high-temperature oven. The surfaces to be bonded were blasted with aluminum oxide, then silica-coated aluminum oxide, and finally cleaned in ultrasonic bath. The specimens were divided into six groups according to the core material tested: Silver alloy (Ag/Sn/Cu, Tecnofix), copper alloy (Cu/Ni/Zn, Goldent LA), core buildup resin (Rebilda DC — VOCO), Y-TZP zirconia (IPS e.max ZirCAD, Ivoclar Vivandent), enamel, and dentin. The zirconia cylinders were bonded to the core substrates using the Futurabond U adhesive system (VOCO) and resinous cement (Bifix QM — VOCO). The specimens were shear tested in a universal testing machine at 1 mm/ min. Data was analyzed using ANOVA and Tukey's test.

Results

Bond strength in MPa (±SD) for the different materials tested were dentin: (12.80 ± 3.18)a; enamel: (15.13 ± 3.09) ab; resin: (17.20 ± 4.67)ab; copper alloy: (18.93 ± 4.66)bc; silver alloy: (22.86 ± 5.47)c; and zirconia: (23.65 ± 3.64)c. Groups followed by the same letters are not significantly different at p < 0.05.

Conclusion

The metallic alloys and zirconia core materials showed significantly higher bond strength than those obtained directly on dentin. The core buildup resin bond strength to zirconia is similar to that obtained with enamel and dentin.

How to cite this article

Frattes FC, de Oliveira JBS, Pucci CR, Borges AB, Torres CRG. Bond Strength of Zirconia to Different Core Materials. World J Dent 2016;7(4):169-174.
Effect of Preoperative Ibuprofen and Acetaminophen on Orthodontic Pain
Authors: Moradinejad Mehrnaz , Jafari Sanaz , Kazemi Parisa , Jafari Farnaz
Published: November 2016

Objectives

Pain in dentistry is a common problem which dentists think about it. Controlling the pain in dentistry is crucial. Nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen are used worldwide for suppressing pain and inflammation. The aim of the present study was to compare the effect of preoperative ibuprofen and acetaminophen therapy on orthodontic pain with a different method.

Materials and methods

Samples were divided into two groups: Group I (they received placebo in first level, acetaminophen at second level, and ibuprofen at third level), group II (they received placebo in first level, ibuprofen at second level, and acetaminophen at third level). All drugs were administered single dose before treatment and the researcher put 1 month gap between levels. After using each drugs in each level, the amount of pain was measured by using a questionnaire based on several activities (chewing, in time of contacting teeth, and noncontacting) with visual analog scale (VAS) in multiple times.

Results

Placebo, ibuprofen, and acetaminophen have significant effect on suppressing pain before starting treatment, during chewing, in time of contacting teeth, and noncontacting (p = 0.000). Although the pain process in this study was ascendant, ibuprofen and acetaminophen were unable to reduce pain significantly in comparison to placebo.

Conclusion

Pain process was ascendant and the mentioned drugs were unable to reduce the pain by passing time. We could not reduce the pain process gradient by this drug dose. So, by increasing the dose, we wish to reduce orthodontic pain

How to cite this article

Moradinejad M, Jafari S, Kazemi P, Jafari F. Effect of Preoperative Ibuprofen and Acetaminophen on Orthodontic Pain. World J Dent 2016;7(4):182-185.
Biomonitoring of Buccal Mucosa Cells in Chronic Smokers and Nonsmokers
Authors: Taneja Neeraj , Sarpal Ruhi S , Shergill Navdeep K , Ravindra SV
Published: November 2016

Background

Despite the well-known presence of carcinogens in tobacco smoke, results in the scientific literature linking smoking habits to micronuclei frequency are rather controversial.

Aim

The study was conducted to compare and evaluate the frequency of micronuclei in chronic smokers and nonsmokers in relation to habit history, personal history, and other related factors like occupation, exposure to radiation, etc.

Materials and methods

A total of 50 randomly selected male subjects were included in the study. Case and control groups (smokers and nonsmokers respectively) comprised 25 subjects each (mean age in controls = 38.24 ± 2.7; mean age in smokers = 39.32 ± 3.8).

Results and conclusion

There was a significant relation between tobacco consumption and frequency of micronucleated cells (p = 0.05) and between radiation exposure and presence of micronuclei (p = 0.05) in controls and subjects. Within the smokers group, left cheek scrapings showed higher count (p = 0.05; significant) for the micronucleated cells as compared with right cheek scrapings.

Clinical significance

In this study, an attempt was made to estimate the cytogenetic damage in oral mucosa in people habituated to smoking beedi. Though tobacco plays an important role in micronuclei generation, other factors like ionizing radiation and personal habits also contribute to micronuclei frequency. Site of smear, sample size, nuclear specific stain usage are some of the contributing factors. In addition, cytogenetic alterations like karyolysis, pyknosis, etc., can be included in future studies to increase the specificity.

