bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract Thinking
Authors: Warner Schaie K.
Published: December 2015

Complementarity criteria, involving the simultaneous or close temporal contiguity of different objects or experiences, are integral components of thinking in young children. Older children and young adults tend to use similarity criteria. In old age, however, the use of complementarity criteria once again increases. Older adults do not necessarily lose the ability to use more abstract criteria, but they often indulge in an alternative mode that offers greater imaginary scope. This reversal to complementarity is likely to be caused by environmental factors rather than changes in competence. Age‐related reductions in abstract thinking are also exasperated by hypertension, and by the presence of the apolipoprotein E
4
gene. Age‐related changes are less pronounced in women, and in individuals with advanced education, challenging work histories, and moderate alcohol use. An alternate explanation for the reduction in abstract reasoning with increasing age has been sought in the reduction of cortical volume in brain areas essential for high levels of abstract thinking.
Stereotype Threat
Authors: Popham Lauren E. , Hess Thomas M.
Published: December 2015

A common stereotype about older adults is that they are forgetful, incompetent, and cognitively inferior to younger adults (Hummert, Garstka, Shaner, & Strahm, 1994). Older adults tend to underperform on tests of cognitive abilities when they are reminded of these negative aging stereotypes, presumably due to the fear of confirming these stereotypes through their behavior. Age differences in ability disappear, however, when the stereotypes are not salient in the testing situation. This phenomenon is called stereotype threat, and its effects have been observed in numerous stereotyped groups. This entry discusses how and why stereotypes lead to threat effects on performance, and evidence of age differences in the underlying mechanisms. It concludes with a discussion of current and future directions in age stereotype research.
Sexuality and Aging
Authors: Aktar Rengin , DeLamater John
Published: December 2015

Sexuality is a relatively neglected topic in discussions of aging. Recent research indicates that continuing sexual expression is an important contributor to health and well‐being throughout life. Aging‐related physiological changes do not inevitably result in declining sexual function. Many aging persons remain sexually active. Levels of activity depend on individual and couple physical and mental health, attitudes about sex in later life, relationship status and quality, and socioeconomic context. Adults need information about maintaining sexual activity and relationships throughout life. Healthcare professionals need education and the willingness to discuss sexuality with older patients.
Endocrine System
Authors: Klein Laura Cousino , Potter Lindsey N. , Berkey Franklin J.
Published: December 2015

The endocrine system primarily is associated with metabolic control of the body, including transport of substances through cell membranes and cellular metabolism for growth and secretion. By definition, hormones are chemical substances that are secreted by a cell (or cells) into bodily fluids which results in a physiological effect on other cells in the body. There are three basic types of hormones: steroids (e.g., estrogen, cortisol); derivatives of tyrosine, an amino acid (e.g., thyroxine); and proteins/peptides (e.g., oxytocin, insulin). The endocrine system changes over the course of the lifespan as a result of changes in amount of hormone secreted or sensitivity of target organs. This entry discusses hormones associated with the pituitary‐thyroid axis, parathyroid, insulin, and adrenal cortical axis, and how they are altered in aging.
Everyday Problem Solving
Authors: Mienaltowski Andrew
Published: December 2015

Everyday problem solving refers to the ability to generate solutions to problems that take place in one's everyday experiences. Everyday problem solving is assessed using psychological measures that include well‐ and/or ill‐defined problems. Efficacy is operationalized in terms of the number of solutions that are offered by individuals, the match between a proposed solution and the ideal solution, and/or the extent to which the strategies that are implemented match the goals of the problem solver. Research on everyday problem solving characterizes the conditions under which problem‐solving performance declines with age as well as the conditions under which performance is maintained. Advancing age is associated with a decline in the number of solutions generated for everyday problems; however, when the context of the problem is ecologically relevant to older adults or evokes emotion, age differences are less common and older adults offer solutions that can be more effective at resolving the problem.
Missing Data/Imputation
Authors: Little Roderick J.
Published: December 2015

Missing data are a common problem in adulthood and aging research. This entry overviews the problem and possible solutions. It begins by offering a definition of missing data, with examples. It presents a widely applied taxonomy of mechanisms that create the missing data. It then considers common, but limited, approaches: complete‐cases, available cases, weighting analyses, and single imputation. More principled methods, namely multiple imputation, maximum likelihood, and inference from Bayesian posterior distributions, are then discussed.
Mixed Methods Approaches
Authors: Jill Suitor J. , Con Gulcin , Gilligan Megan
Published: December 2015

Interest in mixed methods, particularly those combining qualitative and quantitative data, has grown substantially since the 1990s. This entry defines and describes mixed methods approaches in the social sciences, traces the history of the development and use of these approaches, and discusses the benefits these approaches provide. Specific examples of combining quantitative and qualitative data in studies of later life families are presented in detail to illustrate the ways in which mixed methods can be used to expand understanding of social processes.
Internet‐Based Assessment
Authors: Mogle Jacqueline
Published: December 2015

