bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytolith Analysis
Authors: Shillito Lisa‐Marie
Published: December 2018

Phytolith analysis is a technique that can be classified as paleoethnobotany, in that it refers to a type of plant microfossil, and also as geoarchaeology, as the microfossils are biogenic minerals that are often analyzed in association with specific sedimentary analyses. The advantages compared to other types of plant remains are the wide range of environments in which phytoliths are preserved, and the ability to distinguish between different parts of plants. Phytoliths have been utilized for a wide range of research areas in archaeology, including studies of diet, agriculture, fuel use, examination of architectural and craft activities, and detection of activity areas.
Plurality and Multivocality
Authors: Smith Rhianedd
Published: December 2018

Multivocality and pluralism are concepts that attempt to democratize the archaeological research process so as to include a variety of different stakeholders. Debates regarding power and voice in archaeology stem from feminist, postprocessual, and civil rights activist critiques of the discipline. Multivocal research should infuse collaboration into all stages of the research process, from question formation to dissemination. Research should be reflexive, and may challenge archaeologists to relinquish power or accept the legitimacy of alternative viewpoints and systems of knowledge. There is no rulebook for multivocal research, but open dialogue and critical reflection are key. Case studies such as that of Çatalhöyük highlight the challenges of employing these methods in practice. Critics of multivocal and pluralistic methods have noted the danger of glossing over or failing to address unequal power relations, or empowering those who might wish to oppress.
Polymers in Conservation
Authors: McGlinchey Chris
Published: December 2018

The use of polymers in the treatment of art and artifacts by trained conservators is described and classified in this entry. Key constraints that make a polymer suitable for conservation applications include solubility in solvents that do not harm the object and ideally possessing long‐term archival stability. Removability or retreatability helps determine more precisely which specific material may be optimal for a given application, yet there remain objects that are difficult to treat with the current roster of products in use.
Human Populations
Authors: Chamberlain Andrew T.
Published: December 2018

Populations are groups of individuals defined biologically by their mating preferences and culturally by their shared language, social behavior, and historical experience. Key population processes such as birth, death, and migration are responsible for population structure and dynamics (change through time). Modern and historical populations often have documentation of their life histories and such data can be investigated mathematically using conventional demographic methods, but ancient and prehistoric populations may require investigators to explore the use of proxy measures of human activity such as the frequency of artifacts, residues of resource usage, and temporal distributions of radiocarbon dates. Uniformitarian arguments can be used to justify some assumptions about the properties of ancient populations based on historical records. Genetic evidence from both modern and ancient DNA sequences can provide important information about past population events such as population expansions and large‐scale migration.
Preventive Conservation in Archaeological Sites
Authors: Henderson Jane , Lingle Ashley M.
Published: December 2018

Preventive conservation at archaeological sites includes a broad range of measures, aimed at passively mitigating deterioration. Measures such as defining significance, risk management, documentation, understanding the depositional environment and monitoring changes, the use of covers and shelters, emergency preparedness, and site management are briefly discussed. Incorporating preventative measures in a collaborative multidisciplinary approach creates the foundation for extending the useable life of a site and its values.
Principal Component Analysis
Authors: VanDerwarker Amber M. , Marcoux Jon B.
Published: December 2018

Principal component analysis (PCA) is one of a number of exploratory statistical techniques that can be employed to recognize, interpret, and present patterns in multivariate datasets. This technique is ideal for exploring continuous measurement‐based data associated with artifact morphology, elemental composition, and spatiotemporal contexts, particularly with the use of large datasets. Using published archaeological case studies, this entry outlines the procedure for conducting a PCA, while also defining relevant concepts and terms.
Quantification and Social Life
Authors: Aldenderfer Mark
Published: December 2018

Quantification has been fundamental to archaeology since its origins. In its simplest operation—counting—quantification allows us to compare and contrast, through time and across space, the numbers and proportions of the materials we encounter in our excavations. To ask more complex questions of these counted data in order to interpret or test hypotheses about the lives of people in the past, we must, however, create robust quantitative idioms that carefully link data, method, and theory to the social phenomena we seek to understand.
Radar
Authors: Safi Kristin N.
Published: December 2018

Radio detection and ranging (RADAR) has benefitted archaeological research since the 1970s. Two types of RADAR—synthetic aperture radar (SAR) and ground‐penetrating radar (GPR)—are particularly useful for archaeological practice. These active remote‐sensing techniques use generated radio waves to detect and map features and surfaces based on the amplitude and two‐way travel time of energy from a transmitting antenna to a receiving antenna. SAR provides an aerial or satellite view of archaeological landscapes and is useful for site detection, settlement mapping, and the construction of digital elevation models across large regions of interest. GPR surveys generate a volumetric understanding of subsurface features and surfaces across a wide variety of archaeological contexts. Innovations in technology and processing techniques since the turn of this century have increased the range of environmental and cultural settings in which radar can be applied within archaeological research.
Radiation Exposure and Dating
Authors: Bourlès Didier L.
Published: December 2018