How to cite this article

Sarpal RS, Taneja N, Shergill NK, Ravindra SV. Biomonitoring of Buccal Mucosa Cells in Chronic Smokers and Nonsmokers. World J Dent 2016;7(4):189-194.
Double Papilla Graft with Amnion Membrane for Root Coverage of Isolated Recession
Authors: Srivastava Ruchi , Siddiqui Zeba R , Jhingran Rajesh , Bains Vivek K
Published: November 2016

Gingival recession is one of the most common soft tissue problems, especially when it hinders the esthetics of a patient. Gingival recession can further lead to root caries, sensitivity, and difficulty in plaque control. Moreover, exposed roots are prone to abrasion and erosion. Periodontal plastic surgery is one of the emerging fields, which helps to meet such soft tissue problems. Currently, a variety of techniques are being used for root coverage, like pedicle grafts, coronally advanced flap, free mucosal graft, epithelial connective tissue graft, guided tissue regeneration, and acellular dermal matrix. This article highlights a case that was successfully managed by double papilla graft technique in combination with amnion membrane for root coverage of Miller class II recession defect in the mandibular canine region. In this technique, the soft tissues adjacent to the recession area were positioned over the recession defect. The main advantage of this technique is that the flap remains attached at its base so that it retains its own blood supply during transfer to a new position. It also preserves the interdental papilla, thus preserving the gingival height. As an alternative to the epithelial connective tissue graft, amnion membrane has the advantage of no invasive palatal wound, regenerative potential, and improved esthetic results. This procedure is highly sensitive and had predictable results, with a clinically significant amount of root coverage.

How to cite this article

Srivastava R, Siddiqui ZR, Jhingran R, Bains VK. Double Papilla Graft with Amnion Membrane for Root Coverage of Isolated Recession. World J Dent 2016;7(4):213-216.
Effects of urban agglomeration on surface-UV doses: a comparison of Brewer
measurements in Warsaw and Belsk, Poland, for the period 2013–2015
Authors: Czerwińska Agnieszka E. , Krzyścin Janusz W. , Jarosławski Janusz , Posyniak Michał
Published: November 2016

Abstract. Specific aerosols and cloud properties over large urban regions seem to generate an island, similar to the well-known urban heat island, leading to lower ultraviolet (UV) radiation intensity compared to the surrounding less polluted areas, thus creating a shield against excessive human exposure to UV radiation. The present study focuses on differences between erythemal and UVA (324 nm) doses measured by the Brewer spectrophotometers in Warsaw (52.3° N, 21.0° E) and Belsk (51.8° N, 20.8° E). The latter is a rural region located about 60 km south-west of the city. Ratios between erythemal and UVA partly daily doses, obtained during all-sky and cloudless-sky conditions for the period May 2013–December 2015, were analysed to infer a specific cloud and aerosol forcing on the surface UV doses over Warsaw. Radiative model simulations were carried out to find sources of the observed differences between the sites. It was found that Warsaw urban agglomeration induced 8 and 6 % attenuation of the erythemal and UVA doses respectively. This is mostly due to the lower sun elevation in Warsaw during the near-noon measurements and the larger optical depth of the city aerosols and increased cloudiness. It could be hypothesised that the expected stronger absorption of the solar UV radiation by urban aerosols is compensated for here by a higher surface reflectivity over the city.
Microbial communities and their predicted metabolic characteristics in deep
fracture groundwaters of the crystalline bedrock at Olkiluoto, Finland
Authors: Bomberg Malin , Lamminmäki Tiina , Itävaara Merja
Published: November 2016

Abstract. The microbial diversity in oligotrophic isolated crystalline Fennoscandian Shield bedrock fracture groundwaters is high, but the core community has not been identified. Here we characterized the bacterial and archaeal communities in 12 water conductive fractures situated at depths between 296 and 798 m by high throughput amplicon sequencing using the Illumina HiSeq platform. Between 1.7  ×  104 and 1.2  ×  106 bacterial or archaeal sequence reads per sample were obtained. These sequences revealed that up to 95 and 99 % of the bacterial and archaeal sequences obtained from the 12 samples, respectively, belonged to only a few common species, i.e. the core microbiome. However, the remaining rare microbiome contained over 3- and 6-fold more bacterial and archaeal taxa. The metabolic properties of the microbial communities were predicted using PICRUSt. The approximate estimation showed that the metabolic pathways commonly included fermentation, fatty acid oxidation, glycolysis/gluconeogenesis, oxidative phosphorylation, and methanogenesis/anaerobic methane oxidation, but carbon fixation through the Calvin cycle, reductive TCA cycle, and the Wood–Ljungdahl pathway was also predicted. The rare microbiome is an unlimited source of genomic functionality in all ecosystems. It may consist of remnants of microbial communities prevailing in earlier environmental conditions, but could also be induced again if changes in their living conditions occur.
Unveiling the Si cycle using isotopes in an iron-fertilized zone of the
Southern Ocean: from mixed-layer supply to export
Authors: Closset Ivia , Cardinal Damien , Rembauville Mathieu , Thil François , Blain Stéphane
Published: November 2016