Internet‐based assessments became a part of research methodology in the 1990s as the Internet moved into mainstream use. Originally met with skepticism, there is evidence that data collected with this methodology are valid, and these methods are now used to collect data in a variety of studies. The advantages of Internet‐based assessments include reduced burden for both participants and researchers, greater disclosure from individuals, and better access to hard‐to‐reach populations including isolated older adults. As technology advances, these types of assessments are evolving beyond personal computers to deployment using mobile devices.
Palliative Care
Authors: Hopp Faith , Popkin Steven M. , Zalenski Robert J.
Published: December 2015

Palliative care approaches are designed to promote comfort, pain control, and quality of life for persons facing serious illness. The growing number of frail older adults with multiple comorbid illnesses is contributing to the need for comprehensive, integrated, and culturally sensitive approaches to the provision of palliative care services. Palliative care teams, consisting of physicians, nurses, social workers, chaplains, and other medical professionals, work together to address these complex issues by tackling physical, psychosocial, and spiritual sources of pain. Promising new research suggests enhanced outcomes following palliative care approaches, but improved social policies are needed to ensure access to comprehensive and integrated palliative care services.
Adaptation to Loss
Authors: Boerner Kathrin , Jopp Daniela S.
Published: December 2015

This entry outlines influential past and current perspectives on adaptation to loss. As the death of a loved one constitutes one of the most universal loss experiences, this entry begins with a description and discussion of conceptual thinking and relevant empirical evidence on bereavement. It then moves to more general lifespan perspectives on adaptation to loss and major life change that specify adjustment processes that have been found to be important in dealing with age‐related losses and limitations. It closes with a discussion of areas that deserve more attention and that would help to advance our understanding of adaptation to loss.
General Slowing Hypothesis
Authors: Choi HeeSun , Feng Jing
Published: December 2015

Age‐related slowing of responses to cognitive tasks is a ubiquitous phenomenon in research on cognitive aging. The general slowing hypothesis is built upon broad observations in many studies of age‐related slowing and suggests that age‐related general slowing is the primary contributor to the declines in cognitive functioning associated with aging. This entry provides a brief overview of the general slowing hypothesis and its research background, the evolution of models and debates, and cognitive training research based on the hypothesis.
Life Satisfaction
Authors: Röcke Christina
Published: December 2015

Life satisfaction is one key element of subjective well‐being (SWB). It represents the evaluation of one's life in general or within specific domains (e.g., health, social relations). This cognitive component of SWB has been examined in the aging literature as well as in the social‐cognitive and personality domains. Life satisfaction is only weakly related to objective life contexts, resources, and life events, and remains relatively intact during adulthood. Longitudinal evidence is sparse and often focuses on the Third Age. The available longitudinal evidence suggests that life satisfaction slightly increases until the retirement years and then slightly decreases. Stronger decline can be observed prior to death, with accelerated decline during the Fourth Age and particularly in the last few years before individuals die. Future research should combine short‐ and long‐term longitudinal designs to better understand the pathways leading to the maintenance of life satisfaction and possible limitations to the ability to maintain this satisfaction into late life.
Emotions and Aging
Authors: Murry Matthew W. E. , Isaacowitz Derek M.
Published: December 2015

Unlike the age‐related decline suggested in areas such as cognition, emotion‐related processes appear to show some areas of age‐related improvement, some of stability, and some of decline. Three major topics of research on emotion and aging are reviewed: emotional experience, emotion regulation, and emotion perception. After considering descriptive findings within each of these domains, theories and evidence concerning potential underlying mechanisms are considered.
Weak Ties/Consequential Strangers
Authors: Fingerman Karen L. , Tennant Patrick S.
Published: December 2015

Most studies examining older adults' social ties have focused on intimate and close ties, but acquaintances, consequential strangers, and weak ties also have an impact on the lives of older adults. Older adults have ties to weak partners via social partners who once were more intimate but are currently less so, formal service providers (e.g., hairdressers), formal and religious groups (e.g., Rotary, churches, mosques), informal groups (e.g., book clubs), geographical locations, and virtual communities. This entry details how acquaintances function similarly to, and differently from, close ties in late life. Acquaintances may provide opportunities to engage in novel activities, serve as a connection to the past, offer liaisons to other social partners, and even provide support. Benefits and costs associated with older adults' weak ties are explored. Several examples of important weak ties in older adults' lives are described. Acquaintances are valuable, and valued, connections for older adults.
Longitudinal/Panel Designs
Authors: Infurna Frank J. , Mayer Axel
Published: December 2015

Longitudinal panel surveys are essential for studying development across the lifespan and have been instrumental in studying the course of development from infancy through adolescence to young adulthood and into old age. This entry mentions characteristics and design aspects of longitudinal panel surveys and give references to available data resources and to relevant statistical models. In addition, it highlights two substantive research areas where longitudinal panel surveys are used to examine development. First, the entry discusses the utility of longitudinal panel surveys for studying developmental change to and from major life events, which can provide insights into how development occurs beyond mechanisms such as age. Second, it focuses on the utility of longitudinal panel surveys for predicting health outcomes such as disease, disability, and mortality.
Technology in Long‐Term Care
Authors: Claßen Katrin , Wahl Hans‐Werner
Published: December 2015

