bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodeterioration of Classroom Wall Surfaces in the University of Port Harcourt, Nigeria
Authors: Anele B. C. , Okerentugba P. O. , Stanley H. O. , Ugboma C. J. 
Published: March 2019

Aim: This study investigated the biodeterioration of classroom wall surfaces in the University of Port Harcourt, Nigeria.
Study Design: Scrapings from selected classroom wall surfaces were analyzed for their microbiological and physicochemical parameters. Isolated bacteria were screened for their antibiotics susceptibility.
Place and Duration of Study: This study was carried out at the University of Port Harcourt between March - June 2018.
Methods: The population of culturable bacterial and fungal biodeteriogens was determined by plating. Physicochemical parameters were determined using standard methods. Antibiotic susceptibility pattern of the bacterial isolates was determined using the disc diffusion method.
Results: The total culturable heterotrophic bacterial counts ranged from 6.48 to 8.23 log CFU/g while the total fungal counts ranged from 5.00 to 7.28 log CFU/g. The bacterial isolates identified by biochemical characterization and their frequency of occurrence are Micrococcus spp. (7.3%), Citrobacter spp. (3.2%), Bacillus spp. (39.1%), Serratia spp. (3.2%), Corynebacterium spp. (10.9%), Staphylococcus aureus (20.1%), Proteus spp. (9.2%) and Shigella spp (7.0%). The fungal isolates and their frequency of occurrence are Aspergillus flavus (39.1%), Penicillium spp. (20.1%), Microsporium canis (14.3%), Coccidioides spp. (10.9%), Aspergillus fumigates (3.2%) and Tricophyton spp (3.2%). All antibiotics used showed activity against all bacterial isolates except Proteus spp. From the results of the physicochemical parameters, pH values ranged from 6.15 to 9.01, nitrate ranged from 5.30 to 14.83 mg/kg, phosphate ranged 2.19 to 5.94 mg/kg, sulphate ranged from 12.97 to 19.07 mg/kg and Total Organic Carbon ranged from 74.89 to 119.43 mg/kg.
Conclusions: This study has shown the potential public health risk associated with classroom building deterioration owing to the presence of pathogenic microorganisms. Therefore, measures towards prevention and mitigation of classroom building biodeterioration should be in place.
Accuracy of Demirjian’s Method to Estimate Chronological Age in 5‒17-Year-Old Iranian Population
Authors: Sheikhi Mahnaz , Dakhilalian Ali , Jalalian Faranak 
Published: March 2019

Introduction: To detect physiological maturity of a child, use of dental and skeletal development can be helpful. The Demirjian’s Method is one of the commonly used methods to estimate dental age. The aim of the present study was to evaluate the validity of Demirjian method in Iranian population with different races.
Materials and Methods: The present cross-sectional study was performed on a randomly selected sample of panoramic radiographs of 3073 patients aged 5‒17 years. The chronological age (CA) was calculated by subtracting the date of birth from the date on which the radiographs were taken. Estimated age (EA) was performed by Demirjian method using seven left mandibular teeth. Paired t-test was used to compare differences between chronological and estimated age.
Results: The mean of CA was 11.14±2.61 years whereas the mean EA was 11.35±2.62; therefore, EA was calculated 2.5 months more than CA. According to paired t-test the difference between CA & EA was significant (P≤ 0.001). Pearson’s correlation coefficient showed a strong linear correlation between CA and EA in total (r=0.891, P≤0.001), in girls (r=0.895, P≤ 0.001) and in boys (r=0.876, P≤ 0.001). The new regression line equation based on Iranian standards would be CA=1.08±0.89EA in total, CA=1.09±0.89EA in girls and CA=1.12+0.88EA in boys.
Conclusion: Using Demirjian’s Method overestimated dental age in the Iranian population. A new regression line equation based on Iranian standards was obtained according to the results of the present study.
Challenges of the Teaching Profession: Student Teacher Wiev of the Status of Teachers in the Society and Their Own Engagement with Their Future Profession
Authors: Lazzarich Marinko 
Published: March 2019