Abstract. A massive diatom bloom forms annually in the surface waters of the naturally iron-fertilized Kerguelen Plateau (Southern Ocean). In this study, silicon isotopic signatures (δ30Si) of silicic acid (DSi) and suspended biogenic silica (BSi) were investigated through the whole water column with unprecedented spatial resolution, during the KEOPS-2 experiment (spring 2011). We used δ30Si measurements to track the sources of silicon that fuelled the bloom, and investigated the seasonal evolution of the Si biogeochemical cycle in the iron-fertilized area. We compared the results from stations with various degrees of iron enrichment and bloom conditions to an HNLC reference station. Dissolved and particulate δ30Si signatures were highly variable in the upper 500 m, reflecting the effect of intense silicon utilization in spring, while they were quite homogeneous in deeper waters. The Si isotopic and mass balance identified a unique Winter Water (WW) Si source for the iron-fertilized area that originated from southeast of the Kerguelen Plateau and spread northward. When the WW reached a retroflection of the Polar Front (PF), the δ30Si composition of the silicic acid pool became progressively heavier. This would result from sequential diapycnal and isopycnal mixings between the initial WW and ML water masses, highlighting the strong circulation of surface waters that defined this zone. When comparing the results from the two KEOPS expeditions, the relationship between DSi depletion, BSi production, and their isotopic composition appears decoupled in the iron-fertilized area. This seasonal decoupling could help to explain the low apparent fractionation factor observed in the ML at the end of summer. Taking into account these considerations, we refined the seasonal net BSi production in the ML of the iron-fertilized area to 3.0 ± 0.3 mol Si m−2 yr−1, which was exclusively sustained by surface water phytoplankton populations. These insights confirm that the isotopic composition of dissolved and particulate silicon is a promising tool to improve our understanding of the Si biogeochemical cycle since the isotopic and mass balance allows resolution of processes in the Si cycle (i.e. uptake, dissolution, mixing).
Landslide susceptibility mapping on global scale using method of logistic regression
Authors: Lin Le , Lin Qigen , Wang Ying
Published: November 2016

Abstract. This paper proposes a statistical model for mapping global landslide susceptibility based on logistic regression. After investigating explanatory factors for landslides in the existing literature, five factors were selected to model landslide susceptibility: relative relief, extreme precipitation, lithology, ground motion and soil moisture. When building model, 70 % of landslide and non-landslide points were randomly selected for logistic regression, and the others were used for model validation. For evaluating the accuracy of predictive models, this paper adopts several criteria including receiver operating characteristic (ROC) curve method. Logistic regression experiments found all five factors to be significant in explaining landslide occurrence on global scale. During the modeling process, percentage correct in confusion matrix of landslide classification was approximately 80 % and the area under the curve (AUC) was nearly 0.87. During the validation process, the above statistics were about 81 % and 0.88, respectively. Such result indicates that the model has strong robustness and stable performance. This model found that at a global scale, soil moisture can be dominant in the occurrence of landslides and topographic factor may be secondary.
Evaluation of Chemistry Questions in the General Secondary Examination in Jordan for Years 2010 – 2015
Authors: Allouh Zuhair M
Published: November 2016

This study aimed to evaluate chemistry questions from the General Secondary Examination
in Jordan (Altawjihi) for the years 2010 – 2015. Criteria for evaluation included type of
questions (objective vs. essay), inclusion of Bloom's Taxonomy of Cognitive Domain, and
the availability of chemistry processes. This study was accomplished by following the style
of content analysis that considers the sub-question as the unit of analysis and then determines
which standards are included in the questions. The number of questions that were analyzed
reached to 540 sub-questions. The researcher used frequencies, percentages, chi-square
distribution, and Holsti's method in the statistical treatment to calculate the stability of the
question analysis. The results exhibited the domination of objective questions over essay
questions and questions of completion. Objective questions dominated the findings (57.6%).
Essay questions were second most frequently used (36.7%), with completion questions used
least frequently (5.7%). Questions that measure lower cognitive levels also outperformed the
other types, reaching 85.7%. However, the questions that measure higher cognitive levels (as
based on Bloom’s Taxonomy of the Cognitive Domain— analysis, synthesis, and evaluation)
were only sparingly used, at 7.8%, 3.0%, and 3.5%, respectively. Chemical calculation and
recognition occupied center stage in the educational processes for achieving chemical
knowledge and chemical expression, whereas the assumption process has been used almost
not at all (0.5%).
The Disproportionate Representation of Black Students within Special Education
Authors: Alqarni Turki
Published: November 2016

The purpose of this research is to discuss the causes of disproportionality of African American
students within special education program. Also, this research is discussing the misuse of
special education law against this population as well as represents suggestions to reduce the
increase of black students in special education. Furthermore, this research has showed previous
suggestions to decrease the overrepresentation of black students in special education along
with the author’s suggestions. The aim of this research is to enhance the concept of inclusion
and find methods to increase the inclusion of those marginalized groups in public schools.
A Validation Study of the What’s My School Mindset? Survey
Authors: Hanson Janet , Bangert Arthur , Ruff William
Published: November 2016

The What’s My School Mindset? (WMSM) survey is purported to operationalize teachers’ beliefs of their school’s ability to help all children learn and grow. In today’s data driven educational climate it is important to select a reliable instrument for collecting teacher perceptions about their school culture. Accurate data is necessary to support development of realistic continuous improvement goals and to measure progress toward those goals. This study collected teacher and administrator responses (n = 348) from a stratified random sample of 31 PK-12 public schools in a large northwestern state. A split-half exploratory factor analysis (n = 178) was used to identify a proposed factor structure model. The proposed model was tested using the second half confirmatory factor analysis sample (n = 174) and confirmed the model revealing school mindset is a second order, unidimensional factor with three subfactors. The results of this study are useful for school leaders and researchers who seek to use the What’s My School Mindset? scale to measure growth mindset within a school’s culture. Accurately interpreting the measurement of one’s school culture can increase administrator effectiveness and provide a foundation for opening realistic dialogues with teachers about their self-reported beliefs. A useful discussion of the background of school growth mindset, development of the What’s My School Mindset? instrument, and theoretical framework of learning organization theory is provided.
Poly-Paper: A Sustainable Material for Packaging, Based on Recycled Paper and Recyclable with Paper
Authors: Del Curto Barbara , Barelli Nadia , Profaizer Mauro , Farè Silvia , Tanzi Maria Cristina , Cigada Alberto , Ognibene Giulia , Recca Giuseppe , Cicala Gianluca
Published: November 2016

Background

Until now, environmental sustainability issues are almost entirely unsolved for packaging materials. With the final aim of finding materials with a single recycling channel, cellulose fiber/poly(vinyl)alcohol composites were investigated.