Produced in the terrestrial environment during nuclear reactions between primary and secondary energetic cosmic‐ray particles and the atoms of the Earth's environment, cosmogenic radionuclides such as beryllium‐10 (
10
Be, T
½
∼ 1.4 Ma), aluminum‐26 (
26
Al, T
½
∼ 0.7 Ma), and chlorine‐36 (
36
Cl, T
½
∼ 0.3 Ma) enable use of the fraction produced in the atmosphere to date possibly over the last 10 Ma the sedimentary deposits in which they have accumulated over the last 10 Ma. The fraction produced in the crust (in‐situ production) that accumulates over time in specific mineral species allows, through the measurement of its concentration (a function of both the duration of exposure to cosmic radiation and the stability of the studied surface), dating of artifacts over a time span of 0.2–5 Ma. To achieve such dating, a dedicated method able to separate the very rare cosmogenic radionuclides from their abundant isobaric interferences had to be developed: the accelerator mass spectrometry (AMS) technique.
R
aman Spectroscopy and Material Analysis
Authors: Casanova‐González Edgar
Published: December 2018

Raman spectroscopy has emerged as a specific, nondestructive technique, providing an alternative to more common invasive analytical methods. The technique has proven successful in the study of diverse materials, from lithic objects to mural paintings. It does, however, present limitations related to its low sensibility and a high fluorescence background, and several ways to overcome such drawbacks have been explored. The availability of portable spectrometers and the higher sensibility and accuracy of benchtop equipment have made Raman a very valuable technique for the identification and characterization of several materials relevant to cultural heritage.
R
aman Spectroscopy in Conservation
Authors: Leona Marco
Published: December 2018

Since its first application to the study of cultural heritage material in the 1980s, Raman spectroscopy has become an essential technique in the study of pigments, dyes, minerals, gems, glass, and ceramic materials and in the identification of their corrosion and degradation products. Raman instrumentation allows for rapid, nondestructive, or microanalytical investigation of works of art and archaeological material, with microscope‐based systems, fiber optics setups, or portable instrumentation. Key advantages of the technique are its minimal requirements in terms of sampling and sample preparation, its ability to provide molecular‐ or crystallographic‐level species characterization, and its high spatial resolution. Among its principal limitations is low sensitivity resulting from the weakness of the Raman effect, and interference from luminescent materials or impurities. More recently, the introduction of surface‐enhanced Raman spectroscopy has begun to address both these limitations, with particular advantages for the study of organic colorants.
Realist Philosophies of Science
Authors: Gibbon Guy
Published: December 2018

At its most general level, scientific realism is a view of the nature of reality and how that reality can be studied and understood. A basic assumption of the perspective is that there is a real world, both observable and unobservable, that different observers can independently experience through their naked eye, instrumentation, or theoretical modeling. The assumption of a completely objective reality is the underlying principle of science and is taken to explain the success of science. This entry reviews assumptions of scientific realism, challenges to it, and the status of scientific realism in the historical sciences.
Re‐Enactment and Engagement
Authors: Daugbjerg Mads
Published: December 2018

Re‐enactment (or historical re‐enactment) refers to the staging and animation of selected fragments of the past in the present, often conducted by costumed participants to an audience. Within the archaeology and heritage sector, typical performances include battles and other dramatic or pivotal events, but re‐enactment approaches are also utilized in historical markets and “living history” demonstrations, sometimes overlapping with tenets of experimental archaeology. Many view historical re‐enactment and living history contexts as particularly accessible and engaging educational settings, while critics have pointed to the dangers of uncontrolled experimentation and play, conjectural dramatization, and the tendency among some re‐enactors to focus heavily on material details while ignoring larger historical or political contexts.
Airborne Remote Sensing
Authors: Cowley David C.
Published: December 2018

Airborne remote sensing encompasses applications using a range of airborne/satellite sensors for detecting and understanding sites and landscapes without making direct physical contact. These noninvasive and nondestructive approaches underpin primary reconnaissance survey in many environments. The main data sources are described, with discussion of applications, scale, and future developments.
Sampling in Environmental Studies
Authors: Huntley Jacqui
Published: December 2018

Sampling is needed to retrieve a reasonable representation of biological remains from any context, since these remains, used in environmental studies to investigate landscape and economy, are generally not visible during archaeological excavation. A good sampling strategy, using appropriate sizes of sample and methods of processing, will optimize recovery of material to address the aims and objectives of the archaeological project.
Sampling Theory
Authors: Peregrine Peter N.
Published: December 2018

There is a single objective underlying sampling theory: to create a subset of a population in which all cases in the subset have an equal probability of being selected from the population. A sample produced in this way will accurately reflect the range of variation in the population. All probabilistic methods of sampling are designed to achieve this basic objective. A variety of probabilistic sampling methods have been developed for archaeology so that appropriate methods can be applied to a wide range of sampling contexts. There are also non‐probabilistic sampling methods used in archaeology, although they do not produce samples that accurately reflect the parent population.
Satellite Hyperspectral and Multispectral Imaging
Authors: Verhoeven Geert
Published: December 2018