Technology plays an increasingly important role in a wide range of everyday‐life domains—and those of older adults are no exception. Yet, long‐term care (LTC), with its highly vulnerable population of multimorbid and cognitively impaired older adults, may be perceived as distant to technology use. This entry demonstrates that the opposite is the case and that we will see pronounced technology applications in LTC in the near future. This entry discusses functions of technology in LTC as serving not only compensatory purposes but also optimization purposes. To develop its full potential, however, technology in LTC has to fulfill specific requirements, which this entry also examines. Finally, organizational as well as person‐related factors that play a critical role for the acceptance of technology in LTC are considered.
Caregiving: Alzheimer's Disease and Related Disorders
Authors: Whitlatch Carol J. , Zarit Steven H. , Femia Elia E.
Published: December 2015

Providing support to a relative with a neurocognitive disorder such as Alzheimer's disease or a related disorder (ADRD) can be both stressful and fulfilling. As the number of ADRD persons continues to grow, so will the number of family caregivers. Yet, the development of services and interventions for family caregivers has not kept pace with the growing needs of families. Despite evidence about the efficacy of several interventions, most caregivers receive little or no help. This entry focuses on the experience of providing care to a relative with ADRD, highlighting the physical and psychological consequences and the most recent interventions designed to ameliorate caregiving stress and enhance well‐being.
Ego Integrity
Authors: Kivnick Helen Q. , Wells Courtney K.
Published: December 2015

Most scholarship on ego integrity has grown out of Erik Erikson's early presentation of his theory of life‐cycle development. However, at the end of a long career, Erikson rearticulated his theory and described three structural principles that weave together the well‐known eight thematic tensions, over eight stages of life: Dynamic Balance of Opposites, Vital Involvement, and Life in Time. Review of the empirical research indicates that ego integrity has been operationalized in a number of ways, in an attempt to understand what older individuals actually
do
to consolidate a sense of coherence and come to terms with the life they have lived so far. This research suggests a growing recognition that studying lifelong processes of reworking and preworking psychosocial themes may be more important than investigating stage sequentiality.
Invariance
Authors: John Geldhof G. , Stawski Robert S.
Published: December 2015

Before comparing constructs between participant subpopulations, or within a single subpopulation across repeated observations, researchers must provide evidence that the meaning of measured constructs is sufficiently equivalent across groups, or time, respectively. Such equivalence is called
measurement invariance
. This entry describes the process of establishing measurement invariance and discusses the tests of latent invariance (i.e., structural invariance) that measurement invariance allows for. Implications for applied research are discussed.
Workforce Planning
Authors: DiazGranados Deborah , Lall Priya , Curtis Michael T.
Published: December 2015

Workforce planning is the talent management business process that identifies and addresses gaps or overlaps between the employable labor pool and the needs of an organization or industry. At an organizational level, this process helps to ensure that an organization has access to talent for its future success. Advances in workforce planning have enabled organizations to collect data to answer such questions as: How many employees will be needed to achieve objectives in the next five years? Which competencies and expertise will be most critical for meeting organizational objectives? Workforce planning can help organizational leaders to improve recruiting methods and hiring decisions and to retain their best talent. As a result of engaging in predictive analytics and workforce planning, organizations are positioned to make impactful and data‐driven decisions that will guide future operations.
Friendships
Authors: Blieszner Rosemary
Published: December 2015

Friendships are voluntary personal relationships based on affection, companionship, trust, understanding, and reciprocity. They serve important purposes in socialization, support, and affirmation at all stages of life. At the same time, varying developmental circumstances and needs point to different friendship structures, functions, and processes across young, middle, and late adulthood. Although friends and relatives play complementary support roles and both bonds contribute to well‐being, friendships have some unique features. Unlike family ties, which may involve burdensome obligations, friend ties are often antidotes to life's stresses and strains. Thus, friendships play significant roles in promoting and sustaining physical and mental health.
Elder Abuse and Neglect
Authors: Sarkinen Kristen , Dykes Kaitlyn
Published: December 2015

Every year an alarming number of elders are abused and neglected. Studies estimate that between 3.2 and 27.5% of all elders worldwide are subjected to abuse or neglect. Elder abuse and neglect is defined as a known or intentional act by a caregiver or any other person that is harmful or poses serious risk of harm to persons aged 60 and older. Elder abuse and neglect can be detected by recognition of victim risk factors, perpetrator characteristics, and other warning signs. If abuse or neglect is suspected, the incident must be reported and investigated by various organizations and healthcare professionals. Elder abuse and neglect can be prevented by frequent assessment of all older adults by health professionals, via elder and caregiver education, and through the use of programs designed to reduce caregiver burden.
Effects of Coping on Psychological and Physical Health
Authors: Proulx Jeffrey , Aldwin Carolyn M.
Published: December 2015

Stress can adversely affect both psychological and physical health when environmental demands outweigh an individual's psychological and physical resources. Coping strategies are evoked in response to stress and refer to how a person manages and adapts to external and internal difficulties associated with stress. The popularity of coping research coincided with increased attention to stress in the second half of the 20th century because coping is thought to be a major factor in individual differences in psychological and physical response to stress. This entry briefly describes the development of three basic approaches to research in coping (psychoanalytic defense mechanisms, personality‐based coping styles, and coping processes), the changes in coping as people age, and the effects of coping on psychological and physical health.
Caregiver Stress and Coping
Authors: Savla Jyoti , Zarit Steven H.
Published: December 2015