Methods

After extrusion and injection molding, samples of composite with different cellulose fiber content (30%, 50% and 70% w/w) were tested.

Results

Tensile mechanical tests exhibited an improvement in composite stiffness when the reinforcement content was increased together with a decrease in composite elongation. Solubility tests performed at room temperature and 45°C showed different behavior depending on the water-resistant film applied on the composite (50% cellulose fiber content). In particular, the uncoated composite showed complete solubility after 2 hours, whereas at the same time point, no solubility occurred when a non-water-soluble varnish was used.

Conclusions

The proposed composites, named Poly-paper, appear to warrant further investigation as highly sustainable packaging.
The Specter of Landscape: The Postcolonial Gothic, Preternatural, and Aboriginal Spiritual in Alexis Wright's Plains of Promise
Authors: Bartha Kathrin
Published: November 2016

This article examines the use of preternatural landscapes within the Australian novel Plains of Promise (1997) by the Aboriginal author Alexis Wright, exploring her themes of memory, reconciliation, and connection to “place.” The novel is concerned with the traumas of three generations of Aboriginal women who have been forcibly separated and displaced from their traditional homeland. There is a sense in which haunted and “sacred” country coincide, and at times, uncanny nature is able to empower the dispossessed via its role of witness. Rather than a relationship to country being represented as a special spiritual capacity of Aboriginal people, however, connection to place is productively utopian. Discussing the uses and limits of such labels as the “Postcolonial Gothic” and considering the preternatural's role, I argue that the novel provides a space for the unknown as Wright portrays the freedom to maintain difference as a kind of resistance to colonialism.
Grotesque Gaming: The Monstrous in Online Worlds
Authors: Geraci Robert M. , Recine Nat , Fox Samantha
Published: November 2016

Videogames and virtual worlds that provoke dread and horror have grown in popularity throughout the twenty-first century. Based on the online games Requiem: Memento Mori and DayZ, this article shows how players relish such dread and enjoy landscapes of the monstrous and the grotesque in order to engage with and tentatively conquer inner fears and anxieties. As such, the game worlds continue the age-old work of horror—to exorcise one's inner fears and demons—but do so with the viscerality that is the hallmark of gaming. Using theoretical analysis, “textual” interpretation, and empirical data garnered through interviews and surveys, we show that Requiem and DayZ produce cathartic experiences associated with long traditions of popular and religious approaches to human fear and sin. It is this visceral engagement with the horrific and monstrous that connects the games and their environments to long-standing folk traditions in pop culture.
Becoming a Specialist Nurse in Psychiatric Mental Health Care
Authors: Södergren Ulrika , Benjaminsson Carin , Mattsson Janet
Published: November 2016

Background Specialist nurse students are upon graduation certified to have increased their professional competence to an advanced level. But how do specialist nurse students themselves experience and understand their professional competence and its development upon graduation? This is what this study aims at describing. Method This study has a phenomenographic approach. Data consists of student written narratives. Results The participants understood their professional competence developed in various degrees as a transformation in me and a transition in my encounter with the patient. Being able to integrate theory in practice was crucial for this competence to develop. Conclusion The specialist programme needs to support students in developing an alliance with the patient and promote patients’ self-management, self-efficacy and promote students’ possibility to integrate theoretical knowledge into practice. The result becomes an important input in the formulation of the assessment criteria for professional competence.
Auditing Standard Change and Auditors' Everyday Practice: A Field Study
Authors: De Santis Federica
Published: November 2016

The analysis of inertial phenomena in business context has been developed with reference to management and financial accounting (Hopwood, 1990; Hopwood and Miller, 1994). In the auditing field, however, only a few studies have attempted the inertial phenomenon (Salterio, 1996; Salterio & Koonce, 1997; O'Reilly, et al., 2004; Messier, et al., 2012). An opportunity to investigate more in depth the topic of auditing inertia is offered by the recent change of the auditing principles in Italy.

Stemming from the aforementioned consideration, this paper aims to analyze the phenomenon of auditing inertia making reference to a case of change in the auditing standards and procedures to which auditors refer to in performing audit works. In order to achieve this aim, a field study methodology was adopted.