Some people view teaching as a mission, many others consider it as just another job. Teaching profession is publicly perceived as socially valuable and important, a job essential for the development of fundamental societal and human values. However, in 2019 Croatia, one still cannot speak of teaching as a profession. The public perceives teacher's expected high level of enthusiasm as a basic quality of an educator, rather than expecting a high degree of professionalism. Consequently, unlike education policies in some European countries, the historical development of the upgrade to the teaching profession in Croatia is somewhat lagging behind.
The text analyses the status of teachers and the acceptance of the educational profession in Croatia as well as the working conditions in the Croatian education. We present research results of attitudes towards the teaching profession and the social status of teachers expressed by students enrolled in the Faculty of Teacher Education, University of Rijeka. The main objective of the research was to determine the attitudes of students on the current status of teachers in Croatia, concurrently examining the level of their readiness to actively engage in achieving better social and material status of teachers. The research was conducted in 2018 using the survey method. The results confirmed that the respondents possess developed awareness of the deficiencies in the Croatian school system and the underpaid teaching staff. Aware of the basic weaknesses in the education policy, respondents expressed their willingness to engage in solving these problems. The results also clearly pointed to the need for an essential educational reform to improve the status of the teaching staff.
Comparison and Evaluation of Seven Animal Models of Ischemic Skin Wound: A Review Article
Authors: Bayat Mohammad , Chien Sufan 
Published: March 2019

Focusing on pathophysiology, prevention, and treatment of ischemic wounds is apriority for medical and basic scientists in order to develop new clinical approaches. However it is not always easy for researchers to choose optimal animal models for their particular assessments. This review provides concise information on all currently available ischemic animal models, including rabbits’ ear ischemic models, axial skin flaps (axial pattern flaps), burns, ischemic limbs, localized ischemic wounds, pressure ulcers, and skin flaps, along with their citations as a measure of their acceptance among other researchers. We searched the numerous databases consisting of PubMed, Scopus, Science Direct, and Google Scholar. Key words included ischemic wound, skin, and animals alone or in combination. Some important features of the seven types of ischemia as well as their results are presented in Tables 1 -7. Table eight presents the results of entire groups of ischemic animal models, with their number of papers, number of wounds, and total and average Google Scholar citations, and web of science citations. We found that rabbits’ ear ischemic models, localized ischemic wounds, and pressure ulcers have the highest total and average citations amongst the studied groups. It was concluded that the rabbits’ ear ischemic model, rat pressure ulcer models, and localized ischemic wound models, have made the greatest contribution to our understanding of the pathophysiology of the ischemic wounds and increased production of new therapeutic protocols based on the citations reported by Google scholar and the web of science databases between 1977 and 2017.
Salivary Alpha-amylase Activity Level in ST-segment Elevation Myocardial Infarction Patients
Authors: Kakhki Behrang Rezvani , Salarirad Mohsen , Shamsian Seyed Ali Akbar , Ramezani Javad , Moradi Elnaz Vafadar , Mousavi Seyed Mohammad , Hashemian Amir Masoud 
Published: March 2019

Background and Objective: Sudden death is the main cause of mortality and disability in patients with coronary artery disease or myocardial infarction. The aim of this study was to evaluate the activity level of salivary alpha-amylase to predict malignant ventricular arrhythmias in ST-segment elevation myocardial infarction (STEMI) patients.
Materials and Methods: In this analytical cross-sectional study, 42 patients with STEMI who referred to Imam Reza Hospital participated. First, salivary amylase was taken from all STEMI patients and then these patients were divided into two groups of patients with malignant ventricular arrhythmia or without malignant ventricular arrhythmia during 72 hours.
Results: A total of 42 patients were included in the study out of which 30 (71.4%) were females and 12 (28.6%) males. The average salivary amylase in patients was 118/41 ± 96/87. There was no significant difference in the frequency of diabetes, blood pressure, blood lipids, ischemic heart disease, and involvement severity in both groups with arrhythmia and lack of arrhythmias (P> 0.05). Also there was no significant difference in systolic and diastolic blood pressure, respiratory rate, heart rate, oxygen saturation, blood glucose, temperature and severity of infarction (P> 0.05). However, the two groups were different in terms of salivary amylase levels. Salivary amylase levels were significantly higher in arrhythmic group than in the non-arrhythmic group (P< 0.001).
Conclusions: Our result shows that there is a difference in the concentrations of salivary Alpha-amylase activity level in with and without ventricular arrhythmias groups.
Tuning Thermal Transport Through Atomically Thin Ti3C2Tz MXene by Current Annealing in Vacuum
Authors: Hemmat Zahra , Yasaei Poya , Schultz Jeremy F. , Hong Liang , Majidi Leily , Behranginia Amirhossein , Verger Louisiane , Jiang Nan , Barsoum Michel W. , Klie Robert F. , Salehi‐Khojin Amin 
Published: March 2019