Although family members often embrace the opportunity to care for a loved one, caregiving is stressful and takes a toll on the caregiver's health and well‐being. In light of the considerable consequences of caregiving on the carer, the beginning point of planning programs and policies to support family caregivers is an understanding of the stress process. The process by which caregiving stress leads to poor health outcomes has been informed by well‐established paradigms such as Pearlin's stress process model, Lazarus and Folkman's transactional stress model, and McEwen and Stellar's concepts of allostatic load. These theoretical frameworks inform understanding of caregivers' primary and secondary stressors, appraisals of stressors, coping strategies, and outcomes for health and well‐being.
Polypharmacy
Authors: Bellotti Gina DeSevo , Hajjar Emily R.
Published: December 2015

Polypharmacy is a well‐documented drug‐related problem particularly in older adults. Polypharmacy can be defined in two ways. The first definition is the use of multiple medications. Definitions of what quantity of medications constitutes polypharmacy vary. The second is the use of more medications than are clinically indicated for a specific patient or the use of medications that are medically unnecessary for a specific patient. Polypharmacy is associated with significant consequences, such as adverse effects, medication nonadherence, drug–drug and drug–disease interactions, and increased risk of geriatric syndromes. Healthcare providers should routinely review patients' medications for appropriateness, risks and benefits, and the potential for adverse consequences.
Dissociative Disorders
Authors: Kluft Richard P.
Published: December 2015

The dissociative disorders are characterized by failures of integration and continuity in numerous areas of experience and function, classically those affecting memory, identity, consciousness, and one's experience of one's self and the environment. They include dissociative amnesia, dissociative fugue (combined with dissociative amnesia in the DSM‐5), dissociative identity disorder, other specified dissociative disorder, and unspecified dissociative disorder. Excluding depersonalization disorder, they are increasingly understood as defensive adaptations made by individuals who have experienced severe (often recurrent) psychosocial stress, commonly beginning with overwhelming childhood experiences. Exploring and understanding the dissociative disorders has been hampered by attempts to apply models and theories derived from the study of other populations and phenomena, often leading to their mischaracterization. Sensationalism put aside, the circumspect study of their history, phenomenology, diagnosis, and treatment demonstrates that those who suffer these conditions are suffering severe distress, even if their pain is well concealed, and are usually amenable to psychotherapy.
Unconventional Use of a Photoresist as a Nitrogen Gas Generator Forming Transparent Dome‐Shaped Microcavities
Authors: Han Chang‐Hoon , Seo Min‐Ho , Ko Seung‐Deok , Yoon Young‐Hoon , Yoon Gun‐Wook , Yoon Jun‐Bo
Published: December 2015

The phenomenon that a common positive photoresist (PR) releases nitrogen (N2) gas when exposed to UV light has never been used or received any particular attention. Fabrication process to intentionally trap the generated N2 gas during UV exposure, thereby, to form the microcavity structure is proposed. Various dome‐shaped structures are demonstrated with the proposed process. This process is best suited to make various cavity packages in microelectromechanical systems. Also, microlens arrays are fabricated using plastic replication of the dome‐shaped microcavities. All these results lead to a different view of the conventional positive photoresist and inspire various new applications.
Fabrication of Aluminum Foams with Fine Cell Structure under Increased Pressure
Authors: Cao Zhuokun , Li Min , Yu Yang , Luo Hongjie
Published: December 2015

Foaming of aluminum melts containing titanium hydride powder is processed under increased pressure. The real‐time foam expansion height of aluminum melts is recorded and the cell structure of foam specimens is characterized. It is found that the loss of foaming gas to ambient environment during foaming process is reduced when foaming under increased pressure. Bubble coalescence is slowed down when pressure increases, leading to a significant decrease in mean cell size and its distribution range. The mean cell wall thickness also significantly reduces when foaming at increased pressure, which changes the correlation between mean cell size and foam density.
Preparation of Secondary Mesopores in Mesoporous Anatase–Silica Nanocomposites with Unprecedented‐High Photocatalytic Degradation Performances
Authors: Dong Weiyang , Sun Yaojun , Hua Weiming , Yao Youwei , Zhuang Guoshun , Lv Xinchun , Ma Qingwei , Zhao Dongyuan
Published: December 2015