Satellite‐based imagers have been delivering data products that offer new possibilities to study (archaeological) landscapes via remote recording of the Earth's spectral reflectance (and to some extent thermal emittance) since the 1970s. Although much declassified panchromatic spy footage and some more recent commercial multispectral imagery has already been used with great success in archaeological research, it is expected that the importance and utility of multi‐ and hyperspectral (together denoted spectral) spaceborne imagery will become more important in the near future. This is mainly due to the constant and simultaneous improvements in the spatial and spectral resolving power of these imaging systems. Together with the temporal and radiometric properties, these four characteristics define any remotely‐sensed spaceborne spectral imaging platform. Thus, these parameters allow one to decide on the archaeological usability of the footage acquired.
Science and Politics
Authors: Mizoguchi Koji
Published: December 2018

This entry shows the intrinsic linkage between scientific knowledge production and politics, and traces the transformation of such linkage by describing the paradigmatic shift in the history of archaeology from the diffusionist phase through the processual to the postprocessual phase. The entry concludes by suggesting how to accept the fateful linkage between archaeology as a field of scientific knowledge production and politics and move forward to a better direction.
Scientific Revolutions
Authors: Koerner Stephanie
Published: December 2018

In this entry, key themes in Thomas Kuhn'sThe Structure of Scientific Revolutions(1962, 1970) provide a framework for examining aspects of the philosophical (methodological and theoretical) implications of the topic of “scientific revolutions”—with particular attention to themes that interface with other entries to this section of theEncyclopedia.
Semantic Web and Ontologies
Authors: Wright Holly
Published: December 2018

The Semantic Web and ontologies can help archaeologists combine and share data, making it more open and useful. Archaeologists create diverse types of data, using a wide variety of technologies and methodologies. Like all research domains, these data are increasingly digital. The creation of data that are now openly and persistently available from disparate sources has also inspired efforts to bring archaeological resources together and make them more interoperable. This allows functionality such as federated cross‐search across different datasets, and the mapping of heterogeneous data to authoritative structures to build a single data source. Ontologies provide the structure and relationships for Semantic Web data, and have been developed for use in cultural heritage applications generally, and archaeology specifically. A variety of online resources for archaeology now incorporate Semantic Web principles and technologies.
Sequencing
DNA
Authors: Brown Terence A.
Published: December 2018

DNA sequencing is used to study the small amounts of ancient DNA that are sometimes preserved in archaeological material. Recent advances in the methodology for DNA sequencing have increased the amount of data that can be obtained from ancient DNA. Sequencing of ancient DNA can provide information on the sex of skeletons and their kinship relationships, and on the disease status of individuals. DNA sequencing with preserved plant remains is used to study prehistoric agriculture and in particular can give insights into the genetic adaptation of crops to new environments. Genome sequences of extinct hominins and of early examples of
Homo sapiens
are revealing novel aspects of human evolution, including the extent and impact of interbreeding between Neanderthals, Denisovans, and modern humans.
Sheep and Goats
Authors: Baker Polydora
Published: December 2018

The study of sheep and goats (ovicaprids) is central to much archaeological research, with topics ranging from domestication to the textile and dairy industries, colonial impact, and international trade. Sheep and goats have been hunted or husbanded for meat, dairy, fibers, carcass by‐products, and dung. Sheep in particular have been the subject of intense selective breeding for wool. The relative frequency of ovicaprids in archaeological sites can vary widely by area and period, providing insight into past societies, economies, and environments. Traditional morphometric methods and increasingly biochemical techniques are used to explore herd composition, management, and use.
Simulation Modeling
Authors: Wurzer Gabriel
Published: December 2018

The investigation of systems by means of experiments acting on formalized models is called simulation modeling. It is a process that produces a mathematical description of a system (
modeling
) and translates the resulting rules into a computer program (
implementation
). The execution of the program may then be used to infer statements about the modeled system (
experimentation
).
Soil Chemistry in Archaeology
Authors: Terry Richard E. , Brown Bryce M.
Published: December 2018

The chemical and physical processes of soils allow for the accumulation and storage of the chemical residues of ancient human activities. There are a variety of soil characteristics and chemical analyses that can be used to examine the chemical signature of activity areas. Both the inorganic and organic soil components affect ion exchange and sorption. These properties allow for the analysis of anthropogenic soil markers including: phosphorus, trace elements, plant nutrients and heavy metals, stable carbon isotopes, and biomarkers.
Soil Phosphate Chemistry
Authors: Bair Daniel A. , Terry Richard E.
Published: December 2018

Phosphorus (P) and other chemical residues of ancient activities represent invisible yet critical artifacts of ancient lives. Human activities can either increase the P content of soils and floors as organic materials are gathered and processed, or the P levels may be decreased as dwelling floors, and plaza surfaces were constructed of materials that were naturally low in P. Several studies have shown that extractable phosphate procedures are not only better because of more interpretative detail in the resulting chemical patterns, but it is also more cost‐effective and functional in both formal and field laboratory settings.
Soil Survey
Authors: Tricarico Anthony R.
Published: December 2018