AbstractHeat transport across vertical interfaces of heterogeneous 2D materials is usually governed by the weak Van der Waals interactions of the surface‐terminating atoms. Such interactions play a significant role in thermal transport across transition metal carbide and nitride (MXene) atomic layers due to their hydrophilic nature and variations in surface terminations. Here, the metallicity of atomically thin Ti3C2Tz MXene, which is also verified by scanning tunneling spectroscopy for the first time, is exploited to develop a self‐heating/self‐sensing platform to carry out direct‐current annealing experiments in high (<10−8 bar) vacuum, while simultaneously evaluating the interfacial heat transport across a Ti3C2Tz/SiO2 interface. At room temperature, the thermal boundary conductance (TBC) of this interface is found, on average, to increase from 10 to 27 MW m−2 K−1 upon current annealing up to the breakdown limit. In situ heating X‐ray diffraction and X‐ray photo‐electron spectroscopy reveal that the TBC values are mainly affected by interlayer and interface spacing due to the removal of absorbents, while the effect of surface termination is negligible. This study provides key insights into understanding energy transport in MXene nanostructures and other 2D material systems.
Droplet Microfluidics XRD Identifies Effective Nucleating Agents for Calcium Carbonate
Authors: Levenstein Mark A. , Anduix‐Canto Clara , Kim Yi‐Yeoun , Holden Mark A. , González Niño Carlos , Green David C. , Foster Stephanie E. , Kulak Alexander N. , Govada Lata , Chayen Naomi E. , Day Sarah J. , Tang Chiu C. , Weinhausen Britta , Burghammer Manfred , Kapur Nikil , Meldrum Fiona C. 
Published: March 2019

AbstractThe ability to control crystallization reactions is required in a vast range of processes including the production of functional inorganic materials and pharmaceuticals and the prevention of scale. However, it is currently limited by a lack of understanding of the mechanisms underlying crystal nucleation and growth. To address this challenge, it is necessary to carry out crystallization reactions in well‐defined environments, and ideally to perform in situ measurements. Here, a versatile microfluidic synchrotron‐based technique is presented to meet these demands. Droplet microfluidic‐coupled X‐ray diffraction (DMC‐XRD) enables the collection of time‐resolved, serial diffraction patterns from a stream of flowing droplets containing growing crystals. The droplets offer reproducible reaction environments, and radiation damage is effectively eliminated by the short residence time of each droplet in the beam. DMC‐XRD is then used to identify effective particulate nucleating agents for calcium carbonate and to study their influence on the crystallization pathway. Bioactive glasses and a model material for mineral dust are shown to significantly lower the induction time, highlighting the importance of both surface chemistry and topography on the nucleating efficiency of a surface. This technology is also extremely versatile, and could be used to study dynamic reactions with a wide range of synchrotron‐based techniques.
Versatile Crystal Structures and (Opto)electronic Applications of the 2D Metal Mono‐, Di‐, and Tri‐Chalcogenide Nanosheets
Authors: Cui Yu , Zhou Ziqi , Li Tao , Wang Kaiyou , Li Jingbo , Wei Zhongming 
Published: March 2019

AbstractEmerging 2D metal chalcogenides present excellent performance for electronic and optoelectronic applications. In contrast to graphene and other 2D materials, 2D metal chalcogenides possess intrinsic bandgaps, versatile band structures, and superior atmospheric stability. The many categories of 2D metal chalcogenides ensure that they can be applied to various practical scenarios. 2D metal monochalcogenides, dichalcogenides, and trichalcogenides are the three main categories of these materials. They have distinct crystal structures resulting in different characteristics. Some basic device characteristics, such as the charge carrier characteristics, scattering mechanisms, interfacial contacts, and band alignments of heterojunctions, are vital factors for practical device applications that ensure that the desired properties can be achieved. Various electronic, optoelectronic, and photonic applications based on 2D metal chalcogenides have been extensively investigated. 2D metal chalcogenides are considered as competitive candidates for future electronic and optoelectronic applications.
Nanoimprinted Grating‐Embedded Perovskite Solar Cells with Improved Light Management
Authors: Deng Kaimo , Liu Zhongze , Wang Min , Li Liang 
Published: March 2019