In this article, a simple and mild preparation of secondary pores are reported, for the first time, with uniform and tunable sizes (in a wide range of 0.9–4.8 nm) in the walls highly connecting the primary mesochannels in 3D mesopore networks. The uniform secondary pores are obtained by using ordered 2D hexagonal mesoporous anatase TiO2–SiO2 nanocomposites as precursors, NaOH as an etchant via an “extracting SiO2” approach. The strategy here adopts diluted NaOH solution, appropriate extraction temperature, and solid/liquid ratio. The photocatalytic degradation rates of Rhodamine B (0.347 min–1), Acid Red 1 (0.0487 min–1), microcystin–LR (1.66 min–1) on the representative resultant nanocomposite are very high, which are 4.63, 11.7, 1.84 times that of the precursor without secondary mesopores; even up to 18.9, 8.21, 4.66 times that of P25, respectively. These results clearly demonstrate that the secondary mesopores play an overwhelming role to the increments of activities. The mesoporous anatase–silica nanocomposites with secondary mesopores present unprecedented‐high degradation activities to various organic pollutants in the mesoporous metal‐oxides‐based materials reported up to now and are considerably stable and reusable. It is believed that the fundamentals in this study will provide new insights for rational design and preparation of 3D highly interconnected mesoporous metal‐oxides‐based materials with super‐high performances.
Molecular and Genomic Impact of Large and Small Lateral Dimension Graphene Oxide Sheets on Human Immune Cells from Healthy Donors
Authors: Orecchioni Marco , Jasim Dhifaf A. , Pescatori Mario , Manetti Roberto , Fozza Claudio , Sgarrella Francesco , Bedognetti Davide , Bianco Alberto , Kostarelos Kostas , Delogu Lucia Gemma
Published: December 2015

Graphene oxide (GO) is attracting great interest in biomedical sciences. The impact of GO on immune cells is one fundamental area of study that is often overlooked, but critical in terms of clinical translation. This work investigates the effects of two types of thoroughly characterized GO sheets, different in their lateral dimension, on human peripheral immune cells provided from healthy donors using a wide range of assays. After evaluation of cell viability, the gene expression was analyzed, following GO exposure on 84 genes related to innate and adaptive immune responses. Exposure to GO small sheets was found to have a more significant impact on immune cells compared to GO large sheets, reflected in the upregulation of critical genes implicated in immune responses and the release of cytokines IL1β and TNFα. These findings were further confirmed by whole‐genome microarray analysis of the impact of small GO sheets on T cells and monocytes. Activation in both cell types was underlined by the overexpression of genes such as CXCL10 and receptor CXCR3. Significant energy‐dependent pathway modulation was identified. These findings can potentially pave the foundations for further design of graphene that can be used for immune modulation applications, for example in cancer immunotherapy.
Biodegradable, Elastomeric, and Intrinsically Photoluminescent Poly(Silicon‐Citrates) with high Photostability and Biocompatibility for Tissue Regeneration and Bioimaging
Authors: Du Yuzhang , Xue Yumeng , Ma Peter X. , Chen Xiaofeng , Lei Bo
Published: December 2015

Biodegradable polymer biomaterials with intrinsical photoluminescent properties have attracted much interest, due to their potential advantages for tissue regeneration and noninvasive bioimaging. However, few of current biodegradable polymers possess tunable intrinsically fluorescent properties, such as high photostability, fluorescent lifetime, and quantum field, and strong mechanical properties for meeting the requirements of biomedical applications. Here, by a facile one‐step thermal polymerization, elastomeric poly(silicone‐citrate) (PSC) hybrid polymers are developed with controlled biodegradability and mechanical properties, tunable inherent fluorescent emission (up to 600 nm), high photostability (beyond 180 min for UV and six months for natural light), fluorescent lifetime (near 10 ns) and quantum yield (16%–35%), high cellular biocompatibility, and minimal inflammatory response in vivo, which provide advantages over conventional fluorescent dyes, quantum dots, and current fluorescent polymers. The promising applications of PSC hybrids for cell and implants imaging in vitro and in vivo are successfully demonstrated. The development of elastomeric PSC polymer may provide a new strategy in synthesizing new inorganic–organic hybrid photo­luminescent materials for tissue regeneration and bioimaging applications.
Heteroepitaxial Growth of GaN on Unconventional Templates and Layer‐Transfer Techniques for Large‐Area, Flexible/Stretchable Light‐Emitting Diodes
Authors: Choi Jun Hee , Kim Jinwoo , Yoo Hyobin , Liu Jinyun , Kim Sunil , Baik Chan‐Wook , Cho Chae‐Ryong , Kang Jin Gu , Kim Miyoung , Braun P. V. , Hwang Sungwoo , Jung Tae‐Sung
Published: December 2015

There have been significant recent developments in the growth of single‐crystal gallium nitride (GaN) on unconventional templates for large‐area blue or green light‐emitting diodes (LEDs) which, together with layer transfer onto foreign substrates, can enable flexible and stretchable lighting applications. Here, the heteroepitaxial growth of GaN on amorphous and single‐crystal substrates employing various interlayers and nucleation layers is reviewed, as well as the use of weak interfaces for layer‐transfer onto foreign substrates. Recent progress in low‐temperature GaN‐based red–green–blue (RGB) LEDs on glass substrates, which has exhibited a calculated efficiency of 11% compared with that from commertial LEDs, is discussed. Layer‐transfer techniques with various interlayers are also discussed. These heteroepitaxial GaN growth and layer‐transfer technologies are expected to lead to new lighting and display devices with high efficiency and full‐color tunability, which are suitable for large‐area, stretchable display and lighting applications.
Surface Plasmon Resonance of an Individual Nano‐Object on an Absorbing Substrate: Quantitative Effects of Distance and 3D Orientation
Authors: Pertreux Etienne , Lombardi Anna , Florea Ileana , Spuch‐Calvar Miguel , Gómez‐Graña Sergio , Ihiawakrim Dris , Hirlimann Charles , Ersen Ovidiu , Majimel Jérôme , Tréguer‐Delapierre Mona , Hettich Mike , Maioli Paolo , Crut Aurélien , Vallée Fabrice , Fatti Natalia Del
Published: December 2015