Contemporary applications of soil survey in archaeology intersect the boundaries of theoretical, interdisciplinary geoarchaeology and increasing methodological emphases on macro‐ rather than micro‐level scales of analysis. The widespread use of soil survey in investigations of soil distribution and the relationship between landscape and cultural interaction dates back to the early nineteenth century. Soil survey and mapping has been relatively underutilized in geoarchaeological investigations. However, geochemical investigations of land‐use patterns within the last decade have increasingly relied on soil survey to inform differential spatial patterns of past human–environmental interaction. Soil survey and mapping has seen an infusion of new digital methodologies emphasizing the quantitative power of spatial soil prediction. These new methods seek to address the confounding problems of scale and spatial distribution inherent in earlier soil maps, while addressing contemporary research foci including human health, food security, and water quality.
Sonar and Sidescan Sonar
Authors: Gkionis Panagiotis , Papatheodorou George
Published: December 2018

Sonar systems are widely used in support of maritime archaeology, leaving behind the disadvantages of diving operations. They provide underwater imaging and help archaeologists to better understand natural underwater processes and the impact of human activities on the underwater cultural resources, and hence to assess the evolution of an underwater archaeological site. Sidescan sonars provide acoustic imaging of seafloor features of archaeological interest. Some of their common applications include mapping of submerged landscapes, detection and visualization of shipwrecks, artifacts, and features related to human activity, acoustic seafloor classification, and seafloor geomorphological characterization. Advances in sonar technology have led to the development of sophisticated systems like multibeam echosounders for three‐dimensional, high‐resolution mapping. With the combined use of sonar systems, archaeologists can better assess the archaeological potential of a site, the conditions of historical events at sea, and the interactions between the environment, human activities, and archaeological material.
Spatial Analysis
Authors: Kvamme Kenneth L.
Published: December 2018

Spatial analysis in archaeology has seen constant evolution since it was conceived in the 1970s. The initial focus was on statistical analyses of spatial data to elucidate patterns, trends, differences, or associations within intra‐site or regional distributions. The adoption of geographical information systems (GIS) by the 1990s fostered a more visual approach to spatial analysis, permitted consideration of large regional datasets, and expanded the nature of spatial questions. Initial applications focused on predictive models of archaeological location, with a later focus on viewshed studies, least‐cost pathways, and territory definitions as they bear on archaeological distributions. In the 2000s, more powerful computing, geospatial technologies that yield vast amounts of spatial data from the ground, air, or space, and improved software have promoted further changes. Computer‐intensive algorithms have expanded GIS into new domains and have led to new spatial statistics that recognize interdependencies and perform at multiple scales.
Inferential Statistics
Authors: Crema Enrico R.
Published: December 2018

Statistical inference lies at the foundation of modern science and at the core of scientific inquiry in archaeology. It provides a suite of formal methods for describing populations from sample data, and enables the assessment and comparison of archaeological hypotheses formulated as statistical models. This essay reviews the basic premises of the three main paradigms of statistical inference used in archaeology.
Statistics and
GIS
Authors: Connolly Matthew H.
Published: December 2018

Since the inception of computerized geographical information systems (GIS) in the late 1960s, statistics have played an essential role in GIS analysis activities. Spatial and aspatial descriptive statistics are used to explore, classify, and visualize geospatial data, helping to evaluate cursory distributions and patterns, as well as suggesting more advanced analysis methods. Inferential statistics inform spatial analysis of point and areal patterns, and contribute to interpolation procedures and statistical surface generation for unmeasured locations. Statistical models provide explanatory or predictive insights into spatial patterns and processes. Statistics are also used to evaluate errors in modeling and interpolation results, GIS data creation processes, global navigation satellite system (GNSS) data collection, and remotely sensed data correction.
Stature Estimation
Authors: Auerbach Benjamin M.
Published: December 2018

The height of individuals, stature, is used for various applications in anthropology, including studies of human evolution, and studies of individual identification from skeletal remains. Within archaeological contexts, comparisons of stature between groups or within a group over time may be applied to better understand changes in health, diet, the environment, and cultural and political structures. Stature also has applications for studies of biological scaling, as well as mechanics. This entry provides a review of the primary applications of stature to these contexts, and the methods by which stature is estimated from human skeletal remains. An emphasis is placed on the historical development of these methods within anthropology, and the relationship of this growing knowledge with increasing awareness about the variation present among human groups. The entry especially notes what methods are available for stature estimation currently, and specific concerns that are the focus of recent studies.
An Introduction to Transition Services and Support—Where are We and How did We Get Here?
Authors: Johnson Cinda , Taga Brendon , Hughes Bob
Published: December 2018

The transition of students with special needs to postsecondary experiences is shaped by the history, context, and causes that combine to create policies, systems, and practices that help or hinder those transitions.
Self‐Determination and Adult Transitions and Supports
Authors: Wehmeyer Michael L. , Shogren Karrie A. , Thompson James R.
Published: December 2018

This chapter describes the importance of self‐determination for transitions and supports for adults with disabilities. Self‐determination is defined and its application to the disability context examined, followed by an overview of a multicomponent model to engage adults with disabilities to self‐regulate problem solving to set and attain life and career goals and to enhance self‐determination.
Facilitating College Supports to Ensure Student Success
Authors: Fowler Catherine H. , Getzel Elizabeth Evans , Lombardi Allison
Published: December 2018