AbstractOrganic–inorganic halide perovskite solar cells are one of the most efficient photovoltaic devices, and their power conversion efficiency (PCE) continues to grow rapidly due to the optimization of device architecture and functional materials. The involved optical design has an important impact on performance by affecting the light harvesting capability. Here, demonstrated is a simple and effective strategy to boost device performance from the perspective of light management. A diffraction grating pattern into the TiO2 scaffold and antireflection layer is simultaneously introduced to construct a double grating design for perovskite solar cells. The grating pattern obtained using a commercial compact disk as the hard mold can modulate light transport by enhancing the light transmittance and, thus, light absorption in perovskite solar cells. The grating pattern‐induced light trapping can significantly increase the short‐circuit current density and PCE by 4.8% and 7.9%, respectively, on average. The present work develops a feasible method by tailoring the morphology‐related optical property to further improve the performance of perovskite solar cells. The double grating design can also generate structural color and can provide an alternative solution for fabricating colorful solar cells.
Enhanced Photoresponsivity of Multilayer MoS2 Phototransistor Using Localized Au Schottky Junction Formed by Spherical‐Lens Photolithography
Authors: Lee Sanghyun , Park Jinwoo , Yun Yeojun , Lee Jaejin , Heo Junseok 
Published: March 2019

AbstractThe photoresponsivity of a MoS2 phototransistor is limited owing to its low light absorption. Many studies aiming to improve the photoresponsivity have enhanced the light absorption in MoS2 by optical resonance or by integrating an absorbing layer. However, the light‐absorbing overlayer changes the spectral photoresponsivity and forms a leakage path. In this study, an enhanced photoresponsivity of a multilayer MoS2 phototransistor is obtained by localized Au/MoS2 Schottky junctions without light‐absorbing overlayer. Au disks are formed on the MoS2 surface using a simple spherical‐lens photolithography technique, forming localized Schottky junctions between MoS2 and Au disks. Photogenerated holes drift to the interface due to the built‐in electric field around the Schottky junction and are trapped in the interface states between MoS2 and Au disks. The holes captured in the states lead to photogain. Consequently, after the patterning of the Au disks, the photoresponsivity is enhanced 8.2 times while maintaining other electrical properties. The findings obtained in this study are very valuable as the photoresponsivity enhancement is achieved using the simple method with a minimal damage to MoS2. The multilayer MoS2 phototransistor with Au disks is promising for applications in next‐generation optoelectronics with photodetector devices.
Multifunctional Metasurfaces Based on Direct Nanoimprint of Titania Sol–Gel Coatings
Authors: Checcucci Simona , Bottein Thomas , Gurioli Massimo , Favre Luc , Grosso David , Abbarchi Marco 
Published: March 2019

AbstractDielectric Mie resonators are taking momentum in the last years thanks to their peculiar properties in light management at visible and near‐infrared frequencies. However, their full exploitation demands for cheap materials and versatile fabrication methods, extendible over large surfaces and potentially C‐MOS compatible. Here, a sol–gel deposition and nanoimprint lithography method is used to obtain titania‐based Mie resonators over large areas (several square millimeters), showing that this platform can potentially be exploited for light management with different devices. First, their use for structural colors and efficient band pass filters covering the visible spectrum is demonstrated. Then, exploiting sharp Fano resonances in reflection, their potential for refractive index sensing is addressed obtaining a figure of merit of ≈20. Finally, when placing the resonators on porous silica, a large and reversible color tuning can be produced as a result of water adsorption within the substrate porosity. These results open the path to titania sub‐micrometric structures for applications as a multifunctional metamaterial for smart windows, displays, and all‐optical sensing.
Development of VO2‐Nanoparticle‐Based Metal–Insulator Transition Electronic Ink
Authors: Vaseem Mohammad , Zhen Su , Yang Shuai , Li Weiwei , Shamim Atif 
Published: March 2019