Modification of the plasmonic response of a metal nano‐object due to interaction with a substrate is experimentally investigated measuring the quantitative optical extinction spectra of individual nano‐objects with various elongated shapes (bipyramids and rods) deposited on a dielectric (silica) or absorbing (carbon) membrane. Apart from the expected dependence of the nanoparticle surface plasmon resonance (SPR) frequency on the nature of the substrate, large substrate and particle shape dependent modifications of its SPR width are demonstrated. These dependencies are ascribed to strong localization of the electromagnetic field associated with the longitudinal SPR of an elongated nano‐object around its tips, leading to different interaction with the substrate depending on the particle shape and 3D orientation relative to the substrate. Both parameters have been precisely determined by electron tomography, permitting excellent reproduction of the experimental data. Experiments performed on silver‐encapsulated bipyramids, whose shape evolves from a pyramidal one towards a cylindrical one, further confirm this effect.
Real‐Time Investigation of Intercalation and Structure Evolution in Printed Polymer:Fullerene Bulk Heterojunction Thin Films
Authors: Kassar Thaer , Güldal Nusret S. , Berlinghof Marvin , Ameri Tayebeh , Kratzer Andreas , Schroeder Bob C. , Destri Giovanni Li , Hirsch Andreas , Heeney Martin , McCulloch Iain , Brabec Christoph J. , Unruh Tobias
Published: December 2015

The complex intermixing morphology is critical for the performance of the nanostructured polymer:fullerene bulk heterojunction (BHJ) solar cells. Here, time resolved in situ grazing incidence X‐ray diffraction and grazing incidence small angle X‐ray scattering are used to track the structure formation of BHJ thin films formed from the donor polymer poly(2,5‐bis(3‐hexadecylthiophen‐2‐yl)thieno[3,2‐b]thiophene) with different fullerene derivative acceptors. The formation of stable bimolecular crystals through the intercalation of fullerene molecules between the side chains of polymer crystallites is investigated. Such systems exhibit more efficient exciton dissociation but lower photo‐conductance and faster decay of charges. On the basis of the experimental observations, intercalation obviously takes place before or with the formation of the crystalline polymer domains. It results in more stable structures whose volume remains constant upon further drying. Three distinct periods of drying are observed and the formation of unidimensional fullerene channels along the π‐stacking direction of polymer crystallites is confirmed.
Poly(vinyl alcohol)/ZIF‐8‐NH2 mixed matrix membranes for ethanol dehydration via pervaporation
Authors: Zhang Hao , Wang Yan
Published: December 2015

Ethanediamine‐modified zeolitic imidazolate framework (ZIF)‐8 particles (ZIF‐8‐NH2) is synthesized and incorporated in the poly(vinyl alcohol) (PVA) matrix to fabricate novel PVA/ZIF‐8‐NH2 mixed matrix membranes (MMMs) for pervaporation dehydration of ethanol. The PVA/ZIF‐8‐NH2 MMMs exhibit enhanced membrane homogeneity and separation performance because of the higher hydrophilicity and restricted agglomeration of the particles, as compared to corresponding MMMs loaded with unmodified particles. The effect of ZIF‐8‐NH2 loading in the MMMs is studied and the MMM with a 7.5 wt % ZIF‐8‐NH2 loading shows the best pervaporation performance for ethanol dehydration at 40°C. Various characterization techniques (Fourier transform infrared, scanning electron microscope, contact angle, sorption test, etc.) are used to investigate the MMMs loaded with ZIF‐8 and ZIF‐8‐NH2 particles. The impact of operation conditions on pervaporation performance is also performed. The performance benchmarking shows that the MMMs have superior separation factors and comparable flux to most other PVA hybrid membranes. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1728–1739, 2016
Supramolecular Polymerization of a Pillar[5]arene Induced by a Symmetric Biaryl Sulfonate with Dual Binding Sites
Authors: Hong Meiling , Zhang Ying‐Ming , Liu Yan‐Cen , Liu Yu
Published: December 2015

Macrocycle‐based supramolecular polymers have attracted more interest in recent years and found many practical applications with controlled shape and unique physical and chemical properties. In this work, a binary supramolecular polymer is prepared in water by the strong host‐guest interactions between a cationic pillar[5]arene and a symmetric sulfonate with dual binding sites. Isothermal titration calorimetry measurements show that the binding process of host‐guest complexation is governed in a thermodynamically favorable way with a high stability constant of up to 107 m−1 order of magnitude. Moreover, spectroscopic and microscopic investigations jointly demonstrate that the resulting stable polymer is multistimuli responsive towards temperature and competitive metal coordination. We anticipate that our obtained multistimuli‐responsive supramolecular polymer may offer a new way in the construction of more functionalized pillararene‐based nanoassemblies.
Design and Synthesis of Substituted Pyridazinone‐1‐Acetylhydrazones as Novel Phosphodiesterase 4 Inhibitors
Authors: Abdel‐Rahman Hamdy M. , Abdel‐Aziz Mohamed , Tinsley Heather N. , Gary Bernard D. , Canzoneri Joshua C. , Piazza Gary A.
Published: December 2015