This chapter examines the changes in supports and services from secondary to postsecondary for students with disabilities. It recommends ways organizations, practitioners, and students must coordinate and collaborate to affect the environment and increase student success in postsecondary education.
Biomimetic 3D Printing of Hierarchical and Interconnected Porous Hydroxyapatite Structures with High Mechanical Strength for Bone Cell Culture
Authors: Song Xiaolei , Tetik Halil , Jirakittsonthon Thitikan , Parandoush Pedram , Yang Guang , Lee Donghee , Ryu Sangjin , Lei Shuting , Weiss Mark L. , Lin Dong
Published: December 2018

Human bone demonstrates superior mechanical properties due to its sophisticated hierarchical architecture spanning from the nano/microscopic level to the macroscopic. Bone grafts are in high demand due to the rising number of surgeries because of increasing incidence of orthopedic disorders, non‐union fractures, and injuries in the geriatric population. The bone scaffolds need to provide porous matrix with interconnected porosity for tissue growth as well as sufficient strength to withstand physiological loads, and be compatible with physiological remodeling by osteoclasts/osteoblasts. The‐state‐of‐art additive manufacturing (AM) technologies for bone tissue engineering enable the manipulation of gross geometries, for example, they rely on the gaps between printed materials to create interconnected pores in 3D scaffolds. Herein, the authors firstly print hierarchical and porous hydroxyapatite (HAP) structures with interconnected pores to mimic human bones from microscopic (below 10 µm) to macroscopic (submillimeter to millimeter level) by combining freeze casting and extrusion‐based 3D printing. The compression test of 3D printed scaffold demonstrates superior compressive stress (22 MPa) and strain (4.4%). The human mesenchymal stromal cells (MSCs) tests demonstrate the biocompatibility of printed scaffold.
Particulate Coatings with Optimized Haze Properties
Authors: Semmler Johannes , Bley Karina , Klupp Taylor Robin N. , Stingl Michael , Vogel Nicolas
Published: December 2018

The haze factor, which describes the fraction of light that is scattered when passing through a transparent material, is of general importance for any optical device, from milk glass shielding visibility while providing ambient lighting to solar cells that are optimized by sophisticated light management layers. Often, such active layers are fabricated from particulate materials that are deposited as thin films on a substrate. Here, the effect of structural arrangement, position, and orientation of particles on the resulting haze factor is investigated. A mathematical optimization model that iteratively alters the particle layer structure to maximize or minimize the haze factor for a range of optimization scenarios is designed. Colloidal self‐assembly techniques are then used to replicate typical particle structures found in the optimized designs and correlate the macroscopically measured haze values to the predictions of the optimization. The results indicate general design rules that control the haze value in particle layers. Non close‐packed structures with distributed scatterers and high degrees of order provide minimal haze values while chain‐like arrangements and small clusters maximize the haze of a particle layer. Finally, the findings are transferred to metal nanohole films as model transparent electrodes with controlled haze values.
DNA‐Based Biomaterials for Immunoengineering
Authors: Maeda Midori , Kojima Taisuke , Song Yang , Takayama Shuichi
Published: December 2018

Man‐made DNA materials hold the potential to modulate specific immune pathways toward immunoactivating or immunosuppressive cascades. DNA‐based biomaterials introduce DNA into the extracellular environment during implantation or delivery, and subsequently intracellularly upon phagocytosis or degradation of the material. Therefore, the immunogenic functionality of biological and synthetic extracellular DNA should be considered to achieve desired immune responses. In vivo, extracellular DNA from both endogenous and exogenous sources holds immunoactivating functions which can be traced back to the molecular features of DNA, such as sequence and length. Extracellular DNA is recognized as damage‐associated molecular patterns (DAMPs), or pathogen‐associated molecular patterns (PAMPs), by immune cell receptors, activating either proinflammatory signaling pathways or immunosuppressive cell functions. Although extracellular DNA promotes protective immune responses during early inflammation such as bacterial killing, recent advances demonstrate that unresolved and elevated DNA concentrations may contribute to the pathogenesis of autoimmune diseases, cancer, and fibrosis. Therefore, addressing the immunogenicity of DNA enables immune responses to be engineered by optimizing their activating and suppressive performance per application. To this end, emerging biology relevant to the generation of extracellular DNA, DNA sensors, and its role concerning existing and future synthetic DNA biomaterials are reviewed.
Ultrathin Visible‐Light‐Driven Mo Incorporating In2O3–ZnIn2Se4 Z‐Scheme Nanosheet Photocatalysts
Authors: Chao Yuguang , Zhou Peng , Li Na , Lai Jianping , Yang Yong , Zhang Yelong , Tang Yonghua , Yang Wenxiu , Du Yaping , Su Dong , Tan Yisheng , Guo Shaojun
Published: December 2018