The main findings are the following. First, it emerges that the reactions of the audit firms to the analyzed change of auditing standards are different. Second, the analyzed cases have shown that single auditors have undergone passively through the process of change. Third, the collected evidences also suggest some of the items that contribute to the adoption of an inertial behavior. Fourth, it emerges that the aim of the EU project, the harmonization and adaptability-flexibility of auditing procedures, is only partially achieved as sometimes occurs a substantial harmonization while in other cases it is only formal.
¿Qué ciencias se enseñan y cómo se hace en las aulas de educación infantil? La visión de los maestros en formación inicial
Authors: Cantó Doménech José , De Pro Bueno Antonio , Solbes Jordi
Published: November 2016

Los conocimientos científicos están presentes en los currículos de todos los niveles educativos. Sin embargo, son pocas las investigaciones orientadas a saber qué contenidos se enseñan, cómo lo hacen, qué aprende el alumnado… en la etapa de educación infantil. En este trabajo estudiamos la percepción que tienen los futuros maestros sobre la enseñanza de las ciencias que se realiza en las aulas de segundo ciclo de esta etapa. A partir de sus vivencias en las prácticas de enseñanza, unos estudiantes del Grado de Educación Infantil han respondido a un cuestionario elaborado para conocer mejor la realidad educativa que estamos estudiando. Los resultados ponen de manifiesto el escaso tratamiento de algunos contenidos y la ausencia de actividades claves para aprender ciencias en estas edades. Por último, se realizan algunas consideraciones en relación con la formación del profesorado, inicial y en ejercicio.
Significado escolar de las razones trigonométricas elementales
Authors: Martin Fernández Enrique , Ruiz Hidalgo Juan Francisco , Rico Luis
Published: November 2016

En este artículo presentamos algunos resultados de un estudio exploratorio relativo a los modos en que un grupo de estudiantes de bachillerato expresan e interpretan las nociones trigonométricas de seno y coseno. El objetivo de la investigación es indagar sobre las representaciones, conceptos, nociones y sentidos que los estudiantes emplean cuando se les pide describir o mostrar el seno y el coseno de un ángulo. El análisis realizado sobre las producciones de este grupo hace emerger una categorización de distintas respuestas, cuyas relaciones se discuten e interpretan. Los resultados muestran varios tipos de representaciones y sentidos, algunos ya reconocidos en otros estudios, junto con otros nuevos. La escasez de investigaciones relacionadas con el significado escolar de las nociones de seno y coseno aporta interés añadido a este estudio.
Ideas de los alumnos sobre radiactividad al finalizar la enseñanza secundaria obligatoria y su relación con los libros de texto y la prensa. Un estudio de caso
Authors: Corbelle Cao Javier , Domínguez Castiñeiras José Manuel
Published: November 2016

En el presente trabajo se exploran, mediante un cuestionario diseñado ad hoc, algunas de las ideas de una muestra de alumnos sobre radiactividad al finalizar su enseñanza obligatoria. Además, se estudia hasta qué punto dichas ideas se relacionan con el tratamiento que sobre este tema hacen los libros de texto y la prensa. Para ello, se revisan los contenidos sobre radiactividad en una muestra de libros de texto de 3.º de ESO y se analiza el tratamiento que estos conceptos recibieron en una muestra de prensa digital durante el accidente en la central nuclear de Fukushima.
Comprensión de los sistemas de numeración. Modelos y tareas
Authors: Ortiz Villarejo Antonio Luis , González Marí José Luis
Published: November 2016

En el presente artículo se exponen los aspectos fundamentales de un estudio realizado con alumnos del grado de Maestro de Educación Primaria, en el que se utiliza un modelo para la interpretación y valoración de la comprensión del conocimiento matemático de los sistemas de representación numérica. Los resultados ponen de manifiesto que los alumnos inician los estudios con un dominio meramente técnico, limitado y con lagunas de comprensión que mejoran significativamente a lo largo del proceso formativo.
Créditos vol. 34, n.3, noviembre 2016
Authors: Enseñanza de las Ciencias Revista
Published: November 2016

Créditos
A specific role for serotonin in overcoming effort cost
Authors: Meyniel Florent , Goodwin Guy M , Deakin JF William , Klinge Corinna , MacFadyen Christine , Milligan Holly , Mullings Emma , Pessiglione Mathias , Gaillard Raphaël
Published: November 2016

Serotonin is implicated in many aspects of behavioral regulation. Theoretical attempts to unify the multiple roles assigned to serotonin proposed that it regulates the impact of costs, such as delay or punishment, on action selection. Here, we show that serotonin also regulates other types of action costs such as effort. We compared behavioral performance in 58 healthy humans treated during 8 weeks with either placebo or the selective serotonin reuptake inhibitor escitalopram. The task involved trading handgrip force production against monetary benefits. Participants in the escitalopram group produced more effort and thereby achieved a higher payoff. Crucially, our computational analysis showed that this effect was underpinned by a specific reduction of effort cost, and not by any change in the weight of monetary incentives. This specific computational effect sheds new light on the physiological role of serotonin in behavioral regulation and on the clinical effect of drugs for depression.

Clinical trial Registration: ISRCTN75872983
Environmental, land cover and land use constraints on the distributional patterns of anurans:Leptodacylusspecies (Anura, Leptodactylidae) from Dry Chaco
Authors: Medina Regina Gabriela , Ponssa Maria Laura , Aráoz Ezequiel
Published: November 2016