AbstractThe metal–insulator transition (MIT) phase change of vanadium dioxide (VO2) materials has facilitated many exciting applications. Among the various crystal phases of VO2, the monoclinic (M) phase is the only one that demonstrates low‐temperature (≈68 °C) MIT behavior. However, the synthesis of pure VO2 (M) is challenging because various polymorphs, such as VO2 (A), VO2 (B), and VO2 (D), are also typically formed during the process. Furthermore, to achieve pure crystalline VO2 (M) phase, very long reaction times, up to 2–4 days, are typically required. In this work, an additional annealing step is introduced post nanoparticle preparation, which not only reduces the complete synthesis time from days to only 6 h but also removes the impure phases and helps in achieving the desired pure VO2 (M) phase. This work covers the complete synthesis and characterization details of such as‐prepared nanoparticles. A VO2 (M)‐nanoparticle‐based ink is formulated for the inkjet printing of films with controlled thicknesses. The inkjet‐printed films are investigated for their electrical conductivity with external stimuli such as temperature and electrical current. Finally, a fully printed antenna is devised that can change its frequency based on the different states of the VO2 film.
Sexual dimorphism of dental tissues in modern human mandibular molars
Authors: Sorenti Mark , Martinón‐Torres María , Martín‐Francés Laura , Perea‐Pérez Bernardo 
Published: March 2019

AbstractObjectivesPrevious studies have revealed that human permanent dental tissue proportions differ significantly between males and females, with females having relatively thicker enamel relative to overall crown area than males. The aims of this study are to investigate sexual dimorphism in permanent mandibular molars and to determine whether such differences can be used to estimate sex in modern humans reliably.Materials and MethodsThe permanent mandibular molars used in this study (n = 51) originate from 36 individuals of known sex from a Spanish anthropological collection. Eight variables were assessed from two‐dimensional (2D) mesial planes of section obtained from microtomographic scans. Binary stepwise logistic regression was then applied to the data.ResultsMale molars possess significantly greater quantities of dentine than females, both absolutely and proportionally. Females differed significantly from males by having greater relative enamel thickness. Logistic regression identified the proportion of dentine (relative dentine area [RDA]) as the most important sex discriminator, which can be used to correctly classify specimens with an overall accuracy rate of 74.36%.DiscussionThese results confirm that sexual dimorphism in mandibular molar size is a result of males having a greater amount of dentine, both absolutely and proportionally. The findings suggest that 2D measurements of RDA may be useful for sex determination, although further research is required to test the reliability of these predictive techniques across different populations.
Nonlinear Optical Switching in Regioregular Porphyrin Covalent Organic Frameworks
Authors: Biswal Bishnu P. , Valligatla Sreeramulu , Wang Mingchao , Banerjee Tanmay , Saad Nabil A. , Mariserla Bala Murali Krishna , Chandrasekhar Naisa , Becker Daniel , Addicoat Matthew , Senkovska Irena , Berger Reinhard , Rao D. Narayana , Kaskel Stefan , Feng Xinliang 
Published: March 2019

AbstractCovalent organic frameworks (COFs) have garnered immense scientific interest among porous materials because of their structural tunability and diverse properties. However, the response of such materials toward laser‐induced nonlinear optical (NLO) applications is hardly understood and demands prompt attention. Three novel regioregular porphyrin (Por)‐based porous COFs—Por‐COF‐HH and its dual metalated congeners Por‐COF‐ZnCu and Por‐COF‐ZnNi—have been prepared and present excellent NLO properties. Notably, intensity‐dependent NLO switching behavior was observed for these Por‐COFs, which is highly desirable for optical switching and optical limiting devices. Moreover, the efficient π‐conjugation and charge‐transfer transition in ZnCu‐Por‐COF enabled a high nonlinear absorption coefficient (β=4470 cm/GW) and figure of merit (FOM=σ1/σo, 3565) value compared to other state‐of‐the‐art materials, including molecular porphyrins (β≈100–400 cm/GW), metal–organic frameworks (MOFs; β≈0.3–0.5 cm/GW), and graphene (β=900 cm/GW).