Inspired by natural photosynthesis, the design of new Z‐scheme photocatalytic systems is very promising for boosting the photocatalytic performance of H2 production and CO2 reduction; however, until now, the direct synthesis of efficient Z‐scheme photocatalysts remains a grand challenge. Herein, it is demonstrated that an interesting Z‐scheme photocatalyst can be constructed by coupling In2O3 and ZnIn2Se4 semiconductors based on theoretical calculations. Experimentally, a class of ultrathin In2O3–ZnIn2Se4 (denoted as In2O3–ZISe) spontaneous Z‐scheme nanosheet photocatalysts for greatly enhancing photocatalytic H2 production is made. Furthermore, Mo atoms are incorporated in the Z‐scheme In2O3–ZISe nanosheet photocatalyst by forming the MoSe bond, confirmed by X‐ray photoelectron spectroscopy, in which the formed MoSe2 works as cocatalyst of the Z‐scheme photocatalyst. As a consequence, such a unique structure of In2O3–ZISe–Mo makes it exhibit 21.7 and 232.6 times higher photocatalytic H2 evolution activity than those of In2O3–ZnIn2Se4 and In2O3 nanosheets, respectively. Moreover, In2O3–ZISe–Mo is also very stable for photocatalytic H2 production by showing almost no activity decay for 16 h test. Ultraviolet–visible diffuse reflectance spectra, photoluminescence spectroscopy, transient photocurrent spectra, and electrochemical impedance spectroscopy reveal that the enhanced photocatalytic performance of In2O3–ZISe–Mo is mainly attributed to its widened photoresponse range and effective carrier separation because of its special structure.
Roll‐to‐Roll (R2R) Production of Ultrasensitive, Flexible, and Transparent Pressure Sensors Based on Vertically Aligned Lead Zirconate Titanate and Graphene Nanoplatelets
Authors: Yildirim Armen , Rahimi Rahim , Shams Es‐haghi Siamak , Vadlamani Anand , Peng Fang , Oscai Mark , Cakmak Mukerrem
Published: December 2018

Despite extensive advances in the use of piezoelectric materials in flexible electronics, they have numerous shortcomings, including low efficiency, limited flexibility, and lack of transparency. Additionally, the production of these materials is often limited to small batch processes which are difficult to scale up for mass production. A novel method to produce ultrasensitive, high performance, flexible, and transparent piezoelectric materials where both lead zirconate titanate nanoparticles, and graphene nanoplatelets are aligned together in polydimethylsiloxane under an AC electric field in the thickness (“Z”) direction, is reported here for the first time. The electric field alignment improves the piezoelectric response along with transparency and also reduces the amount of filler required to achieve outstanding piezoelectric properties. The resulting ultrasensitive piezoelectric film is able to sense the pressure of a bird feather (1.4 mg) dropped from a certain distance, whereas at the touch of a fingertip, it can generate up to 8.2 V signal. Moreover, the mass production compatibility of the system is also demonstrated by producing a 3 m long and 15 cm wide large‐area sample via a novel 44′ long roll‐to‐roll manufacturing line which is designed and developed by the group.
A Facile Realization Scheme for Tactile Sensing with a Structured Silver Nanowire‐PDMS Composite
Authors: Li Yunxia , Han Dongyan , Jiang Changjun , Xie Erqing , Han Weihua
Published: December 2018

To mimic the sensing function of human skin, the rational design of force‐sensitive materials is highly required for sensors. Here, a facile design of resistive‐type tactile sensors based on a structured silver nanowire‐polydimethylsiloxane composite is reported for applications in electronic skins and wearable electronics. The composite has a hollow microstructure of interconnected channels, and the inner surface of the channels is a conductive layer consisting of silver nanowires. The sensing function to external force is realized by measuring the resistance change upon deforming. The deforming causes the distance change of silver nanowires and the contact‐area change of the inner surfaces. Such a unique structure promises a robust mechanical property due to the half‐embedded silver nanowires which are free of peeling off, and also makes it possible to control the device sensitivity by its mechanical structure and the elastic property of the polydimethylsiloxane. The results show that the composite has steady‐state responses to various pressures and stretches, even to mouth blowing, a response time of ≈90 ms, and favorable repeatability over 2000 cycles of bending/unbending. The 3D structure enables pressing, bending, pulling and torsional force sensing, and promises real‐time monitoring of various human motions ranging from blood pulses to joint movements.
Double Helix Actuators
Authors: Shepherd David J. , Spinks Geoffrey M.
Published: December 2018

Tensile actuators that reversibly generate large length change strokes are of great interest in many biomedical and robotic applications. Guest–host composite materials comprising volume change guests with multi‐filament yarn hosts can be exploited as large stroke tensile actuators when the fiber host is formed into helices. Here, a new type of double helix actuator is introduced by plying two yarns together. The helical geometry suggests large length contractions are possible when the ply angle approaches the limit of 45° and when the yarn swells predominantly in the diameter direction as it occurs when reinforcing filaments are aligned in the yarn direction. Prototype double helix actuators are constructed from cotton yarn infused with a water‐swellable hydrogel. A series of actuator samples are made with differing ply angles and the length changes monitored during repeated hydration/dehydration cycles. Water swelling causes length contractions of up to 9% and it increases in magnitude with an increase in ply twist. The experimental results are in good agreement with those calculated using the helical geometry model.
Fano Resonance in Asymmetric Plasmonic Nanostructure: Separation of Sub‐10 nm Enantiomers
Authors: Cao Tun , Mao Libang , Qiu Yimei , Lu Li , Banas Agnieszka , Banas Krzysztof , Simpson Robert E. , Chui Hsiang‐Chen
Published: December 2018