A series of novel pyridazin‐6‐one‐1‐acetylhydrazone hybrids were rationally designed to inhibit phosphodiesterase 4 (PDE4B). The prepared compounds were evaluated for their in vitro ability to inhibit the PDE4B enzyme; several of these compounds showed moderate activity compared to the reference drug, rolipram. Compounds 6, 12, and 14 emerged as the most potent inhibitors in this series. The [3‐(4‐methoxyphenyl)‐6‐oxo‐5,6‐dihydro‐4H‐pyridazin‐1‐yl]acetic acid [1‐(3,4,5‐trimethoxyphenyl)ethylidene]hydrazide (12) showed an IC50 value of 13 μM against PDE4B. Docking of 6, 12, and 14 into the active site of PDE4B illustrates their possible binding mode and provides insights for further optimization of this drug scaffold.
Chlorella vulgaris as a lipid source: Cultivation on air and seawater‐simulating medium in a helicoidal photobioreactor
Authors: Frumento Davide , Aliakbarian Bahar , Casazza Alessandro Alberto , Converti Attilio , Al Arni Saleh , da Silva Milena Fernandes
Published: December 2015

The freshwater microalga Chlorella vulgaris was cultured batchwise on the seawater‐simulating Schlösser medium either in a 1.1‐L‐working volume helicoidal photobioreactor (HeP) or Erlenmeyer flask (EF) as control and continuously supplying air as CO2 source. In these systems, maximum biomass concentration reached 1.65 ± 0.17 g L−1 and 1.25 ± 0.06 g L−1, and maximum cell productivity 197.6 ± 20.4 mg L−1 day−1 and 160.8 ± 12.2 mg L−1 day−1, respectively. Compared to the Bold's Basal medium, commonly employed to cultivate this microorganism on a bench‐scale, the Schlösser medium ensured significant increases in all the growth parameters, namely maximum cell concentration (268% in EF and 126% in HeP), maximum biomass productivity (554% in EF and 72% in HeP), average specific growth rate (67% in EF and 42% in HeP), and maximum specific growth rate (233% in EF and 22% in HeP). The lipid fraction of biomass collected at the end of runs was analyzed in terms of both lipid content and fatty acid profile. It was found that the seawater‐simulating medium, despite of a 56–63% reduction of the overall biomass lipid content compared to the Bold's Basal one, led in HeP to significant increases in both the glycerides‐to‐total lipid ratio and polyunsaturated fatty acid content compared to the other conditions taken as an average. These results as a whole suggest that the HeP configuration could be a successful alternative to the present means to cultivate C. vulgaris as a lipid source. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:279–284, 2016
Prediction of protein retention times in hydrophobic interaction chromatography by robust statistical characterization of their atomic‐level surface properties
Authors: Hanke Alexander T. , Klijn Marieke E. , Verhaert Peter D. E. M. , van der Wielen Luuk A. M. , Ottens Marcel , Eppink Michel H. M. , van de Sandt Emile J. A. X.
Published: December 2015

The correlation between the dimensionless retention times (DRT) of proteins in hydrophobic interaction chromatography (HIC) and their surface properties were investigated. A ternary atomic‐level hydrophobicity scale was used to calculate the distribution of local average hydrophobicity across the proteins surfaces. These distributions were characterized by robust descriptive statistics to reduce their sensitivity to small changes in the three‐dimensional structure. The applicability of these statistics for the prediction of protein retention behaviour was looked into. A linear combination of robust statistics describing the central tendency, heterogeneity and frequency of highly hydrophobic clusters was found to have a good predictive capability (R2 = 0.78), when combined a factor to account for protein size differences. The achieved error of prediction was 35% lower than for a similar model based on a description of the protein surface on an amino acid level. This indicates that a robust and mathematically simple model based on an atomic description of the protein surface can be used for the prediction of the retention behaviour of conformationally stable globular proteins with a well determined 3D structure in HIC. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:372–381, 2016
Percutaneous carotid artery access in infants < 3 months of age
Authors: Choudhry Swati , Balzer David , Murphy Joshua , Nicolas Ramzi , Shahanavaz Shabana
Published: December 2015

Background

Carotid artery access in infants with congenital heart disease undergoing cardiac catheterization via a surgical cut down has been well described. There is a paucity of information regarding percutaneous carotid artery (CA) access in infants <3 months.

Methods

A retrospective review of infants <3 months of age undergoing cardiac catheterization via percutaneous CA approach was performed after IRB approval. Between January 2012 and May 2015, 18 patients underwent 20 procedures; median age 13 days (2–77); median weight 3.3 kg (1.6–5). Procedures performed were patent ductus arteriosus (PDA) stenting (8), modified blalock taussig (BT) shunt stenting (3), balloon aortic valvuloplasty (6), and balloon angioplasty of coarctation (3).