Subtropical dry forests are among the most vulnerable biomes to land transformation at a global scale. Among them, the Dry Chaco suffers an accelerated change due to agriculture expansion and intensification. The Dry Chaco ecoregion is characterized by high levels of endemisms and species diversity, which are the result of a variety of climates and reliefs, allowing a wide variety of environments. The amphibian group exhibits a high richness in the Dry Chaco, which has been barely studied in relation to land cover changes. We used ecological niche models (ENMs) to assess the potential geographic distribution of 10Leptodactylusspecies (Anura, Leptodactylidae), which are mainly distributed within the Dry Chaco. We characterized these distributions environmentally, analyzed their overlap with land cover classes, and assessed their diversity of ecoregions. Also, we evaluated how these species potential distribution is affected by the transformation of land, and quantified the proportional area of the potential distribution in protected areas. We found that temperature seasonality is the main constraint to the occurrence of the species studied, whose main habitats are savannas, grasslands and croplands. The main threats to these species are the effects of climate change over spatial patterns of seasonality, which could affect their breeding and reproduction mode; the loss of their natural habitat; the exposure to contaminants used by intensive agriculture and their underrepresentation in protected areas.
Alterations to the middle cerebral artery of the hypertensive-arthritic rat model potentiates intracerebral hemorrhage
Authors: Randell Amy , Chokshi Killol , Kane Brittany , Chang Hilary , Naiel Safaa , Dickhout Jeffrey G. , Daneshtalab Noriko
Published: November 2016

Aims

We have recently created an age-dependent hypertensive-mono-arthritic animal model from the stroke-resistant spontaneously hypertensive rat to model populations with autoimmune disease who are hypertensive and are prone to stroke. The model exhibits signs of hemorrhagic stroke (HS) subsequent to chronic inflammation and hypertension. HS is also associated with the inability of middle cerebral arteries to undergo pressure dependent constriction (PDC). We investigated alterations in the cerebrovasculature of our hypertensive mono-arthritic animals that develop stroke.

Main Methods

Animals were fed either a high salt diet (HSD) (4% NaCl) or Purina chow (0.58% NaCl) from weaning. Complete Freund’s Adjuvant (CFA) was injected into the left hind paw at 21–28 weeks; controls received saline and histological and functional studies were performed.

Results

Brain damage was more prominent with the high salt, with inflammation exacerbating the damage. High salt alone significantly decreased middle cerebral artery’s (MCA’s) ability to undergo PDC. Inflammation significantly decreased the ability of cerebrovasculature to respond to pressure step in the regular salt diet. The responses to vasoactive peptides were also significantly attenuated in both inflamed groups regardless of diet.

Conclusion

Induction of chronic systemic inflammation increases brain damage, and affect the MCA’s vasogenic function, decreasing its ability to respond to intraluminal pressure. HSD further exacerbates organ damage associated with chronic inflammation, further compromising cerebrovascular function, and likely increasing the incidence of intracerebral hemorrhage and injury.
Foliar fungal communities strongly differ between habitat patches in a landscape mosaic
Authors: Fort Thomas , Robin Cécile , Capdevielle Xavier , Delière Laurent , Vacher Corinne
Published: November 2016

Background

Dispersal events between habitat patches in a landscape mosaic can structure ecological communities and influence the functioning of agrosystems. Here we investigated whether short-distance dispersal events between vineyard and forest patches shape foliar fungal communities. We hypothesized that these communities homogenize between habitats over the course of the growing season, particularly along habitat edges, because of aerial dispersal of spores.

Methods

We monitored the richness and composition of foliar and airborne fungal communities over the season, along transects perpendicular to edges between vineyard and forest patches, using Illumina sequencing of the Internal Transcribed Spacer 2 (ITS2) region.

Results

In contrast to our expectation, foliar fungal communities in vineyards and forest patches increasingly differentiate over the growing season, even along habitat edges. Moreover, the richness of foliar fungal communities in grapevine drastically decreased over the growing season, in contrast to that of forest trees. The composition of airborne communities did not differ between habitats. The composition of oak foliar fungal communities change between forest edge and centre.

Discussion

These results suggest that dispersal events between habitat patches are not major drivers of foliar fungal communities at the landscape scale. Selective pressures exerted in each habitat by the host plant, the microclimate and the agricultural practices play a greater role, and might account for the differentiation of foliar fugal communities between habitats.
Sevoflurane postconditioning attenuates cardiomyocyte hypoxia/reoxygenation injury via restoring mitochondrial morphology
Authors: Yu Jin , Wu Jianjiang , Xie Peng , Maimaitili Yiliyaer , Wang Jiang , Xia Zhengyuan , Gao Feng , Zhang Xing , Zheng Hong
Published: November 2016

Background

Anesthetic postconditioning is a cellular protective approach whereby exposure to a volatile anesthetic renders a tissue more resistant to subsequent ischemic/reperfusion event. Sevoflurane postconditioning (SPostC) has been shown to exert cardioprotection against ischemia/reperfusion injury, but the underlying mechanism is unclear. We hypothesized that SPostC protects cardiomyocytes against hypoxia/reoxygenation (H/R) injury by maintaining/restoring mitochondrial morphological integrity, a critical determinant of cell fate.

Methods

Primary cultures of neonatal rat cardiomyocytes (NCMs) were subjected to H/R injury (3 h of hypoxia followed by 3 h reoxygenation). Intervention with SPostC (2.4% sevoflurane) was administered for 15 min upon the onset of reoxygenation. Cell viability, Lactate dehydrogenase (LDH) level, cell death, mitochondrial morphology, mitochondrial membrane potential and mitochondrial permeability transition pore (mPTP) opening were assessed after intervention. Mitochondrial fusion and fission regulating proteins (Drp1, Fis1, Mfn1, Mfn2 and Opa1) were assessed by immunofluorescence staining and western blotting was performed to determine the level of protein expression.