Separating enantiomers is vital in chemical syntheses, life sciences, and physics. However, the usual chemical processes are inefficient. Recently, plasmonic nanostructures have drawn considerable attention for manipulating nanoparticles; however, only a few approaches are proposed to discriminate between entities that differ in terms of their handedness. This is because the chiral polarizability is much smaller than the electric polarizability, and therefore the non‐chiral gradient force dominates over the chiral gradient force. This limit means that the enantioselective sorting of chiral nanoparticles is a formidable challenge. A plasmonic nanostructure consisting of a disc‐double split ring resonator exhibiting a dipole–octupole (DO) Fano resonance (FR) is designed and fabricated. It is theoretically demonstrated that such a DO‐FR can markedly enhance the chiral gradient force on the paired enantiomers. The coaxial channel of the resonator possessing high chirality density gradients around the DO‐FR is derived. This provides an enhanced chiral gradient force that dominates over the non‐chiral gradient forces on sub‐10 nm chiral nanoparticles. Enantiomeric pairs can thus experience distinct potential wells in terms of signs. This proposed structure may advance the techniques of enantiopurification and enantioseparation, bringing a new perspective to state‐of‐the‐art all‐optical enantiopure synthesis.
Control of Barrier Width in Perovskite Multiple Quantum Wells for High Performance Green Light–Emitting Diodes
Authors: Yu Maotao , Yi Chang , Wang Nana , Zhang Liangdong , Zou Renmeng , Tong Yunfang , Chen Hong , Cao Yu , He Yarong , Wang Ying , Xu Mengmeng , Liu Yang , Jin Yizheng , Huang Wei , Wang Jianpu
Published: December 2018

Solution‐processed, self‐organized multiple quantum well (MQW) perovskites possess good film coverage and high photoluminescence quantum efficiency, which are promising for high performance light‐emitting diodes (LEDs). However, due to the inclusion of insulating large organic cation as barrier layer, the charge transport in MQW perovskites is not as efficient as 3D perovskites, which limits the improvement of power conversion efficiency of MQW perovskite LEDs. Here, it is demonstrated that by molecular engineering, the conductivity of MQW perovskite film can be effectively increased by reducing the barrier width in QWs, thus leading to enhanced device performance. By controlling the constitution of the narrow‐barrier‐width MQW perovskites, one can achieve green LEDs with a high luminance of 30 000 cd m−2 at a low voltage of 6 V and a peak external quantum efficiency of 7.7%. Moreover, the green perovskite LEDs show a lifetime of 63 min with initial luminance of 1330 cd m−2, representing one of the best performing green perovskite LEDs. Here, a promising strategy is provided to further boost the efficiency, brightness, and stability of MQW perovskite LEDs.
Recent Developments in Enantioselective Metal‐Catalyzed Domino Reactions
Authors: Pellissier Hélène
Published: December 2018

This review collects the very recent developments in enantioselective metal‐catalyzed domino reactions published since the beginning of 2016. It illustrates that many types of enantioselective metal‐catalyzed domino processes continue to be developed, allowing an easy one‐pot access to complex molecular architectures from simple starting materials while providing economic advantages, such as avoiding costly protecting groups and time‐consuming purification procedures after each step.

Abbreviations: acac: acetylacetonate; Ar: aryl; BINAP: 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl; BINOL: 1,1′‐bi‐2‐naphthol; Bn: benzyl; Boc: tert‐butoxycarbonyl; Box: bisoxazoline; BOXAX: 2,2′‐bis(oxazolyl)‐1,1′‐binaphthyl; Bz: benzoyl; cod: cyclooctadiene; Cy: cyclohexyl; DBDMH: 1,3‐dibromo‐5,5‐dimethylhydantoin; DBU: 1,8‐diazabicyclo[5.4.0]undec‐7‐ene; DCE: dichloroethane; de: diastereomeric excess; DIPEA: diisopropylethylamine; dr: diastereomeric ratio; ee: enantiomeric excess; Hex: hexyl; L: ligand; MTBE: methyl tert‐butyl ether; Naph: naphthyl; Ms: mesyl; M.S.: molecular sieves; NMP: N‐methyl‐2‐pyrrolidone; Ns: nosyl; PG: protecting group; Phos: phosphinyl; PHOX: phosphinooxazoline; Phth: phthaloyl; Pin: pinacolato; Piv: pivaloyl; Pybox: 2,6‐bis(2‐oxazolyl)pyridine; r.t.: room temperature; TBS: tert‐butyldimethylsilyl; Tf: trifluoromethanesulfonyl; TFA: trifluoroacetic acid; THF: tetrahydrofuran; TMS: trimethylsilyl; Tol: tolyl; Ts: 4‐toluenesulfonyl (tosyl).