Results

Percutaneous access was obtained with a Doppler needle under ultrasound guidance into the right (16) and left CA (4). Sheath size used was 4 Fr (17), 5 Fr (2), and 6 Fr (1). Median time to sheath insertion was 6.5 min (2–20). Percutaneous access was obtained successfully in all cases. There were no major procedural complications. There were two minor complications; hypotension, and ductal spasm. Hemostasis was achieved by manual compression; median time was 14.5 min (8–36). There were two post‐procedural complications involving development of CA pseudo aneurysms that were repaired surgically. Post‐procedure CA patency was documented by angiography (3), MRA (3), or vascular ultrasound (14). There were no documented arterial occlusions.

Conclusion

Our experience suggests that percutaneous CA access in infants <3 months of age is safe and feasible with preserved vascular patency and no neurological adverse events. © 2015 Wiley Periodicals, Inc.
Desirability functions as response in a d‐optimal design for evaluating the extraction and purification steps of six tranquillizers and an anti‐adrenergic by liquid chromatography‐tandem mass spectrometry
Authors: Rubio Laura , Oca María Leticia , Sarabia Luis , García Inmaculada , Ortiz María Cruz
Published: December 2015

Internal standards can be added at different stages of an analytical procedure. When they are added at the beginning of a multiresidue method and their behavior is not exactly the same as that of the analytes, the intended correction for small variations within the analytical process could not be achieved. Because of this, in the present work, the use of d‐optimal designs together with desirability functions is proposed to state the experimental response under study. The overall desirability function used relates two analytical criteria: to assess a similar chemical behavior of each analyte in relation to its internal standard and to avoid a significant reduction of the absolute peak area of the internal standards. This strategy has been applied to the analysis of the effect of four factors related to the extraction and purification steps of six tranquillizers and a β‐blocker from pig muscle analyzed by liquid chromatography–tandem mass spectrometry. The effect of those factors has been evaluated by means of an ad hoc d‐optimal design consisting of only 11 experiments. The resulting levels of the four factors that enable to achieve the greatest overall desirability have also been compared with those obtained when either the standardized or absolute peak area has been considered as response. Differences in both the significant factors and their optimum levels have been observed. It is noticeable that the experimental effort necessary to study the effect of the factors has been reduced by more than 50% thanks to the d‐optimal design. Copyright © 2015 John Wiley & Sons, Ltd.
A Hybrid Approach: Indirect Electro‐Oxidation Followed by In Situ Electrogeneration of H2O2 in Real Textile Effluent
Authors: Aravind Priyadharshini , Selvaraj Rajeswari , Sankarmahalingam Angappan , Kandasamy Subramanian
Published: December 2015

A two‐step treatment process has been investigated for effective textile effluent management. In step I, the effluent was decolorized via chlorine‐mediated indirect electrooxidation (InDEO), while H2O2 was electrogenerated during step II in the decolorized textile effluent, by employing an H‐type divided electrochemical cell. The native salts present within the decolorized textile effluent (9.4 g/L Na2SO4 and 0.8 g/L NaCl) were exploited as electrolytes for the catholyte, whereas 0.5 N sulfuric acid was used as the anolyte for the in situ electrochemical generation of H2O2. During the cyclic voltammetry tests, O2 reduction at the activated carbon felt cathode was observed around –0.86 V versus saturated calomel electrode (SCE) at a scan rate of 100 mV/s. Under optimized conditions (cathode potential of –0.9 V vs. SCE and catholyte at pH 6) about 1.45 ± 0.01 mM H2O2 have been generated. The effluent containing H2O2 was subjected to Fenton reaction and the generation of OH• radicals was confirmed by electron paramagnetic resonance spectroscopy. The results indicated a 59% reduction of the chemical oxygen demand; significant modifications of the functional groups were observed by Fourier transform IR spectroscopy. High performance LC analysis confirmed the degradation of the organic compounds during the oxidative treatment process. These findings suggest the application of this method for degradation of highly colored textile effluents.
SipaaS: Spot instance pricing as a Service framework and its implementation in OpenStack
Authors: Nadjaran Toosi Adel , Khodadadi Farzad , Buyya Rajkumar
Published: December 2015

Designing dynamic pricing mechanisms that efficiently price resources in line with a provider's profit maximization goal is a key challenge in cloud computing environments. Despite the large volume of research published on this topic, there is no publicly available software system implementing dynamic pricing for Infrastructure as a Service cloud spot markets. This paper presents the implementation of a framework called Spot instance pricing as a Service (SipaaS) that supports an auction mechanism to price and allocate virtual machine instances. SipaaS is an open‐source project offering a set of web services to price and sell virtual machine instances in a spot market resembling the Amazon EC2 spot instances. Cloud providers, who aim at utilizing SipaaS, should install add‐ons in their existing platform to make use of the framework. As an instance, we provide an extension to the Horizon – the OpenStack dashboard project – to employ SipaaS web services and to add a spot market environment to OpenStack. To validate and evaluate the system, we conducted an experimental study with a group of 10 users utilizing the provided spot market in a real environment. Results show that the system performs reliably in a practical test environment. Copyright © 2015 John Wiley & Sons, Ltd.