Results

Cardiomyocyte H/R injury resulted in significant increases in LDH release and cell death that were concomitant with reduced cell viability and reduced mitochondrial interconnectivity (mean area/perimeter ratio) and mitochondrial elongation, and with reduced mitochondrial membrane potential and increased mPTP opening. All the above changes were significantly attenuated by SPostC. Furthermore, H/R resulted in significant reductions in mitochondrial fusion proteins Mfn1, Mfn2 and Opa1 and significant enhancement of fission proteins Drp1 and Fis1. SPostC significantly enhanced Mfn2 and Opa1 and reduced Drp1, without significant impact on Mfn1 and Fis1.

Conclusions

Sevoflurane postconditioning attenuates cardiomyocytes hypoxia/reoxygenation injury (HRI) by restoring mitochondrial fusion/fission balance and morphology.
Rheum for Improvement? Delayed Diagnosis of Juvenile Idiopathic Arthritis: A Narrative Review
Authors: Costello Anna , Rasooly Irit , Weiss Pamela
Published: September 2024

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease of childhood and a disease for which we have safe and effective therapies. Early diagnosis of JIA enables timely initiation of therapy and improves long‐term disease outcomes. However, many patients with JIA experience prolonged diagnostic delays and have a turbulent course to diagnosis. In this narrative review, we explore the importance of early diagnosis in JIA, what is known about time to diagnosis and diagnostic trajectory, and factors that contribute to delayed diagnosis. We also discuss next steps to improve time to diagnosis for these vulnerable patients.
Inter‐Ion Mutual Repulsion Control for Nonvolatile Artificial Synapse
Authors: Lee Donghwa , Kim Minhui , Park Seonhye , Lee Seonggyu , Sung Junho , Kim Seokkyu , Kang Joonhee , Lee Eunho
Published: September 2024

Organic electrochemical transistors (OECTs) are promising candidates for artificial synapses to achieve high‐performance synaptic characteristics. While most research has focused on modifying the properties of organic semiconductors for efficient ion doping, there is a lack of systematic investigation into the relationship between ion‐mediated mechanisms and synaptic performance. In this study, an effective strategy for enhancing electrochemical doping and de‐doping by utilizing different coulombic anions is proposed. The findings reveal that doped ions in the channel layer affect inter‐ion interactions, influencing the non‐volatile effects by improving the doping performance of the synaptic device. Moreover, electrochemical analysis indicates that ions in the channel layer are sequentially de‐doped, enabling high linearity and symmetry. The fabricated devices demonstrate high‐performance synaptic properties including a retention time of ≈102 s with ≈50% retention over peak current and near‐ideal long‐term potentiation/long‐term depression (LTP/LTD) through effective electrochemical doping and de‐doping. These results show that controlling both the properties of organic semiconductors and ion interactions in the electrolyte is crucial for OECTs, opening up various applications for neuromorphic computing.
Reconfiguring Zn2+ Solvation Network and Interfacial Chemistry of Zn Metal Anode with Molecular Engineered Crown Ether Additive
Authors: Han Ruifeng , Jiang Tao , Wang Zhiqiao , Xue Rongrong , Liu Xinhao , Tang Yinwen , Qi Zhenhui , Ma Yue
Published: September 2024

The practical deployment of rechargeable aqueous zinc‐ion batteries (RAZBs) in the scaled power system suffers from unregulated Zn dendrite growth as well as parasitic reactions at the zinc foil/aqueous electrolyte interface, leading to insufficient zinc utilization and severe electrode corrosion. Herein, a novel crown ether additive is developed, with tailored molecular engineering, to stepwise regulate the Zn2+ solvation network and interfacial chemistry of Zn metal anode. The designed crown ether (C5SeCN), featuring zincophilic cyano group and hydrophobic selenium, efficiently reconstructs the solvation sheath of Zn ions at the 0.3 wt.% dose amount. Additionally, the ozone plasma treatment tethers the O2‐ groups onto the thin‐layer zinc foil, which thus binds Se atoms of the C5SeCN to the Zn anode. The Zn||Zn symmetric cells exhibit a lifespan of over 4500 h at 1 mA cm−2 and high current density endurance of up to 10 mA cm−2. Moreover, the 2 mAh cm−2 Zn||V2O5 full cell model, at the low N/P ratio of 2.8 with a lean electrolyte (E/C ratio = 10 µL mAh−1), enables robust cycling endurance at 2 A g⁻¹ for 300 cycles. This study unravels the interfacial design rationales for maximizing zinc utilization and highlights the commercial potential of crown ether additives for RAZBs development.
Electrochemical Engineering of Anode with Zincophilic Polymer Interface for Reversible Zinc Battery
Authors: Paswan Akash Mukhraj , Thakur Vikas Singh , Banerjee Swastika , Raj C. Retna
Published: September 2024