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Biological One‐Way Functions for Secure Key Generation
Authors: Dodda Akhil , Wali Akshay , Wu Yang , Pannone Andrew , Reddy Likhith Kumar , Raha Arnab , Ozdemir Sahin Kaya , Ozbolat Ibrahim Tarik , Das Saptarshi
Published: December 2018

Disorder is fundamental to nature and natural phenomena, providing countless information sources, which are astronomically difficult to duplicate, but have yet to be exploited for cryptographic applications. While the contemporary crypto systems, relying on the premise of abstract mathematical one‐way functions, are relatively difficult to decipher with reasonable and/or finite resources, the situation is bound to change with the advent of quantum computers, necessitating physically unclonable entropy sources. As such, inspiration is drawn from the disorder that is prevalent in nature and inherent to biological systems for designing disruptive mechanisms for cryptographic key generation. It is demonstrated that the spatiotemporal dynamics of an ensemble of living organisms such as T cells can be used for maximum entropy, high‐density, and high‐speed key generation. Further, such biology based one‐way functions are oblivious to any mathematical representations and are computationally expensive to decipher even if an adversary has an exhaustive knowledge of the key generation mechanisms, which include cell type, cell density, key sampling rate, and sampling instance. The introduction of such biological one‐way functions can greatly enhance the ability to protect information in the post quantum era.
Role of systemic high‐dose methotrexate and combined approaches in the management of vitreoretinal lymphoma: A single center experience 1990‐2018
Authors: Castellino Alessia , Pulido Jose S. , Johnston Patrick B. , Ristow Kay M. , Nora Bennani N. , Inwards David J. , Macon William R. , Micallef Ivana N. M. , King Rebecca L. , Salomao Diva R. , Witzig Thomas E. , Habermann Thomas M. , Nowakowski Grzegorz S.
Published: December 2018

Vitreoretinal lymphoma (VRL) management remains a challenge. We present 72 patients with VRL, diagnosed at Mayo Clinic between 1990‐2018. Three nondiffuse large B‐cell lymphoma (DLBCL) histology cases were excluded. Among 69 DLBCL, 33 patients had primary VRL (PVRL), 18 concurrent intraocular and central nervous system (CNS) or systemic disease and 18 secondary VRL. Patients received intraocular chemotherapy (intraocular injections of rituximab or metothrexate or steroids or in combination), radiotherapy, systemic or combined systemic plus intraocular treatment in 9, 10, 35, and 15 cases, respectively. Among primary and concurrent VRL, median failure free survival (FFS), CNS relapse‐free survival (CNS‐RFS) and overall survival (OS) were: 1.8, 4.9, and 4.1 years, respectively; among PVRL, median FFS, CNS‐RFS, and OS were: 2.6 year, Not Reached and 9.3 year, respectively. No CNS relapse occurred beyond 4 years in PVRL. Median OS for patients diagnosed between 1990 and 1999 vs between 2000 and 2018 was 1.5 vs 9.4 years, respectively (P = .0002). OS was significantly higher in PVRL, as compared with concurrent VRL (P = .04). Previous immunosuppression and poor performance status were predictive of worse outcome. In PVRL, a combined systemic and intraocular therapy showed higher FFS (P = .002) and CNS‐RFS (P = .003), but no differences in OS. Among 18 secondary VRL, at a median follow‐up of 1.1 year after vitreoretinal relapse, median FFS and OS were 0.3 and 1.3 years. An improvement in survival of VRL has been observed over the decades. PVRL should undergo combined systemic and intraocular chemotherapy to prevent CNS progression.
Construction of Pillar[5]arene Tetramer‐Based Cross‐Linked Supramolecular Polymers through Hierarchical Charge‐Transfer and Host‐Guest Interactions
Authors: Ali Wajahat , Ning Guiling , Hassan Mehdi , Gong Weitao
Published: December 2018

A pillar[5]arene tetramer was constructed by naphthalene diimide and naphthalene‐bridged pillar[5]arene dimers through X‐type charge transfer interactions. Furthermore, by adding a ditopic neutral guest, a cross‐linked supramolecular polymer was successfully fabricated. These cross‐linked polymers were confirmed by concentration‐dependent NMR spectroscopy, DOSY NMR, UV, SEM and viscosity measurements.
Impact of population‐specific dental development on age estimation using dental atlases
Authors: Adams Donovan M. , Ralston Claira E. , Sussman Rachel A. , Heim Kelly , Bethard Jonathan D.
Published: December 2018

Objectives

The steady development and subsequent eruption of the dentition is particularly useful for the estimation of age in juveniles. There are few studies that examine and test methods on a population‐diverse sample. Our goal is to test the Ubelaker () and London Atlas (2010) dental charts on a sample representing several different population backgrounds to infer if refinement for population‐specific standards should be developed.

Materials and methods

The first and second authors examined panoramic radiographs of 335 individuals from the James K. Economides Orthodontic Collection blind to chronological age, sex, and ancestry and scored using both dental atlases.

Results

The age of Native Americans and African Americans was generally overestimated, suggesting faster rates of development. European Americans and New Mexico Hispanics, while not always showing the highest success rates, generally were closer to the correct age than other ancestry groups. The overall success rate for Ubelaker () was 80.00% for both observers, while the London Atlas was significantly lower at approximately 21.79–23.28%. Accuracy rates did not differ significantly between ancestry groups, though patterns were evident regarding under‐ or over‐estimation of age.

Discussion

The present study demonstrates that incorrect age estimations were typically still within 1.5 years of the actual age. Ubelaker () had higher rates of success due to broader age ranges. The results suggest that though accuracy rates did not significantly differ, different developmental rates may affect age estimates and population‐specific standards should be considered for known‐ancestry individuals, while aging standards constructed from a diverse sample should be utilized for unknown‐ancestry cases.