Aqueous rechargeable zinc‐ion batteries are emerging as green and safe energy devices owing to their high energy density and eco‐friendliness. The bottleneck is the inhomogeneous nucleation resulting in the growth of Zn dendrites and the parasitic side reactions at the anode. Herein, an electrochemical anode engineering strategy is demonstrated to curb the uncontrolled dendritic growth and side reactions. It involves the in situ generation of a solid‐electrolyte interface based on a Zn nanoparticle‐embedded poly(acrylic acid) hybrid layer (PAA‐nZn) on the anode. The homogeneously distributed polar functionalities and porous nature of the polymer regulate the uniform zinc ion flux, and the embedded zinc particle serves as nucleation sites for zinc plating. The hybrid layer reduces the nucleation overpotential and promotes instantaneous nucleation. The symmetrical cell made with PAA‐nZn@Zn has a lifecycle of >860 h with a voltage gap of 28 mV. The full cell fabricated by pairing the engineered anode with α‐MnO2 cathode showed a high discharge specific capacity of 238.3 mAh g−1 at 0.2 A g−1 with a capacity retention of 81.76% after 200 cycles and a long lifecycle. The electrochemical engineering of the anode suppresses the dendritic growth and protects the anode from unwanted side reactions and passivation.
Extracellular Vesicles Derived from Ligament Tissue Transport Interleukin‐17A to Mediate Ligament‐To‐Bone Crosstalk in Ankylosing Spondylitis
Authors: Wang Kaiyang , Lu Jingshun , Song Chenyu , Qiao Mu , Li Yao , Chang Menghan , Bao Hongda , Qiu Yong , Qian Bang‐Ping
Published: September 2024

Pathological new bone formation is a critical feature of the progression of ankylosing spondylitis (AS), and spine ankylosis is a distinctive feature of this condition. Ligaments are the primary regions of pathological new bone formation in AS. Here, it is demonstrated that ligament tissue‐derived extracellular vesicles (EVs) and their interleukin‐17A (IL‐17A) cargo mediate the communication between the tissue and other cells. The investigation revealed that IL‐17A in EVs can activate the JAK‐STAT3 pathway, thereby stimulating the expression of MMP14 in AS ligament. Overexpression of MMP14 can lead to changes in the cytoskeleton and mechanical signaling of mesenchymal stem cells and other cells. These alterations in cellular cytoskeleton and mechanical signaling at ligament sites in patients with AS or in stem cells treated with EVs can result in pathological new bone formation. Finally, inhibiting IL‐17A activity and EV endocytosis effectively controlled inflammation and pathological new bone formation. Overall, these data suggest that ligament‐derived EVs and the enclosed IL‐17A have a potential role in driving pathological new bone formation in AS, and targeting EVs may therefore emerge as a novel approach to delaying ectopic ossification in AS.
Dual Ionic Pathways in Semi‐Solid Electrolyte based on Binary Metal–Organic Frameworks Enable Stable Operation of Li‐Metal Batteries at Extremely High Temperatures
Authors: Nguyen Minh Hai , Ngo Nhat Minh , Kim Byung‐Kook , Park Sangbaek
Published: September 2024

The rapid development of the electronics market necessitates energy storage devices characterized by high energy density and capacity, alongside the ability to maintain stable and safe operation under harsh conditions, particularly elevated temperatures. In this study, a semi‐solid‐state electrolyte (SSSE) for Li‐metal batteries (LMB) is synthesized by integrating metal–organic frameworks (MOFs) as host materials featuring a hierarchical pore structure. A trace amount of liquid electrolyte (LE) is entrapped within these pores through electrochemical activation. These findings demonstrate that this structure exhibits outstanding properties, including remarkably high thermal stability, an extended electrochemical window (5.25 V vs Li/Li+), and robust lithium‐ion conductivity (2.04 × 10−4 S cm−1), owing to the synergistic effect of the hierarchical MOF pores facilitating the storage and transport of Li ions. The Li//LiFePO4 cell incorporating prepared SSSE shows excellent capacity retention, retaining 97% (162.8 mAh g−1) of their initial capacity after 100 cycles at 1 C rate at an extremely high temperature of 95 °C. It is believed that this study not only advances the understanding of ion transport in MOF‐based SSSE but also significantly contributes to the development of LMB capable of stable and safe operation even under extremely high temperatures.
Temporal trend and attributable risk factors of Alzheimer's disease and other dementias burden in China: Findings from the Global Burden of Disease Study 2021
Authors: Yang Kun , Yang Xuan , Yin Peng , Zhou Maigeng , Tang Yi
Published: September 2024

INTRODUCTION

We examined the burden of Alzheimer's disease and other dementias (ADOD) and attributable factors at the national and provincial levels in China.

METHODS

Using the Global Burden of Diseases Study 2021, we estimated incidence, prevalence, mortality rate, disability‐adjusted life years (DALYs), and the ratio of years lived with disability (YLD) to DALYs for ADOD in China. Estimated annual percentage changes (EAPCs) were used to quantify the temporal trends from 1990 to 2021.

RESULTS

In 2021, China experienced the highest ADOD burden among Group of 20 member nations. The EAPCs for age‐standardized rates for incidence, age‐standardized rates for prevalence, and age‐standardized mortality rate were 0.41 (uncertainty intervals [UIs] 0.34–0.49); 0.44 (UI: 0.36–0.52); and –0.19 (UI: ‐0.23 to ‐0.15), respectively. Between 1990 and 2021, the number of people with ADOD increased by 322.18% and DALYs associated with ADOD increased by 272.71%; most of these increases were explained by population aging.

DISCUSSION

Considering the aging Chinese population, targeted strategies to prevent dementia are urgently needed.

Highlights

China experienced the highest dementia burden among Group of 20 member nations.

High body mass index, high fasting plasma glucose, and smoking were major risk factors for Alzheimer's disease and other dementias (ADOD) burden.

Since 1990, the incidence and prevalence of ADOD increased substantially in China.

The mortality rate related to ADOD decreased consistently.

Considering the aging Chinese population, targeted strategies are urgently needed.